Classification and functional origins of stereocomplementary alcohol dehydrogenases for asymmetric synthesis of chiral secondary alcohols: A review.

Alcohol dehydrogenases (ADHs) mediated biocatalytic asymmetric reduction of ketones have been widely applied in the synthesis of optically active secondary alcohols with highly reactive hydroxyl groups ligated to the stereogenic carbon and divided into (R)- and (S)-configurations. Stereocomplementary ADHs could be applied in the synthesis of both enantiomers and are increasingly accepted as the "first of choice" in green chemistry due to the high atomic economy, low environmental factor, 100 % theoretical yield, and high environmentally friendliness. Due to the equal importance of complementary alcohols, development of stereocomplementary ADHs draws increasing attention. This review is committed to summarize recent advance in discovery of naturally evolved and tailor-made stereocomplementary ADHs, unveil the molecular mechanism of stereoselective catalysis in views of classification and functional basis, and provide guidance for further engineering the stereoselectivity of ADHs for the industrial biosynthesis of chiral secondary alcohol of industrial relevance.

Engineering Glucosamine-6-Phosphate Synthase to Achieve Efficient One-Step Biosynthesis of Glucosamine.

As an important functional monosaccharide, glucosamine (GlcN) is widely used in fields such as medicine, food nutrition, and health care. Here, we report a distinct GlcN biosynthesis method that utilizes engineered Bacillus subtilis glucosamine-6-phosphate synthase (BsGlmS) to convert D-fructose to directly generate GlcN. The best variant obtained by using a combinatorial active-site saturation test/iterative saturation mutagenesis (CAST/ISM) strategy was a quadruple mutant S596D/V597G/S347H/G299Q (BsGlmS-BK19), which has a catalytic activity 1736-fold that of the wild type toward D-fructose. Upon using mutant BK19 as a whole-cell catalyst, D-fructose was converted into GlcN with 65.32% conversion in 6 h, whereas the wild type only attained a conversion rate of 0.31% under the same conditions. Molecular docking and molecular dynamics simulations were implemented to provide insights into the mechanism underlying the enhanced activity of BK19. Importantly, the BsGlmS-BK19 variant specifically catalyzes D-fructose without the need for phosphorylated substrates, representing a significant advancement in GlcN biosynthesis.

Photocatalytic regeneration of nicotinamide cofactor biomimetics drives biocatalytic reduction by Old Yellow enzymes.

A key approach in developing green chemistry involves converting solar energy into chemical energy of biomolecules through photocatalysis. Photocatalysis can facilitate the regeneration of nicotinamide cofactors during redox processes. Nicotinamide cofactor biomimetics (NCBs) are economical substitutes for natural cofactors. Here, photocatalytic regeneration of NADH and reduced NCBs (NCBsred) using graphitic carbon nitride (g-C3N4) was developed. The process involves g-C3N4 as the photocatalyst, Cp*Rh(bpy)H2O2+ as the electron mediator, and Triethanolamine as the electron donor, facilitating the reduction of NAD+ and various oxidative NCBs (NCBsox) under light irradiation. Notably, the highest reduction yield of 48.32 % was achieved with BANA+, outperforming the natural cofactor NAD+. Electrochemical analysis reveals that the reduction efficiency and capacity of cofactors relies on their redox potentials. Additionally, a coupled photo-enzymatic catalysis system was explored for the reduction of 4-Ketoisophorone by Old Yellow Enzyme XenA. Among all the NCBsox and NAD+, the highest conversion ratio of over 99 % was obtained with BANA+. After recycled for 8 times, g-C3N4 maintained over 93.6 % catalytic efficiency. The photocatalytic cofactor regeneration showcases its outstanding performance with NAD+ as well as NCBsox. This work significantly advances the development of photocatalytic cofactor regeneration for artificial cofactors and its potential application.

Semirational Design Strategy To Enhance the Thermostability and Catalytic Activity of Cytochrome P450 105D7 for the Degradation of the Pharmaceutically Active Compounds: Diclofenac.

