Published papers

BACKGROUND: We aimed to elucidate differences in the characteristics of patients with coronavirus disease 2019 (COVID-19) requiring hospitalization in Japan, by COVID-19 waves, from conventional strains to the Delta variant. METHODS: We used secondary data from a database and performed a retrospective cohort study that included 3261 patients aged ≥ 18 years enrolled from 78 hospitals that participated in the Japan COVID-19 Task Force between February 2020 and September 2021. RESULTS: Patients hospitalized during the second (mean age, 53.2 years [standard deviation {SD}, ± 18.9]) and fifth (mean age, 50.7 years [SD ± 13.9]) COVID-19 waves had a lower mean age than those hospitalized during the other COVID-19 waves. Patients hospitalized during the first COVID-19 wave had a longer hospital stay (mean, 30.3 days [SD ± 21.5], p < 0.0001), and post-hospitalization complications, such as bacterial infections (21.3%, p < 0.0001), were also noticeable. In addition, there was an increase in the use of drugs such as remdesivir/baricitinib/tocilizumab/steroids during the latter COVID-19 waves. In the fifth COVID-19 wave, patients exhibited a greater number of presenting symptoms, and a higher percentage of patients required oxygen therapy at the time of admission. However, the percentage of patients requiring invasive mechanical ventilation was the highest in the first COVID-19 wave and the mortality rate was the highest in the third COVID-19 wave. CONCLUSIONS: We identified differences in clinical characteristics of hospitalized patients with COVID-19 in each COVID-19 wave up to the fifth COVID-19 wave in Japan. The fifth COVID-19 wave was associated with greater disease severity on admission, the third COVID-19 wave had the highest mortality rate, and the first COVID-19 wave had the highest percentage of patients requiring mechanical ventilation.

BACKGROUND: Long-term macrolide therapy for non-cystic fibrosis bronchiectasis (NCFB) can play a significant role. However, such data are insufficient regarding the efficacy against severe exacerbation and adverse effects, including the emergence of macrolide-resistant pathogens and prolonged macrolide use beyond 1 year. METHODS: Randomized controlled trials (RCTs) and prospective observational studies comparing the efficacy and safety of macrolides and placebo in adult patients with NCFB were screened on April 10, 2024. The primary outcome was severe exacerbation frequency. RESULTS: Ten RCTs ≤1 year study durations were included. Most studies mainly included patients with a history of >2 exacerbations. Macrolides had a tendency to reduce the frequency of severe exacerbations compared with placebo (odds ratio = 0.54, 95% confidence interval (CI) = 0.25-1.18). Macrolides significantly reduced the frequency of exacerbations (rate ratio = 0.58, 95% CI = 0.48-0.69), prolonged the time to first exacerbation (rate ratio = 0.41, 95% CI = 0.30-0.55), improved the changes in SGRQ scores [mean difference (MD) = -3.99, 95% CI = -4.63-3.44] and percent predicted forced expiratory volume in 1 s (MD = -2.30, 95% CI = 0.26-4.33), and reduced sputum volume (gram) (MD = -7.44, 95% CI = -9.15-5.74). Additionally, macrolides did not increase drug-related adverse events leading to discontinuation. Qualitative SR of pathogens indicated macrolides might increase the number of macrolide-resistant oropharyngeal and sputum pathogens and the emergence of Pseudomonas aeruginosa. CONCLUSIONS: Our results support macrolide therapy for patients with NCFB. Studies with an observation period of >1 year or those focusing on patients with/without a minimal exacerbation history are required to determine the long-term effects on patients with NCFB.

