Predictive Factors for Tracheal Intubation in Patients with Coronavirus Disease 2019 Treated Using a High-flow Nasal Cannula

Background : In Japan, patients with coronavirus disease 2019 (COVID-19)＊ requiring a high-flow nasal cannula (HFNC) are often initially treated in non-specialized facilities and transferred to an intensive care unit if tracheal intubation is required. We aimed to investigate the factors associated with severe respiratory failure requiring tracheal intubation at an early stage in patients with COVID-19 treated using HFNCs. Methods : This retrospective cohort study compared the clinical features of consecutively enrolled patients with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus-2 infection admitted to two centers in Japan between early February 2020 and late June 2021. Results : A total of 35 patients with COVID-19 treated using HFNCs were included. Treatment success and failure occurred in 25 and 10 patients, respectively. The oxygen saturation (ROX) index (ratio of oxygen saturation [SpO2] to fraction of inspired oxygen [FiO2] and the respiratory rate) 12 h post-HFNC insertion was a useful predictor of HFNC failure (success group, 8.0 ; failure group, 6.5 : P＝0.0005). Moreover, the time from symptom onset to respiratory failure was significantly shorter in the failure group than in the success group (3.0 and 5.0 days, P＝0.004). Conclusions The ROX index and time from symptom onset to respiratory failure were useful predictors of HFNC failure.Article信州医学雑誌 71(6) : 403-409, (2023)journal articl

Genome-wide DNA methylation profile in feline haematological tumours: A preliminary study

Although DNA methylation has been analysed in few studies for a limited number of loci in cats with diseases, genome-wide profile of DNA methylation has never been addressed. The hypothesis for this study is that nextgeneration sequencing with sequential digestion of genomic DNA with SmaI and XmaI enzymes could provide highly quantitative information on methylation levels in cats. Using blood from four healthy control cats and two disease cats as well as three feline lymphoma/leukemia cell lines, approximately 74-94 thousand CpG sites across the cat genome could be analysed. CpG sites in CpG island (CGI) were broadly either methylated or unmethylated in normal blood, while CpG sites in non-CpG islands (NCGI) are largely methylated. Lymphoma cell lines showed thousands of CpG sites with gain of methylation at normally unmethylated CGI sites and loss of methylation at normally methylated NCGI sites. Hypermethylated CpG sites located at promoter regions included genes annotated with 'developmental process' and 'anatomical structure morphogenesis' such as HOXD10. This highly quantitative method would be suitable for studies of DNA methylation changes not only in cancer but also in other common diseases in cats

Manipulating histone acetylation leads to antitumor effects in hemangiosarcoma cells

Canine hemangiosarcoma (HSA) is a malignant tumour derived from endothelial cells. No effective treatment has yet been developed because of the lack of understanding of its pathogenesis. Histone acetylation, an epigenetic modification, is highly associated with cancer pathogenesis. Manipulating histone acetylation by histone deacetylase inhibitors (HDACi) or bromodomain and extraterminal domain inhibitors (BETi) is one approach to treat various cancers. However, the role of histone acetylation in HSA remains unknown. This study aimed to investigate how histone acetylation functions in HSA pathogenesis using two HDACi, suberanilohydroxamic acid (SAHA) and valproic acid (VPA), and one BETi, JQ1, in vitro and in vivo. Histone acetylation levels were high in cell lines and heterogeneous in clinical cases. SAHA and JQ1 induced apoptosis in HSA cell lines. HSA cell lines treated with SAHA and VPA upregulated inflammatory-related genes and attracted macrophage cell line RAW264 cells, which suggests that SAHA and VPA can affect immune responses. JQ1 stimulated autophagy and inhibited the cell cycle in HSA cell lines. Finally, we demonstrated that JQ1 suppressed HSA tumour cell proliferation in vivo although SAHA and VPA did not affect tumour growth. These results suggest that BETi can be alternative drugs for HSA treatment. Although further research is required, our study indicated that dysregulation of histone acetylation is likely to be involved in HSA malignancy

