Exploring near-infrared autofluorescence properties in parathyroid tissue: an analysis of fresh and paraffin-embedded thyroidectomy specimens.

Significance: Near-infrared autofluorescence (NIRAF) utilizes the natural autofluorescence of parathyroid glands (PGs) to improve their identification during thyroid surgeries, reducing the risk of inadvertent removal and subsequent complications such as hypoparathyroidism. This study evaluates NIRAF's effectiveness in real-world surgical settings, highlighting its potential to enhance surgical outcomes and patient safety. Aim: We evaluate the effectiveness of NIRAF in detecting PGs during thyroidectomy and central neck dissection and investigate autofluorescence characteristics in both fresh and paraffin-embedded tissues. Approach: We included 101 patients diagnosed with papillary thyroid cancer who underwent surgeries in 2022 and 2023. We assessed NIRAF's ability to locate PGs, confirmed via parathyroid hormone assays, and involved both junior and senior surgeons. We measured the accuracy, speed, and agreement levels of each method and analyzed autofluorescence persistence and variation over 10 years, alongside the expression of calcium-sensing receptor (CaSR) and vitamin D. Results: NIRAF demonstrated a sensitivity of 89.5% and a negative predictive value of 89.1%. However, its specificity and positive predictive value (PPV) were 61.2% and 62.3%, respectively, which are considered lower. The kappa statistic indicated moderate to substantial agreement (kappa = 0.478; P < 0.001 ). Senior surgeons achieved high specificity (86.2%) and PPV (85.3%), with substantial agreement (kappa = 0.847; P < 0.001 ). In contrast, junior surgeons displayed the lowest kappa statistic among the groups, indicating minimal agreement (kappa = 0.381; P < 0.001 ). Common errors in NIRAF included interference from brown fat and eschar. In addition, paraffin-embedded samples retained stable autofluorescence over 10 years, showing no significant correlation with CaSR and vitamin D levels. Conclusions: NIRAF is useful for PG identification in thyroid and neck surgeries, enhancing efficiency and reducing inadvertent PG removals. The stability of autofluorescence in paraffin samples suggests its long-term viability, with false positives providing insights for further improvements in NIRAF technology.

SiO 2 Induces Iron Overload and Ferroptosis in Cardiomyocytes in a Silicosis Mouse Model.

Objective: The aim of this study was to explore the role and mechanism of ferroptosis in SiO 2-induced cardiac injury using a mouse model. Methods: Male C57BL/6 mice were intratracheally instilled with SiO 2 to create a silicosis model. Ferrostatin-1 (Fer-1) and deferoxamine (DFO) were used to suppress ferroptosis. Serum biomarkers, oxidative stress markers, histopathology, iron content, and the expression of ferroptosis-related proteins were assessed. Results: SiO 2 altered serum cardiac injury biomarkers, oxidative stress, iron accumulation, and ferroptosis markers in myocardial tissue. Fer-1 and DFO reduced lipid peroxidation and iron overload, and alleviated SiO 2-induced mitochondrial damage and myocardial injury. SiO 2 inhibited Nuclear factor erythroid 2-related factor 2 (Nrf2) and its downstream antioxidant genes, while Fer-1 more potently reactivated Nrf2 compared to DFO. Conclusion: Iron overload-induced ferroptosis contributes to SiO 2-induced cardiac injury. Targeting ferroptosis by reducing iron accumulation or inhibiting lipid peroxidation protects against SiO 2 cardiotoxicity, potentially via modulation of the Nrf2 pathway.

Novel coumarin-piperazine-2(5H)-furanone hybrids as potential anti-lung cancer agents: Synthesis, biological evaluation and molecular docking studies.

