Dynamic Observation of the Membrane Interaction Processes of ß-Lactoglobulin by Time-Resolved Vacuum-Ultraviolet Circular Dichroism.

The elucidation of protein-membrane interactions is pivotal for comprehending the mechanisms underlying diverse biological phenomena and membrane-related diseases. In this investigation, vacuum-ultraviolet circular dichroism (VUVCD) spectroscopy, utilizing synchrotron radiation (SR), was employed to dynamically observe membrane interaction processes involving water-soluble proteins at the secondary-structure level. The study utilized a time-resolved (TR) T-shaped microfluidic cell, facilitating the rapid and efficient mixing of protein and membrane solutions. This system was instrumental in acquiring measurements of the time-resolved circular dichroism (TRCD) spectra of ß-lactoglobulin (bLG) during its interaction with lysoDMPG micelles. The results indicate that bLG undergoes a ß-α conformation change, leading to the formation of the membrane-interacting state (M-state), with structural alterations occurring in more than two steps. Global fitting analysis, employing biexponential functions with all of the TRCD spectral data sets, yielded two distinct rate constants (0.18 ± 0.01 and 0.06 ± 0.003/s) and revealed a unique spectrum corresponding to an intermediate state (I-state). Secondary-structure analysis of bLG in its native (N-, I-, and M-states) highlighted that structural changes from the N- to I-states predominantly occurred in the N- and C-terminal regions, which were prominently exposed to the membrane. Meanwhile, transitions from the I- to M-states extended into the inner barrel regions of bLG. Further examination of the physical properties of α-helical segments, such as effective charge and hydrophobicity, revealed that the N- to I- and I- to M-state transitions, which are ascribed to first- and second-rate constants, respectively, are primarily driven by electrostatic and hydrophobic interactions, respectively. These findings underscore the capability of the TR-VUVCD system as a robust tool for characterizing protein-membrane interactions at the molecular level.

pH-dependent regulation of an acidophilic O-acetylhomoserine sulfhydrylase from Lactobacillus plantarum.

Bacteria have two routes for the l-methionine biosynthesis. In one route called the direct sulfuration pathway, acetylated l-homoserine is directly converted into l-homocysteine. The reaction using H2S as the second substrate is catalyzed by a pyridoxal 5'-phosphate-dependent enzyme, O-acetylhomoserine sulfhydrylase (OAHS). In the present study, we determined the enzymatic functions and the structures of OAHS from Lactobacillus plantarum (LpOAHS). The LpOAHS enzyme exhibited the highest catalytic activity under the weak acidic pH condition. In addition, crystallographic analysis revealed that the enzyme takes two distinct structures, open and closed forms. In the closed form, two acidic residues are sterically clustered. The proximity may cause the electrostatic repulsion, inhibiting the formation of the closed form under the neutral to the basic pH conditions. We concluded that the pH-dependent regulation mechanism using the two acidic residues contributes to the acidophilic feature of the enzyme. IMPORTANCE: In the present study, we can elucidate the pH-dependent regulation mechanism of the acidophilic OAHS. The acidophilic feature of the enzyme is caused by the introduction of an acidic residue to the neighborhood of the key acidic residue acting as a switch for the structural interconversion. The strategy may be useful in the field of protein engineering to change the optimal pH of the enzymes. In addition, this study may be useful for the development of antibacterial drugs because the l-methionine synthesis essential for bacteria is inhibited by the OAHS inhibitors. The compounds that can inhibit the interconversion between the open and closed forms of OAHS may become antibacterial drugs.

Impact of the coronavirus disease 2019 pandemic on gastric and colorectal cancer surgeries: a multicenter epidemiologic study from the Kinki region of Japan.