Pharmaceutically active compounds are an important category of emerging pollutants, and their biological transformation processes in the environment are crucial for understanding and evaluating the migration, transformation, and environmental fate of emerging pollutants. The cytochrome P450 105 enzyme family has been proven to play an important role in the degradation of exogenous environmental pollutants. However, its thermostability and catalytic activity still need to be improved to better adapt to complex environmental conditions. This work elucidates the key mechanisms and important residues of the degradation reaction through multiple computational strategies, establishes a mutation library, and obtains 21 single-point mutation designs. Experimental verification showed that 16 single mutants had enhanced thermostability, with the R89F and L197Y mutants showing the highest increases in thermostability at 135 and 119% relative to the wild-type enzyme, respectively. Additionally, as a result of the higher specific activity of D390Q, it was selected for combination mutagenesis, ultimately resulting in three combination mutants (R89F/L197Y, R89F/D390Q, and R89F/L197Y/D390Q) with enhanced thermostability and catalytic activity. This study provides a modification approach for constructing efficient enzyme variants through semirational design and can contribute to the development of control technologies for emerging pollutants.

Structure-Guided Evolution of Cyclohexanone Monooxygenase Toward Bulky Omeprazole Sulfide: Substrate Migration and Stereoselectivity Inversion.

Structure-guided engineering of a CHMO from Amycolatopsis methanolica (AmCHMO) was performed for asymmetric sulfoxidation activity and stereoselectivity toward omeprazole sulfide. Initially, combinatorial active-site saturation test (CASTing) and iteratively saturation mutagenesis (ISM) were performed on 5 residues at the "bottleneck" of substrate tunnel, and MT3 was successfully obtained with a specific activity of 46.19 U/g and R-stereoselectivity of 99 % toward OPS. Then, 4 key mutations affecting the stereoselectivity were identified through multiple rounds of ISM on residues at the substrate binding pocket region, resulting MT8 with an inversed stereoselectivity from 99 % (R) to 97 % (S). MT8 has a greatly compromised specific activity of 0.08 U/g. By introducing additional beneficial mutations, MT11 was constructed with significantly increased specific activity of 2.29 U/g and stereoselectivity of 97 % (S). Enlarged substrate tunnel is critical to the expanded substrate spectrum of AmCHMO, while reshaping of substrate binding pocket is important for stereoselective inversion. Based on MD simulation, pre-reaction states of MT3-OPSproR, MT8-OPSproS, and MT11-OPSproS were calculated to be 45.56 %, 17.94 %, and 28.65 % respectively, which further confirm the experimental data on activity and stereoselectivity. Our results pave the way for engineering distinct activity and stereoselectivity of BVMOs toward bulky prazole thioethers.

Engineering diaryl alcohol dehydrogenase KpADH reveals importance of retaining hydration shell in organic solvent tolerance.

Alcohol dehydrogenases (ADHs) are synthetically important biocatalysts for the asymmetric synthesis of chiral alcohols. The catalytic performance of ADHs in the presence of organic solvents is often important since most prochiral ketones are highly hydrophobic. Here, the organic solvent tolerance of KpADH from Kluyveromyces polyspora was semi-rationally evolved. Using tolerant variants obtained, meticulous experiments and computational studies were conducted to explore properties including stability, activity and kinetics in the presence of various organic solvents. Compared with WT, variant V231D exhibited 1.9-fold improvement in ethanol tolerance, while S237G showed a 6-fold increase in catalytic efficiency, a higher T 50 15 $$ {\mathrm{T}}_{50}^{15} $$ , as well as 15% higher tolerance in 7.5% (v/v) ethanol. Based on 3 × 100 ns MD simulations, the increased tolerance of V231D and S237G against ethanol may be ascribed to their enhanced ability in retaining water molecules and repelling ethanol molecules. Moreover, 6.3-fold decreased KM value of V231D toward hydrophilic ketone substrate confirmed its capability of retaining hydration shell. Our results suggest that retaining hydration shell surrounding KpADH is critical for its tolerance to organic solvents, as well as catalytic performance. This study provides useful guidance for engineering organic solvent tolerance of KpADH and other ADHs.

Mining and tailor-made engineering of a novel keto reductase for asymmetric synthesis of structurally hindered γ- and δ-lactones.

