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.

Apple-shaped obesity: A risky soil for cytokine-accelerated severity in COVID-19.

Obesity has been recognized as one of the most significant risk factors for the deterioration and mortality associated with COVID-19, but the significance of obesity itself differs among ethnicity. Multifactored analysis of our single institute-based retrospective cohort revealed that high visceral adipose tissue (VAT) burden, but not other obesity-associated markers, was related to accelerated inflammatory responses and the mortality of Japanese COVID-19 patients. To elucidate the mechanisms how VAT-dominant obesity induces severe inflammation after severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection, we infected two different strains of obese mice, C57BL/6JHamSlc-ob/ob (ob/ob), C57BLKS/J-db/db (db/db), genetically impaired in the leptin ligand and receptor, respectively, and control C57BL/6 mice with mouse-adapted SARS-CoV-2. Here, we revealed that VAT-dominant ob/ob mice were extremely more vulnerable to SARS-CoV-2 due to excessive inflammatory responses when compared to SAT-dominant db/db mice. In fact, SARS-CoV-2 genome and proteins were more abundant in the lungs of ob/ob mice, engulfed in macrophages, resulting in increased cytokine production including interleukin (IL)-6. Both an anti-IL-6 receptor antibody treatment and the prevention of obesity by leptin replenishment improved the survival of SARS-CoV-2-infected ob/ob mice by reducing the viral protein burden and excessive immune responses. Our results have proposed unique insights and clues on how obesity increases the risk of cytokine storm and death in patients with COVID-19. Moreover, earlier administration of antiinflammatory therapeutics including anti-IL-6R antibody to VAT-dominant patients might improve clinical outcome and stratification of the treatment for COVID-19, at least in Japanese patients.

An anthropometric evidence against the use of age-based estimation of bodyweight in pediatric patients admitted to intensive care units.

Age-based bodyweight estimation is commonly used in pediatric settings, but pediatric ICU patients often have preexisting comorbidity and resulting failure to thrive, hence their anthropometric measures may be small-for-age. Accordingly, age-based methods could overestimate bodyweight in such settings, resulting in iatrogenic complications. We performed a retrospective cohort study using pediatric data (aged < 16 years) registered in the Japanese Intensive Care Patient Database from April 2015 to March 2020. All the anthropometric data were overlaid on the growth charts. The estimation accuracy of 4 age-based and 2 height-based bodyweight estimations was evaluated by the Bland-Altman plot analysis and the proportion of estimates within 10% of the measured weight (ρ10%). We analyzed 6616 records. The distributions of both bodyweight and height were drifted to the lower values throughout the childhood while the distribution of BMI was similar to the general healthy children. The accuracy in bodyweight estimation with age-based formulae was inferior to that with height-based methods. These data demonstrated that the pediatric patients in the Japanese ICU were proportionally small-for-age, suggesting a special risk of using the conventional age-based estimation but supporting the use of height-based estimation of the bodyweight in the pediatric ICU.

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.

Case of laryngeal venous malformations requiring repeated advanced airway management in the perioperative course.

Laryngeal venous malformations rarely but do cause airway obstruction resulting in life-threatening events. The perioperative airway management for the patients with them has not been well established. We suggest a strategy for laryngeal venous malformations management in the patients who undergo surgery in addition to planning for airway management.

Rapid and sensitive SARS-CoV-2 detection using a homogeneous fluorescent immunosensor Quenchbody with crowding agents.

Antigen tests for SARS-CoV-2 are widely used by the public during the ongoing COVID-19 pandemic, which demonstrates the societal impact of homogeneous immunosensor-related technologies. In this study, we used the PM Q-probe and Quenchbody technologies to develop a SARS-CoV-2 nucleocapsid protein (N protein) homogeneous immunosensor based on a human anti-N protein antibody. For the first time, we uncovered the crowding agent's role in improving the performance of the double-labeled Quenchbody, and the possible mechanisms behind this improvement are discussed. The 5% polyethylene glycol 6000 significantly improved both the response speed and sensitivity of SARS-CoV-2 Quenchbodies. The calculated limit of detection for recombinant N protein was 191 pM (9 ng mL-1) within 15 min of incubation, which was 9- to 10-fold lower than the assay without adding crowding agent. We also validated the developed immunosensor in a point-of-care test by measuring specimens from COVID-19-positive patients using a compact tube fluorometer. In brief, this work shows the feasibility of Quenchbody homogeneous immunosensors as rapid and cost-efficient tools for the diagnosis and high-throughput analysis of swab samples in large-scale monitoring and epidemiological studies of COVID-19 or other emerging infectious diseases.

