Crystal structure of activating sulfotransferase SgdX2 involved in biosynthesis of secondary metabolite sungeidine.

Microorganisms synthesize a plethora of complex secondary metabolites, many of which are beneficial to human health, such as anticancer agents and antibiotics. Among these, the Sungeidines are a distinct class of secondary metabolites known for their bulky and intricate structures. They are produced by a specific biosynthetic gene cluster within the genome of the soil-dwelling actinomycete Micromonospora sp. MD118. A notable enzyme in the Sungeidine biosynthetic pathway is the activating sulfotransferase SgdX2. In this pathway, SgdX2 mediates a key sulfation step, after which the product undergoes spontaneous dehydration to yield a Sungeidine compound. To delineate the structural basis for SgdX2's substrate recognition and catalytic action, we have determined the crystal structure of SgdX2 in complex with its sulfate donor product, 3'-phosphoadenosine 5'-phosphate (PAP), at a resolution of 1.6 Å. Although SgdX2 presents a compact overall structure, its core elements are conserved among other activating sulfotransferases. Our structural analysis reveals a unique substrate-binding pocket that accommodates bulky, complex substrates, suggesting a specialized adaptation for Sungeidine synthesis. Moreover, we have constructed a substrate docking model that provides insights into the molecular interactions between SgdX2 and Sungeidine F, enhancing our understanding of the enzyme's specificity and catalytic mechanism. The model supports a general acid-base catalysis mechanism, akin to other sulfotransferases, and underscores the minor role of disordered regions in substrate recognition. This integrative study of crystallography and computational modeling advances our knowledge of microbial secondary metabolite biosynthesis and may facilitate the development of novel biotechnological applications.

Coronary intervention in chronic total occlusion in left main coronary artery.

An 83-year-old man who had undergone coronary aorta bypass graft surgery 25 years ago required treatment for new-onset worsening angina.

Lincosamide Antibiotics: Structure, Activity, and Biosynthesis.

Lincosamides are naturally occurring antibiotics isolated from Streptomyces sp. Currently, lincomycin A and its semisynthetic analogue clindamycin are used as clinical drugs. Due to their unique structures and remarkable biological activities, derivatizations of lincosamides via semi-synthesis and biosynthetic studies have been reported. This review summarizes the structures and biological activities of lincosamides, and the recent studies of lincosamide biosynthetic enzymes.

Precordial ST-Segment Elevation: Anterior Myocardial Infarction or Something Else?

The differential diagnosis of ST-segment elevation on electrocardiogram is multifaceted. Particularly, in cases of precordial ST-segment elevation, considering anterior myocardial infarction is crucial. Herein, we present a case of precordial ST-segment elevation with normal left coronary arteries.

Health and productivity management initiatives to promote worker health and improve the workplace environment at the Fukushima Daiichi nuclear power plant.

BACKGROUND: Since the Fukushima Daiichi nuclear power plant (FDNPP) accident in 2011, measures have been taken to address occupational health risks, such as heat illness and infectious diseases, and ensure fitness for duty with the Tokyo Electric Power Company and its contractors. However, with the decommissioning operations set to span several decades and an aging workforce, there arose a need for proactive occupational health strategies that not only addressed these risks but also promoted employee health and created a comfortable work environment. With the Japanese government's promotion of health and productivity management (HPM) for corporations, an HPM-based initiative was launched at the FDNPP in 2019. CASE: We designed an HPM questionnaire tailored to the unique conditions at the FDNPP for contractors in 2019. Subsequently, we adjusted the questionnaire annually in light of evolving societal contexts and insights derived from contractors' feedback. This initiative also involved the annual recognition of outstanding contractors. These efforts have led to a steady increase in the number of contractors participating in the HPM survey, with respondents' scores continually improving. We also emphasized dissemination of HPM practices from contractors to their subcontractors due to the complex subcontracting structure at FDNPP, and our results showed that more contractors have been extending these efforts to their subcontractors. CONCLUSIONS: Our findings suggest that individual contractors are steadily enhancing their HPM efforts. We are committed to continually offering support to advance HPM throughout the FDNPP.