The coronavirus disease 2019 pandemic affected cancer surgeries and advanced cancer diagnoses; however, the trends in patient characteristics in medical institutions during this time, and the surgical approaches used are unclear. We investigated the impact of the pandemic on gastric and colorectal cancer surgeries in the Kinki region of Japan. We grouped 1688 gastric and 3493 colorectal cancer surgeries into three periods: "pre-pandemic" (April 2019-March 2020), "pandemic 1" (April 2020-March 2021), and "pandemic 2" (April 2021-September 2021), to investigate changes in the number of surgeries, patient characteristics, surgical approaches, and cancer progression after surgery. Gastric and colorectal cancer surgeries decreased from the pre-pandemic levels, by 20% and 4%, respectively, in pandemic 1, and by 31% and 19%, respectively, in pandemic 2. This decrease had not recovered to pre-pandemic levels by September, 2021. Patient characteristics, surgical approaches, and cancer progression of gastric and colorectal surgeries did not change remarkably as a result of the coronavirus disease 2019 pandemic.

Comparison of Minimally Invasive Surgery with Open Surgery for Remnant Gastric Cancer: A Multi-institutional Cohort Study.

BACKGROUND: Despite growing evidence of the effectiveness of minimally invasive surgery (MIS) for primary gastric cancer, MIS for remnant gastric cancer (RGC) remains controversial due to the rarity of the disease. This study aimed to evaluate the surgical and oncological outcomes of MIS for radical resection of RGC. PATIENTS AND METHODS: Patients with RGC who underwent surgery between 2005 and 2020 at 17 institutions were included, and a propensity score matching analysis was performed to compare the short- and long-term outcomes of MIS with open surgery. RESULTS: A total of 327 patients were included in this study and 186 patients were analyzed after matching. The risk ratios for overall and severe complications were 0.76 [95% confidence interval (CI): 0.45, 1.27] and 0.65 (95% CI: 0.32, 1.29), respectively. The MIS group had significantly less blood loss [mean difference (MD), -409 mL; 95% CI: -538, -281] and a shorter hospital stay (MD, -6.5 days; 95% CI: -13.1, 0.1) than the open surgery group. The median follow-up duration of this cohort was 4.6 years, and the 3-year overall survival were 77.9% and 76.2% in the MIS and open surgery groups, respectively [hazard ratio (HR), 0.78; 95% CI: 0.45, 1.36]. The 3-year relapse-free survival were 71.9% and 62.2% in the MIS and open surgery groups, respectively (HR, 0.71; 95% CI: 0.44, 1.16). CONCLUSIONS: MIS for RGC showed favorable short- and long-term outcomes compared to open surgery. MIS is a promising option for radical surgery for RGC.

Effectiveness of Palonosetron, 1-Day Dexamethasone, and Aprepitant in Patients Undergoing Carboplatin-Based Chemotherapy.

INTRODUCTION: Dexamethasone (DEX)-sparing strategy with 5-hydroxytryptamine-3 receptor antagonist (5HT3RA) and aprepitant (APR), as triplet antiemetic prophylaxis, is associated with poor control of delayed chemotherapy-induced nausea and vomiting (CINV) in patients receiving carboplatin (CBDCA)-based chemotherapy. This study aimed to evaluate whether using palonosetron (PALO) as a 5HT3RA provides superior control with CINV than first-generation (1st) 5HT3RA in triplet antiemetic prophylaxis with a DEX-sparing strategy. METHODS: Pooled patient-level data from a nationwide, multicenter, and prospective observational study were analyzed to compare the incidence of CINV between patients administered PALO and 1st 5HT3RA in combination with 1-day DEX and APR. RESULTS: No significant differences were observed in the incidence of CINV, pattern of CINV, or severity of nausea by type of 5HT3RA in triplet antiemetic prophylaxis with DEX-sparing strategy. In both groups, the incidence of nausea gradually increased from day 3, peaked on day 4 or 5, and then declined slowly. The visual analog scale scores in the delayed phase remained high throughout the 7-day observation period. CONCLUSION: Careful patient selection and symptom monitoring are needed when implementing the DEX-sparing strategy in triplet antiemetic prophylaxis for patients undergoing CBDCA-based chemotherapy. Furthermore, additional strategies may be needed to achieve better control of delayed CINV.

Generation of bicistronic Dmp1-Cre knock-in mice using a self-cleaving 2A peptide.

