In vivo screening for toxicity-modulating drug interactions identifies antagonism that protects against ototoxicity in zebrafish.

Introduction: Ototoxicity is a debilitating side effect of over 150 medications with diverse mechanisms of action, many of which could be taken concurrently to treat multiple conditions. Approaches for preclinical evaluation of drug-drug interactions that might impact ototoxicity would facilitate design of safer multi-drug regimens and mitigate unsafe polypharmacy by flagging combinations that potentially cause adverse interactions for monitoring. They may also identify protective agents that antagonize ototoxic injury. Methods: To address this need, we have developed a novel workflow that we call Parallelized Evaluation of Protection and Injury for Toxicity Assessment (PEPITA), which empowers high-throughput, semi-automated quantification of ototoxicity and otoprotection in zebrafish larvae via microscopy. We used PEPITA and confocal microscopy to characterize in vivo the consequences of drug-drug interactions on ototoxic drug uptake and cellular damage of zebrafish lateral line hair cells. Results and discussion: By applying PEPITA to measure ototoxic drug interaction outcomes, we discovered antagonistic interactions between macrolide and aminoglycoside antibiotics that confer protection against aminoglycoside-induced damage to lateral line hair cells in zebrafish larvae. Co-administration of either azithromycin or erythromycin in zebrafish protected against damage from a broad panel of aminoglycosides, at least in part via inhibiting drug uptake into hair cells via a mechanism independent from hair cell mechanotransduction. Conversely, combining macrolides with aminoglycosides in bacterial inhibition assays does not show antagonism of antimicrobial efficacy. The proof-of-concept otoprotective antagonism suggests that combinatorial interventions can potentially be developed to protect against other forms of toxicity without hindering on-target drug efficacy.

In-hospital outcomes of septal myectomy vs. alcohol septal ablation for hypertrophic cardiomyopathy with outflow tract obstruction: An update and insights from the national inpatient sample from 2011 to 2019.

Septal Myectomy (SM) and Alcohol Septal Ablation (ASA) improve symptoms in patients with Hypertrophic Cardiomyopathy with outflow tract obstruction (oHCM). However, outcomes data in this population is predominantly from specialized centers. The National Inpatient Database was queried from 2011 to 2019 for relevant international classification of diseases (ICD)-9 and -10 diagnostic and procedural codes. We compared baseline characteristics and in-hospital outcomes of patients with oHCM who underwent SM vs ASA. A p-value < 0.001 was considered statistically significant. We identified 15,119 patients with oHCM who underwent septal reduction therapies, of whom 57.4% underwent SM, and 42.6% underwent ASA. Patients who underwent SM had higher all-cause mortality (OR: 1.8 (1.3-2.5)), post-procedure ischemic stroke (OR: 2.3 (1.7-3.2)), acute kidney injury (OR: 1.4 (1.2-1.7)), vascular complications (OR: 3.6 (2.3-5.3)), ventricular septal defect (OR: 4.4 (3.2-6.1)), cardiogenic shock (OR: 1.7 (1.3-2.3)), sepsis (OR: 3.2 (1.9-5.4)), and left bundle branch block (OR: 3.5 (3-4)), compared to ASA. Patients who underwent ASA had higher post-procedure complete heart block (OR: 1.3 (1.1-1.4)), right bundle branch block (OR: 6.3 (5-7.7)), ventricular tachycardia (OR: 2.2 (1.9-2.6)), supraventricular tachycardia (OR: 1.6 (1.4-2)), and more commonly required pacemaker insertion (OR: 1.4 (1.3-1.7)) (p < 0.001 for all) compared to SM. This nationwide analysis evidenced that patients undergoing SM had higher in-hospital mortality and periprocedural complications than ASA; however, those undergoing ASA had more post-procedure conduction abnormalities and pacemaker implantation. The implications of these findings warrant further investigation regarding patient selection strategies for these therapies.

Identification of the native Torpedo californica nicotinic acetylcholine receptor's glycan composition after a multi-step sequential purification method using MALDI-ToF MS.

