Mutations in GBA, SNCA, and VPS35 are not associated with Alzheimer's disease in a Chinese population: a case-control study

SNCA, GBA, and VPS35 are three common genes associated with Parkinson’s disease. Previous studies have shown that these three genes may be associated with Alzheimer’s disease (AD). However, it is unclear whether these genes increase the risk of AD in Chinese populations. In this study, we used a targeted gene sequencing panel to screen all the exon regions and the nearby sequences of GBA, SNCA, and VPS35 in a cohort including 721 AD patients and 365 healthy controls from China. The results revealed that neither common variants nor rare variants of these three genes were associated with AD in a Chinese population. These findings suggest that the mutations in GBA, SNCA, and VPS35 are not likely to play an important role in the genetic susceptibility to AD in Chinese populations. The study was approved by the Ethics Committee of Xiangya Hospital, Central South University, China on March 9, 2016 (approval No. 201603198).

[Fruit variation and geographical distribution of citron]

The ripe dried fruit of citron(Citrus medica) is one of the important sources of Chinese herb Citri Fructus. At the same time, it is also grown for edible and ornamental uses. There are many species and abundant genetic variation. To clarify the intraspecific variation and resource distribution of citron, this study investigated the variation in 11 citron fruits, basically covering the main species in China, including Xiaoguo citron(C. medica var. ethrog), Goucheng(C. medica var. yunnanensis), Muli citron(C.medica var. muliensis), Dehong citron(C.medica×Citrus spp.), Fuzhou citron(C.medica×C.grandis?), Mawu(C.medica×C.grandis?), Cangyuan citron, Binchuan citron, Sweet citron, Big citron, and Small citron. The natural communities of citron were proved to be mainly distributed in the southwestern and western Yunnan and southeastern Tibet of China, with Yunnan, Sichuan, Guangxi, Chongqing, Hubei, and Zhejiang identified as the main production areas. Citron has also been widely grown in India, the Mediterranean region, and the Caribbean coast countries. The field investigation revealed the large-scale intraspecific variation of citron fruits. Most of the fruits are oval-like or sphere-like in shape. The fruits are green when raw and yellow when ripe, with oil cell dots on the skin, stripe-likes running from top to bottom, and bulge at the top. Usually, in the smaller citron fruits, the pulp and juice vesicles are better developed and the central columella is tighter. By contrast, the juice vesicles and central columella in larger fruits became more vacant, with carpels visible, and the apex segregation and development of the carpels is one of the reasons for variation. These variations should be given top priority in the future variety selection and breeding, and the quality differences of different citron species and their mechanisms should be further studied. In particular, variety selection and classification management according to their medicinal or edible purposes will provide scientific and technological supports for the orderly, safe, and effective production of citron products consumed as food and medicine.

Three-component 1,2-dicarbofunctionalization of alkenes involving alkyl radicals

1,2-Dicarbofunctionalization of alkenes represents an appealing strategy for chemical bond formation in organic synthesis, which could enable the rapid construction of molecular complexity from simple and readily available starting materials by incorporating two functional groups onto a carbon-carbon double bond in one step. In this field, the dicarbofunctionalization of alkenes with different alkyl radicals in a controlled manner represents an elegant and versatile strategy to access structurally diverse functionalized alkanes, which have witnessed significant progress over the last five years. Due to the importance of alkyl radicals in organic synthesis and medicinal chemistry, this review provides a comprehensive perspective on the development of alkyl radical precursors including electrophilic precursors such as alkyl halides, alkyl peroxides, alkyl NHP esters, cycloketone oxime esters, and Katritzky pyridinium salts, and nucleophilic precursors such as alkyl acids, alkyl oxalates, alkylborates, alkylsilicates, and unactivated hydrocarbons, which generate alkyl radicals by photocatalysis or transition metal catalysis to engage in dicarbofunctionalization under oxidative reaction conditions, redox-neutral conditions, or reductive conditions. The mechanisms of these dicarbofunctionalization reactions have also been discussed in detail.

