Blue-emitting acridine-tagged silver(i)-bis-N-heterocyclic carbene

Herein, the photophysical properties of an acridine derivative of a bis-N-heterocyclic carbene silver complex were investigated. The HOMO and LUMO energy differences between 9-[(N-methyl imidazol-2-ylidene)]acridine and 4,5-bis[(N-methyl-imidazol-2-ylidene)methyl]acridine were theoretically compared. Based on the calculation, the 4,5-bis N-heterocyclic carbene-tethered acridine type of ligand was found to be a potential source for tuning the fluorescent nature of the resultant metal derivatives. Thus, a 4,5-bis N-heterocyclic carbene (NHC)-tethered acridine silver(I) salt was synthesized, and its photophysical properties were investigated. The 4,5-bis[(N-isopropylimidazol-2-ylidene)methyl]acridine silver(I) hexafluorophosphate complex was obtained from the reaction between [4,5-bis{(N-isopropylimidazolium)methyl}acridine] hexafluorophosphate and Ag2O in very good yield; this molecule was characterized by elemental analysis and FTIR, multinuclear (1H and 13C) NMR, UV-Vis, and fluorescence spectroscopic techniques. The molecular structure has been confirmed by single-crystal X-ray diffraction analysis, which has revealed that the complex is a homoleptic mononuclear silver(I) cationic solid. The charge of the Ag(I)–NHC cation is balanced by the hexafluorophosphate anion. The cationic moieties are closely packed in the chair and inverted chair forms where silver(I) possesses a quasi-linear geometry. Moreover, the silver complex provided blue emission from all the three excitations with good fluorescence quantum yield. The fluorescence lifetime of the silver(I) complex has been determined using the time-correlated single photon counting technique. Interestingly, the fluorescence decay pattern and the fluorescence lifetimes of the silver complex are largely different from those of the parent ligand acridine imidazolium salt. Moreover, the theoretical predictions have been found to be in good agreement with the experimental results

The Simons Observatory: Development and Optical Evaluation of Achromatic Half-Wave Plates

The Simons Observatory (SO) experiment is a cosmic microwave background (CMB) experiment located in the Atacama Desert, Chile. The SO' s small aperture telescopes (SATs) consist of three telescopes designed for precise CMB polarimetry at large angular scales. Each SAT uses a cryogenic rotating half-wave plate (HWP) as a polarization modulator to mitigate atmospheric 1/f noise and other systematics. To realize efficient polarization modulation over the observation bands, we fabricated an achromatic HWP (AHWP) consisting of three sapphire plates with anti-reflection coatings. The AHWP is designed to have broadband modulation efficiency and transmittance. This paper reports on the design and the preliminary characterization of the AHWPs for SATs

Impact of once-daily versus multiple-daily dosing of gentamicin on the incidence of acute kidney injury in patients treated with synergistic combinations of antibiotics

Abstract Background Gentamicin is a commonly used antibiotic with synergistic effects that is administered once or multiple times daily. However, the influence of the daily administration frequency on renal function has not yet been identified. This study aimed to investigate the effect of the daily dosing frequency on worsening renal function in patients receiving gentamicin. Methods This study included 35 patients undergoing gentamicin treatment who had at least one serum trough level measured and underwent therapeutic drug monitoring (TDM). We evaluated the influence of daily dosing frequency on gentamicin trough concentration and the risk of acute kidney injury (AKI). Results Compared to patients who received gentamicin once-daily dosing (n = 22), patients who received multiple-daily dosing (n = 13) had significantly higher initial and minimum trough concentrations after TDM. The proportion of patients with trough concentrations lower than 1.0 µg/mL was significantly higher in the once-daily dosing group at the initial trough concentration, whereas there was no significant difference at the minimum trough concentration after TDM. AKI developed in nine patients; however, there was no significant difference in the incidence of AKI according to the frequency of daily gentamicin dosing. In contrast, a higher minimum trough concentration after TDM was found to be a risk factor for AKI development with an odds ratio of 9.2 (95% confidence intervals; 1.3–65.5). Conclusion A higher trough concentration of gentamicin correlated with a higher incidence of AKI. The risk of developing AKI may be reduced by choosing a once-daily dosing regimen or implementing TDM

Supposed pituitary-production of human chorionic Gonadotropin induced by androgen deprivation therapy