The Cys-loop pentameric ligand-gated ion channels comprise a dynamic group of proteins that have been extensively studied for decades, yielding a wealth of findings at both the structural and functional levels. The nicotinic acetylcholine receptor (nAChR) is no exception, as it is part of this large protein family involved in proper organismal function. Our efforts have successfully produced a highly pure nAChR in detergent complex (nAChR-DC), enabling more robust studies to be conducted on it, including beginning to experiment with high-throughput crystallization. Our homogeneous product has been identified and extensively characterized with 100% identity using Nano Lc MS/MS and MALDI ToF/ToF for each nAChR subunit. Additionally, the N-linked glycans in the Torpedo californica-nAChR (Tc-nAChR) subunits have been identified. To study this, the Tc-nAChR subunits were digested with PNGase F and the released glycans were analyzed by MALDI-ToF. The MS results showed the presence of high-mannose N-glycan in all native Tc-nAChR subunits. Specifically, the oligommanose population Man8-9GlcNac2 with peaks at m/z 1742 and 1904 ([M + Na]+ ions) were observed.

Observation of the Anomalous Hall Effect in a Layered Polar Semiconductor.

Progress in magnetoelectric materials is hindered by apparently contradictory requirements for time-reversal symmetry broken and polar ferroelectric electronic structure in common ferromagnets and antiferromagnets. Alternative routes can be provided by recent discoveries of a time-reversal symmetry breaking anomalous Hall effect (AHE) in noncollinear magnets and altermagnets, but hitherto reported bulk materials are not polar. Here, the authors report the observation of a spontaneous AHE in doped AgCrSe2 , a layered polar semiconductor with an antiferromagnetic coupling between Cr spins in adjacent layers. The anomalous Hall resistivity 3 µ Ω c m $\mu \Omega \, \textnormal {cm}$ is comparable to the largest observed in compensated magnetic systems to date, and is rapidly switched off when the angle of an applied magnetic field is rotated to ≈80° from the crystalline c-axis. The ionic gating experiments show that the anomalous Hall conductivity magnitude can be enhanced by modulating the p-type carrier density. They also present theoretical results that suggest the AHE is driven by Berry curvature due to noncollinear antiferromagnetic correlations among Cr spins, which are consistent with the previously suggested magnetic ordering in AgCrSe2 . The results open the possibility to study the interplay of magnetic and ferroelectric-like responses in this fascinating class of materials.

Predicting molecular docking of per- and polyfluoroalkyl substances to blood protein using generative artificial intelligence algorithm DiffDock.

This study computationally evaluates the molecular docking affinity of various perfluoroalkyl and polyfluoroalkyl substances (PFAs) towards blood proteins using a generative machine-learning algorithm, DiffDock, specialized in protein-ligand blind-docking learning and prediction. Concerns about the chemical pathways and accumulation of PFAs in the environment and eventually in the human body has been rising due to empirical findings that levels of PFAs in human blood has been rising. DiffDock may offer a fast approach in determining the fate and potential molecular pathways of PFAs in human body.

In vivo screening for toxicity-modulating drug interactions identifies antagonism that protects against ototoxicity in zebrafish.

Ototoxicity is a debilitating side effect of over 150 medications with diverse mechanisms of action, many of which could be taken concurrently to treat multiple conditions. Approaches for preclinical evaluation of drug interactions that might impact ototoxicity would facilitate design of safer multi-drug regimens and mitigate unsafe polypharmacy by flagging combinations that potentially cause adverse interactions for monitoring. They may also identify protective agents that antagonize ototoxic injury. To address this need, we have developed a novel workflow that we call Parallelized Evaluation of Protection and Injury for Toxicity Assessment (PEPITA), which empowers high-throughput, semi-automated quantification of ototoxicity and otoprotection in zebrafish larvae. By applying PEPITA to characterize ototoxic drug interaction outcomes, we have discovered antagonistic interactions between macrolide and aminoglycoside antibiotics that confer protection against aminoglycoside-induced damage to lateral line hair cells in zebrafish larvae. Co-administration of either azithromycin or erythromycin in zebrafish protected against damage from a broad panel of aminoglycosides, at least in part via inhibiting drug uptake into hair cells via a mechanism independent from hair cell mechanotransduction. Conversely, combining macrolides with aminoglycosides in bacterial inhibition assays does not show antagonism of antimicrobial efficacy. The proof-of-concept otoprotective antagonism suggests that combinatorial interventions can potentially be developed to protect against other forms of toxicity without hindering on-target drug efficacy.

Treatment of a case of septic tibial nonunion by the Capanna technique.