Mizuo-Nakamura phenomenon in X-linked retinoschisis.

Purpose: To determine whether the Mizuo-Nakamura phenomenon, which is an important diagnostic sign of Oguchi's disease, also occurs in patients with genetically proven X-linked retinoschisis (XLRS). Methods: We examined three patients with a clinical and genetic diagnosis of XLRS and one patient who was clinically diagnosed with Oguchi's disease, with an emphasis on the Mizuo-Nakamura phenomenon. We obtained color fundus photographs, especially in the fully dark-adapted state, using the non-mydriatic mode on a digital retinal camera and infrared observation monitor to avoid the bleaching effects caused by the viewing light, which alters the fundus color in a short time. Results: The Mizuo-Nakamura phenomenon was observed in all patients with molecularly proven XLRS, similar to that in the patient with Oguchi's disease. The sets of photographs were obtained in the light- and dark-adapted states using our newly devised techniques needed to witness the Mizuo-Nakamura phenomenon. Conclusions and Importance: The Mizuo-Nakamura phenomenon was identified in three patients with genetically proven XLRS. To the best of our knowledge, this study provided the first genetic evidence of the Mizuo-Nakamura phenomenon in a patient with molecularly proven XLRS without the causative genetic abnormalities for Oguchi's disease. Our findings suggest that XLRS is responsible for the Mizuo-Nakamura phenomenon and its presence in XLRS is not a rare exception but may be a consistent manifestation of XLRS.

Discovery of a Novel Class of ERRα Agonists.

A novel class of estrogen-related receptor α (ERRα) agonists has been discovered. A structure-activity relationship study of high-throughput screening hits 1 and 2 led to the discovery of benzimidazole 3d (DS20362725) and acetophenone analogue 5c (DS45500853). The X-ray crystal structure of the ERRα ligand-binding domain in complex with 5c and PGC-1α coactivator peptide revealed conformational changes in the ligand-binding pocket to accommodate 5c and the key interaction between the protein and ligand. Since both analogues avoided PPARγ transcriptional activity, they can be useful tool compounds for investigating biological ERRα functions.

The Safety and Effect of Early Mobilization in the Intensive Care Unit According to Cancellation Criteria.

OBJECTIVE: The aim of this study was to investigate the effect and risk management of early mobilization in the intensive care unit (ICU) with multidisciplinary collaboration and daily goal planning. METHODS: Rehabilitation of ICU patients in our hospital between April 1, 2019, and September 30, 2019, was investigated retrospectively. The following factors were evaluated: age and sex of the subjects; diseases; the total number of early mobilization therapy sessions done at a lowered goal level; the clinical course of the step-down sessions; reasons for lowering goal levels that corresponded to the cancellation criteria from the officially issued guidelines of the Japanese Association of Rehabilitation Medicine, the expert consensus on ICU, or other reasons for step down; and the rate of planned goals that were achieved. RESULTS: Of the 1908 overall rehabilitation sessions carried out during the period of investigation, 9.6% had the planned level lowered; changes in vital signs accounted for 54.6% of the reasons for lowering the level. Of the step-down sessions, 92.3% corresponded with the cancellation criteria of rehabilitation. Early mobilization in the ICU in accordance with daily goal planning via collaboration within the multidisciplinary team during rounds was accomplished in 90.4% of sessions. No serious mobilization-related adverse events were noted during the study period. CONCLUSION: Early mobilization should be performed with daily goal planning by a multidisciplinary team during rounds and should be governed by the cancellation criteria of rehabilitation.

Intravascular donor monocytes play a central role in lung transplant ischaemia-reperfusion injury.