Establishment of Functional Liver Spheroids From Human Hepatocyte-Derived Liver Progenitor-Like Cells for Cell Therapy

Globally, about two million people die from liver diseases every year. Liver transplantation is the only reliable therapy for severe end-stage liver disease, however, the shortage of organ donors is a huge limitation. Human hepatocytes derived liver progenitor-like cells (HepLPCs) have been reported as a novel source of liver cells for development of in vitro models, cell therapies, and tissue-engineering applications, but their functionality as transplantation donors is unclear. Here, a 3-dimensional (3D) co-culture system using HepLPCs and human umbilical vein endothelial cells (HUVECs) was developed. These HepLPC spheroids mimicked the cellular interactions and architecture of mature hepatocytes, as confirmed through ultrastructure morphology, gene expression profile and functional assays. HepLPCs encapsulated in alginate beads are able to mitigate liver injury in mice treated with carbon tetrachloride (CCL4), while alginate coating protects the cells from immune attack. We confirmed these phenomena due to HUVECs producing glial cell line-derived neurotrophic factor (GDNF) to promote HepLPCs maturation and enhance HepLPCs tight junction through MET phosphorylation. Our results display the efficacy and safety of the alginate microencapsulated spheroids in animal model with acute liver injury (ALF), which may suggest a new strategy for cell therapy.

Recent Advance in Iminyl Radical Triggered C–H and C–C Bond Functionalization of Oxime Esters via 1,5-HAT and β-Carbon Scission

The direct functionalization of C(sp3)–H and C(sp3)–C(sp3) bonds is considered as one of the most valuable synthetic strategies because of its high efficiency and step-economy for the rapid assembly of complex molecules. However, the relatively high bond disassociation energies (BDEs) and similar chemical environment lead to large obstacles in terms of low reactivity and selectivity. Using a radical-based strategy has proved to be an efficient approach to overcome these difficulties via a hydrogen atom transfer (HAT) process for selective C(sp3)–H functionalization and β-carbon scission for C(sp3)–C(sp3) bond derivatization. Oxime esters have emerged as outstanding precursors of iminyl radicals for versatile chemical transformations. This short review summaries the recent advances in site-specific C(sp3)–H functionalization and C(sp3)–C(sp3) bond cleavage starting from oxime esters by our group and pioneering work by others, mainly focusing on the reaction design as well as the reaction mechanism.

1 Introduction

2 C(sp3)–H Bond Functionalization via 1,5-HAT of Acyclic Oxime Esters­

2.1 1,5-HAT/Cyclization

2.2 1,5-HAT/C–C or C–Heteroatom Bond Formation

3 C(sp3)–C(sp3) Bond Functionalization via β-Carbon Scission of Cyclic Oxime Esters

3.1 β-Carbon Scission/C–C or C–Heteroatom Bond Formation

3.2 β-Carbon Scission/Cyclization

4 Conclusion and Outlook

Iron-Catalyzed Thiolation and Selenylation of Cycloalkyl Hydroperoxides via C-C Bond Cleavage

A cheap iron-catalyzed C-C bond cleavage/thiolation and selenylation of cycloalkyl hydroperoxides are presented. This redox-neutral protocol provides efficient access to diverse distal keto-functionalized thioethers and selenium compounds. Remarkably, only some amounts of disulfides are required for this transformation.

Copper-catalyzed radical ring-opening halogenation with HX

An efficient copper-catalyzed radical ring-opening halogenation with HX (aq) is described. This protocol features redox-neutral conditions, green halogen sources, and a broad substrate scope, providing practical access to distally chlorinated, brominated and iodinated alkyl ketones and alkyl nitriles with moderate to good yields.