Novel coumarin-piperazine-2(5H)-furanone hybrids 5a-l were efficiently synthesized by introducing a furanone scaffold into coumarin using piperazine as a linker. The cytotoxicity of all hybrids 5a-l were evaluated by MTT assay on human lung cancer A549 cells and normal human lung fibroblast WI-38 cells with cytarabine (CAR) as a positive control. Hybrid 5l (IC50 = 11.28 µM) was the most toxic to A549 cells, 18-fold more toxic than the reference CAR (IC50 = 202.57 µM). Moreover, hybrid 5l (IC50 = 411.93 µM) was less toxic to WI-38 cells, with a much higher selectivity (5l, SI ≈ 37, WI-38/A549) than CAR (SI ≈ 2). Structure-activity relationship analysis showed that both the cytotoxicity against A549 cells and selectivity (WI-38/A549) were greatly improved when the bornyl group was incorporated in the hybrids (5c, 5f, 5i and 5l). Further, hybrid 5l was more toxic and selective against four types of human lung cancer cells (A549, Calu-1, PC-9 and H460; IC50 = 5.72-45.46 µM; SI ≈ 9-72) than three other types of human cancer cells (SK-BR-3, 786-O and SK-OV-3, IC50 = 39.07-130.82 µM; SI ≈ 0-2), showing remarkable specificity. In particular, hybrid 5l (IC50 = 5.72 µM) showed the highest cytotoxicity against H460 cells with the highest selectivity of up to 72 (WI-38/H460). Flow cytometric analysis showed that hybrid 5l induced apoptosis in H460 cells in a concentration-dependent manner. Molecular docking studies revealed a high binding affinity of hybrid 5l with CDK2 protein. Hybrid 5l is expected to be a leading candidate for anti-lung cancer agents.

Association between tobacco exposure and bladder cancer recurrence: A systematic review and meta-analysis.

BACKGROUND: However, the connection between smoking and the prognosis of patients with bladder cancer remains unclear. AIM: To determine whether smoking is linked to the recurrence and progression of bladder cancer. METHODS: As of July 20, 2022, relevant English-language research was identified by searching PubMed, the Web of Science, and the Cochrane Library. We pooled the available data from the included studies using a random effects model. Subgroup analysis and sensitivity analysis were also conducted. RESULTS: A total of 12 studies were included in this meta-analysis. The combined analysis revealed that tobacco exposure was associated with a significantly greater recurrence rate than nonsmoking status [odd ratios (OR) = 1.76, 95%CI: 1.84-2.93], and the progression of bladder cancer was significantly greater in smokers than in nonsmokers (OR = 1.21, 95%CI: 1.02-1.44). Stratified analysis further revealed that current smokers were more likely to experience relapse than never-smokers were (OR = 1.85, 95%CI: 1.11-3.07). Former smokers also had a greater risk of relapse than did never-smokers (OR = 1.73, 95%CI: 1.09-2.73). Subgroup analysis indicated that non-Caucasians may be more susceptible to bladder cancer recurrence than Caucasians are (OR = 2.13, 95%CI: 1.74-2.61). CONCLUSION: This meta-analysis revealed that tobacco exposure may be a significant risk factor for both the recurrence and progression of bladder cancer.

Unraveling the biological link between diabetes mellitus and prostate cancer: Insights and implications.

This article is a comprehensive study based on research on the connection between diabetes mellitus (DM) and prostate cancer (PCa). It investigates the potential role of DM as an independent risk factor for PCa, delving into the biological links, including insulin resistance and hormonal changes. The paper critically analyzes previous studies that have shown varying results and introduces mendelian randomization as a method for establishing causality. It emphasizes the importance of early DM screening and lifestyle modifications in preventing PCa, and proposes future research directions for further under-standing the DM - PCa relationship.

Application of data-driven blended online-offline teaching in medicinal chemistry for pharmacy students: a randomized comparison.

BACKGROUND: The purpose of this study was to evaluate the effectiveness and efficiency of implementing a data-driven blended online-offline (DDBOO) teaching approach in the medicinal chemistry course. METHODS: A total of 118 third-year students majoring in pharmacy were enrolled from September 2021 to January 2022. The participants were randomly assigned to either the DDBOO teaching group or the traditional lecture-based learning (LBL) group for medicinal chemistry. Pre- and post-class quizzes were administered, along with an anonymous questionnaire distributed to both groups to assess students' perceptions and experiences. RESULTS: There was no significant difference in the pre-class quiz scores between the DDBOO and LBL groups (T=-0.637, P = 0.822). However, after class, the mean quiz score of the DDBOO group was significantly higher than that of the LBL group (T = 3.742, P < 0.001). Furthermore, the scores for learning interest, learning motivation, self-learning skill, mastery of basic knowledge, teamwork skills, problem-solving ability, innovation ability, and satisfaction, as measured by the questionnaire, were significantly higher in the DDBOO group than in the traditional group (all P < 0.05). CONCLUSION: The DDBOO teaching method effectively enhances students' academic performance and satisfaction. Further research and promotion of this approach are warranted.

Ultralow-Frequency Tip-Enhanced Raman Scattering Discovers Nanoscale Radial Breathing Mode on Strained 2D Semiconductors.