A novel carbonyl reductase from Hyphopichia burtoni (HbKR) was discovered by gene mining. HbKR is a NADPH-dependent dual function enzyme with reduction and oxidation activity belonging to SDR superfamily. HbKR strictly follows Prelog priority in the reduction of long-chain aliphatic keto acids/esters containing remote carbonyl groups, such as 4-oxodecanoic acid and 5-oxodecanoic acid, producing (S)-γ-decalactone and (S)-δ-decalactone in >99 % e.e. Tailor-made engineering of HbKR was conducted to improve its catalytic efficiency. Variant F207A/F86M was obtained with specific activity of 8.37 U/mg toward 5-oxodecanoic acid, which was 9.7-fold of its parent. Employing F207A/F86M, 100 mM 5-oxodecanoic acid could be reduced into optically pure (S)-δ-decalactone. Molecular docking analysis indicates that substitution of aromatic Phe with smaller residues renders sufficient space for accommodating substrates in a more stable conformation. This study offers an efficient biocatalyst for the biosynthesis of (S)-lactones, and provides guidance for engineering carbonyl reductases toward structurally hindered substrates.

Pannexin 3 activates P2X7 receptor to mediate inflammation and cartilage matrix degradation in temporomandibular joint osteoarthritis.

Pannexin 3 (Panx3) is involved in regulation of the proliferation and differentiation in chondrocytes and pathological process in osteoarthritis, but its role and potential mechanism in temporomandibular joint osteoarthritis (TMJOA) are still unclear, which are thus explored in our research. We established TMJOA animal model and cell model. In vivo, after silencing Panx3, the pathological changes of condylar cartilage tissue were analyzed by tissue staining, while expressions of Panx3, P2X7 receptor (P2X7R), NLRP3, and cartilage matrix-related genes were measured by immunohistochemistry (for animal model) or immunofluorescence (for cell model), quantitative reverse-transcription polymerase chain reaction (qRT-PCR) or western blot. In addition, the activation of inflammation-related pathways was detected by qRT-PCR or western blot, and intracellular adenosine triphosphate (ATP) level was tested by ATP kit. The role of Panx3 in TMJOA was proved by loss- and gain-of-function assays. P2X7R antagonist was employed to verify the relationship between Panx3 and P2X7R. Panx3 silencing alleviated the damage of condyle cartilage tissue in TMJOA rats, and reduced expressions of Panx3, P2X7R, cartilage matrix degradation related-enzymes, and NLRP3 in condyle cartilage tissue. In TMJOA cell model, the expressions of Panx3, P2X7R, cartilage matrix degradation related-enzymes were increased, and inflammation-related pathways were activated, meanwhile interleukin-1ß treatment promoted the release of intracellular ATP to the extracellular space. The above-mentioned response was enhanced by Panx3 overexpression and reversed by Panx3 silencing. P2X7R antagonist reversed the regulation of Panx3 overexpression. In conclusion, Panx3 may activate P2X7R by releasing ATP to mediate inflammation and cartilage matrix degradation in TMJOA.

Efficient production of hyaluronic acid by Streptococcus zooepidemicus using two-stage semi-continuous fermentation.

Hyaluronic acid is a kind of mucopolysaccharide that has wide applications in cosmetics, health food, and orthopedics. Using Streptococcus zooepidemicus ATCC 39920 as parent, a beneficial mutant SZ07 was obtained by UV mutagenesis, giving 1.42 g/L hyaluronic acid in shake flasks. To enhance the efficiency of hyaluronic acid production, a semi-continuous fermentation process consisted of two-stage 3-L bioreactors was developed, in which 1.01 g/L/h productivity and 14.60 g/L hyaluronic acid were obtained. To further enhance the titer of hyaluronic acid, recombinant hyaluronidase SzHYal was added into 2nd stage bioreactor at 6 h to reduce the viscosity of broth. The highest hyaluronic acid titer of 29.38 g/L was achieved with a productivity of 1.13 g/L/h at 300 U/L SzHYal after 24 h. This newly developed semi-continuous fermentation process provides a promising strategy for the industrial production of hyaluronic acid and related polysaccharides.

Fibroblast growth factor 9 reduces TBHP-induced oxidative stress in chondrocytes and diminishes mouse osteoarthritis by activating ERK/Nrf2 signaling pathway.