RATIONALE: Primary graft dysfunction in lung transplant recipients derives from the initial, largely leukocyte-dependent, ischaemia-reperfusion injury. Intravascular lung-marginated monocytes have been shown to play key roles in experimental acute lung injury, but their contribution to lung ischaemia-reperfusion injury post transplantation is unknown. OBJECTIVE: To define the role of donor intravascular monocytes in lung transplant-related acute lung injury and primary graft dysfunction. METHODS: Isolated perfused C57BL/6 murine lungs were subjected to warm ischaemia (2 hours) and reperfusion (2 hours) under normoxic conditions. Monocyte retention, activation phenotype and the effects of their depletion by intravenous clodronate-liposome treatment on lung inflammation and injury were determined. In human donor lung transplant samples, the presence and activation phenotype of monocytic cells (low side scatter, 27E10+, CD14+, HLA-DR+, CCR2+) were evaluated by flow cytometry and compared with post-implantation lung function. RESULTS: In mouse lungs following ischaemia-reperfusion, substantial numbers of lung-marginated monocytes remained within the pulmonary microvasculature, with reduced L-selectin and increased CD86 expression indicating their activation. Monocyte depletion resulted in reductions in lung wet:dry ratios, bronchoalveolar lavage fluid protein, and perfusate levels of RAGE, MIP-2 and KC, while monocyte repletion resulted in a partial restoration of the injury. In human lungs, correlations were observed between pre-implantation donor monocyte numbers/their CD86 and TREM-1 expression and post-implantation lung dysfunction at 48 and 72 hours. CONCLUSIONS: These results indicate that lung-marginated intravascular monocytes are retained as a 'passenger' leukocyte population during lung transplantation, and play a key role in the development of transplant-associated ischaemia-reperfusion injury.

Inhibition of TNF Receptor p55 By a Domain Antibody Attenuates the Initial Phase of Acid-Induced Lung Injury in Mice.

BACKGROUND: Tumor necrosis factor-α (TNF) is strongly implicated in the development of acute respiratory distress syndrome (ARDS), but its potential as a therapeutic target has been hampered by its complex biology. TNF signals through two receptors, p55 and p75, which play differential roles in pulmonary edema formation during ARDS. We have recently shown that inhibition of p55 by a novel domain antibody (dAb™) attenuated ventilator-induced lung injury. In the current study, we explored the efficacy of this antibody in mouse models of acid-induced lung injury to investigate the longer consequences of treatment. METHODS: We employed two acid-induced injury models, an acute ventilated model and a resolving spontaneously breathing model. C57BL/6 mice were pretreated intratracheally or intranasally with p55-targeting dAb or non-targeting "dummy" dAb, 1 or 4 h before acid instillation. RESULTS: Acid instillation in the dummy dAb group caused hypoxemia, increased respiratory system elastance, pulmonary inflammation, and edema in both the ventilated and resolving models. Pretreatment with p55-targeting dAb significantly attenuated physiological markers of ARDS in both models. p55-targeting dAb also attenuated pulmonary inflammation in the ventilated model, with signs that altered cytokine production and leukocyte recruitment persisted beyond the very acute phase. CONCLUSION: These results demonstrate that the p55-targeting dAb attenuates lung injury and edema formation in models of ARDS induced by acid aspiration, with protection from a single dose lasting up to 24 h. Together with our previous data, the current study lends support toward the clinical targeting of p55 for patients with, or at risk of ARDS.

Serum biotin in Japanese children: Enzyme-linked immunosorbent assay measurement.

