Cell surface architecture of the cultivated DPANN archaeon Nanobdella aerobiophila.

The DPANN archaeal clade includes obligately ectosymbiotic species. Their cell surfaces potentially play an important role in the symbiotic interaction between the ectosymbionts and their hosts. However, little is known about the mechanism of ectosymbiosis. Here, we show cell surface structures of the cultivated DPANN archaeon Nanobdella aerobiophila strain MJ1T and its host Metallosphaera sedula strain MJ1HA, using a variety of electron microscopy techniques, i.e., negative-staining transmission electron microscopy, quick-freeze deep-etch TEM, and 3D electron tomography. The thickness, unit size, and lattice symmetry of the S-layer of strain MJ1T were different from those of the host archaeon strain MJ1HA. Genomic and transcriptomic analyses highlighted the most highly expressed MJ1T gene for a putative S-layer protein with multiple glycosylation sites and immunoglobulin-like folds, which has no sequence homology to known S-layer proteins. In addition, genes for putative pectin lyase- or lectin-like extracellular proteins, which are potentially involved in symbiotic interaction, were found in the MJ1T genome based on in silico 3D protein structure prediction. Live cell imaging at the optimum growth temperature of 65°C indicated that cell complexes of strains MJ1T and MJ1HA were motile, but sole MJ1T cells were not. Taken together, we propose a model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila.IMPORTANCEDPANN archaea are widely distributed in a variety of natural and artificial environments and may play a considerable role in the microbial ecosystem. All of the cultivated DPANN archaea so far need host organisms for their growth, i.e., obligately ectosymbiotic. However, the mechanism of the ectosymbiosis by DPANN archaea is largely unknown. To this end, we performed a comprehensive analysis of the cultivated DPANN archaeon, Nanobdella aerobiophila, using electron microscopy, live cell imaging, transcriptomics, and genomics, including 3D protein structure prediction. Based on the results, we propose a reasonable model of the symbiotic interaction and cell cycle of Nanobdella aerobiophila, which will enhance our understanding of the enigmatic physiology and ecological significance of DPANN archaea.

Cooperative Regulation of the Mucosal Mast Cell-Specific Protease Genes Mcpt1 and Mcpt2 by GATA and Smad Transcription Factors.

Mouse mast cell proteases (mMCP)-1 and -2 are specifically expressed in mucosal mast cells (MCs). However, the transcriptional regulation mechanism of the Mcpt1 and Mcpt2 genes induced in mucosal MCs is largely unknown. In the current study, we found that TGF-ß stimulation drastically induced upregulation of Mcpt1 and Mcpt2 mRNA in mouse bone marrow-derived MCs (BMMCs). TGF-ß-induced expression of Mcpt1 and Mcpt2 was markedly suppressed by transfection with small interfering RNA targeting Smad2 or Smad4 and moderately reduced by Smad3 small interfering RNA. We next examined the roles of the hematopoietic cell-specific transcription factors GATA1 and GATA2 in the expression of Mcpt1 and Mcpt2 and demonstrated that knockdown of GATA1 and GATA2 reduced the mRNA levels of Mcpt1 and Mcpt2 in BMMCs. The recruitment of GATA2 and acetylation of histone H4 of the highly conserved GATA-Smad motifs, which were localized in the distal regions of the Mcpt1 and Mcpt2 genes, were markedly increased by TGF-ß stimulation, whereas the level of GATA2 binding to the proximal GATA motif was not affected by TGF-ß. A reporter assay showed that TGF-ß stimulation upregulated GATA2-mediated transactivation activity in a GATA-Smad motif-dependent manner. We also observed that GATA2 and Smad4 interacted in TGF-ß-stimulated BMMCs via immunoprecipitation and Western blotting analysis. Taken together, these results demonstrate that TGF-ß induced mMCP-1 and -2 expression by accelerating the recruitment of GATA2 to the proximal regions of the Mcpt1 and Mcpt2 genes in mucosal MCs.

