Impact of BK polyomavirus viremia on the outcomes of allogeneic hematopoietic stem cell transplantation.

Although it is known that BK polyomavirus (BKPyV) causes hemorrhagic cystitis (HC) after allogeneic hematopoietic stem cell transplantation (HSCT), the clinical significance of BKPyV viremia has not been fully evaluated. We retrospectively analyzed the results of quantitative polymerase chain reaction (PCR) evaluations for detecting BKPyV in the whole blood samples of patients undergoing allogeneic HSCT during the period from January 2010 to June 2020 at a single institute, Tokyo Medical and Dental University. BKPyV was detected in the blood of 28 of the 107 evaluated patients, and the cumulative incidence of was 27.9% (95%CI: 20.2-37.9%). HC due to BKPyV developed in four of the 28 patients with BKPyV viremia (14.3%) and in two of the 79 patients without it (2.5%; P < 0.05). BKPyV viremia itself did not affect the patients' post-transplant estimated glomerular filtration rate (eGFR), but BKPyV viremia with a high viral load was significantly associated with decreased eGFR values (P < 0.05). BKPyV viremia was also associated with significantly lower progression-free survival at 3 years (35.1% [95%CI: 17.8-53.1%] vs. 60.4% [95%CI: 48.4-70.5], P < 0.05). Our findings demonstrated that BKPyV viremia was associated with onset of HC, an early decline of renal function, and poorer survival after allogeneic HSCT. Further studies are needed to test these results and elucidate the mechanisms of renal dysfunction associated with BKPyV viremia.

Effect of Ferroptosis Inducers and Inhibitors on Cell Proliferation in Acute Leukemia.

BACKGROUND/AIM: Ferroptosis refers to an iron-dependent mechanism of regulated cell death that is attributable to lipid peroxidation. Ferroptosis has been documented as a therapeutic target for various solid cancers; nonetheless, its implication in leukemia remains ambiguous. Therefore, this study aimed at investigating the impact of ferroptosis inducers and inhibitors on in vitro leukemia cell line proliferation. MATERIALS AND METHODS: Six leukemia cell lines, including acute myeloid leukemia (AML)-derived MV4-11, THP-1, HL-60, and U-937, and T-lymphoblastic leukemia (T-ALL)-derived Jurkat and KOPT-K1 with activating NOTCH1 mutations, were assessed. Erastin, which interrupts cystine uptake and depletes intracellular glutathione, and RAS-selective lethal 3 (RSL3), which suppresses glutathione peroxidase 4 (GPX4), were employed as ferroptosis inducers. Lipid peroxidation-arresting ferrostatin-1 and deferoxamine were used as ferroptosis inhibitors. Cells were cultured with these compounds and cell proliferation was assessed using a colorimetric assay. Additionally, signaling protein expression was monitored using immunoblotting, and the outcome of GPX4 knockdown was evaluated. RESULTS: Ferroptosis inducers suppressed proliferation in all cell lines except THP-1 for Erastin and THP-1 and Jurkat for RSL3. Although the ferroptosis inhibitors did not affect cell proliferation, they rescued inducer-mediated growth suppression. Ferroptosis inducers impeded MYC and cyclin D3 expression in certain cell lines and NOTCH1 signaling in T-ALL cells. GPX4 knockdown and RSL3 treatment interrupted MYC and cyclin D3 expression, respectively, in four cell lines. CONCLUSION: Ferroptosis inducers may serve as potential candidates for novel molecular therapy against AML and T-ALL.

Renin-Angiotensin System Inhibitors Suppress the Growth of Leukemia Cells.