INTRODUCTION: The conditional manipulation of genes using the Cre recombinase-locus of crossover in P1 (Cre/loxP) system is an important tool for revealing gene functions and cell lineages in vivo. The outcome of this method is dependent on the performance of Cre-driver mouse strains. In most cases, Cre knock-in mice show better specificity than randomly inserted Cre transgenic mice. However, following knock-in, the expression of the original gene replaced by Cre is lost. MATERIALS AND METHODS: We generated a new differentiated osteoblast- and osteocyte-specific Cre knock-in mouse line that carries the viral T2A sequence encoding a 2A self-cleaving peptide at the end of the coding region of the dentin matrix protein 1 (Dmp1) gene accompanied by the Cre gene. RESULTS: We confirmed that Dmp1-T2A-Cre mice showed high Cre expression in osteoblasts, osteocytes, odontoblasts, and periodontal ligament cells and that the 2A self-cleaving peptide efficiently produced both Dmp1 and Cre proteins. Furthermore, unlike the Dmp1 knockout mice, homozygous Dmp1-T2A-Cre mice showed no skeletal abnormalities. Analysis using the Cre reporter strain confirmed differentiated osteoblast- and osteocyte-specific Cre-mediated recombination in the skeleton. Furthermore, recombination was also detected in some nuclei of skeletal muscle cells, spermatocytes, and intestinal cells. CONCLUSION: 2A-Cre functions effectively in vivo, and Dmp1-T2A-Cre knock-in mice are a useful tool for studying the functioning of various genes in hard tissues.

Characterization of membrane-interaction mechanisms of proteins using vacuum-ultraviolet circular dichroism spectroscopy.

Protein-membrane interactions play an important role in various biological phenomena, such as material transport, demyelinating diseases, and antimicrobial activity. We combined vacuum-ultraviolet circular dichroism (VUVCD) spectroscopy with theoretical (e.g., molecular dynamics and neural networks) and polarization experimental (e.g., linear dichroism and fluorescence anisotropy) methods to characterize the membrane interaction mechanisms of three soluble proteins (or peptides). α1 -Acid glycoprotein has the drug-binding ability, but the combination of VUVCD and neural-network method revealed that the membrane interaction causes the extension of helix in the N-terminal region, which reduces the binding ability. Myelin basic protein (MBP) is an essential component of the myelin sheath with a multi-layered structure. Molecular dynamics simulations using a VUVCD-guided system showed that MBP forms two amphiphilic and three non-amphiphilic helices as membrane interaction sites. These multivalent interactions may allow MBP to interact with two opposing membrane leaflets, contributing to the formation of a multi-layered myelin structure. The antimicrobial peptide magainin 2 interacts with the bacterial membrane, causing damage to its structure. VUVCD analysis revealed that the M2 peptides assemble in the membrane and turn into oligomers with a ß-strand structure. Linear dichroism and fluorescence anisotropy suggested that the oligomers are inserted into the hydrophobic core of the membrane, disrupting the bacterial membrane. Overall, our findings demonstrate that VUVCD and its combination with theoretical and polarization experimental methods pave the way for unraveling the molecular mechanisms of biological phenomena related to protein-membrane interactions.

Secondary structural analyses of histone H2A-H2B proteins extracted from heated cells.

Histone proteins, building blocks of chromatins, participate in enzymatic reactions in cells heated at around 45°C though in vitro the denaturation of histones significantly proceeds at a similar temperature. It implies that unidentified mechanisms prevent thermal denaturation of histones in vivo. However, studies on the histone structures in the heated cells have been scarce. Here, we analyzed the secondary structures of histone H2A-H2B proteins originating from the heated cells using circular dichroism spectroscopy. The secondary structure contents of the H2A-H2B extracted from the heated cells differed from those of H2A-H2B both native and denatured in vitro but reverted to the native structures by incubating the heated cells at 37°C within 2 h. Such structural flexibility may play a role in protecting genomic functions governed by chromatin structures from heat stresses.

Quantitative Threshold Determination of Auditory Brainstem Responses in Mouse Models.