Low-Dose Olanzapine Plus Granisetron and Dexamethasone for Carboplatin-Induced Nausea and Vomiting in Patients with Thoracic Malignancies: A Prospective Multicenter Phase II Trial.

BACKGROUND: Olanzapine is an inexpensive and durable agent for the treatment of chemotherapy-induced nausea and vomiting and is also superior to neurokinin-1 receptor antagonists in the control of nausea. This study aimed to investigate the efficacy and safety of a low dose of 5 mg olanzapine plus granisetron and dexamethasone for treatment of carboplatin (CBDCA)-induced nausea and vomiting in patients with thoracic malignancies. MATERIALS AND METHODS: We conducted a prospective, open-label, single-arm, multicenter, phase II trial in four centers in Japan. Registered patients were scheduled to receive area under the curve (AUC) ≥5 mg/mL per minute of CBDCA and had never received moderately to highly emetogenic chemotherapy. Patients received olanzapine 5 mg/day orally after supper for 4 days, in combination with granisetron and dexamethasone. Primary endpoint was complete response (CR; no emesis and no use of rescue medication) rate during the overall phase (0-120 hours). RESULTS: Between February 2018 and June 2020, 51 patients were enrolled, and 50 patients were evaluated. The CR rates in the overall (0-120 hours), acute (0-24 hours), and delayed phases (24-120 hours) were 94.0%, 100%, and 94.0%, respectively. No grade 3 or higher adverse effects of olanzapine were observed. CONCLUSION: Prophylactic antiemetic therapy with a low dose of 5 mg olanzapine plus granisetron and dexamethasone showed durable efficacy with an acceptable safety profile. This three-drug combination appears to be a reasonable treatment approach in patients with thoracic malignancies receiving an AUC ≥5 mg/mL per minute of CBDCA-based regimen. Clinical trial identification number: UMIN000031267. IMPLICATIONS FOR PRACTICE: The results of this phase II trial indicated that the prophylactic administration of low-dose of 5 mg olanzapine combined with granisetron and dexamethasone has promising activity with acceptable safety profile in patients with thoracic malignancy receiving high-dose carboplatin chemotherapy.

Potentiometric Determination of Circulating Glycoproteins by Boronic Acid End-Functionalized Poly(ethylene glycol)-Modified Electrode.

Despite tremendous complexity in glycan structure, sialic acid (SA) provides an analytically accessible index for glycosylation, owing to its uniquely anionic nature and glycan-chain terminal occupation. Taking advantage of boronic acid (BA) based SA-recognition chemistry, we here demonstrate a label-free, no enzymatic, potentiometric determination of fetuin, a blood-circulating glycoprotein implicated in physiological and various pathological states. A phenylboronic acid (PBA) ω-end-functionalized poly(ethylene glycol) (PEG) with an α-tethering unit bearing pendent alkyne groups was "grafted-to" a gold electrode modified with 11-azide-undecathiol by a copper-catalyzed azide-alkyne cycloaddition reaction. Using the electrode, fetuin was potentiometrically detectable with a µM-order-sensitivity that is comparable to what is found in blood-collected specimen. Our finding may have implications for developing a remarkably economic hemodiagnostic technology with ease of downsizing and mass production.

Impact of One-Carbon Metabolism-Driving Epitranscriptome as a Therapeutic Target for Gastrointestinal Cancer.

One-carbon (1C) metabolism plays a key role in biological functions linked to the folate cycle. These include nucleotide synthesis; the methylation of DNA, RNA, and proteins in the methionine cycle; and transsulfuration to maintain the redox condition of cancer stem cells in the tumor microenvironment. Recent studies have indicated that small therapeutic compounds affect the mitochondrial folate cycle, epitranscriptome (RNA methylation), and reactive oxygen species reactions in cancer cells. The epitranscriptome controls cellular biochemical reactions, but is also a platform for cell-to-cell interaction and cell transformation. We present an update of recent advances in the study of 1C metabolism related to cancer and demonstrate the areas where further research is needed. We also discuss approaches to therapeutic drug discovery using animal models and propose further steps toward developing precision cancer medicine.

