[The destructive role of soluble Robo4 secreted by the M1-polarized-microglia during cerebral ischemia-reperfusion in blood-brain barrier integrity].

This project was aimed to investigate the role and the underlying mechanism of microglia polarization on blood-brain barrier (BBB) during cerebral ischemia-reperfusion. After construction of the mouse model of cerebral ischemia-reperfusion, upregulated IL-6 and TNF-α in peripheral blood and increased IL-6 and iNOS in ischemia tissues were confirmed. The supernatant expression of TNF-α and IL-6, as well as IL-6, iNOS and CD86 mRNA, was significantly increased in the of Bv-2 cells after oxygen-glucose deprivation/reoxygenation (OGD/R) model was constructed in vitro. For further understanding the expression pattern of RNAs, the next-generation RNA sequencing was performed and upregulation of Robo4 (roundabout guidance receptor 4) was found both in M1-polarized and OGD/R treated Bv-2 cells, which was also confirmed by RT-qPCR. Extracellular soluble Robo4 (sRobo4) protein also increased in the supernatant of M1-polarized and OGD/R treated Bv-2 cells. Treating bEND3 cells with the Robo4 recombinant protein, M1-polarized Bv-2 cell supernatant or OGD/R Bv-2 cell supernatant decreased trans-endothelial electrical resistance (TEER), suggesting the injury of BBB. In addition, Robo4 was also highly expressed in the serum of patients who experienced acute ischemia stroke and mechanical thrombectomy operation. All the results suggest that increased secretion of Robo4 by M1-polarized-microglia during cerebral ischemia-reperfusion is most likely one of the causes of BBB injury, and Robo4 may be one of the therapeutic targets for BBB functional protection.

Enantioselective Insertion of Alkynyl Carbenes into Si-H Bonds: An Efficient Access to Chiral Propargylsilanes and Allenylsilanes.

Chiral propargylsilanes and chiral allenylsilanes have emerged as versatile building blocks for organic synthesis. However, efficient methods for preparing these organosilicon compounds are lacking. We herein report a highly enantioselective method for synthesis of chiral propargylsilanes and chiral allenylsilanes from readily available alkynyl sulfonylhydrazones. Specifically, chiral spiro phosphate dirhodium complexes were used to catalyze asymmetric insertion of alkynyl carbenes into the Si-H bonds of silanes to afford a variety of chiral propargylsilanes with excellent enantioselectivity. Subsequently, a platinum catalyst was used for stereospecific isomerization of the chiral propargylsilanes to the corresponding chiral allenylsilanes.

Chiral Dirhodium Tetraphosphate-Catalyzed Enantioselective Si-H Bond Insertion of α-Aryldiazoacetates.

A highly enantioselective Si-H bond insertion reaction of α-aryldiazoacetates catalyzed by chiral spiro dirhodium tetraphosphate was developed. Various chiral α-silyl esters were prepared with high yield (up to 92%) and excellent enantioselectivity (up to >99% ee) through this protocol. It is noteworthy that the 2-substituted aryl diazoacetates, which are challenging substrates for other chiral dirhodium catalysts, also exhibited good results in this reaction. This work represents one of the few successful applications of chiral dirhodium phosphates in asymmetric catalysis.

Dirhodium-Catalyzed Enantioselective B-H Bond Insertion of gem-Diaryl Carbenes: Efficient Access to gem-Diarylmethine Boranes.

The scarcity of reliable methods for synthesizing chiral gem-diarylmethine borons limits their applications. Herein, we report a method for highly enantioselective dirhodium-catalyzed B-H bond insertion reactions with diaryl diazomethanes as carbene precursors. These reactions afforded chiral gem-diarylmethine borane compounds in high yield (up to 99 % yield), high activity (turnover numbers up to 14 300), high enantioselectivity (up to 99 % ee) and showed unprecedented broad functional group tolerance. The borane compounds synthesized by this method could be efficiently transformed into diaryl methanol, diaryl methyl amine, and triaryl methane derivatives with good stereospecificity. Mechanistic studies suggested that the borane adduct coordinated to the rhodium catalyst and thus interfered with decomposition of the diazomethane, and that insertion of a rhodium carbene (generated from the diaryl diazomethane) into the B-H bond was most likely the rate-determining step.

Enantioselective Diarylcarbene Insertion into Si-H Bonds Induced by Electronic Properties of the Carbenes.

