Cu(I)-Catalyzed Three-Component Annulation for the Synthesis of 3-Acyl Imidazo[1, 5-a]Pyridines from 2-Pyridinyl-Substituted p-Quinone Methides, Terminal Alkynes, and TsN3 Using O2 as the Oxygen Source

Currently, most conventional methods to achieve imidazo[1,5-a]pyridines have limitations for the synthesis of 3-acyl imidazo[1,5-a]pyridines. Herein, a novel and efficient Cu(I)-catalyzed three-component annulation method for the synthesis of valuable 3-acyl imidazo[1,5-a]pyridines by the reaction of 2-pyridinyl-substituted p-QMs, terminal alkynes, and TsN3 in the presence of O2 under mild conditions have successfully been developed. The investigation indicated that molecular oxygen (O2) and TsN3, respectively, serving as oxygen and nitrogen sources, were essential for the successful completion of the reaction system.

[A real-world study on the features of postpartum hepatitis flares in pregnant women with chronic HBV infection]

Objective: To analyze the clinical features of postpartum hepatitis flares in pregnant women with hepatitis B virus (HBV) infection. Methods: A retrospective study was conducted. Patients who met the enrollment criteria were included. Liver function and HBV virology tests were collected from pregnant women with chronic HBV infection at delivery, 6, 24, 36, and 48 weeks after delivery through the hospital information and test system. Additionally, antiviral therapy types and drug withdrawal times were collected. Statistical analysis was performed on all the resulting data. Results: A total of 533 pregnant women who met the inclusion criteria were included, with all patients aged (29.5±3.7) years old. A total of 408 cases received antiviral drugs during pregnancy to interrupt mother-to-child transmission. There was no significant difference in the levels of alanine aminotransferase (ALT, z = -1.981, P = 0.048), aspartate aminotransferase (AST, z = -3.956, P < 0.001), HBV load (z = -15.292, P < 0.001), and HBeAg (z = -4.77, P < 0.001) at delivery in patients who received medication and those who did not. All patients ALT, AST, total bilirubin, direct bilirubin, and albumin showed an upward trend within six weeks after delivery. A total of 231 cases developed hepatitis within 48 weeks after delivery. Among them, 173 cases first showed ALT abnormalities within six weeks postpartum. Conclusion: Hepatitis flare incidence peaked six weeks after delivery or six weeks after drug withdrawal in pregnant women with chronic HBV infection.

An Accesss to 4,5,6-Trisubstituted Pyrimidines from 2H-Azirines and α-Isocyanoacetates or α-Isocyanoacetamides Enabled by 1,3-Dipolar [3 + 2] Cycloaddition/Ring-Expanding/Oxidative Aromatization Process

The products containing pyrimidine scaffolds exhibit various important physiological and biological activities. To date, the strategies to generate 4,5,6-trisubstituted pyrimidines were not reported. Here, a copper-catalyzed reaction of 2H-azirines with α-isocyanoacetates or α-isocyanoacetamides has been developed, rapidly preparing 4,5,6-trisubstituted pyrimidines. The mechanistic results reveal that this strategy underwent a formal 1, 3-dipolar [3 + 2] cycloaddition/ring-expanding/oxidative aromatization procedure to construct the desired pyrimidines.

One-Step Protocol for the Synthesis of Cyanoacrylates Promoted by Elemental Sulfur from p-Quinone Methides and Cyanoacetates under Basic Conditions

Cyanoacrylates have a wide range of biological activities and are extensively applied in production and daily life. Classic synthetic routes to cyanoacrylates have many limitations. Herein, we demonstrate an elemental sulfur-promoted method for the synthesis of β,β-diaryl cyanoacrylates by a tandem 1,6-Michael addition/oxidation/elimination process from p-QMs and cyanoacetates under optimal conditions. The effective protocol has good substrate scopes and yields, and the ratio of inseparable E/Z isomers of cyanoacrylates is also determined by 1HNMR.

