Is Reaction Acceleration of Microdroplet Chemistry Favorable to Controlling the Enantioselectivity?

Microdroplet chemistry has been proven to amazingly accelerate many chemical and biological reactions in the past 2 decades. Current microdroplet accelerated reactions are predominantly symmetric synthetic but minorly asymmetric synthetic reactions, where stereoselectivity is scarcely concerned. This study selected unimolecular and bimolecular reactions, multicomponent Passerini reactions, and enzymatic ketone reduction as the model reactions to illustrate whether reaction acceleration of microdroplet chemistry is favorable to retaining a chiral center and controlling the enantioselectivity or not. The results illustrated that microdroplet chemistry did not disrupt pre-existing stereogenic centers in chiral starting materials during reactions but did harm to stereospecificity in asymmetric catalysis by chiral catalysts and chiral organic ligands with the exclusion of enzymatic reactions. Our preliminary study reminds us of more cautions to the product enantioselectivity when conducting asymmetric catalysis in microdroplets. We also hope this study may promote more valuable further research on the stereoselectivity of microdroplet chemistry.

Retrograde Drilling and Bone Graft for Hepple Stage V Subchondral Bone Lesion of Talus Using 3D Image-Based Navigation-Assisted Endoscopic Technique.

BACKGROUND: Retrograde drilling remains technically challenging, because of the difficulty of identifying the accurate location of cysts during surgery. This study's aim was to evaluate the 3-dimensional (3D) image-based surgical navigation-assisted endoscopic retrograde drilling technique for subchondral bone lesions of the talus. METHODS: From March 2017 to June 2020, a total of 21 cases with Hepple stage V subchondral bone lesions of the talus were treated with 3D image-based surgical navigation-assisted endoscopic retrograde drilling and bone graft technique. Arthroscopic views were categorized per Pritsch classifications. The correlation between the drilled tunnel with preoperative cystic lesions were assessed under postoperative computer tomographic (CT) scans. The American Orthopaedic Foot & Ankle Society (AOFAS) scores, visual analog scale (VAS) scores, and Foot and Ankle Ability Measure (FAAM) sports scales were evaluated at the preoperative and final consultation. All complications were recorded. RESULTS: On postoperative CT scans, in 20 cases (95.2%), the drilled tunnel was judged to have been in the center of previous cysts. Only 9 cases (42.9%) showed intact normal cartilage (grade 0, group A); 12 cases (57.1%) had intact, but soft, cartilage (grade I, group B). The median follow-up time was 24 (24, 30) months, and at final follow-up, there were no significant differences between the mean AOFAS and VAS scores in both groups (89.0 ± 6.4 vs 88.3 ± 7.0 and 1 vs 0.5) or postoperative FAAM sports scales (28.2 ± 2.2 vs 26.6 ± 4.9, P = .363). Two patients had revision surgery in group B. CONCLUSION: The 3D image-based surgical navigation-assisted endoscopic retrograde drilling and bone graft technique for the subchondral bone lesions of the talus in this small case series showed encouraging results. LEVEL OF EVIDENCE: Level IV, retrospective case series.

Correlation between the Coaptation and Regeneration of Tendon Stumps in Endoscopic Assisted Achilles Tendon Rupture Repair.