This report presents the case of a 25-year-old male with an infected tibial diaphyseal nonunion caused by a bone transport procedure carried out to treat an open fracture the patient had sustained 10 years before referral to our hospital. After an initial radical debridement, a bone defect was created, which was subsequently obliterated by placement of an antibiotic-impregnated cement spacer and Stimulan beads and covered by an anterolateral thigh flap. As the patient refused to wear an external fixator and his osseous biology was not amenable to a Masquelet procedure, a decision was made to apply the Capanna technique as soon as the infection healed. The second debridement resulted in a 12-cm-long bone defect that was filled with a tibial allograft and a vascularized fibular graft. At six months, the patient had regained full knee function and was able to bear his full weight, without pain or the need of support equipment. At one year, the bone had healed completely, the infection had subsided and the patient was able to resume his everyday activities. Although the Capanna technique was initially developed to reinforce reconstructions at risk of fracture or nonunion as a result of chemotherapy, its use in post-traumatic cases has been shown to be successful in a selected group of patents. Our study demonstrated that increasing the stability of a reconstruction with an allograft can accelerate the time to heal, and that using a vascularized fibular graft can enhance incorporation of the whole construct. It can be concluded that the Capanna technique is a valid treatment option for managing infected segmental bone defects in selected patients.

Synthesis of TiO2-Cu2+/CuI Nanocomposites and Evaluation of Antifungal and Cytotoxic Activity.

Fungal infections have become a significant public health concern due to their increasing recurrence and harmful effects on plants, animals, and humans. Opportunistic pathogens (among others from the genera Candida and Aspergillus) can be present in indoor air, becoming a risk for people with suppressed immune systems. Engineered nanomaterials are novel alternatives to traditional antifungal therapy. In this work, copper(I) iodide (CuI) and a copper-doped titanium dioxide-copper(I) iodide (TiO2-Cu2+/CuI) composite nanomaterials (NMs)-were synthesized and tested as antifungal agents. The materials were synthesized using sol-gel (TiO2-Cu2+) and co-precipitation (CuI) techniques. The resulting colloids were evaluated as antifungal agents against Candida parapsilosis and Aspergillus niger strains. The NMs were characterized by XRD, HRTEM, AFM, and DLS to evaluate their physicochemical properties. The NMs present a high size dispersion and different geometrical shapes of agglomerates. The antifungal capacity of the NMs by the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) was below 15 µg/mL against Candida parapsilosis and below 600 µg/mL against Aspergillus niger for both NMs. Holotomography microscopy showed that the NMs could penetrate cell membranes causing cell death through its rupture and reactive oxygen species (ROS) production. Cytotoxicity tests showed that NMs could be safe to use at low concentrations. The synthesized nanomaterials could be potential antifungal agents for biomedical or environmental applications.

Cobalt-Catalyzed Decarboxylative Allylations: Development and Mechanistic Studies.

In recent years, there has been a concerted drive to develop methods that are greener and more sustainable. Being an earth-abundant transition metal, cobalt offers an attractive substitute for commonly employed precious metal catalysts, though reactions engaging cobalt are still less developed. Herein, we report a method to achieve the decarboxylative allylation of nitrophenyl alkanes, nitroalkanes, and ketones employing cobalt. The reaction allows for the formation of various substituted allylated products in moderate-excellent yields with a broad scope. Additionally, the synthetic potential of the methodology is demonstrated by the transformation of products into versatile heterocyclic motifs. Mechanistic studies revealed an in situ activation of the Co(II)/dppBz precatalyst by the carboxylate salt to generate a Co(I)-species, which is presumed to be the active catalyst.

Seroprevalence and clinical characteristics of SARS-CoV-2 infection in children with cystic fibrosis.