ABSTRACT Introduction: The main cause of slightly elevated human chorionic gonadotropin (HCG) after successful treatment of male germ cell tumors is considered to be pituitary-derived HCG. It is well known that pituitary-derived HCG is frequently detected in postmenopausal women. We evaluated the status of serum HCG in men with elevated gonadotropins, which were induced by androgen deprivation therapy, using commercially available assays. Materials and Methods: We enrolled 44 patients with prostate cancer, who underwent luteinizing-hormone releasing hormone agonist treatment. We measured serum follicle-stimulating hormone (FSH), serum luteinizing hormone (LH), serum total HCG, serum free HCG-β subunit, and urine total HCG 3 times per patient, on the day of treatment initiation, the next day, and 3 months after. Results: On the day after treatment initiation, serum and urine HCG was detected in 61% and 73% of patients, respectively. Markedly strong correlations were observed between serum/urine HCG and FSH/LH. In particular, receiver operating characteristic curve analysis indicated excellent area under the curve (0.977, 95% confidence interval 0.951–1.003)) for serum HCG-detectable LH. At the cutoff value of 21.07 mIU/mL for serum HCG-detectable LH, the sensitivity and specificity were 96.7% and 95.3%, respectively. Serum HCG-β was not detectable at any times in any patients. Conclusions: Suggested pituitary-derived HCG can be frequently detected in patients with elevated gonadotropins, and there is a firm association between HCG detection and gonadotropin levels

Proposal of selective inhibitor for bacterial zinc metalloprotease: Molecular mechanics and ab initio molecular orbital calculations

The zinc metalloprotease pseudolysin (PLN) secreted from Pseudomonas aeruginosa degrades extracellular proteins to produce bacterial nutrition, and various types of PLN inhibitors have been developed to suppress the bacterial growth. However, as the structure of the ligand-binding pocket of PLN has large similarities to those of human matrix metalloproteinases (MMPs) and other human zinc metalloprotease, there is a risk that PLN inhibitors also inhibit human zinc proteases. In this study, we propose a novel agent that may bind stronger to PLN than to MMPs. The compound is proposed based on the specific molecular interactions between existing agents and PLN/MMP metalloproteases evaluated by the present molecular simulations. First, we confirmed that the binding energies of PLN agents evaluated using the ab initio fragment molecular orbital method were comparable to the IC50 values obtained through previous experiments. In addition, the specific molecular interactions between these agents and MMP-9 were investigated to elucidate the fact that some of the agents bind weaker to MMP than PLN. Based on the results, we proposed a novel agent having a succinimide group introduce by a hydroxamic acid group and investigated its binding properties with PLN and MMP. The results may provide useful information for the development of potent inhibitors for PLN with few potential side effects in human bodies

Impact of relative dose intensity in gemcitabine–cisplatin chemotherapy for metastatic urothelial carcinoma

Objectives: To evaluate the impact of relative dose intensity for gemcitabine–cisplatin chemotherapy in patients with metastatic urothelial carcinoma. Methods: We retrospectively reviewed the medical records of 18 patients with metastatic urothelial carcinoma, who received gemcitabine–cisplatin regimen as the first-line chemotherapy between 2009 and 2015. The doses of gemcitabine and cisplatin were reduced or the intervals between treatment cycles were prolonged according to the treatment efficacy and adverse events during the first and second cycles. The individually optimal relative dose intensity was set as the actual dose per the standard dose in the first and second cycles. From the third course onward, patients received the gemcitabine–cisplatin chemotherapy with the same relative dose intensity. Overall survival was compared with the groups according to the value of relative dose intensity. Results: The median age was 72.5 (range, 56–79) years and 15 men and 3 women were enrolled in the study. The median number of cycles of first-line gemcitabine–cisplatin chemotherapy was 8 (range, 2–17), and the median survival time from initiation of first-line chemotherapy was 20.1 (range, 3.5–32.8) months. The total median relative dose intensity of gemcitabine–cisplatin chemotherapy was 56.1%. The median survival time of 10 patients in the group with the relative dose intensity of less than 60% was significantly longer than that of 8 patients in the group with the relative dose intensity of more than 60% (19.2 and 11.0 months, respectively, p = 0.04). Conclusion: Individual low relative dose intensity management in the first-line gemcitabine–cisplatin chemotherapy may be an acceptable option for patients with metastatic urothelial carcinoma

A case of renal cell carcinoma with antiphospholipid syndrome treated by robot‐assisted partial nephrectomy