OBJECTIVE: When the endoscopic Achilles tendon repair technique is utilized, direct stitching of the ruptured site is challenging due to the frayed tendon stumps. To explore whether undesirable coaptation of the tendon stumps influences the generation of the tendons. METHODS: This study is a retrospective analysis of 46 patients who underwent a modified endoscopic Achilles tendon rupture repair from October 2018 to June 2020. Patients were divided into two groups according to the coaptation of tendon stumps on postoperative ultrasonography. Group 1 included 17 cases with undesirable coaptation (<50%), and Group 2 included 29 cases with appropriate coaptation (≥50%). Magnetic resonance imaging (MRI) was obtained postoperatively at 3, 6, and 12 months to evaluate the tendon morphological construction. Clinical evaluations were performed using the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hind foot score, the Achilles Tendon Total Rupture Score (ATRS), muscle power, and the Achilles tendon resting angle at the final follow-up. Complications were also encountered. The Student's t-test and the Mann-Whitney U-test were used to assess differences among both groups. RESULTS: The mean follow-up time was 37.5 ± 10.6 months in Group 1 and 39.0 ± 11.6 months in Group 2, respectively. The average age in Group 1 is slightly older than in Group 2 (37.3 ± 6.1 vs. 32.7 ± 6.3, p = 0.021). The tendon cross-section areas and thickness increased initially and decreased later on postoperative MRI evaluation. It also showed a significantly higher signal/noise quotient (SNQ) in Group 1 at postoperative 3 months. At postoperative 6 and 12 months, the SNQ between both groups was similar. The AOFAS score (95.9 ± 5.1 vs. 96.2 ± 4.9, p = 0.832), ATRS score (97.0 ± 3.6 vs. 97.7 ± 3.3, p = 0.527), and muscle power (21.38 vs. 24.74, p = 0.287) were not significantly different between both groups. However, the resting angle of Group 1 was significantly larger than that of Group 2 (4.6 ± 2.4 vs. 2.4 ± 2.3, p = 0.004). There was no difference in the complications (p = 0.628). CONCLUSION: Although complete regeneration can be finally achieved, the early stage of tendon stump regeneration can be prolonged due to undesirable coaptation when endoscopic Achilles tendon repair technique is applied. The prolonged high signal duration on MRI indicates the less-than-ideal regeneration of the tendon, which might lead to elongation of the tendon.

Reirradiation with stereotactic body radiotherapy for primary or secondary lung malignancies: Tumor control probability and safety analyses.

BACKGROUND: Reirradiation with stereotactic body radiotherapy (SBRT) for patients with primary or secondary lung malignancies represents an appealing definitive approach, but its feasibility and safety are not well defined. The purpose of this study was to investigate the tumor control probability (TCP) and toxicity for patients receiving reirradiation with SBRT. PATIENTS AND METHODS: Eligible patients with recurrence of primary or secondary lung malignancies from our hospital were subjected to reirradiation with SBRT, and PubMed- and Embase-indexed articles were reviewed. The patient characteristics, pertinent SBRT dosimetric details, local tumor control, and toxicities were extracted. The logistic dose-response models were compared for TCP and overall survival (OS) in terms of the physical dose and three-, four-, and five-fraction equivalent doses. RESULTS: The data of 17 patients from our hospital and 195 patients extracted from 12 articles were summarized. Reirradiation with SBRT yielded 2-year estimates of 80% TCP for doses of 50.10 Gy, 55.85 Gy, and 60.54 Gy in three, four, and five fractions, respectively. The estimated TCP with common fractionation schemes were 50%, 60%, and 70% for 42.04 Gy, 47.44 Gy, and 53.32 Gy in five fractions, respectively. Similarly, the 2-year estimated OS was 50%, 60%, and 70% for 41.62 Gy, 46.88 Gy, and 52.55 Gy in five fractions, respectively. Central tumor localization may be associated with severe toxicity. CONCLUSIONS: Reirradiation with SBRT doses of 50-60 Gy in 3-5 fractions is feasible for appropriately selected patients with recurrence of peripheral primary or secondary lung malignancies, but should be carefully considered for centrally-located tumors due to potentially severe toxicity. Further studies are warranted for optimal dose/fractionation schedules and more accurate selection of patients suitable for reirradiation with SBRT.

Modified classifications and surgical decision-making process for chronic anterior talofibular ligament injuries based on the correlation of imaging studies and arthroscopic findings.