The auditory brainstem response (ABR) is a scalp recording of potentials produced by sound stimulation, and is commonly used as an indicator of auditory function. However, the ABR threshold, which is the lowest audible sound pressure, cannot be objectively determined since it is determined visually using a measurer, and this has been a problem for several decades. Although various algorithms have been developed to objectively determine ABR thresholds, they remain lacking in terms of accuracy, efficiency, and convenience. Accordingly, we proposed an improved algorithm based on the mutual covariance at adjacent sound pressure levels. An ideal ABR waveform with clearly defined waves I-V was created; moreover, using this waveform as a standard template, the experimentally obtained ABR waveform was inspected for disturbances based on mutual covariance. The ABR testing was repeated if the value was below the established cross-covariance reference value. Our proposed method allowed more efficient objective determination of ABR thresholds and a smaller burden on experimental animals.

Association between disease severity according to "MN criteria" and 30-day mortality in patients with Clostridioides difficile infection.

INTRODUCTION: A rapid membrane enzyme immunoassays (EIA) are frequently used to diagnose Clostridioides difficile infection (CDI). If EIA does not provide a definitive CDI diagnosis, whether treatment with anti-CD agents is to be performed depends on the pathogenesis and severity of the disease. In Japan, "MN criteria" have been proposed for the classification of disease severity. In this study, we investigated the association between disease severity and CDI prognosis when MN criteria are used. METHODS: This study included 102 patients diagnosed with CDI between April 2015 and March 2020. The disease serverity classification accorditng to MN criteria was divided into two groups: non-severely ill (mild to moderate) and severely ill (severe to critical) group. RESULTS: Mortality was significantly higher in severely ill patients than non-severely ill patients (46.7% vs. 13.8%, p = 0.0025). Multivariable analysis showed that the mortality of patients with CDI was significantly associated with advanced age (odds ratio [OR] = 1.1; 95% confidence interval [CI] = 1.0-1.2; p = 0.019) and disease severity (OR = 4.2; 95% CI = 1.2-14.8; p = 0.023). DISCUSSION: The classification of disease severity according to the MN criteria would be particularly useful in predicting the patients' prognoses.

Lipopolysaccharides affect compressed periodontal ligament cells via Eph-ephrin signaling.

OBJECTIVES: The aim of this study is to investigate the underlying mechanism of the recovery of periodontal ligament cells (PDLCs) sequentially exposed to inflammation and mechanical loading. MATERIALS AND METHODS: We divided PDLCs into four groups: control; compressive force (CF) alone (2.0 g/cm2 ); lipopolysaccharides (LPS) pretreatment (0.1 µg/ml) followed by simultaneous LPS and CF stimulation, simulating uncontrolled periodontitis; and LPS pretreatment followed by CF exposure, simulating controlled periodontitis. The expression of EphB4-ephrinB2 and EphA2-ephrinA2, and the level of osteoclastogenesis and osteogenesis were evaluated. RESULTS: Simultaneous stimulation by LPS and CF, compared with CF alone and sequential LPS and CF exposure, significantly suppressed EphB4 and enhanced ephrinA2 expression. Similarly, the most intense osteoclastic differentiation was observed under simultaneous LPS and CF stimulation, while sequential exposure to LPS and CF only slightly increased osteoclastic cell numbers. Both the activation of EphB4 signaling and ephrinA2 silencing lowered osteoclastic differentiation, which had previously been upregulated by simultaneous LPS and CF stimulation. These treatments also increased osteogenic differentiation. CONCLUSIONS: Simultaneous LPS and CF stimulation critically enhances osteoclastogenesis in PDLCs through the suppression of EphB4 and the induction of ephrinA2 signaling. Sequential LPS and CF exposure partially abolishes the osteolytic effects of simultaneous stimulation.

Quantification and Improvement of the Dynamics of Human Serum Albumin and Glycated Human Serum Albumin with Astaxanthin/Astaxanthin-Metal Ion Complexes: Physico-Chemical and Computational Approaches.

Glycated human serum albumin (gHSA) undergoes conformational changes and unfolding events caused by free radicals. The glycation process results in a reduced ability of albumin to act as an endogenous scavenger and transporter protein in diabetes mellitus type 2 (T2DM) patients. Astaxanthin (ASX) in native form and complexed with metal ions (Cu2+ and Zn2+) has been shown to prevent gHSA from experiencing unfolding events. Furthermore, it improves protein stability of gHSA and human serum albumin (HSA) as it is shown through molecular dynamics studies. In this study, the ASX/ASX-metal ion complexes were reacted with both HSA/gHSA and analyzed with electronic paramagnetic resonance (EPR) spectroscopy, rheology and zeta sizer (particle size and zeta potential) analysis, circular dichroism (CD) spectroscopy and UV-Vis spectrophotometer measurements, as well as molecular electrostatic potential (MEP) and molecular docking calculations. The addition of metal ions to ASX improves its ability to act as an antioxidant and both ASX or ASX-metal ion complexes maintain HSA and gHSA stability while performing their functions.