Osteoarthritis (OA) is a degenerative and progressive disease that affects joints. Pathologically, it is characterized by oxidative stress-mediated excessive chondrocyte apoptosis and mitochondrial dysfunction. Fibroblast growth factor 9 (FGF9) has been shown to exert antioxidant effects and prevent degenerative diseases by activating ERK-related signaling pathways. However, the mechanism of FGF9 in the pathogenesis of OA and its relationship with anti-oxidative stress and related pathways are unclear. In this study, mice with medial meniscus instability (DMM) were used as the in vivo model whereas TBHP-induced chondrocytes served as the in vitro model to explore the mechanism underlying the effects of FGF9 in OA and its association with anti-oxidative stress. Results showed that FGF9 reduced oxidative stress, apoptosis, and mitochondrial dysfunction in TBHP-treated chondrocytes and promoted the nuclear translocation of Nrf2 to activate the Nrf2/HO1 signaling pathway. Interestingly, silencing the Nrf2 gene or blocking the ERK signaling pathway abolished the antioxidant effects of FGF9. FGF9 treatment reduced joint space narrowing, cartilage ossification, and synovial thickening in the DMM model mice. In conclusion, the present findings demonstrate that FGF9 can inhibit TBHP-induced oxidative stress in chondrocytes through the ERK and Nrf2-HO1 signaling pathways and prevent the progression of OA in vivo.

Engineering the Thermostability of a d-Carbamoylase Based on Ancestral Sequence Reconstruction for the Efficient Synthesis of d-Tryptophan.

Employing ancestral sequence reconstruction and consensus sequence analysis, the thermostability of a novel d-carbamoylase derived from Nitratireductor indicus (NiHyuC) was engineered through greedy-oriented iterative combinatorial mutagenesis. A mutant S202P/E208D/R277L (M4Th3) was obtained with significantly elevated thermostability. M4Th3 has a half-life of 36.5 h at 40 °C, about 28.5 times of 1.3 h of its parent M4. For the reaction at 40 °C, M4Th3 can catalyze 10 mM N-carbamoyl-d-tryptophan to produce d-tryptophan with a conversion ratio of 96.4% after 12 h, which is significantly higher than 64.1% of M4. MD simulation reveals that new hydrogen bonds emerging from E208D on the surface can increase the hydrophobicity of the protein, leading to improved stability. More importantly, R277L could contribute to enhanced interface stability of homodimeric M4. This study provides a thermostable d-carbamoylase for the "hydantoinase process", which has potential in the industrial synthesis of optically pure natural and non-natural amino acids.

Self-Sufficient In Vitro Multi-Enzyme Cascade for Efficient Synthesis of Danshensu from l-DOPA.

Danshensu (DSS), a traditional Chinese medicine, is widely used for the treatment of cardiovascular and cancer diseases. Here, a one-pot multi-enzyme cascade pathway was designed for DSS synthesis from l-DOPA using tyrosine aminotransferase from Escherichia coli (EcTyrB) and d-isomer-specific 2-hydroxyacid dehydrogenase from Lactobacillus frumenti (LfD2-HDH). Glutamate dehydrogenase from Clostridium difficile (CdgluD) was also introduced for a self-sufficient system of α-ketoglutaric acid and NADH. Under optimal conditions (35 °C, pH 7.0, EcTyrB:LfD2-HDH:CdgluD = 3:2:1, glutamate:NAD+ = 1:1), 98.3% yield (at 20 mM l-DOPA) and space-time yield of 6.61 g L-1 h-1 (at 40 mM l-DOPA) were achieved. Decreased yields of DSS at elevated l-DOPA concentrations (100 mM) could be attributed to an inhibited CdgluD activity caused by NH4+ accumulation. This developed multi-enzyme cascade pathway (including EcTyrB, LfD2-HDH, and CdgluD) provides an efficient and sustainable approach for the production of DSS from l-DOPA.

Engineering of a Baeyer-Villiger monooxygenase reveals key residues for the asymmetric oxidation of omeprazole sulfide.