Effects of Sex and Seasonal Climatic Changes on the Risk of Incidence of Anti-EGFR Therapy-Induced Rash in Cancer Patients: A Retrospective Study.

Background and Objectives: Seasonal climatic changes may affect the development of the rash that is characteristic of treatment with anti-epidermal growth factor receptor (EGFR) antibodies. We evaluated the association between seasons and rash incidence among patients with cancer. Materials and Methods: Data from patients with colorectal or head and neck cancer treated with cetuximab or panitumumab during summer (S group; n = 34) or winter (W group; n = 37) between June 2014 and February 2019 were collected to retrospectively examine patient characteristics and rash incidence ≤ 8 weeks after treatment initiation. Results: Rashes were observed in 73.5% (n = 25) and 78.4% (n = 29) and grade 3 rashes were observed in 17.6% (n = 6) and 2.7% (n = 1) of the patients in the S and W groups, respectively. The incidence of grade ≥ 2 rashes in males in the S group was higher than that in the rest of the patient groups (p < 0.01). Conclusions: The higher incidence of skin rashes in males during summer might be attributed to the effects of ultraviolet light, lack of skincare, male hormones, and secretion of anti-EGFR antibodies in sweat. These findings highlight the need for research on preventive measures for such rashes.

Correlations of mRNA Levels among Efflux Transporters, Transcriptional Regulators, and Scaffold Proteins in Non-Small-Cell Lung Cancer.

Multidrug resistance (MDR) due to enhanced drug efflux activity of tumor cells can severely impact the efficacy of antitumor therapies. We recently showed that increased activity of the efflux transporter P-glycoprotein (P-gp) associated with activation of Snail transcriptional regulators may be mediated mainly by moesin in lung cancer cells. Here, we aimed to systematically evaluate the relationships among mRNA expression levels of efflux transporters (P-gp, breast cancer resistance protein (BCRP), and multidrug resistance-associated protein 2 (MRP2)), scaffold proteins (ezrin (Ezr), radixin (Rdx), and moesin (Msn); ERM proteins), and SNAI family members (Snail, Slug, and Smac) in clinical lung cancer and noncancer samples. We found high correlations between relative (cancer/noncancer) mRNA expression levels of Snail and Msn, Msn and P-gp, Slug and MRP2, and Smuc and BCRP. These findings support our previous conclusion that Snail regulates P-gp activity via Msn and further suggest that Slug and Smuc may contribute to the functional regulation of MRP2 and BCRP, respectively, in lung cancer cells. This trial is registered with UMIN000023923.

Efficacy and safety of 5 mg olanzapine combined with aprepitant, granisetron and dexamethasone to prevent carboplatin-induced nausea and vomiting in patients with gynecologic cancer: A multi-institution phase II study.

PURPOSE: The aim of this study was to investigate the efficacy and safety of prophylactic administration of 5 mg olanzapine (OLZ) combined with neurokinin 1 receptor antagonist (NK1RA), 5-hydroxytryptamine type-3 receptor antagonist (5-HT3RA), and dexamethasone (DEX) to prevent nausea and vomiting in carboplatin (CBDCA) combination therapy for patients with gynecological cancer. METHODS: We conducted a single-arm, multi-institution, phase II study. Gynecological cancer patients scheduled to receive AUC ≥4 mg/mL/min CBDCA were enrolled. All patients received 5 mg OLZ (once daily after supper on days 1-4) combined with NK1RA, 5-HT3RA, and DEX. The primary end point was complete response (CR; no emesis and rescue therapy) during overall phase (120 h after the start of carboplatin administration). RESULTS: Between May 2018 and June 2019, 60 patients were enrolled from 3 institutions in Japan. A total of 57 patients who met the criteria were included in the efficacy and safety analysis. The CR rate for the overall phase was 78.9%. Acute (0-24 h) and delayed phases (24-120 h) were 96.5% and 80.7%, respectively. Somnolence was observed in 73.7% patients. However, somnolence of grade 2 or higher was observed in only 3.5% of cases. There were no grade 3 or 4 toxicities associated with OLZ. CONCLUSIONS: Preventive use of OLZ combined with standard triplet therapy had promising activity with manageable safety, suggesting that this combination could be an effective standard treatment option for patients with AUC ≥4 mg/mL/min CBDCA combination therapy.

