Pet Animals Were Infected with SARS-CoV-2 from Their Owners Who Developed COVID-19: Case Series Study.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among pets owned by coronavirus disease 2019 (COVID-19) patients has been reported around the world. However, how often the animals are exposed to SARS-CoV-2 by their owners is still unclear. We have collected swab samples from COVID-19 patients' pets and performed real-time RT-PCR to detect the viral genome. In total, 8 of 53 dogs (15.1%) and 5 of 34 cats (14.7%) tested positive for the SARS-CoV-2 N gene. The result of a virus neutralization (VN) test also showed VN antibodies in four cats and six dogs. Our results indicate that the virus often passed from infected owners to their pets, which then excreted the virus despite having no or mild clinical signs.

Characterisation of canine CD34+/CD45 diminished cells by colony-forming unit assay and transcriptome analysis.

Haematopoietic stem and progenitor cells (HSPCs) are used for transplantation to reconstruct the haematopoietic pathways in humans receiving severe chemotherapy. However, the characteristics of canine HSPCs, such as specific surface antigens and gene expression profiles, are still unclear. This study aimed to characterise the haematopoietic ability and gene expression profiles of canine bone marrow HSPCs in healthy dogs. In this study, the CD34 positive (CD34+) cells were defined as classical HSPCs, CD34+/CD45 diminished (CD45dim) cells as more enriched HSPCs, and whole viable cells as controls. Haematopoietic abilities and gene expression profiles were evaluated using a colony-forming unit assay and RNA-sequencing analysis. Canine CD34+/CD45dim cells exhibited a significantly higher haematopoietic colony formation ability and expressed more similarity in the gene expression profiles to human and mouse HSPCs than those of the other cell fractions. Furthermore, the canine CD34+/CD45dim cells expressed candidate cell surface antigens necessary to define the canine haematopoietic hierarchy roadmap. These results indicate that the canine CD34+/CD45dim cells express the HSPC characteristics more than the other cell fractions, thereby suggesting that these cells have the potential to be used for studying haematopoietic stem cells in dogs.

Improvement of anemia in five dogs with nonregenerative anemia treated with allogeneic adipose-derived stem cells.

Background: Nonregenerative anemia is occasionally seen in dogs and can be caused by many factors, among which nonregenerative immune-mediated anemia (NRIMA) and pure red cell anemia are relatively common causes. These are thought to be caused by immune-mediated destruction of the erythroid lineage and are treated with immunosuppressive drugs, but some of them are refractory or recurrent, so new treatments are needed. Objectives: To examine the efficacy of allogeneic adipose-derived stem cells (ADSCs) for the treatment of nonregerative anemia in dogs. Methods: ADSCs were administered to total five nonregenerative anemia cases; two NRIMA cases and two suspected NRIMA cases that were refractory to immunosuppressive agents, and one NRIMA case that has not been treated with immunosuppressive agents. Results: In all cases, anemia was improved, and blood transfusion was no longer necessary. Conclusions: This study suggests that allogeneic ADSCs may be one of the rescue therapies for the refractory immune-mediated anemia in dogs.

Peripheral endothelial function can be improved by daily consumption of water containing over 7 ppm of dissolved hydrogen: A randomized controlled trial.

BACKGROUND: Measurement of the reactive hyperemia index (RHI) using peripheral arterial tonometry (PAT) has shown benefits in the evaluation of vascular endothelial function and prediction of cardiovascular disease prognosis. Thus, it is important to examine the factors that promote the RHI. In this study, we aimed to investigate the effect of molecular hydrogen (H2) on reactive hyperemia-PAT of the small arteries of fingers in healthy people. METHODS: To determine the efficacy of H2 for improving peripheral vascular endothelial function, water containing high H2 concentrations was administered to participants, and the Ln_RHI was measured in the finger vasculature. Sixty-eight volunteers were randomly divided into two groups: a placebo group (n = 34) that drank molecular nitrogen (N2)-containing water and a high H2 group (n = 34) that drank high H2 water (containing 7 ppm of H2: 3.5 mg H2 in 500-mL water). The Ln_RHI was measured before ingesting the placebo or high H2 water, 1 h and 24 h after the first ingestion, and 14 days after daily ingestion of high H2 water or the placebo. The mixed effects model for repeated measures was used in data analysis. RESULTS: The high H2 group had a significantly greater improvement in Ln_RHI than the placebo group. Ln_RHI improved by 22.2% (p<0.05) at 24 h after the first ingestion of high H2 water and by 25.4% (p<0.05) after the daily consumption of high H2 water for 2 weeks. CONCLUSIONS: Daily consumption of high H2 water improved the endothelial function of the arteries or arterioles assessed by the PAT test. The results suggest that the continuous consumption of high H2 water contributes to improved cardiovascular health.