The low vertebral bone computed tomography (CT) Hounsfield unit values measured on CT scans reflect low bone mineral density (BMD) and are known as diagnostic indicators for osteoporosis. The potential prognostic significance of low BMD defined by vertebral bone CT values for the coronavirus disease 2019 (COVID-19) remains unclear. This study aimed to assess the impact of BMD on the clinical outcome in Japanese patients with COVID-19 and evaluate the association between BMD and critical outcomes, such as high-flow nasal cannula, non-invasive and invasive positive pressure ventilation, extracorporeal membrane oxygenation, or death. We examined the effects of COVID-19 severity on the change of BMD over time. This multicenter retrospective cohort study enrolled 1132 inpatients with COVID-19 from the Japan COVID-19 Task Force database between February 2020 and September 2022. The bone CT values of the 4th, 7th, and 10th thoracic vertebrae were measured from chest CT images. The average of these values was defined as BMD. Furthermore, a comparative analysis was conducted between the BMD on admission and its value 3 months later. The low BMD group had a higher proportion of critical outcomes than did the high BMD group. In a subanalysis stratifying patients by epidemic wave according to onset time, critical outcomes were higher in the low BMD group in the 1st-4th waves. Multivariable logistic analysis of previously reported factors associated with COVID-19 severity revealed that low BMD, chronic kidney disease, and diabetes were independently associated with critical outcomes. At 3 months post-infection, patients with oxygen demand during hospitalization showed markedly decreased BMD than did those on admission. Low BMD in patients with COVID-19 may help predict severe disease after the disease onset. BMD may decrease over time in patients with severe COVID-19, and the impact on sequelae symptoms should be investigated in the future.

OBJECTIVE: This study aimed to investigate the clinical features of long COVID cases presenting with upper respiratory symptoms, a topic not yet fully elucidated. STUDY DESIGN: Prospective cohort study. SETTING: A multicenter study involving 26 medical facilities in Japan. METHODS: Inclusion criteria were patients aged ≥18 years old with a confirmed COVID-19 diagnosis via severe acute respiratory syndrome coronavirus 2 polymerase chain reaction or antigen testing, who were hospitalized at the participating medical facilities. Analyzing clinical information and patient-reported outcomes from 1009 patients were analyzed. The outcome measured the degree of initial symptoms for taste or olfactory disorders and assessed the likelihood of these symptoms persisting as long COVID, as well as the impact on quality of life if the upper respiratory symptoms persisted as long COVID. RESULTS: Patients with high albumin, low C-reactive protein, and low lactate dehydrogenase in laboratory tests tended to experience taste or olfactory disorders as part of long COVID. Those with severe initial symptoms had a higher risk of experiencing residual symptoms at 3 months, with an odds ratio of 2.933 (95% confidence interval [CI], 1.282-6.526) for taste disorders and 3.534 (95% CI, 1.382-9.009) for olfactory disorders. Presence of upper respiratory symptoms consistently resulted in lower quality of life scores. CONCLUSION: The findings from this cohort study suggest that severe taste or olfactory disorders as early COVID-19 symptoms correlate with an increased likelihood of persistent symptoms in those disorders as long COVID.

We investigated the association between complete blood count, including neutrophil-to-lymphocyte ratio (NLR) in combination with patient characteristics, and coronavirus disease (COVID-19) outcomes to identify the best prognostic indicator. We analyzed data of patients with confirmed COVID-19 from the nationwide database of the Japan COVID-19 Task Force between February 2020 and November 2021. A composite outcome was defined as the most severe condition, including noninvasive positive-pressure ventilation, high-flow nasal cannula, invasive mechanical ventilation, extracorporeal membrane oxygenation, or death. Of 2425 patients in the analysis, 472 (19.5%) experienced a composite outcome. NLR was the best predictor of composite outcomes, with an area under the curve (AUC) of 0.81, and a sensitivity and specificity of 72.3% and 75.7%, respectively, using a cut-off value of 5.04. The combination of NLR and an oxygen requirement on admission had the highest AUC (0.88). This simple combination may help identify patients at risk of progression to severe disease.