Visible Light-Driven, Copper-Catalyzed Aerobic Oxidative Cleavage of Cycloalkanones

A visible light-driven, copper-catalyzed aerobic oxidative cleavage of cycloalkanones has been presented. A variety of cycloalkanones with varying ring sizes and various α-substituents reacted well to give the distal keto acids or dicarboxylic acids with moderate to good yields.

Risk factors influencing prognosis of patients undergoing primary retroperitoneal tumor surgery

BACKGROUND

Primary retroperitoneal tumors are mostly malignancies with a variety of etiologies. Parameters such as tumor grade, range of resection, and tumor integrity have been shown to influence prognosis.

AIM

To identify the risk factors for postoperative survival in patients undergoing primary retroperitoneal tumor surgery.

METHODS

Seventy-three patients undergoing radical retroperitoneal tumor surgery were divided into a tumor-free survival group (47 cases) and a recurrence-caused death group (26 cases). Factors affecting patients' tumor-free survival after surgery were collected and analyzed, including age, tumor long diameter, lymph node metastasis, first symptom, tumor type, tumor differentiation degree, and complication with other systemic diseases.

RESULTS

The 5-year tumor-free survival rate for primary retroperitoneal tumors was 64.4% (47/73). Single factor analysis showed that age (P < 0.05), tumor long diameter (P < 0.05), lymph node metastasis (P < 0.05), first symptom (P < 0.05), tumor type (P < 0.05), and tumor differentiation degree (P < 0.05) were significantly associated with retroperitoneal tumor surgery disease-free survival rate. Multivariate Cox regression analysis indicated that first symptom (P < 0.05) and tumor type (P < 0.05) were independent risk factors affecting postoperative tumor-free survival in retroperitoneal tumor patients.

CONCLUSION

First symptom and tumor type are the key factors affecting the postoperative tumor-free survival of retroperitoneal tumor patients.

Species distribution and antifungal susceptibilities of clinical isolates of Penicillium and Talaromyces species in China

Morphologically identified Penicillium (n = 103) and Talaromyces marneffei (n = 8) isolates were collected from various clinical sources between 2016 and 2017 at a medical centre in Beijing, China. Identification to species level was confirmed by sequencing of the internal transcribed spacer (ITS) region, β-tubulin gene (benA) and RNA polymerase II second largest subunit (RPB2) gene. Of the 111 isolates, 56 (50.5%) were identified as Penicillium spp. and 55 (49.5%) as Talaromyces spp. Eleven species of Penicillium were detected, of which Penicillium oxalicum was the commonest, accounting for 51.8% (29/56), followed by Penicillium rubens (10.7%; 6/56) and Penicillium citrinum (10.7%; 6/56). Among the 55 Talaromyces isolates, nine species were identified, with Talaromyces funiculosus (36.4%; 20/55), Talaromyces stollii (27.3%; 15/55) and Talaromyces marneffei (14.5%; 8/55) being the most common. Of note, 89.3% (50/56) of the Penicillium isolates and 98.2% (54/55) of the Talaromyces isolates exhibited growth at 37°C. The isolates were mainly recovered from patients with pulmonary disorders (56.8%; 63/111), autoimmune disease (12.6%; 14/111) and AIDS (5.4%; 6/111). The azoles and amphotericin B exhibited potent activity against T. marneffei, while various levels of activity were observed against Penicillium and other Talaromyces species The echinocandins had the lowest MECs (MEC_90, ≤0.12 mg/L) against most Penicillium and Talaromyces species, with the exception of T. marneffei whose MEC₉₀ (4 mg/L) was five or more dilutions higher than that of the other species tested. These data on the species distribution and antifungal susceptibility expand the current clinical knowledge of Penicillium and Talaromyces species.