BACKGROUND/AIM: The renin-angiotensin system (RAS) regulates blood pressure. The RAS is also related to cell growth, and its activation has been reported in various cancer cells. Therefore, we investigated the effects of RAS inhibitors on the in vitro growth of leukemia cell lines. MATERIALS AND METHODS: THP-1, MV4-11, and TMD7 cells derived from acute myeloid leukemia, K-562 cells from chronic myeloid leukemia, and Jurkat and KOPT-K1 cells from T-lymphoblastic leukemia (T-ALL) with NOTCH1 mutations were used. We used four RAS inhibitors: the renin inhibitor aliskiren, angiotensin-converting enzyme 1 inhibitor captopril, angiotensin II type 1 receptor antagonist azilsartan, and angiotensin II type 2 receptor antagonist PD123319. Cells were cultured with the inhibitors and cell growth was assessed using a colorimetric assay. The expression of signaling proteins was assessed using immunoblotting. RESULTS: Treatment with aliskiren, azilsartan, or PD123319 suppressed the growth of all cell lines. Captopril treatment suppressed the growth of K-562, KOPT-K1, and MV4-11 cells. Flow cytometric analysis revealed that the growth suppression was due to the induction of apoptosis. Their suppressive effects on normal lymphocytes were milder than those on leukemia cells. Treatment with these inhibitors decreased MYC expression, induced caspase3 and PARP cleavage, and suppressed mTOR signaling. The treatment also suppressed NOTCH1 signaling in T-ALL cells. CONCLUSION: RAS inhibitors can be repurposed as molecular-targeted drugs for leukemia. However, the concentrations of the inhibitors were much higher than those in the plasma of patients with hypertension. Therefore, further investigation is required for their clinical use.

Association of excess visceral fat and severe illness in hospitalized COVID-19 patients in Japan: a retrospective cohort study.

BACKGROUND/OBJECTIVES: Obesity, defined by body mass index (BMI), is a well-known risk factor for the severity of coronavirus disease 2019 (COVID-19). Adipose tissue distribution has also been implicated as an important factor in the body's response to infection, and excess visceral fat (VF), which is prevalent in Japanese, may contribute significantly to the severity. Therefore, this study aimed to evaluate the association of obesity and VF with COVID-19 severe illness in Japan. SUBJECTS/METHODS: This retrospective cohort study involved 550 COVID-19 patients admitted to a tertiary care hospital with BMI and body composition data, including VF. The primary endpoint was severe illness, including death, due to COVID-19 during hospitalization. Logistic regression analysis was applied to examine the quartiles of BMI and VF on severe illness after adjusting for covariates such as age, sex, subcutaneous fat, paraspinal muscle radiodensity, and comorbidities affecting VF (COPD, cancer within 5 years, immunosuppressive agent use). RESULTS: The median age was 56.0 years; 71.8% were males. During hospitalization, 82 (14.9%) experienced COVID-19 severe illness. In the multivariate logistic regression analysis, Q4 of BMI was not significantly associated with severe illness compared to Q1 of BMI (OR 1.03; 95% CI 0.37-2.86; p = 0.95). Conversely, Q3 and Q4 of VF showed a higher risk for severe illness compared to Q1 of VF (OR 2.68; 95% CI 1.01-7.11; p = 0.04, OR 3.66; 95% CI 1.30-10.26; p = 0.01, respectively). Stratified analysis by BMI and adjusted for covariates showed the positive association of VF with severe illness only in the BMI < 25 kg/m2 group. CONCLUSIONS: High BMI was not an independent risk factor for COVID-19 severe illness in hospitalized patients in Japan, whereas excess VF significantly influenced severe illness, especially in patients with a BMI < 25 kg/m2.

Variation in presepsin and thrombomodulin levels for predicting COVID-19 mortality.

Coronavirus disease (COVID-19) has caused extensive mortality globally; therefore, biomarkers predicting the severity and prognosis of COVID-19 are essential. This study aimed to evaluate the application of presepsin (P-SEP) and thrombomodulin (TM), which are biomarkers of sepsis and endothelial dysfunction, respectively, in the prognosis of COVID-19. Serum P-SEP and TM levels from COVID-19 patients (n = 183) were measured. Disease severity was classified as mild, moderate I, moderate II, or severe based on hemoglobin oxygen saturation and the history of intensive care unit transfer or use of ventilation at admission. Patients in the severe group were further divided into survivors and non-survivors. P-SEP and TM levels were significantly higher in the severe group than those in the mild group, even after adjusting for creatinine values. In addition, TM levels were significantly higher in non-survivors than in survivors. Changes in the P-SEP levels at two time points with an interval of 4.1 ± 2.2 days were significantly different between the survivors and non-survivors. In conclusion, TM and continuous P-SEP measurements may be useful for predicting mortality in patients with COVID-19. Moreover, our data indicate that P-SEP and TM values after creatinine adjustment could be independent predictive markers, apart from renal function.

Thrombosis and antiphospholipid antibodies in Japanese COVID-19: based on propensity score matching.