Molecular hydrogen suppresses superoxide generation in the mitochondrial complex I and reduced mitochondrial membrane potential.

Molecular hydrogen (H2) is recognized as a medical gas applicable to numerous diseases including neurodegenerative diseases, metabolic disorders, and rheumatoid arthritis. Although the efficacy of H2 is reportedly attributed to its scavenging capability against the hydroxyl radical, the mechanisms underlying its therapeutic efficacy are not fully understood. Herein, we estimated the role of H2 in the energy converting system of the mitochondria, the source of reactive oxygen species. To investigate the effects of H2 on mitochondrial function, direction of electron flow, superoxide generation, and mitochondrial membrane potential were investigated. Forward electron transport (FET) or reverse electron transport (RET) was assessed by monitoring the decrease or increase of ß-nicotinamide adenine dinucleotide hydrate (NADH, - or +, µM, respectively) in the presence of ß-nicotinamide adenine dinucleotide (NAD+) and/or succinate in the isolated mitochondria. H2O2 converted from superoxide by superoxide dismutase (SOD) was measured to estimate electron leakage in the mitochondria. The effects of H2 on mitochondrial membrane potential were observed by staining cells with the fluorescence probe, teramethylrhodamine ethyl ester (TMRE). Despite the absence of succinate, a distinct RET was observed (from +0.0313 ± 0.0106 µM to +1.20 ± 0.302 µM) by adding 25 µM H2. In the presence of 5 µM NADH, RET by succinate inverted to FET from +1.62 ± 0.358 µM to -1.83 ± 0.191 µM, accompanied by a suppression of superoxide generated predominantly from complex I by 51.1%. H2 solely reduced mitochondrial membrane potential of the cultured cells by 11.3% as assessed by TMRE. The direction of electron flow was altered by H2 depending on the NAD+/NADH ratio, accompanied by suppression of superoxide generation H2 could suppress superoxide generation in complex I in vitro and reduce membrane potential in vivo. H2 may also neutralize semiquinone radicals to reduce superoxide produced in complex III. H2 may function as a rectifier of the electron flow affecting the mitochondrial membrane potential to suppress oxidative damage in mitochondria.

Ultrasonic-induced tonic convulsion in rats after subchronic exposure to perfluorooctane sulfonate (PFOS).

Perfluorooctane sulfonate (PFOS) is one of the persistent organic pollutants distributed widely in the global environment. We have found that a single oral administration of PFOS induced tonic convulsion in mice and rats when a brief ultrasonic stimulus was applied to the animals. The aim of this study is to examine whether the neurotoxicity is caused by subchronic dietary exposure to PFOS. Rats were treated with dietary PFOS at 0, 2, 8, 32 and 128 ppm for 13 weeks. Animals were carefully observed for pharmacotoxic signs and responses to the ultrasonic stimulus applied biweekly. PFOS increased liver weight and decreased food consumption and body weight. PFOS concentrations in the serum, brain, liver and kidney were increased almost proportional to its total dose, although the ratios of PFOS concentrations in tissues to total doses in the group treated with the highest concentration were a little lower. The ranges of relative concentrations in the brain, liver and kidney to serum concentration were 0.13 to 0.24, 2.7 to 6.3 and 0.82 to 1.6, respectively. PFOS alone did not cause any neurotoxic symptoms; however, 5 rats out of 6 showed tonic convulsion in the 6th week when ultrasonic stimulus was applied to the 128 ppm rats with the total PFOS dose of 338 mg/kg. The ultrasonic stimulus did not cause convulsion in the other groups. Histopathological examination including electron microscopic examination could not detect any abnormality in the brain. Because the acute oral dose of PFOS causing the convulsion was 250 mg/kg (Sato et al., 2009), the convulsion induced by PFOS seemed to depend on its total dose regardless of treatment schedule.

Perfluorooctanoic acid (PFOA) but not perfluorooctane sulfonate (PFOS) showed DNA damage in comet assay on Paramecium caudatum.

Persistent perfluorinated organic compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) are distributed widely in the global environment including wildlife and human. In this study, we investigated the genotoxicity of PFOS and PFOA using the novel in vivo comet assay developed for Paramecium caudatum. For the comet assay, large nuclei squeezed out of the paramecia with 0.25 M sucrose containing 0.6% Triton X-100 were embedded in a layer of agarose gel placed over the slide glass. N-methyl-N´-nitro-N-nitrosoguanidine (MNNG) and 2-aminoanthracene (2-AA) were successfully used for positive controls. Productions of 8-hydroxydeoxyguanosine (8-OH-dG) and intracellular reactive oxygen species (ROS) were also measured in paramecia. PFOS did not cause DNA damage on any conditions examined. On the other hand, 12 and 24 hr exposure to PFOA (100 µM) increased DNA migration in electrophoresis condition at pH 13, but not at pH 12.1, suggesting that the DNA damage may be alkali labile site (such as apurinic/apyrimidinic (AP) site). Exposure of paramecia to 100 µM PFOA for 1, 3 and 24 hr and to 10 µM PFOA for 24 hr significantly increased intracellular ROS. Under the same condition, however, 8-OH-dG level was not affected by PFOA. The PFOA-induced DNA damage was not abolished by the application of 100 µM GSH which completely inhibited the increase of intracellular ROS. In conclusion, the PFOA-induced in vivo DNA damage was first shown in paramecia, and the DNA damage might not be directly attributable to increase in intracellular ROS.