DMSO-promoted direct δ-selective arylation of p-quinone methenylpiperidine bearinides to generate fuchsones under metal-free conditions by employing p-QMs themselves or substituted phenols as aryl sources

Fuchsones have wide applications in modern society. Present methods for generating fuchsones have many disadvantages and there are significant limitations for further exploration of fuchsone applications. Herein, we describe a DMSO-promoted direct δ-selective arylation of p-QMs to synthesize symmetrical and unsymmetrical fuchsones under metal-free conditions by employing p-QMs themselves or substituted phenols as aryl sources. As unprecedented methods, these novel strategies present a great advantage and significance for further exploration of fuchsones and the development of new applications.

Effect modification of the association between diurnal temperature range and hospitalisations for ischaemic stroke by temperature in Hefei, China

OBJECTIVES

Diurnal temperature range (DTR) is an important indicator of global climate change. Many epidemiological studies have reported the associations between high DTR and human health. This study investigated the association between DTR and hospitalisations for ischaemic stroke in Hefei, China.

STUDY DESIGN

This is an ecological study.

METHODS

Data of daily hospital admissions for ischaemic stroke and meteorological variables from 1 January 2009 to 31 December 2017 were collected in Hefei, China. A generalised additive model combined with distributed lag non-linear model was used to quantify the effects of DTR on ischaemic stroke. The interactive effect between DTR and temperature was explored with a non-parametric bivariate response surface model.

RESULTS

High DTR was associated with hospitalisations for ischaemic stroke. The adverse effect of extremely high DTR (99th percentile [17.1 °C]) occurred after 8 days (relative risk [RR] = 1.021, 95% confidence interval [CI] = 1.002, 1.041) and the maximum effect appeared after 12 days (RR = 1.029, 95% CI = 1.011, 1.046). The overall trend of the effect of DTR on ischaemic stroke was decreasing. In addition, there was a significant interactive effect of high DTR and low temperature on ischaemic stroke.

CONCLUSIONS

This study suggests that the impact of high DTR should be considered when formulating targeted measures to prevent ischaemic stroke, especially for those days with high DTR and low mean temperature.

Direct intramolecular double cross-dehydrogentive-coupling (CDC) cyclization of N-(2-pyridyl)amidines under metal-free conditions

A facile transition-metal-free protocol to form 2-iminoimidazo[1, 2-a]-pyridines bearing a -CHBr₂ group and an aza-quaternary carbon center at the 3 position from N-(2-pyridyl)amidines substrates, in which the new heterocyclic skeletons constructed from amidines via radical reactions or nucleophilic substitution reactions are promoted only by CBr₄ under mild conditions, is demonstrated. The reactions were realized by intramolecular CDC reaction involving C-N and C-C bond formation via the sequential C(sp³)-H bifunctionalization mode on the same carbon atom under mild conditions. Moreover, this work also provides an excellent and representative example for CBr₄ as an efficient reagent to initiate radical reactions under initiator-free conditions or to give rise to nucleophilic substitution reactions only by base.

Oxidation and chalcogenylative disproportionation of anionic phosphide ligands in yttrium complexes with elemental sulfur and selenium

The oxidation and disproportionation of anionic phosphide ligands in yttrium complexes with elemental sulfur and selenium are reported. The mixed TpMe2/Cp supported yttrium phosphide complex TpMe2CpYPPh2(THF) (1) reacted with one equiv. of elemental S or Se in THF at room temperature to deliver two structurally characterized yttrium dithio- or monoseleno-phosphinates TpMe2CpYS2PPh2(THF) (2) and TpMe2CpYSePPh2(THF) (4Se), respectively. Further investigations showed that the yttrium thiophosphinate TpMe2CpYSPPh2(THF) (4S) can be isolated from the reactions of 2 and 1 or 1 and elemental S in a short reaction time. Moreover, after keeping 4S or 4Se in THF solution for some days, 2 or [(TpMe2)2Y]+[Se2PPh2]- (5) was obtained by a disproportionation process. The mechanism for the construction of the Ph2PE- and Ph2PE2- (E = S, Se) ligands has been discussed based on the in situ NMR experiments and some designed reactions.