Effect of Ultra High-Resolution Computed Tomography and Model-Based Iterative Reconstruction on Detectability of Simulated Submillimeter Artery.

OBJECTIVE: To evaluate the effect of ultra high-resolution computed tomography (UHRCT) and model-based iterative reconstruction (MBIR) on the detectability of simulated submillimeter artery. METHODS: A small vessel phantom ranging from 0.4 to 2.0 mm in diameter and edge phantoms of low to high attenuation values were scanned by UHRCT (super-high-resolution mode and normal-resolution-mode) and conventional CT, and data were reconstructed by MBIR and filtered back projection (FBP). Vessel detectability was assessed subjectively and the effective size at which 50% of response was achieved (ES50 [mm]) was calculated. Modulation transfer function (MTF) was calculated by an edge spread function method. RESULTS: ES50 of super high-resolution mode (0.36 mm for MBIR and 0.50 mm for FBP) was significantly smaller than those of normal-resolution mode (P < 0.01). In the MTF analysis, the MTF of MBIR improved as the edge phantom attenuation increased, whereas that of FBP was stable. CONCLUSIONS: Both UHRCT and MBIR are effective for the detectability of simulated submillimeter artery.

COVID-19 Drug Discovery Using Intensive Approaches.

Since the infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) was reported in China during December 2019, the coronavirus disease 2019 (COVID-19) has spread on a global scale, causing the World Health Organization (WHO) to issue a warning. While novel vaccines and drugs that target SARS-CoV-2 are under development, this review provides information on therapeutics which are under clinical trials or are proposed to antagonize SARS-CoV-2. Based on the information gained from the responses to other RNA coronaviruses, including the strains that cause severe acute respiratory syndrome (SARS)-coronaviruses and Middle East respiratory syndrome (MERS), drug repurposing might be a viable strategy. Since several antiviral therapies can inhibit viral replication cycles or relieve symptoms, mechanisms unique to RNA viruses will be important for the clinical development of antivirals against SARS-CoV-2. Given that several currently marketed drugs may be efficient therapeutic agents for severe COVID-19 cases, they may be beneficial for future viral pandemics and other infections caused by RNA viruses when standard treatments are unavailable.

Three-dimensional imaging of vocalizing larynx by ultra-high-resolution computed tomography.

PURPOSE: Ultra-high-resolution computed tomography (UHRCT) is an emerging imaging technology that is able to achieve simultaneous 160 slices with super-thin 0.25 mm thickness. The purpose of this study was to assess the feasibility of UHRCT to visualize laryngeal structure and kinetics. METHODS: Three normal volunteers and three patients with unilateral vocal fold paralysis (UVFP) were incorporated in this case series. First, images were taken under five conditions in normal volunteers. Five tasks consisted of (1) air inspiration through the nose (IN), (2) breath holding (BH), (3) sustained vowel /i:/ phonation (IP), (4) humming phonation (HP), and (5) forced glottic closure during exhalation (FC). Three-dimensional CT images of arytenoid and cricoid cartilages, as well as virtual laryngoscopic images, were reconstructed using UHRCT data. Reconstructed images were compared among five conditions to assess the best tasks to picture laryngeal kinetics. Second, pre- and post-phonosurgical images were examined in UVFP patients to evaluate potential role of UHRCT to assess laryngeal pathology in hoarse patients. RESULTS: Among the five conditions, IN and IP conditions were considered suitable to visualize laryngeal structure at rest and during phonation, respectively. Kinetic abnormalities including asymmetric motion of arytenoid cartilages were elucidated in UVFP patients, and virtual endoscopy visualized the clinically invisible posterior three-dimensional glottic chinks. Furthermore, UHRCT was useful to understand changes in laryngeal structure achieved by phonosurgery. CONCLUSIONS: UHRCT is an emerging imaging technology that can be used for minimally invasive visualization and assessment of laryngeal structure and kinetics. Future studies to assess more number of patients with laryngeal dysfunction are warranted.