Collective excitations including plasmons, magnons, and layer-breathing vibration modes emerge at an ultralow frequency (<1 THz) and are crucial for understanding van der Waals materials. Strain at the nanoscale can drastically change the property of van der Waals materials and create localized states like quantum emitters. However, it remains unclear how nanoscale strain changes collective excitations. Herein, ultralow-frequency tip-enhanced Raman spectroscopy (TERS) with sub-10 nm resolution under ambient conditions is developed to explore the localized collective excitation on monolayer semiconductors with nanoscale strains. A new vibrational mode is discovered at around 12 cm-1 (0.36 THz) on monolayer MoSe2 nanobubbles and it is identified as the radial breathing mode (RBM) of the curved monolayer. The correlation is determined between the RBM frequency and the strain by simultaneously performing deterministic nanoindentation and TERS measurement on monolayer MoSe2. The generality of the RBM in nanoscale curved monolayer WSe2 and bilayer MoSe2 is demonstrated. Using the RBM frequency, the strain of the monolayer MoSe2 on the nanoscale can be mapped. Such an ultralow-frequency vibration from curved van der Waals materials provides a new approach to study nanoscale strains and points to more localized collective excitations to be discovered at the nanoscale.

Effects of Kv1.3 knockout on pyramidal neuron excitability and synaptic plasticity in piriform cortex of mice.

Kv1.3 belongs to the voltage-gated potassium (Kv) channel family, which is widely expressed in the central nervous system and associated with a variety of neuropsychiatric disorders. Kv1.3 is highly expressed in the olfactory bulb and piriform cortex and involved in the process of odor perception and nutrient metabolism in animals. Previous studies have explored the function of Kv1.3 in olfactory bulb, while the role of Kv1.3 in piriform cortex was less known. In this study, we investigated the neuronal changes of piriform cortex and feeding behavior after smell stimulation, thus revealing a link between the olfactory sensation and body weight in Kv1.3 KO mice. Coronal slices including the anterior piriform cortex were prepared, whole-cell recording and Ca2+ imaging of pyramidal neurons were conducted. We showed that the firing frequency evoked by depolarization pulses and Ca2+ influx evoked by high K+ solution were significantly increased in pyramidal neurons of Kv1.3 knockout (KO) mice compared to WT mice. Western blotting and immunofluorescence analyses revealed that the downstream signaling molecules CaMKII and PKCα were activated in piriform cortex of Kv1.3 KO mice. Pyramidal neurons in Kv1.3 KO mice exhibited significantly reduced paired-pulse ratio and increased presynaptic Cav2.1 expression, proving that the presynaptic vesicle release might be elevated by Ca2+ influx. Using Golgi staining, we found significantly increased dendritic spine density of pyramidal neurons in Kv1.3 KO mice, supporting the stronger postsynaptic responses in these neurons. In olfactory recognition and feeding behavior tests, we showed that Kv1.3 conditional knockout or cannula injection of 5-(4-phenoxybutoxy) psoralen, a Kv1.3 channel blocker, in piriform cortex both elevated the olfactory recognition index and altered the feeding behavior in mice. In summary, Kv1.3 is a key molecule in regulating neuronal activity of the piriform cortex, which may lay a foundation for the treatment of diseases related to piriform cortex and olfactory detection.

A near-infrared fluorescent probe for imaging peroxynitrite levels in paw edema mice and drug evaluation.

A near-infrared fluorescent probe (TX-P) for detecting peroxynitrite is constructed. The probe has a near-infrared emission (725 nm), large Stokes shift (125 nm) and excellent sensitivity and selectivity. In addition, TX-P can be used to visualize ONOO- in living cells, image ONOO- in paw edema mice and evaluate anti-inflammatory drugs.

Safety and hematological toxicities of PARP inhibitors in patients with cancer: a systematic review of randomized controlled trials and a pharmacovigilance analysis.

