Secondary Amine-Mediated Domino Reaction for the Synthesis of Substituted Quinolines from Dicyanoalkenes and Eneynals

Substituted quinolines, tricyclic and tetracyclic molecules with a quinoline moiety are synthesized by a domino reaction from dicyanoalkenes and 3-aryl-pent-2-ene-4-ynals in one pot. We established two methods: one is catalyzed by chiral diphenylprolinol silyl ether, and the other is catalyzed by di(2-ethyl)hexylamine, in combination with p-nitrophenol. A wide variety of dicyanoalkenes can be employed. As the catalysts are secondary amines, and water is the only by-product, this is an environmentally benign synthetic method for the preparation of substituted quinolines.

Dynamin-related protein 2 interacts with the membrane-associated methyltransferase domain of plantago asiatica mosaic virus replicase and promotes viral replication

Positive-strand RNA viruses replicate their RNA in the viral replication complex, a spherical structure formed by remodeling of host intracellular membranes. This process also requires the interaction between viral membrane-associated replication proteins and host factors. We previously identified the membrane-associated determinant of the replicase of plantago asiatica mosaic virus (PlAMV), a positive-strand RNA virus of the genus Potexvirus, in its methyltransferase (MET) domain, and suggested that its interaction with host factors is required to establish viral replication. Here we identified Nicotiana benthamiana dynamin-related protein 2 (NbDRP2) as an interactor of the MET domain of the PlAMV replicase by co-immunoprecipitation (Co-IP) and mass spectrometry analysis. NbDRP2 is closely related to the DRP2 subfamily proteins in Arabidopsis thaliana, AtDRP2A and AtDRP2B. Confocal microscopy observation and Co-IP confirmed the interaction between the MET domain and NbDRP2. Also, the expression of NbDRP2 was induced by PlAMV infection. PlAMV accumulation was reduced when the expression of NbDRP2 gene was suppressed by virus-induced gene silencing. In addition, PlAMV accumulation was reduced in protoplasts treated with dynamin inhibitor. These results indicate a proviral role of the interaction of NbDRP2 with the MET domain in PlAMV replication.

Diagnostic and prognostic significance of tartrate-resistant acid phosphatase type 5b in newly diagnosed prostate cancer with bone metastasis: A real-world multi-institutional study

OBJECTIVES

Approximately, 90% of men with advanced prostate cancer will develop bone metastasis. However, there have been few reports about noninvasive biomarker to detect and predict clinical outcome of bone metastasis (BM) in prostate cancer patients.

METHODS

We examined 1127 patients who underwent prostate biopsy from August 2012 to June 2017. We also investigated bone turnover markers such as bone-specific alkaline phosphatase, type I collagen cross-linked N-terminal telopeptide, C-terminal pyridinoline cross-linked telopeptide of type I collagen, and tartrate-resistant acid phosphatase type 5b (TRACP 5b).

RESULTS

A total of 282 patients were diagnosed as prostate cancer with complete clinical data, and 34 patients with bone metastasis. Multivariate analysis revealed C-terminal pyridinoline cross-linked telopeptide of type I collagen, tartrate-resistant acid phosphatase type 5b, and prostate-specific antigen (PSA) were independent biomarkers in detection of BM (p < 0.05, respectively). Furthermore, we developed predictive model formula based on tartrate-resistant acid phosphatase type 5b and PSA, for which the area under the curve was 0.95. In patients with bone metastasis, multivariate cox proportional hazards analysis revealed that this model was significantly associated with poor clinical outcome of cancer-specific survival (p < 0.05). In validation cohort with 137 patients, we also confirmed the utility of this model for diagnosis of BM (the area under the curve = 0.95).

CONCLUSIONS

Our developed formula of tartrate-resistant acid phosphatase type 5b in accordance with PSA may serve as the useful tool in diagnosis and prediction of clinical outcome for prostate cancer with bone metastasis.

A case of hypogonadtropic hypogonadism due to hypophysitis discovered by secondary male infertility

Introduction

The main causes of secondary male infertility are varicocele and aging. It is rarely caused by adult-onset hypopituitarism. The onset of hypopituitarism is often due to brain tumors, trauma, surgery, or congenital disorders.

Case presentation

A 29-year-old man was admitted to the hospital with complaints of decreased libido and semen volume, which lasted for 4 months. He had no abnormalities in adolescence and has a 2-year-old child. Blood tests showed low luteinizing hormone and follicle-stimulating hormone, and semen tests showed azoospermia. Magnetic resonance imaging T1-weighted images showed swelling and enhancement effect of the pituitary gland, and lymphocytic hypophysitis was suspected. After an Insulin-thyroid-stimulating hormone releasing hormone-luteinizing hormone-releasing hormone test, a decrease in luteinizing hormone/follicle-stimulating hormone secretion was considered. We diagnosed hypogonadotropic hypogonadism due to lymphocytic hypophysitis. Currently, the patient is being treated with a hormone replacement therapy.