Case Report: Congenital methemoglobinemia in a cat with the reduced NADH-cytochrome b5 reductase 3 activity and missense mutations in CYB5R3

A one-year-old castrated male mixed-breed cat was referred for detailed examination of long-term pale mucous membrane without any clinical episodes that may cause cyanosis. While no causative abnormalities were detected in thoracic radiography and echocardiography, and arterial partial pressure of oxygen was within normal value, methemoglobin concentration of the cat was increased to 30% and cytochrome b5 reductase activity, which converts methemoglobin to hemoglobin, was reduced to 2.0 IU/gHb (13.4 ± 1.7 IU/gHb in control cats, n ＝ 3), indicating congenital methemoglobinemia. Sequence analysis of CYB5R3, which codes cytochrome b5 reductase, showed two missense mutations found in the patient, one of which was predicted to affect protein function

Obese status is associated with accelerated DNA methylation change in peripheral blood of senior dogs

Obesity and its associated comorbidities constitute a major and growing health problem worldwide not only involved with people but also dogs and cats. Although few genetic mutations have been associated with obesity in dogs, molecular mechanism remains to be clearly understood. Given the fact that DNA methylation leads to gene expression variability and has plasticity affected by metabolic phenotypes such as obesity in human, the objective of this study is to identify obesity-associated differentially methylated cytosine-phosphate-guanine (CpG) dinucleotide sites in dogs. With genome-wide DNA methylation analysis using next-generation sequencing for blood samples from fourteen Miniature dachshunds with body condition score (BCS) 4-5 and BCS >6, over 100,000 sites could be analysed to identify genomic locations of differentially methylated CpG sites. As a result, 191 differentially methylated CpG sites (89 CpG sites were hypermethylated in BCS >6 and 102 were hypermethylated in BCS 4-5) were identified. These sites included promoter regions of Kisspeptin receptor (KISS1R) and Calcyphosine 2 (CAPS2) genes which were subsequently validated by bisulfite-pyrosequencing for another set of 157 dog blood samples. KISS1R methylation levels were found to be higher in BCS >6 group than BCS 4-5 in senior (>84 months) dogs. Especially male dogs but not female dogs as well as uncastrated male dogs but not castrated male dogs showed this trend. DNA methylation of KISS1R gene will be useful for understanding of comprehensive epigenetic change in obese dogs

Manipulating histone acetylation leads to antitumor effects in hemangiosarcoma cells

Canine hemangiosarcoma (HSA) is a malignant tumour derived from endothelial cells. No effective treatment has yet been developed because of the lack of understanding of its pathogenesis. Histone acetylation, an epigenetic modification, is highly associated with cancer pathogenesis. Manipulating histone acetylation by histone deacetylase inhibitors (HDACi) or bromodomain and extraterminal domain inhibitors (BETi) is one approach to treat various cancers. However, the role of histone acetylation in HSA remains unknown. This study aimed to investigate how histone acetylation functions in HSA pathogenesis using two HDACi, suberanilohydroxamic acid (SAHA) and valproic acid (VPA), and one BETi, JQ1, in vitro and in vivo. Histone acetylation levels were high in cell lines and heterogeneous in clinical cases. SAHA and JQ1 induced apoptosis in HSA cell lines. HSA cell lines treated with SAHA and VPA upregulated inflammatory-related genes and attracted macrophage cell line RAW264 cells, which suggests that SAHA and VPA can affect immune responses. JQ1 stimulated autophagy and inhibited the cell cycle in HSA cell lines. Finally, we demonstrated that JQ1 suppressed HSA tumour cell proliferation in vivo although SAHA and VPA did not affect tumour growth. These results suggest that BETi can be alternative drugs for HSA treatment. Although further research is required, our study indicated that dysregulation of histone acetylation is likely to be involved in HSA malignancy