INTRODUCTION: This study aimed to estimate the toxicities of PARP inhibitors (PARPis), based on randomized controlled trials (RCTs) and the FDA Adverse Event Reporting System (FAERS) database. METHODS: Four electronic databases were searched from inception to 16 April 2024, for RCTs of approved PARPis. The primary and secondary outcomes were grade 3-5 adverse events (AEs) and grade 3-5 hematological AE, respectively. We conducted network meta-analyses to calculate the relative risks (RRs) and 95% confidence intervals (CIs) of outcomes. A disproportionality analysis was conducted to estimate the signals of hematological AEs associated with PARPis from the FAERS database. RESULTS: Overall, 27 RCTs involving 11,067 patients with cancer were included. Olaparib had the best safety profile for any grade 3-5 AEs and hematological AEs among four approved PARPis. Olaparib did not increase the risk of thrombocytopenia (RR: 1.48; 95%CI: 0.64-3.39), but other PARPis did. Furthermore 14,780 hematological AE reports associated with PARPis were identified in the FAERS database, and all PARPis were associated with strong hematological AE signals. Hematological AEs mainly occurred within the first 3 months (80.84%) after PARPi initiation. CONCLUSION: Olaparib had the best safety profile among five PARPis. PARPi-associated hematological AEs mainly occurred within the first 3 months. REGISTRATION: PROSPERO (CRD42022385274).

T7 peptide-mediated co-delivery platform overcoming multidrug-resistant breast cancer: In vitro and in vivo evaluation.

P-glycoprotein (P-gp) overexpressed mutidrug resistance (MDR) is currently a key factor limiting the effectiveness of breast cancer chemotherapy. Systemic administration based on P-gp-associated mechanism leads to severe toxic side effects. Here, we designed a T7 peptide-modified mixed liposome (T7-MLP@DTX/SchB) that, by active targeting co-delivering chemotherapeutic agents and P-gp inhibitors, harnessed synergistic effects to improve the treatment of MDR breast cancer. This study established drug-resistant cell models and animal models. Subsequently, comprehensive evaluations involving cell uptake, cell apoptosis, cellular toxicity assays, in vivo tumor-targeting capability, and anti-tumor activity assays were conducted to assess the drug resistance reversal effects of T7-MLP@DTX/SchB. Additionally, a systematic assessment of the biosafety profile of T7-MLP@DTX/SchB was executed, including blood profiles, biochemical markers, and histopathological examination. It was found that this co-delivery strategy successfully exerted the synergistic effects, since there was a significant tumor growth inhibitory effect on multidrug-resistant breast cancer. Targeted modification with T7 peptide enhanced the therapeutic efficacy remarkably, while vastly ameliorating the biocompatibility compared to free drugs. The intriguing results supported the promising potential use of T7-MLP@DTX/SchB in overcoming MDR breast cancer treatment.

Electroacupuncture modulates abnormal brain connectivity after ischemia reperfusion injury in rats: A graph theory-based approach.

BACKGROUND: Electroacupuncture (EA) has been shown to facilitate brain plasticity-related functional recovery following ischemic stroke. The functional magnetic resonance imaging technique can be used to determine the range and mode of brain activation. After stroke, EA has been shown to alter brain connectivity, whereas EA's effect on brain network topology properties remains unclear. An evaluation of EA's effects on global and nodal topological properties in rats with ischemia reperfusion was conducted in this study. METHODS AND RESULTS: There were three groups of adult male Sprague-Dawley rats: sham-operated group (sham group), middle cerebral artery occlusion/reperfusion (MCAO/R) group, and MCAO/R plus EA (MCAO/R + EA) group. The differences in global and nodal topological properties, including shortest path length, global efficiency, local efficiency, small-worldness index, betweenness centrality (BC), and degree centrality (DC) were estimated. Graphical network analyses revealed that, as compared with the sham group, the MCAO/R group demonstrated a decrease in BC value in the right ventral hippocampus and increased BC in the right substantia nigra, accompanied by increased DC in the left nucleus accumbens shell (AcbSh). The BC was increased in the right hippocampus ventral and decreased in the right substantia nigra after EA intervention, and MCAO/R + EA resulted in a decreased DC in left AcbSh compared to MCAO/R. CONCLUSION: The results of this study provide a potential basis for EA to promote cognitive and motor function recovery after ischemic stroke.

Mechanisms of myeloid-derived suppressor cell-mediated immunosuppression in colorectal cancer and related therapies.

Severe immunosuppression is a hallmark of colorectal cancer (CRC). Myeloid-derived suppressor cells (MDSCs), one of the most abundant components of the tumor stroma, play an important role in the invasion, metastasis, and immune escape of CRC. MDSCs create an immunosuppressive microenvironment by inhibiting the proliferation and activation of immunoreactive cells, including T and natural killer cells, as well as by inducing the proliferation of immunosuppressive cells, such as regulatory T cells and tumor-associated macrophages, which, in turn, promote the growth of cancer cells. Thus, MDSCs are key contributors to the emergence of an immunosuppressive microenvironment in CRC and play an important role in the breakdown of antitumor immunity. In this narrative review, we explore the mechanisms through which MDSCs contribute to the immunosuppressive microenvironment, the current therapeutic approaches and technologies targeting MDSCs, and the therapeutic potential of modulating MDSCs in CRC treatment. This study provides ideas and methods to enhance survival rates in patients with CRC.