Terminal Alkyne-Assisted One-Pot Synthesis of Arylamidines: Carbon Source of the Amidine Group from Oxime Chlorides

A terminal alkyne-assisted protocol for the one-pot formation of a diverse range of arylamidines from a novel cascade reaction of in situ generated nitrile oxides, sulfonyl azides, terminal alkynes, and water by [3 + 2] cycloaddition and ring opening sequence was developed. The use of aryl oxime chlorides as the carbon source of the amidine group and the addition of water proved to be critical for the reaction. Moreover, terminal alkynes, which can lead to high yields of products by employing a less amount, may play a catalytic role in the reaction. A broader range of substrates was investigated.

[Therapeutic effect of Jin Long capsule combined with neoadjuvant chemotherapy on invasive breast cancer and the expression change of multidrug resistance proteins]

Objective: To investigate the therapeutic effect of Jin Long Capsule (JLC) combined with neoadjuvant chemotherapy on the invasive breast cancer, and to explore the mechanism of JLC in inhibiting multidrug resistance of breast cancer. Methods: 200 patients were divided into experimental group and control group (100 cases per group). The control group used TEC regimen for neoadjuvant chemotherapy. And the experimental group was treated with TEC regimen combined with oral JLC. According to the Miller & Payne grading system (MP), the efficacy of neoadjuvant chemotherapy was evaluated based on histopathological changes of breast cancer after neoadjuvant chemotherapy. Adverse effect was evaluated according to the classification criteria of the National Cancer Institute of the United States-The Common Terminology Criteria for Adverse Events (CTCAE) version 3.0. The expression of P-glycoprotein (P-gp), glutathione thiol transferase (GST)-π and topoisomerase Ⅱα (TopoⅡα) in breast cancer tissues before and after neoadjuvant chemotherapy were detected by immunohistochemical staining. Results: There were 83 effective cases (83%) in the experimental group, which was higher than that in the control group (65.0%, P<0.05). The incidence of leukopenia, gastrointestinal reactions and alopecia in grade 3 to 4 of the experimental group were lower than those of the control group (all P<0.05). The positive rates of P-gp, GST-π and TopoⅡα expression in the control group were 65.0% (65/100), 61.0% (61/100) and 69.0% (69/100), respectively, and they were 80.6% (75/93), 78.5% (73/93) and 37.6% (35/93) after chemotherapy. The positive rates of P-gp and GST-π expression were significantly higher than those before chemotherapy (both P<0.05), whereas the positive rate of TopoⅡα expression was significantly lower than that before chemotherapy (P<0.05). In the experimental group, the positive rates of P-gp, GST-π and TopoⅡα expression before chemotherapy were 62.0% (62/100), 63.0% (63/100) and 69.0% (69/100), respectively, while after chemotherapy, they were 68.2% (60/88), 67.0% (59/88) and 63.6% (56/88). There was no significant difference in the positive rates and expression intensity of P-gp, GST-π and TopoⅡα before and after the chemotherapy (P>0.05). Conclusion: Jin Long Capsule (JLC) can inhibit multidrug resistance, improve the efficacy of neoadjuvant chemotherapy, and reduce adverse reactions of breast cancer.

A new and facile approach to 1,2-dihydroisoquinolin-3(4H)-imines by the Cu(i)-catalyzed reaction of 2-ethynylbenzyl methanesulfonates, sulfonyl azides and amines

A new, step-economical and operationally simple access to unsubstituted 1,2-dihydroisoquinolin-3(4H)-imines by Cu-catalyzed MCRs under mild conditions is described.

Prospective cohort study on the efficacy and safety of telbivudine used throughout pregnancy in blocking mother-to-child transmission of hepatitis B virus