Rationale: Non-cystic fibrosis bronchiectasis (NCFB) may originate in bronchiolar regions of the lung. Accordingly, there is a need to characterize the morphology and molecular characteristics of NCFB bronchioles. Objective: Test the hypothesis that NCFB exhibits a major component of bronchiolar disease manifest by mucus plugging and ectasia. Methods: Morphologic criteria and region-specific epithelial gene expression, measured histologically and by RNA in situ hybridization (RNA-ISH) and immunohistochemistry (IHC), identified proximal and distal bronchioles in excised NCFB lungs. RNA-ISH and IHC assessed bronchiolar mucus accumulation and mucin gene expression. CRISPR-Cas9-mediated IL-1R1 knockout in human bronchial epithelial (HBE) cultures tested IL-1α/β contributions to mucin production. Spatial transcriptional profiling characterized NCFB distal bronchiolar gene expression. Measurements and Main Results: Bronchiolar perimeters and lumen areas/section area were increased in proximal, but not distal, bronchioles in NCFB vs control lungs, suggesting proximal bronchiolectasis. In NCFB, mucus plugging was observed in ectatic proximal bronchioles and associated non-ectatic distal bronchioles in sections with disease. MUC5AC and MUC5B mucins were upregulated in NCFB proximal bronchioles, whereas MUC5B was selectively upregulated in distal bronchioles. Bronchiolar mucus plugs were populated by IL-1β-expressing macrophages. NCFB sterile sputum supernatants induced HBE MUC5B/MUC5AC expression that was >80% blocked by IL-1R1 ablation. Spatial transcriptional profiling identified upregulation of genes associated with secretory cells, hypoxia, interleukin pathways, IL-1β-producing macrophages in mucus plugs, and downregulation of epithelial ciliogenesis genes. Conclusions: NCFB exhibits distinctive proximal and distal bronchiolar disease. Both bronchiolar regions exhibit bronchiolar secretory cell features and mucus plugging but differ in mucin gene regulation and ectasia.

Significance Gaining insights into severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) high transmissibility and the role played by inflammatory mediators in viral proliferation are critical to investigating new therapeutic targets against COVID-19. Electron microscopy reveals important SARS-CoV-2 features, including the combination of large, rapidly released viral clusters and the massive shedding of epithelial cells packed with virions. Interleukin-13 (IL-13), a Th2 cytokine up-regulated in allergic asthma and associated with less severe COVID-19, protects against SARS-CoV-2 viral and cell shedding. Using gene expression analyses and biochemical assays, IL-13 is shown to affect viral entry, replication, and cell-to-cell transmission. Given the broad spectrum of COVID-19 clinical symptoms, it is important to elucidate intrinsic factors that modulate viral load and spreading mechanisms.

A subset of individuals who recover from coronavirus disease 2019 (COVID-19) develop post-acute sequelae of SARS-CoV-2 (PASC), but the mechanistic basis of PASC-associated lung abnormalities suffers from a lack of longitudinal tissue samples. The mouse-adapted severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) strain MA10 produces an acute respiratory distress syndrome (ARDS) in mice similar to humans. To investigate PASC pathogenesis, studies of MA10-infected mice were extended from acute to clinical recovery phases. At 15 to 120 days post-virus clearance, pulmonary histologic findings included subpleural lesions composed of collagen, proliferative fibroblasts, and chronic inflammation, including tertiary lymphoid structures. Longitudinal spatial transcriptional profiling identified global reparative and fibrotic pathways dysregulated in diseased regions, similar to human COVID-19. Populations of alveolar intermediate cells, coupled with focal up-regulation of pro-fibrotic markers, were identified in persistently diseased regions. Early intervention with antiviral EIDD-2801 reduced chronic disease, and early anti-fibrotic agent (nintedanib) intervention modified early disease severity. This murine model provides opportunities to identify pathways associated with persistent SARS-CoV-2 pulmonary disease and test countermeasures to ameliorate PASC.

RATIONALE: Identification of the specific cell types expressing CFTR is required for precision medicine therapies for cystic fibrosis (CF). However, a full characterization of CFTR expression in normal human airway epithelia is missing. OBJECTIVES: To identify the cell types that contribute to CFTR expression and function within the proximal-distal axis of the normal human lung. METHODS: Single cell RNA-seq (scRNA-seq) was performed on freshly isolated human large and small airway epithelial cells. Single cell-based RNA in situ hybridization (scRNA-ISH) and quantitative RT-PCR (scqRT-PCR) were performed for validation. In vitro culture systems correlated CFTR function to cell types. Lentiviruses were used for cell-type specific transduction of wild-type CFTR in CF cells. MEASUREMENTS AND MAIN RESULTS: scRNA-seq identified secretory cells as dominating CFTR expression in normal human large and particularly small airway superficial epithelia, followed by basal cells. Ionocytes expressed the highest CFTR levels but were rare, while expression in ciliated cells was infrequent and low. scRNA-ISH, and scqRT-PCR confirmed the scRNA-seq findings. CF lungs exhibited distributions of CFTR and ionocytes similar to normal controls. CFTR-mediated Cl- secretion in culture tracked secretory cell, not ionocyte, densities. Further, the nucleotide-purinergic regulatory system that controls CFTR-mediated hydration was associated with secretory cells, and not ionocytes. Lentiviral transduction of wild-type CFTR produced CFTR-mediated Cl- secretion in CF airway secretory cells but not ciliated cells. CONCLUSIONS: Secretory cells dominate CFTR expression and function in human airway superficial epithelia. CFTR therapies may need to restore CFTR function to multiple cell types, with a focus on secretory cells.