Efficacy and safety of Yangxinshi tablet for chronic heart failure: A systematic review and meta-analysis.

BACKGROUND: The specific benefits of Yangxinshi tablet (YXST) in the treating chronic heart failure (CHF) remain uncertain. AIM: To systematically evaluate the efficacy and safety of YXST in the treatment of CHF. METHODS: Randomized controlled trials (RCTs) investigating YXST for CHF treatment were retrieved from eight public databases up to November 2023. Meta-analyses of the included clinical studies were conducted using Review Manager 5.3. RESULTS: Twenty RCTs and 1845 patients were included. The meta-analysis results showed that the YXST combination group, compared to the conventional drug group, significantly increased the clinical efficacy rate by 23% [relative risk (RR) = 1.23, 95%CI: 1.17-1.29], P < 0.00001), left ventricular ejection fraction by 6.69% [mean difference (MD) = 6.69, 95%CI: 4.42-8.95, P < 0.00001] and 6-min walk test by 49.82 m (MD = 49.82, 95%C: 38.84-60.80, P < 0.00001), and reduced N-terminal pro-B-type natriuretic peptide by 1.03 ng/L [standardized MD (SMD) = -1.03, 95%CI: -1.32 to -0.74, P < 0.00001], brain natriuretic peptide by 80.95 ng/L (MD = -80.95, 95%CI: -143.31 to -18.59, P = 0.01), left ventricular end-diastolic diameter by 3.92 mm (MD = -3.92, 95%CI: -5.06 to -2.78, P < 0.00001), and left ventricular end-systolic diameter by 4.34 mm (MD = -4.34, 95%CI: -6.22 to -2.47, P < 0.00001). Regarding safety, neither group reported any serious adverse events during treatment (RR = 0.54, 95%CI: 0.15-1.90, P = 0.33). In addition, Egger's test results indicated no significant publication bias (P = 0.557). CONCLUSION: YXST effectively improves clinical symptoms and cardiac function in patients with CHF while maintaining a favorable safety profile, suggesting its potential as a therapeutic strategy for CHF.

Great genetic diversity of vector-borne bacteria and protozoan in wild rodents from Guangxi, China.

BACKGROUND: Rodents are recognized as the hosts of many vector-borne bacteria and protozoan parasites and play an important role in their transmission and maintenance. Intensive studies have focused on their infections in vectors, especially in ticks, however, vector-borne bacterial and protozoan infections in rodents are poorly understood although human cases presenting with fever may due to their infection have been found. METHODS: From May to October 2019, 192 wild rodents were trapped in wild environment of Guangxi Province, and the spleen samples were collected to reveal the presence of vector-borne bacterial and protozoan infections in them. The microorganisms in rodents were identified by detecting their DNA using (semi-)nested PCR. All the PCR products of the expected size were subjected to sequencing, and then analyzed by BLASTn. Furthermore, all the recovered sequences were subjected to nucleotide identity and phylogenetic analyses. RESULTS: As a result, 192 rodents representing seven species were captured, and Bandicota indica were the dominant species, followed by Rattus andamanensis. Based on the (semi-)nested PCR, our results suggested that Anaplasma bovis, Anaplasma capra, Anaplasma ovis, Anaplasma phagocytophilum, "Candidatus Neoehrlichia mikurensis", "Candidatus E. hainanensis", "Candidatus E. zunyiensis", three uncultured Ehrlichia spp., Bartonella coopersplainsensis, Bartonella tribocorum, Bartonella rattimassiliensis, Bartonella silvatica, two uncultured Bartonella spp., Babesia microti and diverse Hepatozoon were identified in six rodent species. More importantly, six species (including two Anaplasma, two Bartonella, "Ca. N. mikurensis" and Bab. microti) are zoonotic pathogens except Anaplasma bovis and Anaplasma ovis with zoonotic potential. Furthermore, dual infection was observed between different microorganisms, and the most common type of co-infection is between "Ca. N. mikurensis" and other microorganisms. Additionally, potential novel Bartonella species and Hepatozoon species demonstrated the presence of more diverse rodent-associated Bartonella and Hepatozoon. CONCLUSIONS: The results in this work indicated great genetic diversity of vector-borne infections in wild rodents, and highlighted the potential risk of human pathogens transmitted from rodents to humans through vectors.