Evaluation of Remdesivir for Mildly to Moderately Ill Patients with COVID-19: A Single-Arm, Single-Center, Retrospective Study.

Background and Objectives: Remdesivir (RDV) is the first antiviral agent approved in Japan for the treatment of coronavirus disease 2019 (COVID-19). The aim of our study was to assess the efficacy and safety of RDV treatment in mildly to moderately ill patients with COVID-19. Materials and Methods: A single-center, retrospective study was performed in Fukuoka University Chikushi Hospital. Patients admitted to our hospital from June to October 2021 for RDV treatment against COVID-19 were enrolled. The primary end point was clinical status on days 10 and 14, using a 6-point ordinal scale ranging from death (category 6) to discharge (category 1). Adverse events were assessed and graded using the Japanese version of Common Terminology Criteria for Adverse Events (CTCAE) v5.0. Results: In total, 47 COVID-19 patients receiving RDV treatment were assessed during the study period. Thirty-four (72.3%) out of 47 patients required oxygen therapy. Out of these 34 patients, 30 (88.2%) showed a 2-point clinical improvement on day 14 after RDV was initiated. Serum alanine aminotransferase levels were elevated in three patients (6.4%) (CTCAE Grade 3) and neutropenia was detected in one patient (2.1%) out of the 47 patients. Conclusions: RDV may be highly effective, with good safety profiles, in patients with COVID-19 requiring oxygen therapy.

Conformation of myelin basic protein bound to phosphatidylinositol membrane characterized by vacuum-ultraviolet circular-dichroism spectroscopy and molecular-dynamics simulations.

The 18.5-kDa isoform of myelin basic protein (MBP) interacts with the membrane surface of the myelin sheath to construct its compact multilamellar structure. This study characterized the conformation of MBP in the membrane by measuring the vacuum-ultraviolet circular-dichroism (VUVCD) spectra of MBP in the bilayer liposome comprising the following essential lipid constituents of the myelin sheath: phosphatidylinositol (PI), phosphatidylinositol-4-phosphate (PIP), and phosphatidylinositol-4,5-bisphosphate (PIP2). The spectra of MBP exhibited the characteristic peaks of the helix structure in the presence of PI liposome, and the intensity increased markedly in the presence of PIP and PIP2 liposomes to show an isodichroic point. This suggests that the amount of the membrane-bound conformation of MBP enhanced due to the increased number of negative net charges on the liposome surfaces. Secondary-structure analysis revealed that MBP in the membrane comprised approximately 40% helix contents and eight helix segments. Molecular-dynamics (MD) simulations of the eight segments were conducted for 250 ns in the presence of PI membrane, which predicted two amphiphilic and three nonamphiphilic helices as the membrane-interaction sites. Further analysis of the distances of the amino-acid residues in each segment from the phosphate group suggested that the nonamphiphilic helices interact with the membrane surface electrostatically, while the amphiphilic ones invade the inside of the membrane to produce electrostatic and hydrophobic interactions. These results show that MBP can interact with the PI membrane via amphiphilic and nonamphiphilic helices under the control of a delicate balance between electrostatic and hydrophobic interactions.

5HT3 RA plus dexamethasone plus aprepitant for controlling delayed chemotherapy-induced nausea and vomiting in colorectal cancer.