Conclusion

We experienced a case of hypogonadotropic hypogonadism due to lymphocytic hypophysitis discovered by secondary infertility.

Stereoselective Construction of Fluorinated Quaternary Stereogenic Centers via an Organocatalytic Asymmetric exo-Selective Diels-Alder Reaction in the Presence of Water

A catalytic, asymmetric Diels-Alder reaction of α-fluoro α,β-unsaturated aldehydes and cyclopentadiene was developed using diarylprolinol silyl ether as an organocatalyst. The reaction proceeds in toluene with trifluoroacetic acid as an additive (condition A). Perchloric acid salt of diarylprolinol silyl ether also promotes the reaction using water as a reaction medium (condition B). In both cases, excellent exo-selectivity and enantioselectivity were obtained with generation of a fluorinated quaternary chiral center.

Diarylprolinol as an Effective Organocatalyst in Asymmetric Cross-aldol Reactions of Two Different Aldehydes

The aldol reaction is one of the most important carbon-carbon bond-forming reactions in organic chemistry. Asymmetric direct cross-aldol reaction of two different aldehydes has been regarded as a difficult reaction because of the side reactions such as self-aldol reaction and over reaction. We found that trifluoromethyl-substituted diarylprolinol, α,α-bis[3,5-bis(trifluoromethyl)phenyl]-2-pyrrolidinemethanol (1), is an effective organocatalyst that promotes several cross-aldol reactions of aldehydes with excellent diastereo- and enantioselectivities. Acetaldehyde can be employed as a suitable nucleophilic aldehyde. Successful electrophilic aldehydes are ethyl glyoxylate, chloroacetaldehyde, dichloroacetaldehyde, chloral, α-alkyl-α-oxo aldehyde, trifluoroacetaldehyde, glyoxal, alkenyl aldehyde, alkynyl aldehyde, and formaldehyde. Some of the aldehydes are commercially available as a polymer solution, an aqueous solution, or in the hydrated form. They can be used directly in the asymmetric aldol reaction as a commercially available form, which is a synthetic advantage. Given that the obtained aldol products possess several functional groups along with a formyl moiety, they are synthetically useful chiral building blocks.

EphA2 on urinary extracellular vesicles as a novel biomarker for bladder cancer diagnosis and its effect on the invasiveness of bladder cancer

BACKGROUND

Urinary extracellular vesicles (uEVs) secreted from bladder cancer contain cancer-specific proteins that are potential diagnostic biomarkers. We identified and evaluated a uEV-based protein biomarker for bladder cancer diagnosis and analysed its functions.

METHODS

Biomarker candidates, selected by shotgun proteomics, were validated using targeted proteomics of uEVs obtained from 49 patients with and 48 individuals without bladder cancer, including patients with non-malignant haematuria. We developed an enzyme-linked immunosorbent assay (ELISA) for quantifying the uEV protein biomarker without ultracentrifugation and evaluated urine samples from 36 patients with and 36 patients without bladder cancer.

RESULTS

Thirteen membrane proteins were significantly upregulated in the uEVs from patients with bladder cancer in shotgun proteomics. Among them, eight proteins were validated by target proteomics, and Ephrin type-A receptor 2 (EphA2) was the only protein significantly upregulated in the uEVs of patients with bladder cancer, compared with that of patients with non-malignant haematuria. The EV-EphA2-CD9 ELISA demonstrated good diagnostic performance (sensitivity: 61.1%, specificity: 97.2%). We showed that EphA2 promotes proliferation, invasion and migration and EV-EphA2 promotes the invasion and migration of bladder cancer cells.

CONCLUSIONS

We established EV-EphA2-CD9 ELISA for uEV-EphA2 detection for the non-invasive early clinical diagnosis of bladder cancer.