Background: Thrombosis is a unique complication of coronavirus disease 2019 (COVID-19). Although antiphospholipid antibodies (aPL) are detected in COVID-19 patients, their clinical significance remains elusive. We evaluated the prevalence of aPL and serum concentrations of beta-2 glycoprotein I (ß2GPI), a major self-antigen for aPL, in Japanese COVID-19 patients with and without thrombosis. Methods: This retrospective single-center nested case-control study included 594 hospitalized patients with COVID-19 between January 2020 and August 2021. Thrombotic complications were collected from medical records. Propensity score-matching method (PSM) (1:2 matching including age, sex, severity on admission, and prior history of thrombosis) was performed to compare the prevalence and titer of aPL (anti-cardiolipin (aCL) IgG/IgM, anti-ß2GPI IgG/IgM/IgA, and anti-phosphatidylserine/prothrombin antibody (aPS/PT) IgG/IgM) and serum ß2GPI concentration. In addition, PSM (1:1 matching including age and sex) was performed to compare the serum ß2GPI concentration between COVID-19 patients and healthy donors. Results: Among the patients, 31 patients with thrombosis and 62 patients without were compared. The prevalence of any aPLs was indifferent regardless of the thrombosis (41.9% in those with thrombosis vs. 38.7% in those without, p =0.82). The positive rates of individual aPL were as follows: anti-CL IgG (9.7% vs. 1.6%, p =0.11)/IgM (0% vs. 3.2%, p =0.55), anti-ß2GP1 IgG (22.6% vs. 9.7%, p =0.12)/IgA (9.7% vs. 9.7%, p =1.0)/IgM (0% vs. 0%, p =1.0), and anti-PS/PT IgG (0% vs. 1.6%, p =1.0)/IgM (12.9% vs. 21.0%, p =0.41), respectively. The aPL titers were also similar regardless of thrombosis. The levels of ß2GPI in COVID-19 patients were lower than those in the healthy donors. Conclusion: Although aPLs were frequently detected in Japanese COVID-19 patients, their prevalence and titer were irrelevant to thrombotic complications. While COVID-19 patients have lower levels of serum ß2GPI than healthy blood donors, ß2GPI levels were indifferent regardless of thrombosis. Although most of the titers were below cut-offs, positive correlations were observed among aPLs, suggesting that the immune reactions against aPL antigens were induced by COVID-19. We should focus on the long-term thromboembolic risk and the development of APS in the aPL-positive patients with high titer or multiple aPLs.

Lymphoproliferative disorder risk after methotrexate treatment for rheumatoid arthritis.

Methotrexate (MTX)-associated lymphoproliferative disorder (MTX-LPD) is a troublesome problem in patients receiving MTX for rheumatoid arthritis (RA). However, its incidence, prognosis, and risk factors remain unclear. In this retrospective study, we evaluated the actual incidence, prognostic impact, and risk factors of MTX-LPD. Of the 986 patients with RA treated with MTX, 90 patients experienced 95 new malignancies (NMs), with LPD as the most frequent in 26 patients. The cumulative LPD incidences were 1.3% and 4.7% at 5 and 10 years after MTX initiation, respectively. Among the 24 patients who discontinued MTX after developing LPD, 15 showed sustained regression, without difference in overall survival between patients with LPD and without NM. Inflammatory markers and absolute lymphocyte counts were not useful for early LPD development detection, but most of the patients with LPD had persistently elevated erythrocyte sedimentation ratios. Regarding concomitant drugs, tacrolimus increased the risk only if patients were not receiving biological disease-modifying antirheumatic drugs (bDMARDs). bDMARDs did not increase the risk for any of the drugs or the number of classes used. The number of LPD cases was lower in patients with IL-6A even after a long period after MTX, although with no statistically significant difference. Thus, approximately 1 in 20 patients with RA developed MTX-LPD over the 10 years of MTX treatment, but it did not affect the survival of patients with RA. Tacrolimus increased the risk of developing LPD for certain patients and should be used with caution.

Effects of MYC Inhibitors on the Growth of Acute Leukaemia Cells.