N-octylpyridine hydrogen sulphate ionic liquid for multifunctional fluorescent response in different solvents.

Ionic liquids (ILs) have attracted considerable interest in the last two decades owing to their unique fluorescent properties. Herein, N-octylpyridine hydrogen sulphate ([OP]HSO4) was synthesised and characterised using 1H NMR and infrared spectroscopies. In addition, the fluorescence spectra of [OP]HSO4 in water, methanol, ethanol and acetonitrile were studied. In a single solvent, as the concentration of the solvent (methanol, ethanol or acetonitrile) increases, the fluorescence intensity of the IL first increases and then decreases. A similar trend was observed in their mixed solvents with water. Moreover, the fluorescence intensity of [OP]HSO4 decreases with increasing temperature. A fluorescence intensity reduction of only 4.46% for [OP]HSO4 after continuous scanning for 40 cycles under the maximum excitation state was analysed. The lack of photobleaching observed in [OP]HSO4 indicates its good photobleaching resistance.

Anaplasma, Bartonella, and Rickettsia infections in Daurian ground squirrels (Spermophilus dauricus), Hebei, China.

Rodents have been confirmed as hosts of various vector-borne zoonotic pathogens and are important for the maintenance of these microbes in nature. However, surveillance for zoonotic pathogens is limited for many wild rodent species in China, so our knowledge of pathogen ecology, genetic diversity, and the risk of cross-species transmission to humans is limited. In this study, 165 spleen samples of Daurian ground squirrels (Spermophilus dauricus) were collected from Weichang Manchu and the Mongolian Autonomous County of Hebei Province, China, and Rickettsia, Bartonella, and Anaplasma were identified by DNA detection using polymerase chain reaction (PCR). Sequence analysis identified eight bacterial pathogens: R. raoultii, R. sibirica, Candidatus R. longicornii, B. washoensis, B. grahamii, B. jaculi, A. capra, and Candidatus Anaplasma cinensis. Co-infection of B. grahamii and R. raoultii in one sample was observed. Our results demonstrated the genetic diversity of bacteria in Daurian ground squirrels and contributed to the distribution of these pathogens. Six species, A. capra, R. raoultii, R. sibirica, Candidatus R. longicornii, B. washoensis, and B. grahamii, are known to be pathogenic to humans, indicating a potential public health risk to the local human population, especially to herders who frequently have close contact with Daurian ground squirrels and are thus exposed to their ectoparasites.

Methylomonas defluvii sp. nov., a type I methane-oxidizing bacterium from a secondary sedimentation tank of a wastewater treatment plant.

An aerobic methanotroph was isolated from a secondary sedimentation tank of a wastewater treatment plant and designated strain OY6T. Cells of OY6T were Gram-stain-negative, pink-pigmented, motile rods and contained an intracytoplasmic membrane structure typical of type I methanotrophs. OY6T could grow at a pH range of 4.5-7.5 (optimum pH 6.5) and at temperatures ranging from 20 °C to 37 °C (optimum 30 °C). The major cellular fatty acids were C14 : 0, C16 : 1ω7c/C16 : 1ω6c and C16 : 1ω5c; the predominant respiratory quinone was MQ-8. The genome size was 5.41 Mbp with a DNA G+C content of 51.7 mol%. OY6T represents a member of the family Methylococcaceae of the class Gammaproteobacteria and displayed 95.74-99.64 % 16S rRNA gene sequence similarity to the type strains of species of the genus Methylomonas. Whole-genome comparisons based on average nucleotide identity (ANI) and digital DNA-DNA hybridisation (dDDH) confirmed that OY6T should be classified as representing a novel species. The most closely related type strain was Methylomonas fluvii EbBT, with 16S rRNA gene sequence similarity, ANI by blast (ANIb), ANI by MUMmer (ANIm) and dDDH values of 99.64, 90.46, 91.92 and 44.5 %, respectively. OY6T possessed genes encoding both the particulate methane monooxygenase enzyme and the soluble methane monooxygenase enzyme. It grew only on methane or methanol as carbon sources. On the basis of phenotypic, genetic and phylogenetic data, strain OY6T represents a novel species within the genus Methylomonas for which the name Methylomonas defluvii sp. nov. is proposed, with strain OY6T (=GDMCC 1.4114T=KCTC 8159T=LMG 33371T) as the type strain.