PURPOSE: Surgical treatment of chronic ankle instability (CAI) typically includes ligament repair or reconstruction. Using preoperative ultrasonography or magnetic resonance imaging (MRI) to choose an appropriate arthroscopic procedure is still difficult. The aim of this study was to evaluate the correlation of imaging studies with arthroscopic findings and support the arthroscopic surgical decision-making process. METHODS: One hundred twelve patients with chronic anterior talofibular ligament (ATFL) injuries were treated using the arthroscopic surgical decision-making process from November 2018 to August 2020. Preoperative imaging assessments using dynamic ultrasonography, MRI, and combined methods were applied to categorize the ATFL remnants into three quality grades ("good," "fair," and "poor"). Arthroscopic findings were classified into 6 major types (7 subtypes) and used to select an appropriate surgical procedure. Correlations between imaging studies, arthroscopic findings, and surgical methods were evaluated. Diagnostic parameters, clinical outcomes, and complications were also assessed. RESULTS: There was a significant interobserver agreement in the evaluation of dynamic ultrasonography (0.954, P < 0.001), MRI (0.958, P < 0.001), and arthroscopy diagnosis (0.978, P < 0.001). There was a significant correlation between the modified imaging classifications, arthroscopic diagnostic types, and surgical procedures. The mean follow-up period was 33.58 ± 8.85 months. Significant improvements were documented in postoperative ankle functions when assessed with Karlson-Peterson scores and Cumberland Ankle Instability Tool scores. The risk of complications is also very low. CONCLUSION: The modified classifications and surgical decision-making process based on dynamic ultrasonography, MRI, and arthroscopic findings, as proposed in this study, might help in selecting an appropriate arthroscopic surgical procedure for chronic ATFL injuries.

Fermentation of NaHCO3-treated corn germ meal by Bacillus velezensis CL-4 promotes lignocellulose degradation and nutrient utilization.

Sodium bicarbonate pretreatment and solid-state fermentation (SSF) were used to maximize the nutritional value of corn germ meal (CGM) by inoculating it with Bacillus velezensis CL-4 (isolated from chicken cecal contents and capable of degrading lignocellulose). Based on genome sequencing, B. velezensis CL-4 has a 4,063,558 bp ring chromosome and 46.27% GC content. Furthermore, genes associated with degradation of lignocellulose degradation were detected. Pretreatment of CGM (PCGM) with sodium bicarbonate (optimized to 0.06 g/mL) neutralized low pH. Fermented and pretreated CGM (FPCGM) contained more crude protein (CP), soluble protein of trichloroacetic acid (TCA-SP), and total amino acids (aa) than CGM and PCGM. Degradation rates of cellulose and hemicellulose were reduced by 21.33 and 71.35%, respectively, after 48 h fermentation. Based on electron microscopy, FPCGM destroys the surface structure and adds small debris of the CGM substrate, due to lignocellulose breakdown. Furthermore, 2-oxoadipic acid and dimethyl sulfone were the most important metabolites during pretreatment. Concentrations of adenosine, cytidine, guanosine, S-methyl-5'-thioadenosine, and adenine decreased significantly after 48 h fermentation, whereas concentrations of probiotics, enzymes, and fatty acids (including palmitic, 16-hydroxypalmitic, and linoleic acids) were significantly improved after fermentation. In conclusion, the novel pretreatment of CGM provided a proof of concept for using B. velezensis CL-4 to degrade lignocellulose components, improve nutritional characteristics of CGM, and expand CGM lignocellulosic biological feed production. KEY POINTS: • Sodium bicarbonate (baking soda) can be used as an economical and green additive to pretreat corn germ meal; • Fermentation with B. velezensis degrades the cellulose and hemicellulose component of corn germ meal and improves its feed quality; • As a novel qualified presumption of safety (QPS) strain, B. velezensis should have broad potential applications in food and feed industries.

Direct Phosphonylation of N-Phenyltetrahydroisoquinolines in Microdroplets.