BACKGROUND/AIM: MYC proto-oncogene bHLH transcription factor (MYC) proteins function as transcription factors by binding to MYC-associated factor X (MAX) proteins and are involved in various cancer growth, including leukaemia. This study aimed to examine the effects of synthetic MYC inhibitors, which block the MYC-MAX complex formation, in in vitro human acute leukaemia cell lines. MATERIALS AND METHODS: Four cell lines, OCI/AML2 derived from acute myeloid leukaemia, NALM-6 from B-lymphoblastic leukaemia, and KOPT-K1 and Jurkat from notch receptor 1 (NOTCH1)-mutated T-lymphoblastic leukaemia (T-ALL), were treated with the small-molecule MYC inhibitors 10058-F4 and MYCi975. The expression of cell proliferation and signalling proteins was studied. RESULTS: These inhibitors suppressed the growth of leukaemia cell lines. Treatment with the two inhibitors down-regulated the protein expression of c-MYC, MAX, and activating enhancer-binding protein 4 (AP4) in all cell lines. Up-regulation of p27 and p21 was observed only in 10058-F4-treated OCI/AML2 cells and MYCi975-treated KOPT-K1 cells. These two inhibitors down-regulated the expression of NOTCH1, cleaved NOTCH1, and hes family bHLH transcription factor 1 (HES1) in both T-ALL cell lines. CONCLUSION: MYC inhibitors appear to be novel molecular-targeted drugs against acute leukaemia, including NOTCH1-mutated T-ALL. However, it is necessary to elucidate the precise molecular mechanisms of these effects before clinical use.

Viral load of SARS-CoV-2 Omicron BA.5 is lower than that of BA.2 despite the higher infectivity of BA.5.

BACKGROUND: Sublineage BA.5 of the SARS-CoV-2 Omicron variant rapidly spread and replaced BA.2 in July 2022 in Tokyo. A high viral load can be a possible cause of high transmissibility. METHODS AND RESULTS: The copy numbers of SARS-CoV-2 in nasopharyngeal swab samples obtained from all patients visiting the hospital where this research was conducted were measured using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). Viral genotypes were determined using PCR-based melting curve analysis. Next, whole-genome sequencing was performed using approximately one fifth of the samples to verify the viral genotypes determined using PCR. Then, the copy numbers of the BA.1, BA.2, and BA.5 cases were compared. Contrary to expectations, the copy numbers of the BA.5 cases (median 4.7 × 104 copies/µL, n = 291) were significantly (p = .001) lower than those of BA.2 cases (median 1.1 × 105 copies/µL, n = 184). There was no significant difference (p = .44) between the BA.5 and BA.1 cases (median, 3.3 × 104 copies/µL; n = 215). CONCLUSION: The results presented here suggest that the increased infectivity of BA.5 is not caused by higher viral loads, but presumably by other factors such as increased affinity to human cell receptors or immune escape due to its L452R mutation.

Effectiveness of remdesivir with corticosteroids for COVID-19 patients in intensive care unit: A hospital-based observational study.

The effectiveness of remdesivir on survival in coronavirus disease 2019 (COVID-19), especially in cases treated in the intensive care unit (ICU), is controversial. We investigated the effectiveness of remdesivir with corticosteroids on the survival of COVID-19 patients in a real ICU clinical practice. For laboratory-confirmed COVID-19 patients admitted to the ICU of a tertiary hospital in Tokyo (April 2020-November 2021) and who received corticosteroids, the effectiveness of remdesivir for survival, stratified by interval length (within 9 or 10+ days), was retrospectively analyzed using Cox regression model. A total of 168 patients were included: 35 with no remdesivir use (control), 96 with remdesivir use within 9 days, and 37 with remdesivir use with an interval of 10+ days. In-hospital mortality was 45.7%, 10.4%, and 16.2%, respectively. After adjusting for possible covariates including comorbidities, laboratory data, oxygen demand, or level of pneumonia, remdesivir use within 9 days from symptom onset reduced mortality risk (hazard ratio [HR]: 0.10; 95% confidence interval (CI): 0.025-0.428) compared to the control group. However, remdesivir use with an interval of 10+ days showed no significant association with mortality (HR: 0.42; 95% CI: 0.117-1.524). Among COVID-19 patients who received corticosteroids in ICU, remdesivir use within 9 days from symptom onset was associated with reduced in-hospital mortality risk.

Complete Genome Sequence of an Enterobacter roggenkampii Strain with Reduced Carbapenem Susceptibility Isolated from a Home-Visit Nursing Agency.

Carbapenem-resistant bacteria represent an emerging threat to global health; nursing homes may be reservoirs for these isolates, which cause life-threatening infections. Here, we present the complete genome sequence of an Enterobacter roggenkampii strain with reduced carbapenem susceptibility that was isolated from a sink in a home-visit nursing agency.