Alkaloids constituents from the roots of Phragmites australis (Cav.) Trin. ex Steud. with their cytotoxic activities

Two new alkaloids, phranisines A-B (1-2), along with two known compounds, N-p-Coumaroyl serotonin (3) and N-p-coumaroyl-tryptamine (4), were isolated from the roots of Phragmites australis. The structures of 1-4 were established on the basis of extensive spectroscopic. The absolute configuration of compounds 1-2 were identified through quantum-chemical electronic circular dichroism (ECD) calculation compared with their experimental CD. All the isolated compounds were tested for their cytotoxic activities against HeLa and MCF-7 human cancer cell lines, and compounds 2-4 showed moderate cytotoxic activities against HeLa cell lines with IC₅₀ values ranging from 13.2 to 18.6 μM.

Copper-catalyzed redox neutral ketoalkylation of Csp2–H bonds via C–C bond cleavage

An efficient copper-catalyzed ketoalkylation of Csp2–H bonds with cycloalkyl silyl peroxides under mild conditions is presented. A series of Csp2–H bonds in quinoxalin-2(1H)-ones, heteroaromatic N-oxides and quinones were amenable to this protocol.

Sulfonamide as Photoinduced Hydrogen-Atom Transfer Catalyst for Regioselective Alkylation of C(sp3)-H Bonds Adjacent to Heteroatoms

Based on the DFT calculations, the sulfonamide was explored as an efficient hydrogen-atom transfer catalyst for the C(sp³)-H alkylation. The combination of a metal-free photoredox catalyst and a sulfonamide catalyst enables highly regioselective alkylation of the C-H bonds adjacent to heteroatoms, which features broad substrate scope and excellent functional group compatibility. Remarkably, the sulfonamide catalyst was also applicable to the C(sp³)-C(sp³) couplings through the merger of photoredox, nickel, and HAT catalysis.

Visible-light-driven palladium-catalyzed Dowd-Beckwith ring expansion/C-C bond formation cascade

A visible-light-induced palladium-catalyzed Dowd-Beckwith ring expansion/C-C bond formation cascade is described. A range of six to nine-membered β-alkenylated cyclic ketones possessing a quaternary carbon center were accessed under mild conditions. Besides styrenes, the electron-rich alkenes such as silyl enol ethers and enamides were also compatible, providing the desired β-alkylated cyclic ketones in moderate to good yields.

Targeted inhibition of myeloid-derived suppressor cells in the tumor microenvironment by low-dose doxorubicin to improve immune efficacy in murine neuroblastoma

BACKGROUND

High agglomeration of myeloid-derived suppressor cells (MDSCs) in neuroblastoma (NB) impeded therapeutic effects. This study aimed to investigate the role and mechanism of targeted inhibition of MDSCs by low-dose doxorubicin (DOX) to enhance immune efficacy in NB.

METHODS

Bagg albino (BALB/c) mice were used as tumor-bearing mouse models by injecting Neuro-2a cells, and MDSCs were eliminated by DOX or dopamine (DA) administration. Tumor-bearing mice were randomly divided into 2.5 mg/kg DOX, 5.0 mg/kg DOX, 50.0 mg/kg DA, and control groups (n = 20). The optimal drug and its concentration for MDSC inhibition were selected according to tumor inhibition. NB antigen-specific cytotoxic T cells (CTLs) were prepared. Tumor-bearing mice were randomly divided into DOX, CTL, anti-ganglioside (GD2), DOX+CTL, DOX+anti-GD2, and control groups. Following low-dose DOX administration, immunotherapy was applied. The levels of human leukocyte antigen (HLA)-I, CD8, interleukin (IL)-2 and interferon (IFN)-γ in peripheral blood, CTLs, T-helper 1 (Thl)/Th2 cytokines, perforin, granzyme and tumor growth were compared among the groups. The Wilcoxon two-sample test and repeated-measures analysis of variance were used to analyze results.