Delayed chemotherapy-induced nausea and vomiting (CINV) is not well controlled in colorectal cancer (CRC) patients undergoing oxaliplatin (L-OHP)-based chemotherapy. Whether neurokinin-1 receptor antagonist addition to a first-generation 5HT3 antagonist (1st 5-HT3 RA) and dexamethasone (DEX) is beneficial to these patients remains controversial. Furthermore, whether palonosetron (PALO) or aprepitant (APR) is more effective in controlling delayed CINV is unclear. We, therefore, investigated whether PALO+DEX or 1st 5-HT3 RA+DEX+APR was more effective in controlling delayed CINV, and the risk factors for delayed CINV, in CRC patients undergoing L-OHP-based chemotherapy. Data were pooled from two prospective observational Japanese studies and a phase III trial to compare CINV incidence between the PALO + DEX (PALO) and 5-HT3 RA+DEX+APR (APR) groups by propensity score-matched analysis. CINV risk factors were identified using logistic regression models. The CINV incidence was higher in the PALO group than in the APR group. Logistic regression analysis revealed alcohol consumption, motion sickness, and the PALO+DEX regimen as independent risk factors for delayed nausea, and female sex and the PALO+DEX regimen as those for delayed vomiting. Compared with prophylactic PALO + DEX, 1st 5-HT3 RA+DEX+APR was more effective in controlling delayed CINV. Thus, CRC patients receiving L-OHP-based chemotherapy should be treated with three antiemetics, including APR.

Chemotherapy-induced nausea and vomiting (CINV) with carboplatin plus pemetrexed or carboplatin plus paclitaxel in patients with lung cancer: a propensity score-matched analysis.

BACKGROUND: Patients with lung cancer who are treated with carboplatin-based chemotherapy regimens often experience chemotherapy-induced nausea and vomiting (CINV). However, knowledge on the effect of regimen and cofactors on the risk of CINV is limited. This study aimed to analyze and compare the incidence of CINV between lung cancer patients undergoing carboplatin plus pemetrexed (CBDCA+PEM) and those undergoing carboplatin plus paclitaxel (CBDCA+PTX) chemotherapy. METHODS: Pooled data of 240 patients from two prospective observational studies were compared using propensity score matching. Separate multivariate logistic regression analyses were used to identify risk factors for nausea and vomiting following chemotherapy. RESULTS: Delayed nausea was significantly more common in patients treated with CBDCA+PEM than in those treated with CBDCA+PTX (51.1% vs. 36.2%, P = 0.04), but the incidence of vomiting did not significantly differ between the two groups (23.4% vs. 14.9%, P = 0.14). The occurrence of CINV peaked on day 4 in the CBDCA+PTX group and on day 5 in the CBDCA+PEM group. Multivariate analysis showed that female sex, younger age, and CBDCA+PEM regimen were independent risk factors for delayed nausea, while female sex was an independent risk factor for delayed vomiting. CONCLUSIONS: The CBDCA + PEM regimen has a higher risk of causing delayed nausea than the CBDCA + PTX regimen, and aggressive antiemetic prophylaxis should be offered to patients treated with CBDCA + PEM.

Efficacy of one-day versus multiple-day dexamethasone for chemotherapy-induced nausea and vomiting in lung cancer patients receiving carboplatin-based chemotherapy: a propensity score-matched analysis.

PURPOSE: Dexamethasone (DEX)-sparing strategies (one-day DEX) with palonosetron as doublet antiemetic prophylaxis have previously been studied. However, DEX-sparing regimens with 5-hydroxytryptamine-3 receptor antagonist (5-HT3RA) and aprepitant (APR), as triplet antiemetic prophylaxis, have not been evaluated. This study aimed to evaluate the efficacy of a combination of 5-HT3RA, APR, and DEX on day 1 of carboplatin (CBDCA)-based chemotherapy in patients with lung cancer. METHODS: Data were pooled from a nationwide, multicenter, prospective observational study using propensity score-matched analysis to compare the incidence of chemotherapy-induced nausea and vomiting (CINV) between one- and multiple-day DEX regimens in combination with 5-HT3RA plus APR. RESULTS: Incidence of delayed nausea was significantly higher in the one-day than in the multiple-day DEX group. Incidence of nausea was also significantly higher in the one-day than in the multiple-day DEX group on days 3-5. Kaplan-Meier curves for nausea showed a significant difference between the two groups; however, there was no significant difference in the occurrence of vomiting or the Kaplan-Meier curves of time to vomiting. CONCLUSION: To the best of our knowledge, this study is the first to evaluate the efficacy of a DEX-sparing regimen by comparing one- and multiple-day DEX combined with 5-HT3RA and APR concerning CINV incidence in lung cancer patients receiving CBDCA-based chemotherapy. Antiemetic regimens of one-day DEX result in poor control of delayed nausea; therefore, we recommend the application of the DEX-sparing strategy only after careful patient selection while considering the development of nausea.