Airway epithelial cells (AECs) play an essential role in the immune response during bacterial pneumonia. Secreted and transmembrane 1a (Sectm1a) is specifically expressed in AECs during early Streptococcus pneumoniae (SP) infection. However, its function remains largely unexplored. Here, we aimed to clarify the function of Sectm1a during serotype 3 pneumococcal pneumonia primarily using an in vivo mouse model. Our findings showed that type Ⅰ interferons (IFNs) directly induced Sectm1a expression in AECs. Sectm1a depletion in an in vivo mouse model improved survival rate and enhanced the clearance of intrapulmonary bacterial burden at an early stage of SP infection. Correspondingly, Sectm1a depletion increased the count of intrapulmonary γδT cells, promoted IL-17A production by these cells, and enhanced intrapulmonary neutrophil responses against SP. Notably, IL-17A production in the isolated lung γδT cells was directly suppressed by Sectm1a ex vivo. Furthermore, Sectm1a depletion altered the migration and activation markers of γδT cells in vivo, indicating that the AEC-derived Sectm1a is associated with the phenotypes of γδT cells. These findings suggest that type Ⅰ IFNs may play an important role via AEC-derived Sectm1a in this model, and Sectm1a signaling modulates excessive neutrophil inflammation and influences bacterial clearance by directly altering γδT cell functions during pneumococcal pneumonia. In summary, this study demonstrates that the type Ⅰ IFN-Sectm1a pathway could be a potential target to modify the acute response to bacterial pneumonia.

BACKGROUND: Krebs von den Lungen-6 (KL-6) is a known biomarker for diagnosis and monitoring of interstitial lung diseases. However, the role of serum KL-6 and the mucin 1 (MUC1) variant (rs4072037) in COVID-19 outcomes remains to be elucidated. We aimed to evaluate the relationships among serum KL-6 levels, critical outcomes and the MUC1 variant in Japanese patients with COVID-19. METHODS: This is a secondary analysis of a multicentre retrospective study using data from the Japan COVID-19 Task Force collected from February 2020 to November 2021, including 2226 patients with COVID-19 whose serum KL-6 levels were measured. An optimal serum KL-6 level cut-off to predict critical outcomes was determined and used for multivariable logistic regression analysis. Furthermore, the relationship among the allele dosage of the MUC1 variant, calculated from single nucleotide polymorphism typing data of genome-wide association studies using the imputation method, serum KL-6 levels and COVID-19 critical outcomes was evaluated. RESULTS: Serum KL-6 levels were significantly higher in patients with COVID-19 with critical outcomes (511±442 U/mL) than those without (279±204 U/mL) (p<0.001). Serum KL-6 levels ≥304 U/mL independently predicted critical outcomes (adjusted OR (aOR) 3.47, 95% CI 2.44 to 4.95). Moreover, multivariable logistic regression analysis with age and sex indicated that the MUC1 variant was independently associated with increased serum KL-6 levels (aOR 0.24, 95% CI 0.28 to 0.32) but not significantly associated with critical outcomes (aOR 1.11, 95% CI 0.80 to 1.54). CONCLUSION: Serum KL-6 levels predicted critical outcomes in Japanese patients with COVID-19 and were associated with the MUC1 variant. Therefore, serum KL-6 level is a potentially useful biomarker of critical COVID-19 outcomes.