The structure-guided engineering of a BVMO from Rhodococcus aetherivorans (RaBVMO) was performed for its asymmetric sulfoxidation activity toward omeprazole sulfide. Based on the structural model of RaBVMO, key residues that line the substrate entrance tunnel and the binding pocket were identified, and variants were interrogated with sulfides of varied sizes. The best mutant MT2 (F442A/R337P) was obtained with a specific activity of 2.54 U g-1 and excellent enantioselectivity (≥99%, S) toward omeprazole sulfide, while wild-type RaBVMO exhibited no activity. Further structural analysis reveals that both mutations, F442A and R337P, could render an expanded substrate tunnel and an enlarged substrate binding pocket to enable easier access to the catalytic center for omeprazole sulfide. This work provides valuable guidance for engineering-related BVMOs for improved activity and enantio-preference toward bulky substrates.

Directed reconstruction of a novel ancestral alcohol dehydrogenase featuring shifted pH-profile, enhanced thermostability and expanded substrate spectrum.

Ancestral enzymes are promising for industrial biotechnology due to high stability and catalytic promiscuity. An effective protocol was developed for the directed resurrection of ancestral enzymes. Employing genome mining with diaryl alcohol dehydrogenase KpADH as the probe, descendant enzymes D10 and D11 were firstly identified. Then through ancestral sequence reconstruction, A64 was resurrected with a specific activity of 4.3 U·mg-1. The optimum pH of A64 was 7.5, distinct from 5.5 of D10. The T15 50 and Tm values of A64 were 57.5 °C and 61.7 °C, significantly higher than those of the descendant counterpart. Substrate spectrum of A64 was quantitively characterized with a Shannon-Wiener index of 2.38, more expanded than D10, especially, towards bulky ketones in Group A and B. A64 also exhibited higher enantioselectivity. This study provides an effective protocol for constructing of ancestral enzymes and an efficient ancestral enzyme of industrial relevance for asymmetric synthesis of chiral alcohols.

Development, In-Vitro Characterization and In-Vivo Osteoinductive Efficacy of a Novel Biomimetically-Precipitated Nanocrystalline Calcium Phosphate With Internally-Incorporated Bone Morphogenetic Protein-2.

The repair of large-volume bone defects (LVBDs) remains a great challenge in the fields of orthopedics and maxillofacial surgery. Most clinically available bone-defect-filling materials lack proper degradability and efficient osteoinductivity. In this study, we synthesized a novel biomimetically-precipitated nanocrystalline calcium phosphate (BpNcCaP) with internally incorporated bone morphogenetic protein-2 (BpNcCaP + BMP-2) with an aim to develop properly degradable and highly osteoinductive granules to repair LVBDs. We first characterized the physicochemical properties of the granules with different incorporation amounts of BMP-2 using scanning electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. We evaluated the cytotoxicity and cytocompatibility of BpNcCaP by assessing the viability and adhesion of MC3T3-E1 pre-osteoblasts using PrestoBlue assay, Rhodamine-Phalloidin and DAPI staining, respectively. We further assessed the in-vivo osteoinductive efficacy in a subcutaneous bone induction model in rats. In-vitro characterization data showed that the BpNcCaP + BMP-2 granules were comprised of hexagonal hydroxyapatite with an average crystallite size ranging from 19.7 to 25.1 nm and a grain size at 84.13 ± 28.46 nm. The vickers hardness of BpNcCaP was 32.50 ± 3.58 HV 0.025. BpNcCaP showed no obvious cytotoxicity and was favorable for the adhesion of pre-osteoblasts. BMP-2 incorporation rate could be as high as 65.04 ± 6.01%. In-vivo histomorphometric analysis showed that the volume of new bone induced by BpNcCaP exhibited a BMP-2 amount-dependent increasing manner. The BpNcCaP+50 µg BMP-2 exhibited significantly more degradation and fewer foreign body giant cells in comparison with BpNcCaP. These data suggested a promising application potential of BpNcCaP + BMP-2 in repairing LVBDs.

Application Effect of the 6S Care Model in Sterilization in the Department of Stomatology and Its Impact on the Incidence of Nosocomial Infection.