A double-blind randomized phase II dose-finding study of olanzapine 10 mg or 5 mg for the prophylaxis of emesis induced by highly emetogenic cisplatin-based chemotherapy.

PURPOSE: The aim of this phase II study was to evaluate the efficacy and safety of two doses (10 and 5 mg) of olanzapine in combination with standard antiemetic treatment (aprepitant, palonosetron, and dexamethasone) for patients receiving highly emetogenic chemotherapy (HEC). METHODS: A multi-institutional, double-blind, randomized phase II, dose-finding study of olanzapine was performed in patients with a malignant solid tumor who were receiving HEC with cisplatin (≥ 50 mg/m2). Patients were randomly assigned either olanzapine 10 or 5 mg orally on days 1-4, combined with standard antiemetic treatment. The primary endpoint was a complete response (CR; no emesis and no use of rescue medications) in the delayed phase (24-120 h after the start of cisplatin treatment). RESULTS: 153 patients were randomized to the 10 mg group (n = 76) or the 5 mg group (n = 77). The CR rate in the delayed phase was 77.6% (80% CI: 70.3-83.8, P = 0.01) in the 10 mg group and 85.7% (80% CI: 79.2-90.7, P < 0.001) in the 5 mg group (P value for H 0: complete response rate ≤ 65%). The most common adverse event was somnolence, which had an incidence of 53.3 and 45.5% in the 10 and 5 mg olanzapine groups, respectively. CONCLUSIONS: Both doses of 10 and 5 mg olanzapine provided a significant improvement in delayed emesis. A dose of 5 mg olanzapine was determined as the recommended dose for a further phase III study based on higher CR and lower somnolence rates. CLINICAL TRIAL INFORMATION: UMIN000014214.

Mound-like Epiretinal Material: Its Short-term Changes and Association with Posterior Vitreous Detachment.

PURPOSE: To describe clinical characteristics of a retinal finding termed mound-like epiretinal material (MOLEM), and distinguish it from epiretinal proliferation, a similar epiretinal finding previously described in various pathologies. METHODS: Five eyes from five patients were retrospectively identified from medical records. Clinical findings and images, including fundus photographs and optical coherence tomography (OCT), were reviewed. RESULTS: All eyes displayed mound-like material with uniform and low-to-moderate reflectivity on an otherwise intact retinal surface detected on OCT. No eyes presented with concurrent pathology typically observed in cases of epiretinal proliferation, such as lamellar/full-thickness macular hole, epiretinal membrane, vitreomacular traction, or uveitis. Two eyes exhibited central serous chorioretinopathy, but there was no association of MOLEM with serous retinal detachment. In three out of five eyes, MOLEM appeared simultaneously with posterior vitreous detachment (PVD). Some lesions underwent irregular transformations over months and occasionally disappeared. While all cases were monitored without intervention, no visual decline or complications attributed to MOLEM were detected. CONCLUSION: MOLEM represents a novel clinical finding, characterized by transient morphological changes without symptoms and potential association with PVD. It may occur in eyes lacking macular diseases linked with epiretinal proliferation, a similar yet distinct lesion. The incidence, etiology, and clinical significance of MOLEM warrant further investigation by accumulating comparable cases, although the lesion appears benign and self-limiting.

Excess suicides in Japan: A three-year post-pandemic assessment of gender and age disparities.

This study offers an in-depth analysis of Japan's suicide trends three years after the COVID-19 outbreak. Using data from the National Police Agency (January 2010-May 2023), we examined suicide rates across genders and age groups. Employing the quasi-Poisson regression, we predicted monthly death counts. Findings indicate a steady rise in female suicides from April 2020 to January 2023. Notably, male cohorts aged 50-59 and over 80 in 2022 displayed heightened death rates. While these trends may reflect the impacts of the pandemic, it is essential to consider other factors, including socio-economic changes, to fully understand the context of Japan's suicide patterns.