BACKGROUND: Biotin deficiency has been reported in Japanese infants fed special formulas for medical reasons, including those with milk allergy and congenital metabolic diseases, because these formulas contain little biotin. Serum biotin measurement is useful for diagnosing biotin deficiency. We applied a simple and rapid method to analyze serum biotin, and established normal ranges for children and adults. METHODS: Serum biotin in 188 healthy Japanese children aged 0-4 years and in 25 healthy adults was analyzed using a Biotin ELISA Kit (immundiagnostik). The effects of various conditions on the measurement of serum biotin were also examined. RESULTS: Median biotin in children aged 0-4 years was 10.4 ng/dL (IQR, 7.9-13.4 ng/dL), and that in adults was 12.9 ng/dL (IQR, 10.8-15.8 ng/dL). Normal range was 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults (calculated using two-sided 95%CI). Measurements obtained with this method were not affected by frozen storage, freeze-thaw, or hemolysis, indicating that serum biotin can be analyzed accurately under these conditions, with a possible application to plasma samples. CONCLUSIONS: Serum biotin was significantly lower in children than in adults, with the normal range being 4.7-22.0 ng/dL in children and 8.4-20.5 ng/dL in adults. This simple and accurate enzyme-linked immunosorbent assay method is useful for diagnosing biotin deficiency.

Low serum biotin in Japanese children fed with hydrolysate formula.

BACKGROUND: Given that nutritional biotin deficiency in Japanese infants has been reported, a straightforward method for estimating biotin level is needed. The biotin content in infant formula, breast milk, and the sera of infants fed with various types of formula were measured using avidin-binding assay. METHODS: A commercially available ELISA kit was used for the measurement of biotin in 54 types of formula, including hydrolysate formulas for milk allergy, as well as in breast milk and in the sera of 27 infants fed with these formulas. RESULTS: The biotin content reached the recommended value in only five formulas. All of the hydrolysate formulas and more than half of the special formulas contained biotin <0.1 µg/dL. Serum biotin was low in infants fed only with the hydrolysate formulas, and one of them had alopecia related to biotin deficiency. CONCLUSION: While many were asymptomatic, infants fed with formulas lacking biotin are at risk of developing symptomatic disease. The addition of biotin to breast milk substitutes was finally approved in the middle of 2014, however pediatricians in Japan should still be vigilant with regard to nutritional biotin deficiency in infants for the time being.

Post-operative cardiac arrest induced by co-administration of amiodarone and dexmedetomidine: a case report.

We firstly report a postoperative hemodialysis patient who was co-administered with amiodarone and dexmedetomidine and developed severe bradycardia followed by cardiac arrest. A 79-year-old male patient underwent an amputation of the right lower extremity. The electrocardiogram of the patient showed a complete right bundle branch block with left anterior fascicular block before the anesthesia, and paroxysmal atrial tachycardia over 200 beats/min lasting 15 min was observed during surgery. After admission to the intensive care unit, the intensivist and the consultant cardiologist decided to treat tachycardia using amiodarone. The initial dosing of amiodarone and the maintenance infusion succeeded to decrease the heart rate. Approximately 2 h and a half after the start of dexmedetomidine infusion for sedation, the heart rate gradually declined and severe bradycardia suddenly followed by cardiac arrest was observed. Resuscitation was promptly initiated and the patient regained sinus rhythm without delay. In retrospective analysis, the monitoring record of the electrocardiogram revealed the marked atrioventricular conduction abnormalities. This is the first case report concerning a cardiac arrest induced by amiodarone and dexmedetomidine.

Discovery and structure-guided optimization of tert-butyl 6-(phenoxymethyl)-3-(trifluoromethyl)benzoates as liver X receptor agonists.

To obtain potent liver X receptor (LXR) agonists, a structure-activity relationship study was performed on a series of tert-butyl benzoate analogs. As the crystal structure analysis suggested applicable interactions between the LXR ligand-binding domain and the ligands, two key functional groups were introduced. The introduction of the hydroxyl group on the C6-position of the benzoate part enhanced the agonistic activity in a cell-based assay, and the carboxyl group in terminal improved the pharmacokinetic profile in mice, respectively. The obtained compound 32b increased blood ABCA1 mRNA expression without plasma TG elevation in both mice and cynomolgus monkeys.

Influence of glutathione-S-transferase (GST) inhibition on lung epithelial cell injury: role of oxidative stress and metabolism.