Objective: The study aimed to explore the effectiveness of the 6S care model in sterilization in department of stomatology and its impact on the incidence of nosocomial infections. Methods: The infection surveillance indicators of the department of stomatology implementing the routine sterilization care model in 2019 were selected as the general group (including 140 patients and 140 cases of oral instrument kits for unpacking), and the infection surveillance indicators of the department of stomatology implementing the 6S care model in 2020 were selected as the 6S group (including 140 patients and 140 cases of oral instrument kits for unpacking). Analysis of the air culture qualification rate of the consultation room + operating room, medical equipment sterilization qualification rate, medical equipment damage rate, incidence of nosocomial infections, satisfaction of medical and nursing staff with instrument sterilization, and patient satisfaction with medical and nursing staff care services under different care models was carried out. Result: The air culture pass rate of the consultation room + operating room in the 6S group was 96.43% (135/140), which was higher than 90.00% (126/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The sterilization pass rate of medical devices in the 6S group was 100% (140/140), which was higher than 95.71% (134/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The medical device damage rate in the 6S group was 0.71% (1/140), which was lower than 7.14% (10/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). The incidence of nosocomial infection in the 6S group was 0.71% (1/140), lower than 5.71% (8/140) in the general group, and the difference between the two groups was statistically significant (P > 0.05). In the 6S care model, the satisfaction score of 38 healthcare workers with the disinfection of instruments was (96.55 ± 2.40), which was higher than that of the general group (87.79 ± 3.14), and the difference between the two groups was statistically significant (P > 0.05). The total nursing satisfaction of the 6S group was 97.86% (137/140), which was higher than 91.43% (128/140) of the general group, and the difference between the two groups was statistically significant (P > 0.05). Conclusion: The application of the 6S care model in the sterilization of the department of stomatology can significantly improve the passing rate of infection monitoring indicators in the department of stomatology, reduce the occurrence of medical device damage and nosocomial infection, and have high satisfaction among doctors and patients, which has the value of promotion.

Zoledronate promotes ECM degradation and apoptosis via Wnt/ß-catenin.

This study examined the potential mechanism of zoledronate on interleukin (IL)-1ß-induced temporomandibular joint osteoarthritis (TMJOA) chondrocytes, using IL-1ß-induced rabbit immortalized mandibular condylar chondrocytes cultured with zoledronate. Cell viability, apoptosis, mRNA, and protein expression of relevant genes involved in extracellular matrix (ECM) degradation, apoptosis, and Wnt/ß-catenin signaling were examined. The involvement of the Wnt/ß-catenin signaling was examined using Wnt/ß-catenin inhibitor (2-(4-(trifluoromethyl)phenyl)-7,8-dihydro-5H-thiopyrano[4,3-d]pyrimidin-4-ol (XAV-939)) and activator lithium chloride (LiCl). Aggrecan and type II collagen were downregulated by zoledronate, especially with 100 nM for 48 h (p < 0.01), consistently with the upregulation of A disintegrin and metalloproteinase with thrombospondin motifs-4 (ADAMTS-4) (p < 0.001), matrix metalloprotease-9 (MMP-9) (p < 0.01), caspase-3 (p < 0.001) and downregulation of proliferating cell nuclear antigen (PCNA) (p < 0.01). The apoptotic rate increased from 34.1% to 45.7% with 100 nM zoledronate for 48 h (p < 0.01). The effects of zoledronate on ADAMTs4 (p < 0.001), MMP-9 (p < 0.001), caspase-3 (p < 0.001), and PCNA (p < 0.01) were reversed by XAV-939, while LiCl increased caspase-3 expression (p < 0.01). In conclusion, zoledronate enhances IL-1ß-induced ECM degradation and cell apoptosis in TMJOA chondrocytes. Wnt/ß-catenin signaling might be involved in this process, but additional studies are necessary to determine the exact involvement of Wnt/ß-catenin signaling in chondrocytes after zoledronate treatment.

Hydrogen Abstraction by Alkoxyl Radicals: Computational Studies of Thermodynamic and Polarity Effects on Reactivities and Selectivities.

Density functional theory calculations (ωB97X-D) are reported for the reactions of methoxy, tert-butoxy, trichloroethoxy, and trifluoroethoxy radicals with a series of 26 C-H bonds in different environments characteristic of a variety of hydrocarbons and substituted derivatives. The variations in activation barriers are analyzed with modified Evans-Polanyi treatments to account for polarity and unsaturation effects. The treatments by Roberts and Steel and by Mayer have inspired the development of a simple treatment involving the thermodynamics of reactions, the difference between the reactant radical and product radical electronegativities, and the absence or presence of α-unsaturation. The three-parameter equation (ΔH⧧ = 0.52ΔHrxn(1 - d) - 0.35ΔχAB2 + 10.0, where d = 0.44 when there is α-unsaturation to the reacting C-H bond), correlates well with quantum mechanically computed barriers and shows the quantitative importance of the thermodynamics of reactions (dictated by the reactant and the product bond dissociation energies) and polar effects.