Because of their unique properties and high biological activities, organophosphorus compounds have been used worldwide in agricultural, industrial, medicinal, and veterinary applications. Conventional strategies for direct phosphonylation suffer from the usage of stoichiometric or excessive metallic or nonmetallic catalysts and long reaction times under harsh conditions, leading to a strong desire for environment-friendly protocols for phosphonylation. A protocol for the accelerated phosphonylation of N-phenyltetrahydroisoquinolines in minutes was developed without the use of any catalyst in microdroplets. The phosphonylation process was completed (>85% yields) in 10 min at 40 °C using 0.8 equiv 2,3-dicyano-5,6-dichlorobenzoquinone as the oxidant and acetonitrile as the solvent. The microdroplet phosphonylation strategy showed good suitability to alkyl phosphites and N-phenyltetrahydroisoquinolines bearing electron-withdrawing and electron-donating substitutes, and the yields of the microdroplet reaction were much greater than those of the bulk (accelerated by two orders of magnitude from the ratio of the rate constants using the microdroplet and the bulk method). Furthermore, microdroplet phosphonylation can be scaled up to a 1-phenyl-2-dimethylphosphonite-1,2,3,4-tetrahydroisoquinoline amount of 510 mg h-1 by spraying 0.1 mol L-1 N-phenyltetrahydroisoquinoline at 300 µL min-1. These figures of merit make it a promising alternative to classic organic methodologies for the synthesis of organophosphorus compounds.

STAT3/miR-135b/NF-κB axis confers aggressiveness and unfavorable prognosis in non-small-cell lung cancer.

Non-small-cell lung cancer (NSCLC) is one of the most commonly diagnosed cancers worldwide but has limited effective therapies. Uncovering the underlying pathological and molecular changes, as well as mechanisms, will improve the treatment. Dysregulated microRNAs (miRNAs) have been proven to play important roles in the initiation and progression of various cancers, including NSCLC. In this manuscript, we identified microRNA-135b (miR-135b) as a tumor-promoting miRNA in NSCLC. We found that miR-135b was significantly upregulated and that its upregulation was associated with poor prognosis in NSCLC patients. miR-135b was an independent prognostic factor in NSCLC. Overexpressing miR-135b significantly promoted the aggressiveness of NSCLC, as evidenced by enhanced cell proliferation, migration, invasion, anti-apoptosis, and angiogenesis in vitro and in vivo, and knockdown of miR-135b had the opposite effects. Mechanistically, our results reveal that miR-135b directly targets the 3'-untranslated region (UTR) of the deubiquitinase CYLD, thereby modulating ubiquitination and activation of NF-κB signaling. Moreover, we found that interleukin-6 (IL-6)/STAT3 could elevate miR-135b levels and that STAT3 directly bound the promoter of miR-135b; thus, these findings highlight a new positive feedback loop of the IL-6/STAT3/miR-135b/NF-κB signaling in NSCLC and suggest that miR-135b could be a potential therapeutic target for NSCLC.

Down-regulation of SORL1 is associated with Alzheimer's disease through activating ABC transporter pathway.

Alzheimer's disease (AD) is a common neurodegenerative disease with high morbidity among elderly people. A genetic attribution has been extensively proved. Here, we propose to further prioritize genes that harbor single nucleotide variation (SNV) or structural variation (SV) for AD and explore the underlying potential mechanisms through exploiting their expression and methylation spectra. A high-confidence AD-associated candidate gene list was obtained from the ClinVar and Human Gene Mutation Database (HGMD). Genome-wide methylation and expression profiles of AD and normal subjects were downloaded from the Gene Expression Omnibus (GEO). Through comprehensive comparison of expression and methylation levels between AD and normal samples, as well as different stages of AD samples, SORL1 was identified as the most plausible gene for AD incidence and progression. Gene Set Enrichment Analysis (GSEA) revealed significant activation of the ABC (ATP binding cassette) transporter with the aberrant up-regulation of SORL1 within AD samples. This study unfolds the expression and methylation spectra of previously probed genes with SNV or SV in AD for the first time, and reports an aberrant activation of the ABC transporter pathway that might contribute to AD progression. This should shed some light on AD diagnosis and precision treatment.

Bioinformatics method combined with logistic regression analysis reveal potentially important miRNAs in ischemic stroke.