Viral load of SARS-CoV-2 Omicron is not high despite its high infectivity.

Patients infected with the Omicron variant of severe acute respiratory syndrome coronavirus 2 has increased worldwide since the beginning of 2022 and the variant has spread more rapidly than the Delta variant, which spread in the summer of 2021. It is important to clarify the cause of the strong transmissibility of the Omicron variant to control its spread. In 694 patients with coronavirus disease 2019, the copy numbers of virus in nasopharyngeal swab-soaked samples and the viral genotypes were examined using quantitative polymerase chain reaction (PCR) and PCR-based melting curve analysis, respectively. Whole-genome sequencing was also performed to verify the viral genotyping data. There was no significant difference (p = 0.052) in the copy numbers between the Delta variant cases (median 1.5 × 105 copies/µl, n = 174) and Omicron variant cases (median 1.2 × 105 copies/µl, n = 328). During this study, Omicron BA.1 cases (median 1.1 ×105 copies/µl, n = 275) began to be replaced by BA.2 cases (median 2.3 × 105 copies/µl, n = 53), and there was no significant difference between the two groups (p = 0.33). Our results suggest that increased infectivity of the Omicron variant and its derivative BA.2 is not caused by higher viral loads but by other factors, such as increased affinity to cell receptors or immune escape.

Association of SARS-CoV-2 RNA Copy Number with the COVID-19 Mortality Rate and Its Effect on the Predictive Performance of Mortality in Severe Cases.

Factors associated with mortality are important in the treatment of coronavirus disease 2019 (COVID-19). Polymerase chain reaction (PCR) is the gold standard for diagnosing COVID-19, which reflects the viral load in the upper respiratory tract. In total, 523 patients were enrolled in this study; of them, 441 and 75 patients underwent PCR testing of nasopharyngeal swabs and sputum samples, respectively, within 20 days from onset of COVID-19. We investigated the association between RNA copy number and the COVID-19 severity and mortality rate and its effect on the predictive performance for severity and mortality. RNA copy numbers in nasopharyngeal swabs were higher in the non-survivor group than in the survivor group. Multivariate logistic regression analysis identified that the high RNA copy number (≥9 log10 /swab) in nasopharyngeal swabs was a factor associated with mortality (odds ratio, 4.50; 95% confidence interval, 1.510-13.100; P = 0.008). Furthermore, adding RNA copy number (≥9 log10 /swab) in severe cases, adjusted by duration from onset to PCR, improved mortality predictive performance based on known factors. The RNA copy number is a factor associated with the mortality of patients with COVID-19 and can improve the predictive performance of mortality in severe cases.

[Perioperative management of laparoscopic cholecystectomy in a patient with paroxysmal nocturnal haemoglobinuria undergoing ravulizumab treatment].

Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by hemolysis, thrombosis, and bone marrow failure. Infection, pregnancy, and surgical operation have the potential to evoke severe episodes of hemolysis and thrombosis. Therefore, the use of an antibody agent against complement component 5 (C5), eculizumab, one day before the operation is recommended. Ravulizumab is a newly approved long-acting antibody agent against C5. Thus, little is known about perioperative management with ravulizumab. We experienced a 43-year-old female patient who safely underwent laparoscopic cholecystectomy under ravulizumab treatment for PNH. Ravulizumab was administered one day before the operation. Laparoscopic cholecystectomy for cholelithiasis was performed under intravenous anesthesia, intermittent air compression of the lower extremities, and low pneumoperitoneum pressure. Additionally, heparin was administered, and the patient left the sickbed early without significant postoperative complications. Like eculizumab, complement inhibition by ravulizumab is also considered effective in the perioperative management of patients with PNH. However, close cooperation with surgeons and anesthesiologists and careful management based on clinical symptoms and laboratory data such as LDH, CH50, and D-dimer are essential.

Penicillin- and Ciprofloxacin-Resistant Invasive Neisseria meningitidis Isolates from Japan.