RESULTS

The slowest tumor growth (F = 6.095, P = 0.018) and strongest MDSC inhibition (F = 14.632, P = 0.001) were observed in 2.5 mg/kg DOX group. Proliferation of T cells was increased (F = 448.721, P < 0.001) and then decreased (F = 2.047, P = 0.186). After low-dose DOX administration, HLA-I (F = 222.489), CD8 (F = 271.686), Thl/Th2 cytokines, CD4+ and CD8+ lymphocytes, granzyme (F = 2376.475) and perforin (F = 488.531) in tumor, IL-2 (F = 62.951) and IFN-γ (F = 240.709) in peripheral blood of each immunotherapy group were all higher compared with the control group (all of P values < 0.05). The most significant increases in the aforementioned indexes and the most notable tumor growth inhibition were observed in DOX+anti-GD2 and DOX+CTL groups.

CONCLUSIONS

Low-dose DOX can be used as a potent immunomodulatory agent that selectively impairs MDSC-induced immunosuppression, thereby fostering immune efficacy in NB.

Efficacy and safety of nebivolol in hypertensive patients: a meta-analysis of randomized controlled trials

Purpose

Our meta-analysis was undertaken to evaluate the efficacy and safety of nebivolol compared with other second-generation β blockers for hypertensive patients.

Methods

We searched PubMed, the Cochrane Library, EMBASE, and Clinical Trials.gov databases for randomized controlled trials (RCTs). The efficacy endpoints included systolic blood pressure (SBP), diastolic blood pressure (DBP), reduction of SBP and DBP, heart rate (HR), and adverse events (AEs).

Findings

Eight RCTs with 1514 patients met the inclusion criteria. HR was significantly lower in patients receiving other second-generation β blockers compared with patients receiving nebivolol. There was no difference the reduction of blood pressure (SBP and DBP) or the reduction of SBP or DBP between the groups. The incidence of AEs was lower in patients taking nebivolol compared with patients taking other second-generation β blockers.

Conclusions

No significant difference was demonstrated between nebivolol and other second-generation β blockers in the reduction of blood pressure, SBP, and DBP. The tolerability of nebivolol was significantly better compared with other second-generation β blockers, and nebivolol was also associated with a stable HR and a lower risk of AEs compared with other second-generation β blockers.

Clinical and Microbiological Characterization of Invasive Pulmonary Aspergillosis Caused by Aspergillus lentulus in China

Invasive aspergillosis (IA) due to Aspergillus lentulus is associated with high mortality. In this study, we investigated the clinical and microbiological characteristics of 6 fatal cases of proven or probable IA caused by A. lentulus in China. Underlying immunosuppression, prior antifungal exposure, and intensive care unit (ICU) hospitalization were important risk factors for invasive A. lentulus infection. Phenotypic differences were observed for A. lentulus isolates including slower growth, reduced sporulation, and inability to grow at 48°C, compared with Aspergillus fumigatus complex. ITS sequencing was unable to distinguish A. lentulus from A. fumigatus, but sequencing of the benA, CaM, and rod A loci enabled reliable distinction of these closely related species. Phylogenetic analysis further confirmed that the ITS region had little variation within the Aspergillus section Fumigati while the benA gene offered the highest intraspecific discrimination. Microsatellite typing results revealed that only loci on chromosomes 1, 3, 5, and 6b generated detectable amplicons for identification. All A. lentulus isolates showed in vitro resistance to multiple antifungal drugs including amphotericin B (MIC range 4 to 8 μg/ml), itraconazole (MIC 2 μg/ml), voriconazole (MIC of 4–16 μg/ml), and posaconazole (MIC of 0.5–1 μg/ml). However, MECs for the echinocandin drugs ranged from 0.03–0.25, ≤0.008–0.015, and ≤0.015–0.03 μg/ml for caspofungin, micafungin, and anidulafungin, respectively. A. lentulus is an emerging fungal pathogen in China, causing fatal disease, and clinicians as well as laboratories should be alert to their increasing presence.

Species Distribution and Antifungal Susceptibility of Invasive Candidiasis: A 2016-2017 Multicenter Surveillance Study in Beijing, China

OBJECTIVE

Invasive candidiasis (IC), a life-threatening fungal infection prevalent among hospitalized patients, has highly variable regional epidemiology. We conducted a multicenter surveillance study to investigate recent trends in species distribution and antifungal susceptibility patterns among IC-associated Candida spp. in Beijing, China, from 2016 to 2017.