Assignment of Absolute Configuration of Bromoallenes by Vacuum-Ultraviolet Circular Dichroism (VUVCD).

A new application of vacuum-ultraviolet circular dichroism (VUVCD), which enables the measurement of CD spectra in the vacuum-ultraviolet region (140-200 nm), for the assignment of the absolute configurations of bromoallenes is described. Bromoallene moieties are found in natural products obtained from many marine organisms. To date, the absolute configuration of bromoallenes has been assigned almost exclusively with Lowe's rule, which is based on specific rotation. However, exceptions to Lowe's rule have been reported arising from the presence of other substituents with large specific rotations. For the unambiguous assignment of the absolute configuration of the bromoallene moiety with its characteristic absorption wavelength at 180-190 nm due to the π-π* transition, VUVCD was applied to four pairs of bromoallene diastereomers prepared by modifying the synthetic scheme of omaezallene. The VUVCD spectra clearly showed positive or negative Cotton effects around 180-190 nm according to the configuration of the bromoallene employed, revealing the potential of VUVCD for determining absolute stereochemistry.

[A Case of Rheumatoid Arthritis Caused by Pembrolizumab Treatment for Non-Small Cell Lung Cancer].

A man in his 40s underwent a transbronchial lung biopsy and received a diagnosis of adenocarcinoma of the right upper lobe of the lung(cT4N0M0, Stage Ⅲ)with no EGFR gene mutation, no ALK fusion gene, no ROS1 fusion gene, and a tumor proportion score(TPS)of 50-74%. During the postoperative follow-up period, enlarged right supraclavicular lymph nodes and right upper and lower paratracheal lymph nodes were detected, diagnosed as recurrence by positron emission tomography-computed tomography. Although a positive rheumatoid factor test, as the patient had no symptoms of rheumatoid arthritis(RA), treatment with pembrolizumab was initiated. Before the second treatment course, a pharmacist conversing with the patient observed that the patient was experiencing pain in his fingers. After discussing the possibility of treatment continuation and test items with the attending physician, the patient underwent tests and received a diagnosis of RA.

Regulation of plant ER oxidoreductin 1 (ERO1) activity for efficient oxidative protein folding.

In the endoplasmic reticulum (ER), ER oxidoreductin 1 (ERO1) catalyzes intramolecular disulfide-bond formation within its substrates in coordination with protein-disulfide isomerase (PDI) and related enzymes. However, the molecular mechanisms that regulate the ERO1-PDI system in plants are unknown. Reduction of the regulatory disulfide bonds of the ERO1 from soybean, GmERO1a, is catalyzed by enzymes in five classes of PDI family proteins. Here, using recombinant proteins, vacuum-ultraviolet circular dichroism spectroscopy, biochemical and protein refolding assays, and quantitative immunoblotting, we found that GmERO1a activity is regulated by reduction of intramolecular disulfide bonds involving Cys-121 and Cys-146, which are located in a disordered region, similarly to their locations in human ERO1. Moreover, a GmERO1a variant in which Cys-121 and Cys-146 were replaced with Ala residues exhibited hyperactive oxidation. Soybean PDI family proteins differed in their ability to regulate GmERO1a. Unlike yeast and human ERO1s, for which PDI is the preferred substrate, GmERO1a directly transferred disulfide bonds to the specific active center of members of five classes of PDI family proteins. Of these proteins, GmPDIS-1, GmPDIS-2, GmPDIM, and GmPDIL7 (which are group II PDI family proteins) failed to catalyze effective oxidative folding of substrate RNase A when there was an unregulated supply of disulfide bonds from the C121A/C146A hyperactive mutant GmERO1a, because of its low disulfide-bond isomerization activity. We conclude that regulation of plant ERO1 activity is particularly important for effective oxidative protein folding by group II PDI family proteins.