Neisseria meningitidis causes a life-threatening invasive meningococcal disease (IMD). Isolates resistant to antibiotics, such as penicillin, ceftriaxone, and ciprofloxacin that are recommended for the treatment of IMD patients and their close contacts have been serious public health concerns globally. However, susceptibility profiles to critically important antibiotics and the genetic characteristics of isolates possessing antibiotic resistance are extremely limited as IMD incidence is low in Japan. We assessed the susceptibility profiles of 87 randomly selected, sterile site-derived N. meningitidis strains isolated from hospitals nationwide, recovered between April 1998 and March 2018 in Japan, to seven antibiotics. As a result, we demonstrated, for the first time, that the isolates remained highly susceptible to ceftriaxone, meropenem, azithromycin, ciprofloxacin, chloramphenicol, and rifampin, but not to penicillin. We then characterized the genetic relatedness of six penicillin- and/or ciprofloxacin-resistant isolates obtained in this study with global 112 genomes using core-genome phylogenetic analysis. These results provide the first evidence that invasive lineages such as a penicillin-resistant serogroup W, sequence type (ST)-11 clonal complex (CC), and a ciprofloxacin-resistant serogroup B/C, ST-4821 CC that is considered as a global threat, have been sporadically identified in Japan. Our findings highlight the need to monitor antibiotic resistance in clinical isolates of N. meningitidis, thereby preventing the spread of antibiotic-resistant invasive lineages and maintaining effective treatment for IMD patients and their close contacts. IMPORTANCE Although antibiotics such as penicillin and ceftriaxone can treat invasive meningococcal disease (IMD), the emergence and spread of antibiotic-resistant Neisseria meningitidis have become a global concern. To provide effective treatment, including chemoprophylaxis to IMD patients and their close contacts, we highlighted the importance of recognizing the antibiotic resistance and genetic features of N. meningitidis isolates.

TYRO3 Knockdown Suppresses the Growth of Myeloid Leukaemia Cells.

BACKGROUND/AIM: TYRO3 is a member of the TAM family (TYRO3, AXL, and MERTK) of receptor tyrosine kinases. While the roles of activated AXL and MERTK in the growth of leukaemia cells have been reported, the effect of TYRO3 has not been determined. Therefore, we examined the effects of TYRO3 knockdown on the growth of leukaemia cell lines. MATERIALS AND METHODS: Three human leukaemia cell lines (AA derived from pure erythroid leukaemia, OCI/AML2, and K562), which express TYRO3 protein were used in this study. To induce TYRO3 knockdown, small interfering RNA (siRNA) against TYRO3 was transfected using an electroporation system. Cell growth was assessed by a colorimetric assay. The expression levels and activation of various signalling proteins were examined by immunoblotting. Changes in comprehensive gene expression after TYRO3 knockdown were examined by microarray analysis. RESULTS: TYRO3 knockdown suppressed cell growth in the leukaemia cell lines tested. Additionally, the knockdown suppressed phosphorylation of signal transducer and activator of transcription-3 in AA cells, and extracellular signal-regulated kinase (ERK) 1/2 in AA and OCI/AML2 cells; both are downstream molecules of TYRO3 signalling. TYRO3 knockdown also suppressed the expression of survivin in all the cell lines. TYRO3 knockdown potently suppressed TYRO3 mRNA expression but not that of AXL and MERTK. Furthermore, TYRO3 knockdown suppressed cyclin D1 mRNA expression, which is a downstream molecule of ERK. CONCLUSION: TYRO3 plays a role in leukaemia cell growth and is a potential therapeutic target for leukaemia.

Effect of myeloperoxidase oxidation and N-homocysteinylation of high-density lipoprotein on endothelial repair function.

Endothelial cell (EC) migration is essential for healing vascular injuries. Previous studies suggest that high-density lipoprotein (HDL) and apolipoprotein A-I (apoA-I), the major protein constituent of HDL, have endothelial healing functions. In cardiovascular disease, HDL is modified by myeloperoxidase (MPO) and N-homocysteine, resulting in apoA-I/apoA-II heterodimer and N-homocysteinylated (N-Hcy) apoA-I formation. This study investigated whether these modifications attenuate HDL-mediated endothelial healing. Wound healing assays were performed to analyze the effect of MPO-oxidized HDL and N-Hcy HDL in vitro. HDL obtained from patients with varying troponin I levels were also examined. MPO-oxidized HDL reduces EC migration compared to normal HDL in vitro, and N-Hcy HDL showed a decreasing trend toward EC migration. EC migration after treatment with HDL from patients was decreased compared to HDL isolated from healthy controls. Increased apoA-I/apoA-II heterodimer and N-Hcy apoA-I levels were also detected in HDL from patients. Wound healing cell migration was significantly negatively correlated with the ratio of apoA-I/apoA-II heterodimer to total apoA-II and N-Hcy apoA-I to total apoA-I. MPO-oxidized HDL containing apoA-I/apoA-II heterodimers had a weaker endothelial healing function than did normal HDL. These results indicate that MPO-oxidized HDL and N-Hcy HDL play a key role in the pathogenesis of cardiovascular disease.