MATERIALS AND METHODS

A total of 1496 non-duplicate Candida isolates, recovered from blood and other sterile body fluids of IC patients, were identified using matrix-assisted laser desorption/ionization time of flight mass spectrometry combined with ribosomal DNA internal transcribed spacer (ITS) region sequencing. Broth microdilution-based susceptibility testing using six antifungal agents was also conducted.

RESULTS

Candida albicans was the most frequently isolated species (49.9%), followed by Candida tropicalis (15.5%), Candida glabrata (14.7%) and Candida parapsilosis (14.2%). No significant differences in species distribution were observed when compared with a 2012-2013 dataset. Overall, the rates of susceptibility to fluconazole and voriconazole were high among C. albicans (98% and 97.2%, respectively) and C. parapsilosis species complex (91.1% and 92%, respectively) isolates but low among C. tropicalis (81.5% and 81.1%, respectively) isolates. In addition, the rate of azole resistance among C. tropicalis isolates increased significantly (1.8-fold, P<0.05) compared with that observed in 2012-2013, while micafungin resistance rates were <5% for all tested Candida species.

CONCLUSION

Our results suggest that species distribution has remained stable among IC-associated Candida isolates in Beijing. Resistance to micafungin was rare, but increased azole resistance among C. tropicalis isolates was noted. Our study provides information on local epidemiology that will be important for the selection of empirical antifungal agents and contributes to global assessments of antifungal resistance.

Copper-catalyzed alkylarylation of vinylarenes with cycloalkylsilyl peroxides and boronic acids

A mild and efficient copper-catalyzed alkylarylation of vinylarenes with cycloalkylsilyl peroxides and boronic acids is described.

Iron catalyzed ketoalkylation and ketoalkylation/etherification of styrenes initiated by selective C–C bond cleavage

A mild and efficient iron-catalyzed ketoalkyl-Heck-type coupling initiated by radical C–C bond cleavage is described. Furthermore, this concise catalytic system was also applicable for the three-component ketoalkylation/etherification of styrenes.

Stress Recovery of Campus Street Trees as Visual Stimuli on Graduate Students in Autumn

Human stress recovery response to landscapes is under discussion in Chinese settings. The present study aimed to clarify the stress recovery effects of campus street trees on graduate students in autumn. A total of 150 participants (23.75 ± 1.01 years old) completed the Trier Social Stress Test (TSST) and were then randomly assigned to view one of five virtual environments, including the street trees Sophora japonica, Ginkgo biloba, Platanus acerifolia, Koelreuteria paniculata, and the indoor environment (control). Physiological responses were measured by R-R interval and electroencephalography (EEG). Psychological responses were examined through the state version of the State-Trait Anxiety Inventory (STAI-S) and the Perceived Restorativeness Scale (PRS). Results showed that R-R intervals significantly increased while viewing all street trees. Both alpha and beta brainwave activities while viewing S. japonica and G. biloba were remarkably higher than those while viewing P. acerifolia and K. paniculata. The STAI-S scores significantly decreased, and the positive PRS scores were registered after viewing street trees. We concluded that a brief virtual visual experience of campus street trees in autumn has stress recovery effects on graduate students, and the different levels of stress recovery are associated with different types of street trees.

Visible Light Driven Alkylation of C(sp3)-H Bonds Enabled by 1,6-Hydrogen Atom Transfer/Radical Relay Addition

A visible-light-driven sulfamate esters guided alkylation of unactivated C(sp³)-H bonds enabled by a 1,6-HAT/radical addition cascade is described. Not only structurally diverse Michael acceptors but also styrenes are amenable to this alkylation reaction. Notably, the N-H bonds activation radical relay refrained from prefunctionalization and using excess external oxidants.