Catalytic enantioselection usually depends on differences in steric interactions between prochiral substrates and a chiral catalyst. We have discovered a carbene Si-H insertion in which the enantioselectivity depends primarily on the electronic characteristics of the carbene substrate, and the log(er) values are linearly related to Hammett parameters. A new class of chiral tetraphosphate dirhodium catalysts was developed; it shows excellent activity and enantioselectivity for the insertion of diarylcarbenes into the Si-H bond of silanes. Computational and mechanistic studies show how the electronic differences between the two aryls of the carbene lead to differences in energies of the diastereomeric transition states. This study provides a new strategy for asymmetric catalysis exploiting the electronic properties of the substrates.

Mechanism Studies of Ir-Catalyzed Asymmetric Hydrogenation of Unsaturated Carboxylic Acids.

The Ir-catalyzed asymmetric hydrogenation of olefins is widely used for production of value-added bulk and fine chemicals. The iridium catalysts with chiral spiro phosphine-oxazoline ligands developed in our group show high activity and high enantioselectivity in the hydrogenation of olefins bearing a coordinative carboxyl group, such as α,ß-unsaturated carboxylic acids, ß,γ-unsaturated carboxylic acids, and γ,δ-unsaturated carboxylic acids. Here we conducted detailed mechanistic studies on these Ir-catalyzed asymmetric hydrogenation reactions by using (E)-2-methyl-3-phenylacrylic acid as a model substrate. We isolated and characterized several key intermediates having Ir-H bonds under the real hydrogenation conditions. Particularly, an Ir(III) migratory insertion intermediate was first isolated in an asymmetric hydrogenation reaction promoted by chiral Ir catalysts. That this intermediate cannot undergo reductive elimination in the absence of hydrogen strongly supports the involvement of an Ir(III)/Ir(V) cycle in the hydrogenation. On the basis of the structure of the Ir(III) intermediate, variable-temperature NMR spectroscopy, and density functional theory calculations, we elucidated the mechanistic details of the Ir-catalyzed hydrogenation of unsaturated carboxylic acids and explained the enantioselectivity of the reactions. These findings experimentally and computationally elucidate the mechanism of Ir-catalyzed asymmetric hydrogenation of olefins with a strong coordinative carboxyl group and will likely inspire further catalyst design.

Cinchona Alkaloid Catalyzed Enantioselective [4 + 2] Annulation of Allenic Esters and in Situ Generated ortho-Quinone Methides: Asymmetric Synthesis of Functionalized Chromans.

A novel enantioselective [4 + 2] annulation of the allenoates having a unique positive ortho-effect with in situ generated ortho-quinone methides has been developed under the catalysis of Cinchona alkaloid. This chiral amine-catalyzed reaction provides an alternative route to asymmetric catalytic construction of synthetically interesting, highly functionalized chiral chromans in good to excellent enantioselectivities (up to 97% ee).

Efficacy and safety of subcutaneous semaglutide in adults with overweight or obese: a subgroup meta-analysis of randomized controlled trials.

Introduction: Semaglutide shows significant performance on weight reduction in several clinical trials. However, it is not clear what kind of administration frequency or dosage will achieve better effects. This study aims to explore the different therapeutic effect of semaglutide on weight control under the diverse administration circumstances. Methods: The PubMed, Embase, Web of Science, Cochrane Library, and the Clinical Trials.gov were searched from inception until 6 June, 2022 to include randomized controlled trials evaluating the Efficacy and safety of subcutaneous semaglutide in overweight or obese adults. Random effects or fixed effects model was conducted based on the heterogeneity among trials. Subgroup analysis was performed to identify the detailed effects under different intervention situations. Results and discussion: Our study included 13 RCTs involving 5,838 participants with 3,794 ones in semaglutide group and 2,044 in placebo group. Semaglutide was associated with a significant reduction on weight loss related outcomes, including the absolute value of weight loss (WMD -8·97, 95% CI -10·73 to -7·21), percentage of weight loss (WMD -10·00, 95% CI -11·99 to -8·00), body mass index (WMD-3·19, 95% CI -4·02 to -2·37) and waist circumference (WMD -7·21,95% CI -8·87 to -5·56). Subgroup analyses illustrated participants with high weekly dosage, long-term treatment duration and severe baseline BMI (Class II obesity) had a more remarkably decreasing on the main outcomes of weight loss (P for interaction<0·05). Total adverse reactions occurred more frequently in the daily administration group than that in the weekly group (P for interaction =0·01). During the treatment, the incidence rate of hypoglycemia was higher in the group without lifestyle intervention compared with that with lifestyle intervention (P for interaction =0·04). Interpretation Subcutaneous semaglutide had significant benefits on weight loss with reasonable safety in overweight or obese adults. Moreover, additional benefits on cardiometabolic profiles were also seen. We recommended semaglutide treatment to be coupled with lifestyle interventions, and target dose of 2·0 mg or more subcutaneously once weekly. Clinicians can choose suitable treatment schemes based on diverse individual situations. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=337099, identifier PROSPERO (CRD42022337099).