BACKGROUND AND OBJECTIVE: The lack of useful biomarkers reflecting the disease state limits the management of Mycobacterium avium complex lung disease (MAC-LD). We clarified the associations between serum KL-6 level, disease progression and treatment response. METHODS: Resected lung tissues from MAC-LD patients were immunostained for KL-6. We compared serum KL-6 levels between MAC-LD and healthy control or bronchiectasis patients without nontuberculous mycobacterial lung disease (NTM-LD). Serum KL-6 level was assessed in a prospective observational study at Keio University Hospital between May 2012 and May 2016. We investigated associations between serum KL-6 level and disease progression and treatment response in patients untreated for MAC-LD on registration (n = 187). RESULTS: The KL-6+ alveolar type 2 cell population in the lung and serum KL-6 level were significantly higher in MAC-LD patients than in controls. Serum KL-6 level in bronchiectasis patients without NTM-LD showed no significant increase. Of the 187 patients who did not receive treatment on registration, 53 experienced disease progression requiring treatment. Multivariable Cox analysis revealed that the serum KL-6 level (aHR: 1.18, P = 0.005), positive acid-fast bacilli smear (aHR: 2.64, P = 0.001) and cavitary lesions (aHR: 3.01, P < 0.001) were significantly associated with disease progression. The change in serum KL-6 (ΔKL-6) was significantly higher in the disease progression group; it decreased post-treatment, reflecting the negative sputum culture conversion. CONCLUSION: Serum KL-6 level is associated with disease progression and treatment response. Longitudinal assessment combined with AFB smear status and presence of cavitary lesions may aid MAC-LD management.

Mechanisms underpinning the dysfunctional immune response in severe acute respiratory syndrome coronavirus 2 infection are elusive. We analyzed single-cell transcriptomes and T and B cell receptors (BCR) of >895,000 peripheral blood mononuclear cells from 73 coronavirus disease 2019 (COVID-19) patients and 75 healthy controls of Japanese ancestry with host genetic data. COVID-19 patients showed a low fraction of nonclassical monocytes (ncMono). We report downregulated cell transitions from classical monocytes to ncMono in COVID-19 with reduced CXCL10 expression in ncMono in severe disease. Cell–cell communication analysis inferred decreased cellular interactions involving ncMono in severe COVID-19. Clonal expansions of BCR were evident in the plasmablasts of patients. Putative disease genes identified by COVID-19 genome-wide association study showed cell type-specific expressions in monocytes and dendritic cells. A COVID-19-associated risk variant at the IFNAR2 locus (rs13050728) had context-specific and monocyte-specific expression quantitative trait loci effects. Our study highlights biological and host genetic involvement of innate immune cells in COVID-19 severity.

OBJECTIVE: To reveal the clinical features and assess risk factors linked to brain fog and its societal implications, including labor productivity, providing valuable insights for the future care of individuals who have experienced coronavirus disease 2019 (COVID-19). METHODS: We analyzed a comprehensive cohort dataset comprising 1,009 patients with COVID-19 admitted to Japanese hospitals. To assess brain fog, we analyzed patients who responded to a questionnaire indicating symptoms such as memory impairment and poor concentration. RESULTS: The prevalence of brain fog symptoms decreased 3 months posthospitalization but remained stable up to 12 months. Neurological symptoms such as taste and smell disorders and numbness at hospitalization correlated with a higher frequency of identifying brain fog as a long COVID manifestation. Our findings indicated that advanced age, female sex, a high body mass index, oxygen required during hospitalization, chronic obstructive pulmonary disease, asthma, and elevated C-reactive protein and elevated D-dimer levels were risk factors in patients exhibiting brain fog. Additionally, we demonstrated the negative impact of brain fog on labor productivity by presenteeism scores. INTERPRETATIONS: This study clarified the clinical characteristics of patients experiencing brain fog as a long COVID manifestation, specifically emphasizing neurological symptoms during hospitalization and their correlation with brain fog. Additionally, the study identified associated risk factors for its onset and revealed that the emergence of brain fog was linked to a decline in labor productivity.