Introduction Antiphospholipid syndrome is an autoimmune disease that presents with thrombus hyperplasia. Although very rare, this disease is reported to become severe after the surgical invasion and other interventions. To our knowledge, there are no reports of partial nephrectomy in patients with antiphospholipid. Case presentation A 45‐year‐old man visited our hospital for treatment of left renal cell carcinoma. He had a history of antiphospholipid syndrome and took two antithrombotic agents. We performed a robot‐assisted partial nephrectomy. We selectively ligated only the feeding branch during the procedure. Postoperatively, there were no complications, and the patient was discharged on postoperative day 10. One year after surgery, there was no worsening of antiphospholipid syndrome. Conclusion We reported the first case of robot‐assisted partial nephrectomy for an antiphospholipid syndrome patient. Selective ligation of the renal artery might not have contributed to the severe antiphospholipid syndrome

A case of bloodstream co-infection of Saccharomyces cerevisiae and Candida glabrata while using micafungin

Abstract Background Saccharomyces cerevisiae is ubiquitous in the gastrointestinal tract and known as brewer's or baker's yeast. We experienced a case of S. cerevisiae and Candida glabrata co-infectious bloodstream infection. It is rare to detect both S. cerevisiae and Candida species in blood cultures together. Case We treated a 73-year-old man who developed a pancreaticoduodenal fistula infection after pancreaticoduodenectomy. The patient had a fever on postoperative day 59. We took blood cultures and detected C. glabrata. Thus, we started micafungin. On postoperative day 62, we retested blood cultures, and detected S cerevisiae and C. glabrata. We changed micafungin to liposomal amphotericin B. Blood cultures became negative on postoperative day 68. We changed liposomal amphotericin B to fosfluconazole and micafungin because of hypokalemia. He got well, and we terminated antifungal drugs 18 days after the blood cultures became negative. Conclusion Co-infection with S. cerevisiae and Candida species is rare. In addition, in this case, S. cerevisiae developed from blood cultures during micafungin administration. Thus, micafungin may not be effective enough to treat S. cerevisiae fungemia, although echinocandin is considered one of the alternative therapy for Saccharomyces infections

Usefulness of a 3D-printing air sampler for capturing live airborne bacteria and exploring the environmental factors that can influence bacterial dynamics

We created a handmade 3D-printed air sampler to effectively collect live airborne bacteria, and determined which environmental factors influenced the bacteria. Bacterial colony forming units (CFUs) in the air samples (n = 37) were monitored by recording the environmental changes occurring over time, then determining the presence/absence of correlations among such changes. The bacterial CFUs changed sharply and were significantly correlated with the DNA concentrations, indicating that the captured bacteria made up most of the airborne bacteria. Spearman's rank correlation analysis revealed significant correlations between the bacterial CFU values and some environmental factors (humidity, wind speed, insolation, and 24-h rainfall). Similarly the significant associations of CFU with humidity and wind speed were also found by multiple regression analysis with box-cox transformation. Among our panel of airborne bacteria (952 strains), 70 strains were identified as soil-derived Bacillus via the production of Escherichia coli- and Staphylococcus aureus-growth inhibiting antibiotics and by 16S rDNA typing. Soil-derived protozoa were also isolated from the air samples. We conclude that the airborne bacteria mainly derived from soil can alter in number according to environmental changes. Our sampler, which was created by easy-to-customize 3D printing, is a useful device for understanding the dynamics of live airborne bacteria. (C) 2021 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved

Specific interactions between the alkaline protease of P. aeruginosa and its natural peptide inhibitor: ab initio molecular simulations

Alkaline protease aeruginolysin (APR) is an important virulence factor in the evasion of the immune system by Pseudomonas aeruginosa (P. aeruginosa). The P. aeruginosa genome also encodes the highly potent and specifc APR peptide inhibitor (APRin). However, the structural reason for the signifcant inhibition has not been revealed. Using ab initio molecular simulations, we here investigated the specifc interactions between APR and APRin to elucidate which amino acid residues of APRin and APR contribute strongest to the inhibition. Since APR has a Zn2+ ion at the ligand-binding site and histidine and glutamic acid residues are coordinated with Zn2+, it is essential to precisely describe these coordination bonds to elucidate the specifc interactions between APR and APRin. Therefore, we employed the ab initio fragment molecular orbital method to investigate the specifc interactions at an electronic level. The results revealed that Ser1 and Ser2 at the N-terminus of APRin signifcantly contribute to the binding between APRin and APR. In particular, Ser1 binds strongly to Zn2+ as well as to the sidechains of His176(Hid), His180(Hid), and His186(Hid) in APR. This is the main reason for the strong interaction between APR and APRin. The results also elucidated signifcant contributions of the positively charged Arg83 and Arg90 residues of APRin to the binding with APR. These fndings may provide information useful for the design of novel small agents as potent APR inhibitors