BACKGROUND: People with cystic fibrosis (PwCF) have chronic lung disease and may be at increased risk of coronavirus disease 2019 (COVID-19)-related morbidity and mortality. This study aimed to determine seroprevalence and clinical characteristics of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in children with cystic fibrosis (CF), and to assess antibody responses following SARS-CoV-2 infection or vaccination. METHODS: Children and adolescents with CF followed at Seattle Children's Hospital were enrolled between July 20, 2020 and February 28, 2021. SARS-CoV-2 serostatus was determined on enrollment at 6 and 11 months (±2 months) for nucleocapsid and spike IgG. Participants completed intake and weekly surveys inquiring about SARS-CoV-2 exposures, viral/respiratory illnesses, and symptoms. RESULTS: Of 125 PwCF enrolled, 14 (11%) had positive SARS-CoV-2 antibodies consistent with recent or past infection. Seropositive participants were more likely to identify as Hispanic (29% vs. 8%, p = 0.04) and have pulmonary exacerbations requiring oral antibiotics in the year prior (71% vs. 41%, p = 0.04). Five seropositive individuals (35.7%) were asymptomatic, while six (42.9%) reported mild symptoms, primarily cough and nasal congestion. Antispike protein IgG levels were approximately 10-fold higher in participants following vaccination compared with participants who had natural infection alone (p < 0.0001) and resembled levels previously reported in the general population. CONCLUSIONS: A majority of PwCF have mild or no symptoms of SARS-CoV-2 making it difficult to distinguish from baseline respiratory symptoms. Hispanic PwCF may be disproportionately impacted, consistent with racial and ethnic COVID-19 disparities among the general US population. Vaccination in PwCF generated antibody responses similar to those previously reported in the general population.

Global blood pressure screening during the COVID-19 pandemic: results from the May Measurement Month 2021 campaign.

BACKGROUND: Raised blood pressure (BP) remains the biggest risk factor contributing to the global burden of disease and mortality, despite the COVID-19 pandemic. May Measurement Month (MMM), an annual global screening campaign aims to highlight the importance of BP measurement by evaluating global awareness, treatment and control rates among adults with hypertension. In 2021, we assessed the global burden of these rates during the COVID-19 pandemic. METHODS: Screening sites were set up in 54 countries between May and November 2021 and screenees were recruited by convenience sampling. Three sitting BPs were measured, and a questionnaire completed including demographic, lifestyle and clinical data. Hypertension was defined as a systolic BP at least 140 mmHg and/or a diastolic BP at least 90 mmHg (using the mean of the second and third readings) or taking antihypertensive medication. Multiple imputation was used to impute the average BP when readings were missing. RESULTS: Of the 642 057 screenees, 225 882 (35.2%) were classified as hypertensive, of whom 56.8% were aware, and 50.3% were on antihypertensive medication. Of those on treatment, 53.9% had controlled BP (<140/90 mmHg). Awareness, treatment and control rates were lower than those reported in MMM campaigns before the COVID-19 pandemic. Minimal changes were apparent among those testing positive for, or being vaccinated against COVID-19. Of those on antihypertensive medication, 94.7% reported no change in their treatment because of the COVID-19 pandemic. CONCLUSION: The high yield of untreated or inadequately treated hypertension in MMM 2021 confirms the need for systematic BP screening where it does not currently exist.

Assessment of Purity, Functionality, Stability, and Lipid Composition of Cyclofos-nAChR-Detergent Complexes from Torpedo californica Using Lipid Matrix and Macroscopic Electrophysiology.

The main objective of the present study was to find detergents that can maintain the functionality and stability of the Torpedo californica nicotinic acetylcholine receptor (Tc-nAChR). We examined the functionality, stability, and purity analysis of affinity-purified Tc-nAChR solubilized in detergents from the Cyclofos (CF) family [cyclofoscholine 4 (CF-4), cyclofoscholine 6 (CF-6), and cyclofloscholine 7 (CF-7)]. The functionality of the CF-Tc-nAChR-detergent complex (DC) was evaluated using the Two Electrode Voltage Clamp (TEVC) method. To assess stability, we used the florescence recovery after photobleaching (FRAP) in Lipidic Cubic Phase (LCP) methodology. We also performed a lipidomic analysis using Ultra-Performance Liquid Chromatography (UPLC) coupled to electrospray ionization mass spectrometry (ESI-MS/MS) to evaluate the lipid composition of the CF-Tc-nAChR-DCs. The CF-4-Tc-nAChR-DC displayed a robust macroscopic current (- 200 ± 60 nA); however, the CF-6-Tc-nAChR-DC and CF-7-Tc-nAChR-DC displayed significant reductions in the macroscopic currents. The CF-6-Tc-nAChR and CF-4-Tc-nAChR displayed higher fractional florescence recovery. Addition of cholesterol produced a mild enhancement of the mobile fraction on the CF-6-Tc-nAChR. The lipidomic analysis revealed that the CF-7-Tc-nAChR-DC displayed substantial delipidation, consistent with the lack of stability and functional response of this complex. Although the CF-6-nAChR-DC complex retained the largest amount of lipids, it showed a loss of six lipid species [SM(d16:1/18:0); PC(18:2/14:1); PC(14:0/18:1); PC(16:0/18:1); PC(20:5/20:4), and PC(20:4/20:5)] that are present in the CF-4-nAChR-DC. Overall, the CF-4-nAChR displayed robust functionality, significant stability, and the best purity among the three CF detergents; therefore, CF-4 is a suitable candidate to prepare Tc-nAChR crystals for structural studies.