Women with chronic hepatitis B should maintain nucleotide analogue treatment to prevent disease progression during pregnancy. The aim of this study was to prospectively evaluate the efficacy and safety of telbivudine used throughout pregnancy for preventing hepatitis B virus (HBV) mother-to-child transmission (MTCT). From January 2012 to June 2014, women who were receiving telbivudine therapy and became pregnant were enrolled in group A at 28 weeks of gestation. Pregnant women with an HBV DNA level >10⁶  IU/mL were enrolled in either group B (telbivudine started at 28 weeks of gestation) or group C (control group without treatment). MTCT was defined as infants who were positive for serum hepatitis B surface antigen at 7 months after birth. There were 41, 179 and 177 pregnant women (397 infants) enrolled in groups A, B and C, respectively. The HBV DNA load at 28 weeks of gestation and delivery was 1.50 ± 0.62 vs 1.45 ± 0.61, 8.05 ± 0.37 vs 4.24 ± 0.89 and 7.94 ± 0.62 vs 7.86 ± 0.73 log₁₀ IU/mL in groups A, B and C, respectively. The rate of MTCT in group C was 4.60%, which was significantly higher than the rates in groups A and B (0% and 0.6%, respectively) (P = .043). The difference between group A and group B was not significant. The rates of neonatal congenital abnormalities were 2.4%, 0.6% and 2.3% in groups A, B and C, respectively, and there were no significant differences (P = .140). Telbivudine used throughout pregnancy may be safe and effective for mothers and infants, but it may not enhance the efficacy of an HBV MTCT block compared with treatment starting at 28 weeks of gestation (NCT02253485).

Mutation screening of 10 cancer susceptibility genes in unselected breast cancer patients

Variants of cancer susceptibility genes other than BRCA1/2 have been proved to be associated with increased risks of breast cancer. This study was performed to investigate the spectrum and prevalence of mutations in 10 cancer susceptibility genes in paired tumor/normal tissues of 292 unselected Chinese breast cancer patients. We performed an analysis of germline and somatic variants in ATM, CDH1, CHEK2, ESR1, GATA3, MAP3K1, MSH2, PALB2, RB1 and STK11 genes by integrating microfluidic PCR-based target enrichment and next-generation sequencing technologies. In total, 3 germline and 25 somatic deleterious mutations were found among 27 patients (9.25%), and 17 of them were novel mutations. Most deleterious mutations were prevalent in luminal A invasive breast cancer (P = .014). We also observed 83 variants of uncertain significance (VUS) in 100 patients (34.25%), 23 of which were predicted to be deleterious by in silico prediction programs (MetaSVM and MetaLR). VUS carriers had higher positive rate of lymph node metastasis than non-carriers (P = .008) and were predominantly present in ER+ tumors (P = .018). Our findings would enhance the understanding of the molecular mechanisms of breast cancer in Chinese population.

Lamivudine therapy during the second vs the third trimester for preventing transmission of chronic hepatitis B

There are little data on the timing of initiating lamivudine therapy for preventing transmission of hepatitis B in highly viremic mothers. Between May 2008 and January 2015, we retrospectively enrolled mothers with HBV DNA >6 log₁₀  copies/mL who received lamivudine during pregnancy, and we compared them to untreated mothers. The primary measurement was the vertical transmission rate. The secondary outcomes were the mothers' and infants' safety. Among 249 consecutive mothers enrolled, 66 and 94 received lamivudine during the second and third trimesters, respectively, and 89 were untreated. At delivery, maternal mean HBV DNA levels were significantly lower in mothers who received lamivudine (4.45 log_10; vs 7.16 log₁₀  copies/mL; P<.001). Lamivudine treatment was well tolerated. However, early treatment during the second trimester did not significantly increase the percentage of mothers achieving HBV DNA levels of <6 log₁₀  copies/mL compared to those treated during the third trimester (98.5% vs 94.7%; P=.40). At the age of 28 weeks, the vertical transmission rates were significantly lower in the lamivudine-treated mothers vs in the untreated mothers (0% [0/160] vs 5.62% [5/89]; P<.001), but the rates were similar when comparing the two subgroups treated with lamivudine (0% [0/66] vs 0% [0/94], P>.05). The birth defect rates and mothers' and infants' adverse events were similar among the groups. Lamivudine treatment initiated in the second or third trimester for mothers with HBV DNA levels below 9 log₁₀  copies/mL was equally safe and effective in preventing vertical transmission. Thus, lamivudine should be deferred until the third trimester to minimize foetal exposure and drug resistance.