Oxidant-mediated tissue injury is key to the pathogenesis of acute lung injury. Glutathione-S-transferases (GSTs) are important detoxifying enzymes that catalyze the conjugation of glutathione with toxic oxidant compounds and are associated with acute and chronic inflammatory lung diseases. We hypothesized that attenuation of cellular GST enzymes would augment intracellular oxidative and metabolic stress and induce lung cell injury. Treatment of murine lung epithelial cells with GST inhibitors, ethacrynic acid (EA), and caffeic acid compromised lung epithelial cell viability in a concentration-dependent manner. These inhibitors also potentiated cell injury induced by hydrogen peroxide (H2O2), tert-butyl-hydroperoxide, and hypoxia and reoxygenation (HR). SiRNA-mediated attenuation of GST-π but not GST-µ expression reduced cell viability and significantly enhanced stress (H2O2/HR)-induced injury. GST inhibitors also induced intracellular oxidative stress (measured by dihydrorhodamine 123 and dichlorofluorescein fluorescence), caused alterations in overall intracellular redox status (as evidenced by NAD(+)/NADH ratios), and increased protein carbonyl formation. Furthermore, the antioxidant N-acetylcysteine completely prevented EA-induced oxidative stress and cytotoxicity. Whereas EA had no effect on mitochondrial energetics, it significantly altered cellular metabolic profile. To explore the physiological impact of these cellular events, we used an ex vivo mouse-isolated perfused lung model. Supplementation of perfusate with EA markedly affected lung mechanics and significantly increased lung permeability. The results of our combined genetic, pharmacological, and metabolic studies on multiple platforms suggest the importance of GST enzymes, specifically GST-π, in the cellular and whole lung response to acute oxidative and metabolic stress. These may have important clinical implications.

The role of ex vivo lung perfusion in lung transplantation.

Whilst lung transplantation is a viable solution for end-stage lung disease, donor shortages, donor lung inflammation and perioperative lung injury remain major limitations. Ex vivo lung perfusion has emerged as the next frontier in lung transplantation to address and overcome these limitations, with multicentre clinical trials ongoing in the UK, rest of Europe and North America. Our research seeks to identify the poorly understood cellular and molecular mechanisms of primary graft dysfunction through the development of an isolated perfused lung model of transplantation and investigation of the role of pulmonary inflammation in this paradigm.

Volutrauma, but not atelectrauma, induces systemic cytokine production by lung-marginated monocytes.

OBJECTIVES: Ventilator-induced lung injury has substantive impact on mortality of patients with acute respiratory distress syndrome. Although low tidal volume ventilation has been shown to reduce mortality, clinical benefits of open-lung strategy are controversial. In this study, we investigated the impact of two distinct forms of ventilator-induced lung injury, i.e., volutrauma and atelectrauma, on the progression of lung injury and inflammation, in particular alveolar and systemic cytokine production. DESIGN: Ex vivo study. SETTING: University research laboratory. SUBJECTS: C57BL/6 mice. INTERVENTIONS: Isolated, buffer-perfused lungs were allocated to one of three ventilatory protocols for 3 hours: control group received low tidal volume (7 mL/kg) with positive end-expiratory pressure (5 cm H2O) and regular sustained inflation; high-stretch group received high tidal volume (30-32 mL/kg) with positive end-expiratory pressure (3 cm H2O) and sustained inflation; and atelectasis group received the same tidal volume as control but neither positive end-expiratory pressure nor sustained inflation. MEASUREMENTS AND MAIN RESULTS: Both injurious ventilatory protocols developed comparable levels of physiological injury and pulmonary edema, measured by respiratory system mechanics and lavage fluid protein. High-stretch induced marked increases in proinflammatory cytokines in perfusate and lung lavage fluid, compared to control. In contrast, atelectasis had no effect on perfusate cytokines compared to control but did induce some up-regulation of lavage cytokines. Depletion of monocytes marginated within the lung microvasculature, achieved by pretreating mice with i.v. liposome-encapsulated clodronate, significantly attenuated perfusate cytokine levels, especially tumor necrosis factor, in the high-stretch, but not atelectasis group. CONCLUSIONS: Volutrauma (high-stretch), but not atelectrauma (atelectasis), directly activates monocytes within the pulmonary vasculature, leading to cytokine release into systemic circulation. We postulate this as a potential explanation why open-lung strategy has limited mortality benefits in ventilated critically ill patients.