Systematic review and meta-analysis: influence of iron deficiency anemia on blood glycosylated hemoglobin in diabetic patients.

BACKGROUND: Diabetes is a common metabolic disease with an increasing incidence in middle-aged and elderly people in recent years. Chronic hyperglycemia is the basic feature of diabetes, which can cause long-term damage to eyes, kidneys, nerves, heart, and blood vessels, resulting in functional decline or even failure. Glycosylated hemoglobin (HbA1c) can be used as an indicator of an individual's blood sugar status over the past 3 months; however, it is slightly affected by ischemic anemia. METHODS: The data retrieval was performed in the databases of PubMed, Embase, and Ovid-Medline from their inception to April 2021, including keywords such as iron deficiency anemia (IDA), diabetes, HbA1c, immunoassay, and ion-exchange chromatography. After passing of sensitivity and heterogeneity analysis, Review Manager 5.3 was employed for meta-analysis. RESULTS: A total of 6 studies were included in this paper. The analysis results showed that IDA could be considered to have an impact on HbA1c outcomes in non-diabetic populations. In people with diabetes, IDA is not thought to have an impact on HbA1c outcomes. DISCUSSION: A total of 6 articles were included to discuss the effects of IDA on blood HbA1c in diabetic patients. The study found that when patients with diabetes were tested for blood sugar, the HbA1c did not accurately reflect their blood sugar control over the past 3 months.

Relationship between the absolute lymphocyte count/absolute monocyte count ratio, soluble interleukin 2 receptor level, serum programmed cell death 1 level, and the prognosis of patients with diffuse large B-cell lymphoma.

BACKGROUND: To analyze the relationship between the peripheral blood absolute lymphocyte count (ALC)/absolute monocyte count (AMC) ratio, soluble interleukin 2 receptor (sIL-2R) level, serum programmed cell death 1 (PD-1) level, and the prognosis of patients with diffuse large B-cell lymphoma (DLBCL). METHODS: A total of 78 patients with DLBCL admitted to hospital and 30 healthy controls were enrolled as the case group and control group between August 2019 and June 2020, respectively. The ALC/AMC ratio and the levels of sIL-2R and serum PD-1 between the 2 groups and among patients with different prognoses were compared. The evaluation efficiency of these 3 factors for the prognosis of DLBCL patients was analyzed by receiver operating characteristic (ROC) curves. The risk factors affecting the 1-year survival rate were analyzed by the Cox hazard model. RESULTS: The levels of sIL-2R, AMC, and PD-1 in the case group were significantly higher than those in the control group, while the ALC/AMC ratio was lower than that in the control group (P<0.05). The levels of sIL-2R and PD-1 in the poor prognosis group were significantly higher than those in the good prognosis group, while the ALC/AMC ratio was lower than that in the good prognosis group (P<0.05). The areas under the ROC curve (AUCs) of sIL-2R level, serum PD-1 level, and the ALC/AMC ratio in evaluating the prognosis of DLBCL patients were 0.805 (95% CI: 0.700-0.886), 0.825 (95% CI: 0.722-0.902), 0.792 (95% CI: 0.685-0.876), respectively. The critical values were 474.80 µg/L, 206.85 pg/mL and 3.01, respectively. The differences in the 1-year survival rate among DLBCL patients with different tumor sizes, B symptoms, sIL-2R levels, and ALC/AMC ratios were statistically significant (P<0.05). B symptoms (RR =1.721) and ALC/AMC ratio lower than 3.01 (RR =1.484) were independent influencing factors of the 1-year survival rate in DLBCL patients (P<0.05). CONCLUSIONS: The ALC/AMC ratio, sIL-2R level, and serum PD-1 level can effectively assess the prognosis of DLBCL patients. B symptoms and ALC/AMC ratio lower than 3.01 are risk factors affecting the 1-year survival rate of patients.