The Influenza A Virus Non-structural Protein NS1 Upregulates The Expression of Collagen Triple Helix Repeat Containing 1 Protein

Influenza A virus (IAV) infection induces a strong immune response and regulates the expression of many host proteins. The collagen triple helix repeat containing 1 (CTHRC1) protein is a secreted protein that exhibits increased expression during the viral infection process. However, the regulatory function of IAV on CTHRC1 expression is obscure. In this study, we investigated the effect of IAV on CTHRC1 expression and its regulatory mechanism. A total of 106 serum specimens from healthy people and 80 serum specimens from patients infected with IAV were collected. The CTHRC1 levels in the sera from the IVA patients and healthy individuals were measured using an enzyme-linked immunosorbent assay (ELISA), and the differences were statistically analysed. A549 cells were infected with the IAV or delNS1 virus. Additionally, A549 cells were cotransfected with a eukaryotic non-structural NS1 protein gene expression plasmid and the CTHRC1 gene promoter reporter plasmid (pCTHRC1-Luc), and, the luciferase activities were assessed. The CTHRC1 mRNA and protein expression were detected using reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting, respectively. The serum CTHRC1 level was significantly higher in the IAV patients than in the healthy individuals. IAV upregulated the CTHRC1 mRNA and protein expression. The non-structural NS1 protein specifically activated CTHRC1 gene promoter activity and upregulated CTHRC1 mRNA and protein expression. The activation function had a dose-dependent effect, indicating that influenza virus upregulated CTHRC1 expression through its NS1 protein.

The emerging role of Toll-like receptor 4 in myocardial inflammation

Toll-like receptors (TLRs) are a family of pattern recognition receptors involved in cardiovascular diseases. Notably, numerous studies have demonstrated that TLR4 activates the expression of several of pro-inflammatory cytokine genes that play pivotal roles in myocardial inflammation, particularly myocarditis, myocardial infarction, ischemia-reperfusion injury, and heart failure. In addition, TLR4 is an emerging target for anti-inflammatory therapies. Given the significance of TLR4, it would be useful to summarize the current literature on the molecular mechanisms and roles of TLR4 in myocardial inflammation. Thus, in this review, we first introduce the basic knowledge of the TLR4 gene and describe the activation and signaling pathways of TLR4 in myocardial inflammation. Moreover, we highlight the recent progress of research on the involvement of TLR4 in myocardial inflammation. The information reviewed here may be useful to further experimental research and to increase the potential of TLR4 as a therapeutic target.

High expression of HIF-2α and its anti-radiotherapy effect in lung cancer stem cells

Hypoxia-inducible factor-2 alpha (HIF-2α) has been shown to regulate cell stemness, although the expression and effects of HIF-2α in lung cancer stem cells remained unclear. This study investigated HIF-2α expression in lung cancer stem cells, as well as the relationship between HIF-2α expression and radioresistance in lung cancer cells. Stem-like cells (CD133(+)) in the non-small-cell lung cancer cell line A549 were enriched by serum-free culture conditions, and CD133(+) cells were sorted via fluorescence-activated cell sorting. A549 cells were treated with middle-infrared radiation, and the level of HIF-2α expression was determined by a quantitative polymerase chain reaction assay and western blot analysis. The level of HIF-2α expression in tissue sections from 50 cases of clinically confirmed non-small-cell lung cancer was determined via immunohistochemical analysis, and its correlation with prognosis after radiotherapy was analyzed. HIF-2α levels in CD133(+) cells were significantly higher than those in CD133(-) cells (P = 0.032). However, after radiation treatment, these levels were significantly upregulated in both CD133(+) and CD133(-) cells (P = 0.031 and P = 0.023, respectively). After irradiation, the proportions of apoptotic, dead, and autophagic CD133(+) A549 cells were considerably lower than those of CD133(-) A549 cells (P < 0.05). Furthermore, the recovery of carcinoembryonic antigen to pre-radiation levels was more rapid in lung cancer patients with high levels of HIF-2α expression, and these patients had shorter survival times (P = 0.018). HIF-2α is highly expressed in lung cancer stem cells, which may lead to radioresistance. In conclusion, HIF-2α is a potential prognostic marker for lung cancer.

An Improvement to the Preparation of Prasugrel Hydrochloride

An efficient synthesis of prasugrel, a thienopyridine ADP-receptor antagonists, is described. A thienopyridine inter-mediate was prepared by N-protection, boric acid substitution and N-substitution. After acid hydrolysis of the methyl ether and subsequent acetylation, prasugrel was obtained with a total yield of 50% after seven linear steps from 4,5,6,7-tetrahydrothieno [3,2-c]pyridine and 2-bromo-1-cyclopropyl-2-(2- fluorophenyl)ethan-1-one as raw materials.