Viral loads and profile of the patients infected with SARS-CoV-2 Delta, Alpha, or R.1 variants in Tokyo.

The rapid spread of the Delta variant of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) became a serious concern worldwide in summer 2021. We examined the copy number and variant types of all SARS-CoV-2-positive patients who visited our hospital from February to August 2021 using polymerase chain reaction (PCR) tests. Whole genome sequencing was performed for some samples. The R.1 variant (B.1.1.316) was responsible for most infections in March, replacing the previous variant (B.1.1.214); the Alpha (B.1.1.7) variant caused most infections in April and May; and the Delta variant (B.1.617.2) was the most prevalent in July and August. There was no significant difference in the copy numbers among the previous variant cases (n = 29, median 3.0 × 104 copies/µl), R.1 variant cases (n = 28, 2.1 × 105 copies/µl), Alpha variant cases (n = 125, 4.1 × 105 copies/µl), and Delta variant cases (n = 106, 2.4 × 105 copies/µl). Patients with Delta variant infection were significantly younger than those infected with R.1 and the previous variants, possibly because many elderly individuals in Tokyo were vaccinated between May and August. There was no significant difference in mortality among the four groups. Our results suggest that the increased infectivity of Delta variant may be caused by factors other than the higher viral loads. Clarifying these factors is important to control the spread of Delta variant infection.

Effect of the recording condition on the quality of a single-lead electrocardiogram.

Although many wearable single-lead electrocardiogram (ECG) monitoring devices have been developed, information regarding their ECG quality is limited. This study aimed to evaluate the quality of single-lead ECG in healthy subjects under various conditions (body positions and motions) and in patients with arrhythmias, to estimate requirements for automatic analysis, and to identify a way to improve ECG quality by changing the type and placement of electrodes. A single-lead ECG transmitter was placed on the sternum with a pair of electrodes, and ECG was simultaneously recorded with a conventional Holter ECG in 12 healthy subjects under various conditions and 35 patients with arrhythmias. Subjects with arrhythmias were divided into sinus rhythm (SR) and atrial fibrillation (AF) groups. ECG quality was assessed by calculating the sensitivity and positive predictive value (PPV) of the visual detection of QRS complexes (vQRS), automatic detection of QRS complexes (aQRS), and visual detection of P waves (vP). Accuracy was defined as a 100% sensitivity and PPV. We also measured the amplitude of the baseline, P wave, and QRS complex, and calculated the signal-to-noise ratio (SNR). We then focused on aQRS and estimated thresholds to obtain an accurate aQRS in more than 95% of the data. Finally, we sought to improve ECG quality by changing electrode placement using offset-type electrodes in 10 healthy subjects. The single-lead ECG provided 100% accuracy for vQRS, 87% for aQRS, and 74% for vP in healthy subjects under various conditions. Failure for accurate detection occurred in several motions in which the baseline amplitude was increased or in subjects with low QRS or P amplitude, resulting in low SNR. The single-lead ECG provided 97% accuracy for vQRS, 80% for aQRS in patients with arrhythmias, and 95% accuracy for vP in the SR group. The AF group showed higher baseline amplitude than the SR group (0.08 mV vs. 0.02 mV, P < 0.01) but no significant difference in accuracy for aQRS (79% vs. 81%, P = 1.00). The thresholds to obtain an accurate aQRS were a QRS amplitude > 0.42 mV and a baseline amplitude < 0.20 mV. The QRS amplitude was significantly influenced by electrode placement and body position (P < 0.01 for both, two-way analysis of variance), and the maximum reduction by changing body position was estimated as 30% compared to the sitting posture. The QRS amplitude significantly increased when the inter-electrode distance was extended vertically (1.51 mV for vertical extension vs. 0.93 mV for control, P < 0.01). The single-lead ECG provided at least 97% accuracy for vQRS, 80% for aQRS, and 74% for vP. To obtain stable aQRS in any body positions, a QRS amplitude > 0.60 mV and a baseline amplitude < 0.20 mV were required in the sitting posture considering the reduction induced by changing body position. Vertical extension of the inter-electrode distance increased the QRS amplitude.