Total Synthesis of the Sesquiterpene (-)-Merrillianin.

The first total synthesis of (-)-merrillianin (1), which is a natural sesquiterpene with a tricyclic structure having a cyclopentane ring and five- and seven-membered lactone parts, is demonstrated. This asymmetric total synthesis enabled the absolute stereostructure determination of naturally occurring (-)-1.

Impact of Medina classification on clinical outcomes of imaging-guided coronary bifurcation stenting.

Background: Intracoronary imaging improves clinical outcomes after stenting of complex coronary bifurcation lesions (CBLs), but the impact of Medina classification-based CBL distribution on outcomes of imaging-guided bifurcation stenting is unclear. Methods: In this integrated analysis of four previous studies, in which all CBLs were treated with drug-eluting stents under intravascular ultrasound or optical coherence tomography guidance, the distribution of 763 CBLs was assessed using angiographic Medina classification. Major adverse cardiac events (MACE), including target lesion revascularization (TLR), myocardial infarction, stent thrombosis, and cardiac death, were investigated at 1-year follow-up. Results: The most and least prevalent Medina subtypes were 0-1-0 (27.9 %) and 0-0-1 lesions (2.8 %). The most and least frequent MACE/TLR rates were 18.2 %/18.2 % for 0-0-1 lesions and 4.1 %/2.8 % for 0-1-0 lesions. Risks were higher for 0-0-1 lesions than for 0-1-0 lesions for both MACE (hazard ratio [HR]: 4.04, 95 % confidence interval [CI]: 1.21-13.45, p = 0.02) and TLR (HR: 6.19, 95 % CI: 1.69-22.74, p = 0.006). MACE rates were similar for true and non-true CBLs excluding 0-0-1 lesions (8.2 % and 5.9 %, HR 1.54, 95 % CI: 0.86-2.77, p = 0.15), while MACE (HR: 3.25, 95 % CI: 1.10-9.63, p = 0.03) and TLR (HR: 4.24, 95 % CI: 1.38-12.96, p = 0.01) risks were higher for 0-0-1 lesions. Conclusions: This integrated analysis of imaging-guided bifurcation stenting demonstrated similar clinical outcomes in true and non-true CBLs, except for 0-0-1 lesions, which had a significantly higher risk of MACE/TLR.

Sociodemographic factors affecting not receiving COVID-19 vaccine in Japan among people who originally intended to vaccinate: a prospective cohort study.

Objective: Vaccine hesitancy is a major issue for acquiring herd immunity. However, some individuals may go unvaccinated owing to inhibitory factors other than vaccine hesitancy. If there is even a small number of such people, support is needed for equitable vaccine distribution and acquiring herd immunity. We investigated sociodemographic factors that affected not undergoing COVID-19 vaccination in Japan among individuals who had strong intention to vaccinate before beginning the vaccination. Methods: We conducted this prospective cohort study on workers aged 20-65 years from December 2020 (baseline), to December 2021 using a self-administered questionnaire survey. There were 27,036 participants at baseline and 18,560 at follow-up. We included 6,955 participants who answered yes to this question at baseline: "Would you like to receive a COVID-19 vaccine as soon as it becomes available?" We applied multilevel logistic regression analyses to examine the association between sociodemographic factors and being unvaccinated at follow-up. Results: In all, 289 participants (4.2%) went unvaccinated. The odds ratios (ORs) for being unvaccinated were significantly higher for participants aged 30-39 and 40-49 than those aged 60-65 years. Being divorced, widowed, or single, having low income, and having COVID-19 infection experience also had higher ORs. Discussion: We found that some participants who initially had strong intention to vaccinate may have gone unvaccinated owing to vaccine side effects and the financial impact of absenteeism due to side effects. It is necessary to provide information repeatedly about the need for vaccination as well as social support to ensure that those who intend to vaccinate are able to do so when aiming for acquiring herd immunity through vaccination against COVID-19 as well as other potential infection pandemics in the future.

Functional analysis of a fungal P450 enzyme.