Safety of telbivudine treatment for chronic hepatitis B for the entire pregnancy

Orally administered nucleus(t)ide analogues (NA) have brought about a simple, safe and effective therapeutic approach for chronic hepatitis B (CHB). However, treatment duration is long and some female patients become pregnant during treatment. In recent years, there have been gradually increasing reports on the safety of telbivudine (LdT) treatment for chronic hepatitis B virus (HBV) infection in the third trimester of pregnancy to block mother-to-infant transmission (MTIT) of HBV; however, the safety of LdT treatment for chronic HBV infection for the entire pregnancy has not been reported. The aim of the present study was to evaluate the safety of LdT treatment for chronic HBV infection for the entire pregnancy and provide a reference for HBV-infected fertile women on how to block MTIT of HBV. Eighty-six pregnant women who received LdT treatment either before or in early pregnancy were enrolled in the study. Adverse events were prospectively observed for the entire pregnancy and perinatal period, and short-term and long-term follow-up of infants was conducted, monitoring the abnormalities of infants and blocking rate of MTIT with LdT treatment. Eighty-six pregnant women treated with LdT had a total of 89 pregnancies: 6 (6.7%) had early embryonic death or spontaneous abortion, 1 (1.1%) had ectopic pregnancy and three had a second pregnancy after initial abortion. Fifty-one mothers completed pregnancy: one had induction of labour at 24 weeks of pregnancy for cleft lip and palate of the foetus and 50 delivered 52 full-term live infants. One infant had right ear accessories, and the total occurrence of congenital abnormality was 3.8%. Thirty-nine infants were followed up for more than 6 months and completed all examinations for MTIT. None of the infants were HBsAg positive, resulting in a 100% success rate of blocking MTIT. All mothers maintained good liver function during the third trimester of pregnancy; 86% maintained complete virological response (HBV DNA <500 copies/mL) prior to delivery, and none developed progression of liver disease. Factors leading to increased adverse effects and drug resistance were not found. LdT treatment is safe and effective in chronic HBV-infected pregnant mothers for the entire pregnancy.

Genetic link among Hani, Bulang and other Southeast Asian populations: evidence from HLA -A, -B, -C, -DRB1 genes and haplotypes distribution

Human leucocyte antigen (HLA) genetic characteristic of different ethnic minorities would be useful for tracing the origin of modern human HLA matching in transplantation and disease associations. In this study, we reported HLA-A, -B, -C and -DRB1 alleles and haplotypes in the Bulang and Hani populations of southwestern China using a high-resolution polymerase chain reaction-Luminex (PCR-Luminex) typing method. A total of nine HLA-A, 22 HLA-B, 13 HLA-C and 18 HLA-DRB1 alleles were identified in the Bulang population, and 11 HLA-A, 25 HLA-B, 14 HLA-C and 19 HLA-DRB1 alleles were in the Hani population. Compared with other populations, the predominant A*1101-B*1502-DRB1*1202 haplotype in the Bulang and Hani populations was also common in Jinuo, Wa, Dai, Maonan and Vietnamese populations. The distribution of HLA genes indicate that Bulang and Hani populations belong to the Southeast Asia group and they have maintained their original genetic characteristics and kept a long genetic distance from other populations owing to founder effects and subsequent geographic isolation. In addition, the close relationship among ethnic groups in Yunnan province and the Thai and Vietnamese populations were confirmed, whereas the Mon-Kmer-speaking populations shared other common HLA alleles and haplotypes compared with other linguistic groups.

Dissipation-induced d-wave pairing of fermionic atoms in an optical lattice

We show how dissipative dynamics can give rise to pairing for two-component fermions on a lattice. In particular, we construct a parent Liouvillian operator so that a BCS-type state of a given symmetry, e.g., a d-wave state, is reached for arbitrary initial states in the absence of conservative forces. The system-bath couplings describe single-particle, number-conserving and quasilocal processes. The pairing mechanism crucially relies on Fermi statistics. We show how such Liouvillians can be realized via reservoir engineering with cold atoms representing a driven dissipative dynamics.