Endoscopic transcortical expanded transforaminal transvenous transchoroidal approach to third ventricle lesion resection using an endoport.

OBJECTIVE: To investigate the clinical experience and application value of endoscopic resection of lesions in and around the third ventricle using a transcortical expanded transforaminal transvenous transchoroidal approach with an endoport. METHODS: Clinical data and follow-up results of seven patients who underwent the removal of lesions in the third ventricle and its adjacent area with an endoport-guided endoscopic system from January 2018 to December 2020 in the Department of Neurosurgery, Zhongshan Hospital Affiliated to Fudan University, were analyzed retrospectively. Two other patients from the Affiliated Pediatric Hospital of Fudan University and the Affiliated Hospital of Guizhou Medical University, respectively, were included in the analysis. RESULTS: A total of nine cases of third ventricle tumors were included in the study, including six women and three men, with an average age of 37.8 years (4-84 years old) and a follow-up time of 6-44 months. These nine tumor cases included two pilocytic astrocytomas, one diffuse midline glioma (H3 K27-altered), two craniopharyngiomas, two choroid plexus (CP) papillomas, one germinoma, and one pineal parenchymal tumor of intermediate differentiation. Total resection was completed in eight cases, with one near-total resection. There were no complications related to the surgical approach, such as epilepsy, aphasia, or hemiplegia. CONCLUSIONS: The endoscope transcortical expanded transforaminal transvenous transchoroidal approach using an endoport can safely and effectively remove third ventricle lesions. This approach can reach a wide area, from the anterior to the posterior third ventricle.

Nickel-Catalyzed Desymmetrizing Cyclization of 1,6-Dienes to Construct Quaternary Stereocenters.

A highly enantioselective and diastereoselective nickel-catalyzed desymmetrizing cyclization of 1,6-dienes was developed by using chiral spiro phosphoramidite ligands. The reaction provides a new atom- and step-economical approach to chiral spiro lactones and analogues bearing a quaternary stereocenter.

Surgical therapy for hemangioma of the azygos vein arch under thoracoscopy: A case report.

BACKGROUND: Azygos vein aneurysms are extremely rare, and their pathogenesis is not clear. The overwhelming majority of patients have no obvious clinical symptoms and are found to have the disease by physical examination or by chance. There are few reports on the diagnosis of and treatment strategy for this disease. Moreover, the choice of therapeutic schedule and the treatment window are controversial. CASE SUMMARY: We report a case of azygos vein arch aneurysm in a 53-year-old woman. The patient had symptoms of back pain, chest tightness, and choking. Enhanced chest computed tomography showed a soft-tissue mass in the right posterior mediastinum, which was connected to the superior vena cava. The enhancement degree in the venous phase was the same as that of the superior vena cava. The patient received video-assisted thoracoscopic surgery. After the operation, her back pain disappeared, and her dysphagia and chest tightness were also significantly relieved. The postoperative pathology confirmed hemangioma. The patient was discharged on the seventh day after surgery without any comp-lications. CONCLUSION: Some patients with hemangioma of the azygos vein arch may experience dysphagia and chest tightness caused by the tumor compressing the esophagus and trachea. Enhanced computed tomography scanning is vital for the diagnosis of azygos vein aneurysms. In addition, despite the difficulty and risk of surgery, thoracoscopic surgery for azygos vein aneurysms is completely feasible.

Exploration of exact significance of lymph node ratio and construction of a novel stage in colon cancer with no distant metastasis.