Fungal cytochrome P450s participate in various physiological reactions, including the synthesis of internal cellular components, metabolic detoxification of xenobiotic compounds, and oxidative modification of natural products. Although functional analysis reports of fungal P450s continue to grow, there are still some difficulties as compared to prokaryotic P450s, because most of these fungal enzymes are transmembrane proteins. In this chapter, we will describe the methods for heterologous expression, in vivo analysis, enzyme preparation, and in vitro enzyme assays of the fungal P450 enzyme Trt6 and isomerase Trt14, which play important roles in the divergence of the biosynthetic pathway of terretonins, as a model for the functional analysis of fungal P450 enzymes.

Mechanistic Analysis of Stereodivergent Nitroalkane Cyclopropanation Catalyzed by Nonheme Iron Enzymes.

BelL and HrmJ are α-ketoglutarate-dependent nonheme iron enzymes that catalyze the oxidative cyclization of 6-nitronorleucine, resulting in the formation of two diastereomeric 3-(2-nitrocyclopropyl)alanine (Ncpa) products containing trans-cyclopropane rings with (1'R,2'R) and (1'S,2'S) configurations, respectively. Herein, we investigate the catalytic mechanism and stereodivergency of the cyclopropanases. The results suggest that the nitroalkane moiety of the substrate is first deprotonated to produce the nitronate form. Spectroscopic analyses and biochemical assays with substrates and analogues indicate that an iron(IV)-oxo species abstracts proS-H from C4 to initiate intramolecular C-C bond formation. A hydroxylation intermediate is unlikely to be involved in the cyclopropanation reaction. Additionally, a genome mining approach is employed to discover new homologues that perform the cyclopropanation of 6-nitronorleucine to generate cis-configured Ncpa products with (1'R,2'S) or (1'S,2'R) stereochemistries. Sequence and structure comparisons of these cyclopropanases enable us to determine the amino acid residues critical for controlling the stereoselectivity of cyclopropanation.

Clinical effects of tranexamic acid on bleeding tendency due to fibrinolytic activation of AL amyloidosis.

We report a case where tranexamic acid, which is an antifibrinolytic agent, was used to effectively treat bleeding tendency in a patient with immunoglobulin light chain (AL) amyloidosis. A male patient in his 80s without a history of bleeding disorders was admitted to our hospital for the examination of bleeding tendency and was diagnosed with a bleeding disorder due to AL amyloidosis. Blood tests revealed elevated plasmin-α2-plasmin inhibitor complex levels, suggesting fibrinolytic activation. Managing the bleeding was difficult; however, we suspected fibrinolytic activation associated with AL amyloidosis and initiated treatment with oral tranexamic acid, which markedly improved the bleeding disorder and abnormalities of the fibrinolytic system. Therefore, in cases of bleeding due to fibrinolytic activation of AL amyloidosis, tranexamic acid administration can be an effective treatment.

Structural and Mechanistic Insights into the C-C Bond-Forming Rearrangement Reaction Catalyzed by Heterodimeric Hinokiresinol Synthase.

Hinokiresinol synthase (HRS) from Asparagus officinalis consists of two subunits, α and ß, and catalyzes an unusual decarboxylative rearrangement reaction of 4-coumaryl 4-coumarate to generate (Z)-hinokiresinol with complete stereoselectivity. Herein, we describe the mechanism of rearrangement catalysis and the role played by the heterodimeric HRS, through structural and computational analyses. Our results suggest that the HRS reaction is unlikely to proceed via the previously hypothesized Claisen rearrangement mechanism. Instead, we propose that the 4-coumaryl 4-coumarate substrate is first cleaved into coumarate and an extended p-quinone methide, which then recombine to generate a new C-C bond. These processes are facilitated by proton transfers mediated by the basic residues (α-Lys164, α-Arg169, ß-Lys168, and ß-Arg173) in the cavity at the heterodimer interface. The active site residues, α-Asp165, ß-Asp169, ß-Trp17, ß-Met136, and ß-Ala171, play crucial roles in controlling the regioselectivity of the coupling between the fragmented intermediates as well as the stereoselectivity of the decarboxylation step, leading to the formation of the (Z)-hinokiresinol product.

First Total Synthesis of Tanzawaic Acid B.