Air purifiers that diffuse reactive oxygen species potentially cause DNA damage in the lung.

Several appliance manufacturers have recently released new type air purifiers that can disinfect bacteria, fungi and viruses by diffusing reactive oxygen species (ROS) into the air. In this study, mice were exposed to the outlet air from each of 3 air purifiers from different manufacturers (A, B, C), and the lung was examined for DNA damage, lipid peroxidation and histopathology to confirm the safety of these air purifiers. Neither abnormal behavior during exposure nor gross abnormality at necropsy was observed. No histopathological changes were also observed in the lung. However, significant increase of DNA damage was detected by the comet assay in the lung immediately after the direct exposure for 48 hr to models A and B, and for 16 hr to model B. As for model B, DNA migration was also increased by 2 hr exposure in a 1 m(3) plastic chamber but not by 48 hr exposure in a room (12.6 m(3)). Model C did not cause DNA damage. Lipid peroxidation and 8-hydroxy deoxyguanosine (8-OH-dG) was not increased under the conditions DNA damage was detected by the comet assay. The present results revealed that some models of air purifiers that diffuse ROS potentially cause DNA damage in the lung although the mechanism was left unsolved.

Neurotoxicity of perfluorooctane sulfonate (PFOS) in rats and mice after single oral exposure.

Perfluorooctane sulfonate (PFOS) and perfluorooctanoate (PFOA) are widely used in industrial fields and consumer products, and are ubiquitously found in the environment and animal tissues. In the present study, their neurotoxicity was examined using rats and mice by means of neurobehavioral observation, histopathological inspection and chemical assays. PFOS and PFOA alone did not cause any neurotoxic symptoms up to their sublethal doses (PFOS: 500 mg/kg, PFOA: 1,000 mg/kg). However, tonic convulsions were caused in the PFOS-treated rats (> or = 250 mg/kg) and mice (> or = 125 mg/kg) when ultrasonic stimulus was applied to the animals. The same ultrasonic stimulus never induced convulsions in the control animals and in the animals treated with PFOA. Concentration of PFOS in the brain was considerably lower than in other tissue, but it seemed to increase gradually with time after exposure. No morphological changes were detected by histopathological examination of the brain. There were also no changes in concentrations of norepinephrine, dopamine, serotonin, glycine, 4-aminobutylic acid and glutamic acid in the brain. The present study revealed neurotoxic effects of PFOS in animals. Convulsive effect of PFOS may not be attributed to the quantitative alterations of neurotransmitters or lesions of nerve cells in the brain, although the mechanism of its neurotoxicity has not been cleared.

Effects of perfluorooctane sulfonate (PFOS) on swimming behavior and membrane potential of paramecium caudatum.

Persistent perfluorinated organic compounds such as perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) were distributed widely in the global. PFOS (15 microM or higher) caused backward swimming of paramecia. The Triton-extracted paramecia, where the membrane was disrupted and the externally applied chemicals are freely accessible to the ciliary apparatus, showed forward swimming up to 0.1 microM Ca2+ in the medium and backward swimming at about 0.2 microM and higher. PFOS (0.1 mM) did not change the relationship between the swimming directions and free Ca2+ concentrations. Effects of various surfactants including PFOS and PFOA on the swimming direction of paramecia were compared with the hemolysis of mouse erythrocytes as an indicator of surfactant activities. The hemolysis did not correlate with their swimming behavior. PFOS caused triphasic membrane potential changes both in the wild-type paramecia and caudatum non-reversal (CNR) mutants, the latter is defective in voltage-gated Ca2+ channels. An action potential of the wild-type specimen was induced at lower current intensity when PFOS was present in the medium. Voltage-clamp study indicated that PFOS had no effect on the depolarization-induced Ca2+ influx responsible for the action potential. The membrane potential responses obtained were similar to those obtained by the application of some bitter substances such as quinine that activate chemoreceptors of paramecia. Since the CNR specimens did not exhibit PFOS-induced backward swimming at concentrations examined, the backward swimming is attributable to the influx of Ca2+ into the cilia through voltage-gated Ca2+ channels. The Ca2+ channels are most probably activated by the depolarizing receptor potentials resulted from the PFOS-induced activation of chemoreceptors.