Discovery of novel 7-membered cyclic amide derivatives that inhibit 11beta-hydroxysteroid dehydrogenase type 1.

A series of novel 5-trans-hydroxyadamantan-2-yl-5,6,7,8-tetrahydropyrazolo[4,3-c]azepin-4(1H)-ones that inhibit 11beta-hydroxysteroid dehydrogenase type 1 are described. We discovered these 7-membered cyclic amide derivatives by introducing a distinctive linker through pharmacophore analysis of known ligands included in X-ray co-crystal structures. Further optimization using docking studies led to highly potent inhibitors 15b and 27, which furthermore showed the potent efficacy in in vivo studies.

Total IgE at 6 months predicts remittance or persistence of atopic dermatitis at 14 months.

Some patients with infantile atopic dermatitis (AD) achieve remission around 1 year old, but in others it persists. The difference between them is unclear. We performed a birth cohort study to find the markers predicting the outcome of infantile AD. We followed up a cohort (n = 314) from birth to 14 months of age, and cord blood was taken from the participants. Some of them (n = 144) had a physical examination and a blood test at 6 and 14 months of age. The subjects who had AD at 6 months (n = 34) were divided into two groups, named the transient group (those who had no AD at 14 months of age; n = 16) and the persistent group (those who still had AD at 14 months of age; n = 18). Then, laboratory data were compared between these two groups. Percentage of CD8 in cord blood lymphocytes and total IgE at 6 months of age in the persistent group was significantly higher than those of the transient group. The area under the curves of a receiver operating characteristic analysis were 0.792 (p = 0.007) and 0.722 (p = 0.027). In the persistent group, total IgE, percentages of T-helper (Th) 2 and phytohemagglutinin-induced IL-4 production from peripheral blood mononuclear cells at 14 months of age were also significantly higher than those of the transient group. Thus Th2 polarization in the persistent group was confirmed. In clinical use, total IgE at 6 months of age is the most useful predictive marker to know the outcome of infantile AD. The clinical trial registration ID is UMIN000002926.

Longitudinal anatomical and visual outcome of macular telangiectasia type 2 in Asian patients.

Limited information regarding the anatomical and visual prognosis of macular telangiectasia (MacTel) type 2 in the Asian population is currently available. Herein, we conducted a retrospective longitudinal analysis of Japanese patients diagnosed with MacTel type 2. Disease progression was evaluated using the Simple MacTel Classification developed by Chew EY et al. in 2023, and its association with visual changes was analyzed. Sixteen eyes of eight Japanese patients were included in the study, with an average follow-up period of 8.2 ± 3.9 years (range, 2.2-14.0). At the initial visit, 7 (44%) and 5 (31%) eyes were classified as Grade 2 (central ellipsoid zone break) and Grade 3 (noncentral pigment), respectively. The proportion of eyes that progressed by 1 or 2-steps in grade after 1, 3, 5, 8, and 12 years was 0%, 14%, 43%, 70%, and 100%, or 0%, 7%, 7%, 30%, and 75%, respectively. The visual acuity significantly deteriorated during the follow-up period, particularly in the two eyes with full-thickness macular holes (FTMH). Three out of 7 patients exhibited low serum serine concentrations, although no apparent correlation with anatomical or visual outcomes was observed. Overall, this cohort demonstrated chronic disease progression, both anatomically and functionally, in eyes with MacTel type 2, with FTMH potentially associated with greater visual loss.

Effective Cell Transfection in An Ultrasonically Levitated Droplet for Sustainable Technology.