The first total synthesis of (+)-tanzawaic acid B, a natural polyketide bearing a pentadienoic ester and octalin moiety, has been accomplished. The synthetic improvement from previous synthetic conditions facilitated our gram-scale synthesis of the chiral octalin that possesses seven stereogenic centers and that is the core skeleton of almost all of the tanzawaic acid family.

Correction to "First Total Synthesis of Tanzawaic Acid B".

[This corrects the article DOI: 10.1021/acsomega.3c03634.].

Factors associated with non-initiation of osteoporosis pharmacotherapy after hip fracture: analysis of claims data in Japan.

In an analysis of claims data from a city in Japan, male patients and patients with dementia were less likely to receive osteoporosis pharmacotherapy after hip fracture. Treatment initiation rate has improved between 2014 and 2017. PURPOSE: Older adults with recent hip fractures are at a high risk of recurrent fractures. However, the post-fracture care gap has been reported globally. This study examines factors associated with pharmacotherapy non-initiation within 1 year after hip surgery. METHODS: Using medical and long-term care (LTC) claims, and LTC needs certification data in Tsukuba City, Japan, we identified individuals aged 65 years or older who had hip fractures with subsequent surgical procedures between October 1, 2014, and December 31, 2017. Patient (age, sex, dementia, and comorbidities) and health service-related characteristics (fiscal year, type of hospital, number of hospital beds, and admission to recovery phase rehabilitation wards) were examined. The association of these factors with non-pharmacotherapy for osteoporosis within 1 year after hip fracture using multivariable logistic models was analyzed. RESULTS: We identified 275 patients with hip fractures who did not receive pharmacotherapy pre-fracture. Forty percent of them received pharmacotherapy within 1 year of post-fracture. Male sex (odds ratio (OR) = 4.49 [2.14-9.44]) and dementia (OR = 1.90 [1.03-3.52]) were associated with no pharmacotherapy, whereas later fiscal year (OR = 0.64 [0.48-0.87]) and admission to rehabilitation wards (OR = 0.25 [0.14-0.46]) were associated with pharmacotherapy initiation within 1 year of post-fracture. Comorbidities were not associated with the initiation of pharmacotherapy. CONCLUSION: Pharmacotherapy for osteoporosis was less likely to be initiated after a hip fracture in male patients and patients with dementia. These patients should be considered for pharmacotherapy because they are at high risk of recurrent fractures.

Aurora A polyubiquitinates the BRCA1-interacting protein OLA1 to promote centrosome maturation.

The BRCA1-interacting protein Obg-like ATPase 1 (OLA1) functions in centriole duplication. In this study, we show the role of the mitotic kinase Aurora A in the reduction of centrosomal OLA1. Aurora A binds to and polyubiquitinates OLA1, targeting it for proteasomal degradation. NIMA-related kinase 2 (NEK2) phosphorylates the T124 residue of OLA1, increases binding of OLA1 to Aurora A and OLA1 polyubiquitination by Aurora A, and reduces centrosomal OLA1 in G2 phase. The kinase activity of Aurora A suppresses OLA1 polyubiquitination. The decrease in centrosomal OLA1 caused by Aurora A-mediated polyubiquitination promotes the recruitment of pericentriolar material proteins in G2 phase. The E3 ligase activity of Aurora A is critical for centrosome amplification induced by its overexpression. The results suggest a dual function of Aurora A as an E3 ubiquitin ligase and a kinase in the regulation of centrosomal OLA1, which is essential for proper centrosome maturation in G2 phase.

Workplace Social Support and Work Engagement Among Japanese Workers: A Nationwide Cross-sectional Study.

OBJECTIVES: We investigated the relationship between employees' perceptions of the number of sources of workplace social support and work engagement and whether each type of workplace social support is independently related to work engagement. METHODS: A cross-sectional study was conducted using a questionnaire survey in Japan. In total, 12,017 participants were analyzed. Participants were asked about 4 sources of workplace social support: supervisors, colleagues/subordinates, occupational health staff, and external counselors contracted by the workplace. Work engagement was measured using the 9-item Utrecht Work Engagement Scale. Coefficients were estimated using multiple regression analyses. RESULTS: The coefficient of work engagement increased as the number of sources of perceived workplace social support increased. Each support was also positively related to work engagement. CONCLUSIONS: Organizations should develop systems comprising various sources of workplace social support to increase employee work engagement.