Background: Tuberculosis (TB) is endemic in many low-income countries, which can affect the spine in 1%–5% of those with an active infection. This study reports the clinical characteristics of patients admitted for spinal TB in Kabul, Afghanistan, a country with very limited resources. Methods: This was a descriptive study among 26 patients treated for spinal TB in three major referral hospitals in Kabul, Afghanistan, between March 2019 and April 2020. The sociodemographic and clinical details, gender, age, site of infection, presenting complaints, signs, and symptoms of the patients were retrieved from their medical records. Summary statistics were analyzed using SPSS version 20. Ethics approval was obtained from the ethics committee of Shahid Beheshti University of Medical Sciences in Tehran, Iran. Results: Data were available for 26 patients with spinal TB admitted consecutively. The mean age of the sample was 38.2 years (SD 17.5), and there were 16 males and 10 females. Median time from symptom onset to hospital admission was 60 days. The most common diagnostic imaging technique used was magnetic resonance imaging (92.3%), followed by computed tomography (7.7%). The majority of the lesions involved the lumbar spine (61.4%), followed by the thoracolumbar spine (30.8%). Back pain was the most common manifestation in 21 patients (80.8%), and varying degrees of neurological impairment were found in 16 (61.5%) patients. There were no deaths among the patients up to the discharge date. Conclusions: This study describes the clinical characteristics of spinal TB among patients in Kabul, Afghanistan. It is essential to strengthen preventive strategies and to improve health awareness about clinical features of spinal TB in patients with chronic back pain even in the absence of signs of TB.

BACKGROUND: Cutis laxa constitutes a diverse group of connective tissue diseases, both inherited and acquired, characterized by loose skin and varying systemic involvement, including pulmonary lesions. While cutis laxa has been linked to conditions like emphysema, asthma, and bronchiectasis, the specific pathological and radiological characteristics underlying pulmonary complications related to cutis laxa remain unclear. CASE PRESENTATION: A 36-year-old woman, diagnosed with cutis laxa at birth, presented to our outpatient clinic with severe obstructive ventilatory impairment, evident in pulmonary function tests (expiratory volume in one second (FEV1)/forced vital capacity (FVC): 34.85%; %residual volume [RV]: 186.5%; %total lung capacity [TLC]: 129.2%). Pulmonary function tests also indicated small airway disease (%FEF50%, 7.9%; %FEF75%, 5.7%; and %FEF25-75%, 6.8%). Computed tomography (CT) revealed the lack of normal increase in lung attenuation on expiratory CT scan, with no discernible emphysematous changes. Exome sequencing was performed to confirm the association between the pulmonary lesions and cutis laxa, revealing a frameshift variant in exon 30 of the elastin gene (ELN). Further analysis employing a parametric response map revealed a longitudinal increase in the percentage of functional small airway disease (fSAD) from 37.84% to 46.61% over the 8-year follow-up, despite the absence of overt changes in CT findings, specifically the lack of normal increase in lung attenuation on expiratory CT scan. Over the same follow-up interval, there was a modest reduction of 25.6 mL/year in FEV1 coupled with a significant increase in %RV. Pulmonary function test metrics, reflective of small airway disease, exhibited a continual decline; specifically, %FEF50%, %FEF75%, and %FEF25-75% diminished from 7.9% to 7.0%, 5.7% to 4.6%, and 6.8% to 5.4%, respectively. CONCLUSIONS: This case highlighted an instance of autosomal dominant cutis laxa arising from a frameshift variant in exon 30 of ELN, accompanied by small airway disease. Comprehensive investigation, utilizing quantitative CT analysis, revealed a longitudinal increase in fSAD percentage with a mild reduction in FEV1. These findings indicate that elastin deficiency may not only diminish elastic fibers in the skin but also be implicated in small airway disease by impacting components of the extracellular matrix in the lungs.

OBJECTIVES: We examined shifts in labor productivity and their economic ramifications among adult patients with long COVID in Japan. METHODS: A total of 396 patients were categorized into three groups based on symptom progression: non-long COVID, long COVID recovered, and long COVID persistent. Patient-reported outcomes were assessed at three time intervals: 3, 6, and 12 months after COVID-19 diagnosis. Labor productivity was gauged through presenteeism and absenteeism, measured using the World Health Organization Health and Work Performance Questionnaire. RESULTS: Long COVID was observed in 52.7% of patients, and 29.3% of all the patients continued to experience long COVID symptoms 1 year after diagnosis. At all three time points (3, 6, and 12 months after diagnosis), the long COVID persistent group showed a statistically significant difference in absolute presenteeism compared with the non-long COVID and long COVID recovered groups (P <0.01). Economic loss owing to decrease in labor productivity was calculated as $21,659 per year in the long COVID persistent group and $9008 per year in the long COVID recovered group (P <0.01). CONCLUSION: The study's results revealed a notable decline in labor productivity over time, underscoring the importance of early detection and intervention to mitigate the socio-economic repercussions of long COVID, in addition to its health implications.