The levitation methodology, which enables us to operate a contactless reaction without a container, is likely to be a revolutionary technology in the fields of chemistry and biology to reduce the plastic waste in life science laboratories. Here, the authors show that plasmid DNA can be effectively transfected into animal cells in a floating droplet of culture medium levitated using ultrasonic standing waves. The data indicate that there is no significant damage to the plasmid and cells during the levitating transfection time, and the transgene expression efficiency and cellular uptake in the droplet are significantly higher than those in the conventional tube, with and without shaking. These results suggest the consolidation of the endocytic uptake pathway into macropinocytosis, indicating that ultrasonic levitation induced a change in cell characteristics. This study suggests that transfection methodology using ultrasonic levitation has the potential to advance the current experimental procedures in the field of cell engineering, in addition to presenting a revolutionary containerless reactor for sustainable technology.

Tumor-associated neutrophils and macrophages exacerbate antidrug IgG-mediated anaphylactic reaction against an immune checkpoint inhibitor.

BACKGROUND: With the increased use of immune checkpoint inhibitors (ICIs), side effects and toxicity are a great concern. Anaphylaxis has been identified as a potential adverse event induced by ICIs. Anaphylaxis is a life-threatening medical emergency. However, the mechanisms and factors that can potentially influence the incidence and severity of anaphylaxis in patients with cancer remain unclear. METHODS: Healthy, murine colon 26, CT26, breast 4T1, EMT6, and renal RENCA tumor-bearing mice were treated with an anti-PD-L1 antibody (clone 10F.9G2). Symptoms of anaphylaxis were evaluated along with body temperature and mortality. The amounts of antidrug antibody and platelet-activating factor (PAF) in the blood were quantified via ELISA and liquid chromatography-mass spectrometry (LC-MS/MS). Immune cells were analyzed and isolated using a flow cytometer and magnetic-activated cell sorting, respectively. RESULTS: Repeated administration of the anti-PD-L1 antibody 10F.9G2 to tumor-bearing mice caused fatal anaphylaxis, depending on the type of tumor model. After administration, antidrug immunoglobulin G (IgG), but not IgE antibodies, were produced, and PAF was released as a chemical mediator during anaphylaxis, indicating that anaphylaxis was caused by an IgG-dependent pathway. Anaphylaxis induced by 10F.9G2 was treated with a PAF receptor antagonist. We identified that neutrophils and macrophages were PAF-producing effector cells during anaphylaxis, and the tumor-bearing models with increased numbers of neutrophils and macrophages showed lethal anaphylaxis after treatment with 10F.9G2. Depletion of both neutrophils and macrophages using clodronate liposomes prevented anaphylaxis in tumor-bearing mice. CONCLUSIONS: Thus, increased numbers of neutrophils and macrophages associated with cancer progression may be risk factors for anaphylaxis. These findings may provide useful insights into the mechanism of anaphylaxis following the administration of immune checkpoint inhibitors in human subjects.

Clinical Efficacy and Safety of Arbekacin against Pneumonia in Febrile Neutropenia: A Retrospective Study in Patients with Hematologic Malignancies.

BACKGROUND: Arbekacin (ABK) is an aminoglycoside that exhibits anti-methicillin-resistant Staphylococcus aureus (MRSA) and anti-Pseudomonas aeruginosa activities. Therefore, for patients with febrile neutropenia (FN) and concurrent pneumonia suspected to be caused by MRSA, ABK may be sufficiently effective even as a single agent. MATERIALS AND METHODS: Patients with hematologic malignancies treated with ABK who met the following criteria were included: 1) fever during neutropenia or functional neutropenia, 2) FN complicated by pneumonia, and 3) possible infection by antimicrobial-resistant Gram-positive cocci. RESULTS: This study encompassed 22 episodes involving 19 patients, of which, 15 (68.2%) were successfully treated with ABK. Of the nine episodes showing inadequate response to other anti-MRSA drugs, eight were successfully treated with ABK. Grade 2 or worse adverse events included acute kidney injury (13.6%) and increased transaminase levels (9.1%). CONCLUSION: The present study demonstrated that ABK is effective and safe in patients with FN and concurrent pneumonia caused by antimicrobial-resistant Gram-positive cocci. ABK may also be effective in patients who are unresponsive to other anti-MRSA drugs. Therefore, ABK may be beneficial in the treatment of pneumonia caused by antimicrobial-resistant Gram-positive cocci in patients with FN.