Tuning electronic and magnetic properties through disorder in V2O5 nanoparticles.

We report on the synthesis and characterization of V2O5 nanoparticles grown using a sol-gel method at different calcination temperatures. We observed a surprising reduction in the optical band gap from 2.20 to 1.18 eV with increasing calcination temperature from 400 to 500 °C. Raman and X-Ray diffraction measurements indicated slight changes in the lattice parameters induced by the growth process. However, density functional theory calculations of the Rietveld-refined and pristine structures revealed that the observed optical gap reduction could not be explained by structural changes alone. By introducing oxygen vacancies to the refined structures, we could reproduce the reduction of the band gap. Our calculations also showed that the inclusion of oxygen vacancies at the vanadyl position creates a spin-polarized interband state that reduces the electronic band gap and promotes a magnetic response due to unpaired electrons. This prediction was confirmed by our magnetometry measurements, which exhibited a ferromagnetic-like behavior. Our findings suggest that oxygen vacancies play a crucial role in band gap reduction and the promotion of a ferromagnetic-like response in an otherwise paramagnetic material. This provides a promising route to engineer novel devices.

Juan Nicolás Dávalos y Betancourt, eminente bacteriólogo cubano

Entre las figuras cimeras de la microbiología en Cuba, se encuentra el Dr. Juan Nicolás Dávalos y Betancourt, conocido en su época como "el sabio que sueña con las bacterias", quien fue el primer médico cubano, dedicado a tiempo completo a la práctica de esta ciencia, en específico a la bacteriología. A pesar de esto, su vida y su obra no están suficientemente difundidas, por lo que este trabajo tiene como objetivo dar a conocer su legado, en un contexto histórico, social y científico, para que se conocido y valorado por las actuales y futuras generaciones de microbiólogos cubanos. Se realizó una investigación biográfica y se adicionan testimonios gráficos. La figura del Dr. Juan Nicolás Dávalos es destacada, no solo para la microbiología, como también para la ciencia en Cuba.

Among the leading figures of microbiology in Cuba, is Dr. Juan Nicolás Dávalos y Betancourt, known in his time as "the wise man who dreams of bacteria", who was the first Cuban doctor dedicated full-time to the practice of this science, specifically bacteriology. Despite this, his life and his work are not sufficiently disseminated, so this work aims to make his legacy known, in a historical, social and scientific context, so that it is known and valued by current and future generations. of Cuban microbiologists. A biographical investigation was carried out and graphic testimonies are added. Dr. Juan Nicolás Dávalos is outstanding, not only for microbiology, but also for science in Cuba.

Winter connectivity and leapfrog migration in a migratory passerine.

Technological advances in migratory tracking tools have revealed a remarkable diversity in migratory patterns. One such pattern is leapfrog migration, where individuals that breed further north migrate to locations further south. Here, we analyzed migration patterns in the Painted Bunting (Passerina ciris) using a genetic-based approach. We started by mapping patterns of genetic variation across geographic space (called a genoscape) using 386 individuals from 25 populations across the breeding range. We then genotyped an additional 230 samples from 31 migration stopover locations and 178 samples from 16 wintering locations to map patterns of migratory connectivity. Our analyses of genetic variation across the breeding range show the existence of four genetically distinct groups within the species: Eastern, Southwestern, Louisiana, and Central groups. Subsequent assignment of migrating and wintering birds to genetic groups illustrated that birds from the Central group migrated during the fall via western Mexico or southern Texas, spent the winter from northeastern Mexico to Panama, and migrated north via the Gulf Coast of Mexico. While Louisiana birds overlapped with Central birds on their spring migratory routes along the Gulf Coast, we found that Louisiana birds had a more restricted wintering distribution in the Yucatan Peninsula and Central America. Further estimation of the straight-line distance from the predicted breeding location to the wintering location revealed that individuals sampled at lower winter latitudes traveled to greater distances (i.e., the predicted breeding area was further north; p > .001), confirming that these species exhibit a leapfrog migration pattern. Overall, these results demonstrate the utility of a genoscape-based approach for identifying range-wide patterns of migratory connectivity such as leapfrog migration with a high degree of clarity.