Highly Sterically Hindered Peptide Bond Formation between α,α-Disubstituted α-Amino Acids and N-Alkyl Cysteines Using α,α-Disubstituted α-Amidonitrile

Peptides and proteins attract enormous attention in many fields of academia and industry. The introduction of unusual amino acids such as α,α-disubstituted α-amino acids or N-alkyl α-amino acids into normal peptide backbones is a well-utilized and useful tool for the modification of properties such as conformation, biological activity, and pharmacological profile. Despite the significant interest in sterically hindered peptides, research on peptides bearing an amide bond between an α,α-disubstituted α-amino acid and an N-alkyl α-amino acid remains underexplored because of the lack of an efficient synthetic approach. Herein, we describe a high-yielding synthetic method to access such extremely sterically hindered peptide bonds between amino acids. The reaction takes place between a peptide with an α,α-disubstituted α-amidonitrile and a second peptide bearing an N-alkyl cysteine, without a coupling reagent.

Catalytic Asymmetric Michael Reaction of Methyl Alkynyl Ketone Catalyzed by Diphenylprolinol Silyl Ether

The asymmetric Michael reaction of methyl alkynyl ketone and α,β-unsaturated aldehyde catalyzed by diphenylprolinol silyl ether was developed. Although methyl alkynyl ketone is a good Michael acceptor, it also acts as a Michael donor to afford the synthetically important δ-oxo aldehydes with excellent enantioselectivity. The products possessing several functional groups, such as alkyne, ketone, and aldehyde moieties, are useful chiral building blocks for further synthesis. Using this reaction as a key step, a side chain of atorvastatin (Lipitor), an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase, was synthesized in a two-pot sequence with excellent diastereo- and enantioselectivities.

Aging of enteric neuromuscular systems in gastrointestinal tract

BACKGROUND

Aging is a complex biological process and associated with a progressive decline in functions of most organs including the gastrointestinal (GI) tract. Age-related GI motor disorders/dysfunctions include esophageal reflux, dysphagia, constipation, fecal incontinence, reduced compliance, and accommodation. Although the incidence and severity of these diseases and conditions increase with age, they are often underestimated due in part to nonspecific and variable symptoms and lack of sufficient medical attention. They negatively affect quality of life and predispose the elderly to other diseases, sarcopenia, and frailty. The mechanisms underlying aging-associated GI dysfunctions remain unclear, and there is limited data examining the effect of aging on GI motor functions. Many studies on aging-associated changes to cells within the tunica muscularis including enteric neurons, smooth muscles, and interstitial cells have proposed that cell loss and/or molecular changes may be involved in the pathogenesis of age-related GI motor disorders/dysfunctions. There is also evidence that the aging contributes to phenotypic changes in innate immune cells, which are physically and functionally linked to other cells in the tunica muscularis and can alter GI (patho) physiology. However, various patterns of changes have been reported, some of which are contradictory, indicating a need for additional work in this area.

PURPOSE

Although GI infection due to intestinal bacterial overgrowth, bleeding, and cancers are also important and common problems in the elderly patients, this mini-review focuses on data obtained from enteric neuromuscular aging research with the goal of better understanding the cellular and molecular mechanisms of enteric neuromuscular aging to enhance future therapy.

Asymmetric Michael reaction of malononitrile and α,β-unsaturated aldehydes catalyzed by diarylprolinol silyl ether

The asymmetric Michael reaction of malononitrile and α,β-unsaturated aldehydes catalyzed by diarylprolinol silyl ether was developed. Michael products were obtained in good yield and with excellent enantioselectivity without formation of overreaction products. As a malononitrile moiety can be transformed into alkoxy or amino carbonyl moieties by oxidative transformation, an α-chiral ester or amide with an all-carbon quaternary center can be synthesized with excellent enantioselectivity.

Experimental evidence of tetrahedral symmetry breaking in SiO2 glass under pressure

Bimodal behavior in the translational order of silicon's second shell in SiO₂ liquid at high temperatures and high pressures has been recognized in theoretical studies, and the fraction of the S state with high tetrahedrality is considered as structural origin of the anomalous properties. However, it has not been well identified in experiment. Here we show experimental evidence of a bimodal behavior in the translational order of silicon's second shell in SiO₂ glass under pressure. SiO₂ glass shows tetrahedral symmetry structure with separation between the first and second shells of silicon at low pressures, which corresponds to the S state structure reported in SiO₂ liquid. On the other hand, at high pressures, the silicon's second shell collapses onto the first shell, and more silicon atoms locate in the first shell. These observations indicate breaking of local tetrahedral symmetry in SiO₂ glass under pressure, as well as SiO₂ liquid.