PURPOSE: The present study aimed to investigate the comprehensive differential expression profile of microRNAs (miRNAs) by screening for miRNA expression in ischemic stroke and normal samples. METHODS: Differentially expressed miRNA (DEM) analysis was conducted using limma R Bioconductor package. Target genes of DEMs were identified from TargetScanHuman and miRTarBase databases. Functional enrichment analysis of the target genes was performed using clusterProfiler R Bioconductor package. The miRNA-based ischemic stroke diagnostic signature was constructed via logistic regression analysis. RESULTS: Compared with the normal cohort, a total of 14 DEMs, including 5 up-regulated miRNAs and 9 down-regulated miRNAs, were identified in ischemic stroke patients. These DEMs have 1600 regulatory targets. Using a logistic regression model, the top five miRNAs were screened for constructing an miRNA-based ischemic stroke diagnostic signature. Using the miRNA-mRNA interaction pairs, two target genes (specificity protein 1 (SP1) and Argonaute 1 (AGO1)) were speculated to be the primary genes of ischemic stroke. DISCUSSION AND CONCLUSION: Here, several potential miRNAs biomarkers were identified and an miRNA-based diagnostic signature for ischemic stroke was established, which can be a valuable reference for future clinical researches.

Depleting PTOV1 sensitizes non-small cell lung cancer cells to chemotherapy through attenuating cancer stem cell traits.

BACKGROUND: Prostate tumor over expressed gene 1 (PTOV1) has been reported as an oncogene in several human cancers. However, the clinical significance and biological role of PTOV1 remain elusive in non-small cell lung cancer (NSCLC). METHODS: The Cancer Genome Atlas (TCGA) data and NCBI/GEO data mining, western blotting analysis and immunohistochemistry were employed to characterize the expression of PTOV1 in NSCLC cell lines and tissues. The clinical significance of PTOV1 in NSCLC was studied by immunohistochemistry statistical analysis and Kaplan-Meier Plotter database mining. A series of in-vivo and in-vitro assays, including colony formation, CCK-8 assays, flow cytometry, wound healing, trans-well assay, tumor sphere formation, quantitative PCR, gene set enrichment analysis (GSEA), immunostaining and xenografts tumor model, were performed to demonstrate the effects of PTOV1 on chemosensitivity of NSCLC cells and the underlying mechanisms. RESULTS: PTOV1 is overexpressed in NSCLC cell lines and tissues. High PTOV1 level indicates a short survival time and poor response to chemotherapy of NSCLC patients. Depleting PTOV1 increased sensitivity to chemotherapy drugs cisplatin and docetaxel by increasing cell apoptosis, inhibiting cell migration and invasion. Our study verified that depleting PTOV1 attenuated cancer stem cell traits through impairing DKK1/ß-catenin signaling to enhance chemosensitivity of NSCLC cells. CONCLUSION: These results suggest that PTOV1 plays an important role in the development and progression of human NSCLC and PTOV1 may serve as a therapeutic target for NSCLC patients.

Antiapoptosis effect of ZiShen prescription to increase learning and memory abilities of compound Alzheimer's disease model rats.

Alzheimer's disease (AD) is a neurodegenerative disease characterized progressive memory loss and cognitive impairment. In previous studies, the activities of extracts of Chinese medicinal herbs to treat brain function disorders caused by AD have already been reported. ZiShen prescription was a traditional Chinese medicine (TCM) compound prescription reformed for AD disease based on the basic theory of TCM. To explore the effect of ZiShen (kidney-reinforcing) prescription on the learning and memory abilities, we made compound AD model rats by injecting d-galactose and ibotenic acid into the abdominal cavity to damage both sides of the nucleus basalis of Meynert with ibotenic acid. The trisected Y-maze was used to test the learning and memory abilities of AD model rats before and after treatment by ZiShen prescription and Piracetam. To investigate the mechanism of ZiShen prescription, the expressions of apoptosis-related genes (Bcl-2/Bax) in the cortex and hippocampus of compound AD model rats were detected in the cortex and hippocampus. The results show that, comparing with Piracetam, a clinical medicine to promote the thinking and memory for AD patients, ZiShen prescription significantly increased the learning and memory abilities of the compound AD model rats. After the treatment of ZiShen prescription, the expression of Bcl-2 was upregulated, along with a downregulation of Bax in the cortex and hippocampus of compound AD model rats. And the results indicated that the clinical benefits of ZiShen prescription were slightly better than Piracetam. Still, further well-designed studies are required to ensure the clinical effect of ZiShen.