Formulation of a Simulated Wastewater Influent Composition for Use in the Research of Technologies for Managing Wastewaters Generated during Manned Long-Term Space Exploration and Other Similar Situations-Literature-Based Composition Development.

The prospect of humans inhabiting planetary bodies is gaining interest among research and development communities, with the moon being considered as a transitory base camp and Mars the next planet humans will inhabit. NASA's Mission to Mars program is set to have humans inhabiting Mars within on-planet space camps by the Year 2030, which has tremendously increased research and development for space exploration-including research oriented toward human life support in long-term planetary lodging camps. The sustenance of human life on Mars will not be trivial due to the unavailability of an appropriate atmosphere and usable water. This situation requires a self-sustaining human life support system that can provide the basic needs such are breathable air, potable water, food, and energy. The feasibility of sending a payload with resources adequate to support long-term human inhabitation is not reasonable, which means every resource within a Mars space camp is valuable, including human-produced wastes. A biorefinery system that treats wastewater and can also produce valuable products such as oxygen, food, and energy offers a form of circular utilization of valuable resources. To conduct research for such systems requires a wastewater influent that is representative of the wastewater to be generated by the space crew within this isolated, confined environment, which is different from what is generated on Earth due to limited variability in diet, human activity, and lifestyle in this confined area. Collection of actual wastewater influent from an isolated environment supporting humans is challenging. Additionally, to ensure a safe working environment in the laboratory and avoid the imposed threat of handling actual human feces, the proposed synthetic, non-human feces containing wastewater influent formulation offers an easy-to-produce and safer-to-handle option. This paper reviews several synthetic wastewater compositions that have been formulated for space exploration purposes. None of the formulations were found to be realistic nor adequate for a space-camp-type scenario. Thus, the formulation of a synthetic wastewater for simulating a wastewater influent from a human space-based camp is proposed in this paper. In addition, the physical, chemical, and biodegradation characteristics of the final formulation designed are presented to illustrate the value of the proposed influent formulation.

Important advances in regenerative medicine. A vision to the future of ophthalmology / Avances importantes en medicina regenerativa. Una visión al futuro de la oftalmología

The treatment of corneal lesions continues to be a topic of great interest. However, despite the development of new technologies and due to the slow evolution and uncertain healing of corneal lesions, they still represent a public health problem since patients can be affected for life, affecting the family and the health system due to the costly and uncertain response to treatment. For this reason, the need arises to seek therapeutic alternatives to treat these patients.

El tratamiento de lesiones corneales sigue siendo un tema de gran interés. Pese al desarrollo de nuevas tecnologías y debido a la evolución lenta, e incierta cicatrización que tienen las lesiones corneales, estas todavía representan un problema de salud pública, ya que los pacientes pueden verse afectados de por vida afectando a la familia y al sistema de salud por lo costoso e incierta respuesta al tratamiento. Por esta razón, surge la necesidad de buscar alternativas terapéuticas para tratar a estos pacientes.

Chiral Magnons in Altermagnetic RuO_{2}.

Magnons in ferromagnets have one chirality, and typically are in the GHz range and have a quadratic dispersion near the zero wave vector. In contrast, magnons in antiferromagnets are commonly considered to have bands with both chiralities that are degenerate across the entire Brillouin zone, and to be in the THz range and to have a linear dispersion near the center of the Brillouin zone. Here we theoretically demonstrate a new class of magnons on a prototypical d-wave altermagnet RuO_{2} with the compensated antiparallel magnetic order in the ground state. Based on density-functional-theory calculations we observe that the THz-range magnon bands in RuO_{2} have an alternating chirality splitting, similar to the alternating spin splitting of the electronic bands, and a linear magnon dispersion near the zero wave vector. We also show that, overall, the Landau damping of this metallic altermagnet is suppressed due to the spin-split electronic structure, as compared to an artificial antiferromagnetic phase of the same RuO_{2} crystal with spin-degenerate electronic bands and chirality-degenerate magnon bands.