Turbulence Spreading into an Edge Stochastic Magnetic Layer Induced by Magnetic Fluctuation and Its Impact on Divertor Heat Load

Turbulence spreading into the edge stochastic magnetic layer induced by magnetic fluctuation is observed at the sharp boundary region in the large helical device. The density fluctuation excited at the sharp boundary region with a large pressure gradient does not propagate into the boundary region due to the blocking of turbulence spreading by the large second derivative of the pressure gradient. Once the magnetic fluctuation appears at the boundary, the density fluctuation begins to penetrate the edge stochastic layer and the second derivative of the pressure gradient also decreases. The increase of density fluctuation in this layer results in the broadening and reduction of the peak divertor heat load. It is demonstrated that magnetic fluctuation plays a key role in controlling the turbulence spreading at the boundary of plasma which contributes to the reduction of divertor heat load.

Perioperative Circulating Tumor DNA Enables Identification of Patients with Poor Prognosis in Upper Tract Urothelial Carcinoma

Perioperative systemic chemotherapy improves the prognosis of upper tract urothelial carcinoma (UTUC). The first objective of this study is to verify whether perioperative circulating tumor DNA (ctDNA) analysis using a pan-cancer gene panel and next-generation sequencing can identify patients with poor prognosis who require perioperative chemotherapy. Secondly, we will investigate whether ctDNA is useful for minimal residual disease (MRD) detection and treatment monitoring in UTUC. This study included fifty patients with untreated UTUC, including 43 cases of localized UTUC. We performed targeted ultradeep sequencing of plasma cfDNA and buffy coat DNA and whole-exome sequencing of cancer tissues, allowing exclusion of possible false positives. We attempted to stratify the prognosis according to the perioperative ctDNA levels in patients with localized UTUC. In patients with metastatic UTUC, ctDNA was evaluated before, during, and after systemic treatment. Twenty-three (46%) of 50 patients with untreated UTUC were ctDNA-positive, and 17 (40%) of 43 patients with localized UTUC were ctDNA-positive. Of the detected TP53 mutations, 19% were false-positive due to clonal hematopoiesis of indeterminate potential (CHIP). Among preoperative risk factors, only the preoperative ctDNA fraction>2% was a significant and independent risk factor associated with worse recurrence-free survival (RFS). Furthermore, the existence of ctDNA early point after the operation was significantly associated with worse RFS, suggesting the presence of MRD. ctDNA also showed potential as a real-time marker for systemic therapy in patients with metastatic UTUC. Detection of ctDNA may indicate potential metastasis and guide decisions of perioperative chemotherapy.

Self-Sustained Divertor Oscillation Driven by Magnetic Island Dynamics in Torus Plasma

A new type of self-sustained divertor oscillation is discovered in the Large Helical Device stellarator, where the peripheral plasma is detached from material diverters by means of externally applied perturbation fields. The divertor oscillation is found to be a self-regulation of an isolated magnetic field structure (the magnetic island) width induced by a drastic change in a poloidal inhomogeneity of the plasma radiation across the detachment-attachment transitions. A predator-prey model between the magnetic island width and a self-generated local plasma current (the bootstrap current) is introduced to describe the divertor oscillation, which successfully reproduces the experimental observations.

Early dynamics of circulating tumor DNA predict clinical response to immune checkpoint inhibitors in metastatic renal cell carcinoma

Objectives

Detection of genomic alterations in circulating tumor deoxyribonucleic acid of peripheral blood can guide the selection of systemic therapy in cancer patients. The predictive significance of circulating tumor deoxyribonucleic acid in metastatic renal cell carcinoma remains unclear, especially for patients treated with immune checkpoint inhibitors.

Methods

In this study, we collected plasma samples before and 1 month after commencing nivolumab monotherapy or nivolumab plus ipilimumab therapy from 14 metastatic renal cell carcinoma patients. We performed circulating tumor deoxyribonucleic acid genomic profiling in plasma cell‐free deoxyribonucleic acid by next‐generation sequencing using a commercially available pan‐cancer panel (Guardant360 CDx). Additionally, we also performed whole exome sequencing of tumor tissues and compared the concordance of genomic profiles with circulating tumor deoxyribonucleic acid.

Results

Nine patients had circulating tumor deoxyribonucleic acid in pretreatment plasma samples with a total of 20 mutations (15 single nucleotide variants, three insertions/deletions, and two copy number amplification). VHL (30.0%) was the most frequently mutated gene, followed by TP53 (20.0%), and 45.0% of circulating tumor deoxyribonucleic acid mutations were concordant with somatic mutations in tumor tissues. Patients with decreasing circulating tumor deoxyribonucleic acid mutant allele frequency had better progression free survival when compared to those with increasing mutant allele frequency (P = 0.0441).

Conclusions

Our findings revealed that early circulating tumor deoxyribonucleic acid dynamics can serve as a predictive biomarker for response to immune checkpoint inhibitors in metastatic renal cell carcinoma patients.