AIM: Lymph node ratio (LNR) seems to be more precise than classic N stage in classifying cancer stage. Thus, we aim to construct a modified classification system based on LNR for colon cancer without distant metastasis. METHODS: This study enrolled two independent cohorts of patients. The primary cohort enrolled 2,152 patients from 2008 to 2013 in Zhongshan Hospital, Fudan University. The validation cohort consisted of 77,406 patients from the Surveillance, Epidemiology, and End Results (SEER) registry from 2004 to 2014. The inclusion criteria were: pathologically confirmed colon cancer, and American Joint Committee on Cancer (AJCC) stage I/II/III. The exclusion criteria included: incomplete follow-up information, rectal cancer, and multiple primary sites. The prognostic value of LNR for overall survival was evaluated. The cutoff value of LNR was determined by the X-tile. Predictive performance of modified classification was determined by the concordance index. RESULTS: After analysis, 0.05 and 0.50 were determined as the best threshold values of LNR. A value of <0.05, 0.05-0.50 and >0.50 was reclassified as the mN0, mN1 and mN2 stage. A modified classification based on mN0, mN1, and mN2 was further constructed for stage I/II/III colon cancer. C-index of the modified classification was statistically more precise than AJCC classification (0.687 versus 0.605, P<0.001). The same results can also be determined in the validation cohort (0.715 versus 0.640, P<0.001). Furthermore, a prognostic nomogram including independent factors was constructed. The constructed nomogram showed good performance according to the calibration curve. CONCLUSION: The clinical value of LNR level was preferable to classic N stage in colon cancer patients. Our proposed classification based on LNR and AJCC T category can effectively differentiate patients with varied survival outcomes.

The role of Pyk2 in the CCR7-mediated regulation of metastasis and viability in squamous cell carcinoma of the head and neck cells in vivo and in vitro.

In the present study, we aimed to demonstrate whether praline-rich tyrosine kinase-2 (Pyk2) participates in the chemokine receptor 7 (CCR7) downstream signaling network, and to determine the role of this molecule and the related mechanism in the CCR7-mediated regulation of viability and metastasis in vivo and in vitro of squamous cell carcinoma of the head and neck (SCCHN). We constructed the stable Pyk2 related non-kinase (PRNK)-expressing SCCHN cell line, and examined the viability, apoptosis, migration, invasion and adhesion ability in the transfected and untransfected SCCHN cells. An SCCHN tumor model in nude mice was designed and the tumor growth rate was assayed. E-cadherin and vimentin expression was assessed when Pyk2 was inactivated. We found that the stable PRNK-expressing SCCHN cells exhibited low viability, a high rate of apoptosis, low migratory ability, low invasive ability and low adhesion capacity. In the nude mouse body, the tumors formed by these cells grew slowly when compared to the tumor growth in the control group. When Pyk2 was inactivated, CCR7-induced E-cadherin and vimentin expression levels were altered. Thus, Pyk2 is a key downstream signaling molecules of CCR7 in SCCHN, which promotes SCCHN tumorigenesis and progression.

NF-κB participates in chemokine receptor 7-mediated cell survival in metastatic squamous cell carcinoma of the head and neck.

Metastatic squamous cell carcinoma of the head and neck (SCCHN) has been shown to express chemokine receptor 7 (CCR7), which activates phosphoinositide-3 kinase/Akt/mammalian target of rapamycin (PI3K/Akt/mTOR) signal pathway to promote the invasion and survival of SCCHN cells. Since nuclear factor-kappa B (NF-κB) is shown to be the downstream signal molecule of PI3K/Akt in many tumors, we investigated whether it also exists in the CCR7 pathway in SCCHN, and the relationship between NF-κB and PI3K/Akt/mTOR, and the role it plays in SCCHN. We assayed the phosphorylation of the inhibitor of NF-κB (IκBα), the NF-κB DNA-binding capacity and location. The results showed that the interaction between CCR7 and the ligand for CCR7, CCL19, induces phosphorylation of IκBα, causes NF-κB to translocate to the nucleus and raises the DNA-binding capacity of NF-κB. The phosphorylation and DNA-binding capacity were abolished by the inhibition of CCR7, PI3K, Akt and mTOR. Further research demonstrated that inhibitors of NF-κB and CCR7-PI3K attenuate the survival of CCR7-mediated cells, causing decreased viability, increased apoptosis and increased cell cycle arrest in SCCHN cells. In clinical samples from 78 patients, immunohistochemical assay also showed that CCR7 and NF-κB are not only highly expressed in SCCHN, but also correlated with each other, and related to lymph node metastasis and clinical stage. Together, our data indicate that NF-κB is activated by CCR7 via PI3K/Akt/mTOR, and this signal pathway plays an important role in regulating the cell survival and prognosis of SCCHN.