Structure-Function Analysis of the S-Glycosylation Reaction in the Biosynthesis of Lincosamide Antibiotics.

The S-glycosyltransferase LmbT, involved in the biosynthesis of lincomycin A, is the only known enzyme that catalyzes the enzymatic incorporation of rare amino acid L-ergothioneine (EGT) into secondary metabolites. Here, we show the structure and function analyses of LmbT. Our in vitro analysis of LmbT revealed that the enzyme shows promiscuous substrate specificity toward nitrogenous base moieties in the generation of unnatural nucleotide diphosphate (NDP)-D-α-D-lincosamides. Furthermore, the X-ray crystal structures of LmbT in its apo form and in complex with substrates indicated that the large conformational changes of the active site occur upon binding of the substrates, and that EGT is strictly recognized by salt-bridge and cation-π interactions with Arg260 and Trp101, respectively. The structure of LmbT in complex with its substrates, the docking model with the EGT-S-conjugated lincosamide, and the structure-based site-directed mutagenesis analysis revealed the structural details of the LmbT-catalyzed SN 2-like S-glycosylation reaction with EGT.

Phase II study of biweekly cetuximab plus mFOLFOX6 or mFOLFIRI as second-line treatment for metastatic colorectal cancer and exploratory analysis of associations between DNA methylation status and the efficacy of the anti-EGFR antibody: T-CORE1201.

Background: Little is known about the biweekly combined use of cetuximab and chemotherapy as second-line treatment of metastatic colorectal cancer (mCRC). Recently, DNA methylation status has been reported to be a new possible predictor of the efficacy from the anti-epidermal growth factor receptor (EGFR) antibody treatment. The purpose of this study was to examine the efficacy and safety of biweekly cetuximab plus mFOLFOX6 or mFOLFIRI as a second-line treatment for KRAS exon 2 wild-type mCRC. We also investigated the predictability of DNA methylation status on the efficacy of the EGFR antibody-containing treatment. Methods: Patients who were refractory or intolerant to the first-line chemotherapy were enrolled and received biweekly cetuximab plus mFOLFOX6 or mFOLFIRI. The primary endpoint was progression-free survival (PFS). Tumor evaluations were performed every 2 months using Response Evaluation Criteria in Solid Tumor (RECIST) version 1.1. Adverse events (AEs) were evaluated according to the Common Terminology Criteria for Adverse Events version 4.0. DNA methylation status of colorectal cancer cells was defined by a modified MethyLight assay. Results: Sixty-six cases were enrolled. The median PFS (mPFS) was 5.1 [95% confidence interval (CI), 3.8-7.6] months. The median overall survival (mOS) was 12.7 (95% CI, 7.5-15.3) months. Grade 3 or higher neutropenia occurred in 53.0% of patients, whereas skin disorders with a grade 3 or higher occurred in <15% of patients. In multivariate analysis, DNA methylation status could not be an independent predictor of PFS [hazard ratio (HR), 1.43; P=0.39] and OS (HR, 2.13; P=0.086). However, in RAS/BRAF wild-type patients, the mPFS and mOS in the low-methylated colorectal cancer (LMCC) group was numerically better than those in the highly-methylated colorectal cancer (HMCC) group, although the difference was not statistically significant [mPFS: 8.5 (95% CI, 6.1-10.9) vs. 3.3 (95% CI, 1.2-not reached) months, P=0.79; ΔmPFS, 5.2 months; mOS: 15.3 (95% CI, 11.9-23.5) vs. 6.5 (95% CI, 3.1-not reached) months, P=0.53; ΔmOS, 8.8 months]. Conclusions: Biweekly cetuximab plus mFOLFOX6 or mFOLFIRI is a useful second-line therapy for mCRC. DNA methylation status warrants further exploration as a predictive biomarker for anti-EGFR efficacy in mCRC.