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Abstract Introduction This study aimed to evaluate the effectiveness of ensitrelvir, an oral antiviral, in reducing hospitalization risk in outpatients at high-risk for severe COVID-19 during the Omicron era. Methods This was a retrospective study using a large Japanese health insurance claims database. It included high-risk outpatients for severe symptoms who received their first COVID-19 diagnosis between November 2022 and July 2023. The study included outpatients aged ≥ 18 years. The primary endpoint was all-cause hospitalization during the 4-week period from the date of outpatient diagnosis and medication, comparing the ensitrelvir group (n = 5177) and the no antiviral treatment group (n = 162,133). The risk ratio and risk difference were evaluated after adjusting patient background distribution by the inverse probability of treatment weight (IPTW) method. Secondary endpoints were incidence of respiratory and heart rate monitoring, oxygen therapy, ventilator use, intensive care admission, and all-cause death. Results The risk ratio for all-cause hospitalization between the ensitrelvir group (n = 167,385) and the no antiviral treatment group (n = 167,310) after IPTW adjustment was 0.629 [95% confidence interval (CI) 0.420, 0.943]. The risk difference was − 0.291 [95% CI − 0.494, − 0.088]. The incidence of both respiratory and heart rate monitoring and oxygen therapy was lower in the ensitrelvir group. Ventilator use, intensive care admission, and all-cause death were difficult to assess because of the limited events. Conclusions The incidence of all-cause hospitalization was significantly lower in the ensitrelvir group than in the no antiviral treatment group, suggesting ensitrelvir is an effective treatment in patients at risk of severe COVID-19.

Abstract Lung tissue resident memory (TRM) cells are thought to play crucial roles in lung host defense. We have recently shown that immunization with the adjuvant LTA1 (derived from the A1 domain of E. coli heat labile toxin) admixed with OmpX from K. pneumoniae can elicit antigen specific lung Th17 TRM cells that provide serotype independent immunity to members of the Enterobacteriaceae family. However, the upstream requirements to generate these cells are unclear. Single-cell RNA-seq showed that vaccine-elicited Th17 TRM cells expressed high levels of IL-1R1, suggesting that IL-1 family members may be critical to generate these cells. Using a combination of genetic and antibody neutralization approaches, we show that Th17 TRM cells can be generated independent of caspase-1 but are compromised when IL-1α is neutralized. Moreover IL-1α could serve as a molecular adjuvant to generate lung Th17 TRM cells independent of LTA1. Taken together, these data suggest that IL-1α plays a major role in vaccine-mediated lung Th17 TRM generation.

Objectives: In the present study, we aimed to clarify the mechanisms by which periodontal pathogens, particularly Prevotella intermedia, induce severe neutrophilic inflammation. In addition, we aimed to test the efficacy of macrolides, which has not been resolved in the neutrophilic inflammation induced by P. intermedia. Methods: NCl-H292 human airway epithelial cells were pre-incubated with clarithromycin for 2 h before incubation with P. intermedia supernatants. Then, C-X-C motif chemokine ligand 8 (CXCL8) transcription and interleukin (IL)-8 production were measured. To elucidate the signaling pathway, mitogen-activated protein kinase inhibitors were added to the cell culture, and the cells were subjected to Western blotting. Results:P. intermedia supernatants promoted CXCL8 transcription and IL-8 production, and the reactions were significantly suppressed by clarithromycin pretreatment. Only trametinib, the selective mitogen-activated extracellular signal-regulated kinase inhibitor, downregulated CXCL8 transcription and IL-8 production. Furthermore, Western blotting revealed that stimulation with P. intermedia supernatants specifically induces extracellular signal-regulated kinases (ERK) 1/2 phosphorylation, which is suppressed by clarithromycin pretreatment. Notably, the interference analysis revealed that ERK3 might be dispensable for IL-8 production under the stimulation of P. intermedia supernatants. Conclusions: Our results provide new insight into the mechanism underlying P. intermedia-induced production of IL-8 from human airway epithelial cells. Furthermore, macrolides might have therapeutic potential in regulating periodontal pathogen-induced neutrophilic inflammation in the lungs.

Candida vulturna is a recently discovered and not widely documented ascomycetous yeast phylogenetically related to the outbreak-causing and multidrug-resistant Candida auris. A middle-aged Japanese man with no discernible immunodeficiency was admitted to hospital with ileal diverticulitis. Following laparoscopic right hemicolectomy against abscess formation on postoperative day (POD) 7, continuous fungemia occurred due to Candida haemulonii, identified using a conventional method by confirming the biochemical phenotype. Micafungin was initiated; however, the fungus was persistently isolated from blood cultures. Eventually, the antifungal agent was changed to a combination of liposomal amphotericin B (L-AMB) and caspofungin (CPFG), which cleared the infection, and no pathogens were detected in the blood cultures on POD 31. Contrast-enhanced computed tomography showed septic emboli in the lungs and spleen; however, no evidence of vasculitis was observed. Moreover, sequential echocardiography did not reveal any signs of infectious endocarditis. Finally, CPFG and L-AMB were administered to the patient for 7 and 9 weeks, respectively, during which the patient's symptoms did not relapse. The strain was later genetically identified as C. vulturna. This case report illustrates a clinical presentation of C. vulturna and provides the diagnostic approach and treatment methods for this pathogen.

ABSTRACTInvasive aspergillosis (IA) and mucormycosis are life-threatening diseases, especially among immunocompromised patients. Drug-resistant Aspergillus fumigatus strains have been isolated worldwide, which can pose a serious clinical problem. As IA mainly occurs in patients with compromised immune systems, the ideal therapeutic approach should aim to bolster the immune system. In this study, we focused on Vγ9Vδ2 T cells that exhibit immune effector functions and examined the possibility of harnessing this unconventional T cell subset as a novel therapeutic modality for IA. A potent antifungal effect was observed when A. fumigatus (Af293) hyphae were challenged by Vγ9Vδ2 T cells derived from peripheral blood. In addition, Vγ9Vδ2 T cells exhibited antifungal activity against hyphae of all Aspergillus spp., Cunninghamella bertholletiae, and Rhizopus microsporus but not against their conidia. Furthermore, Vγ9Vδ2 T cells also exhibited antifungal activity against azole-resistant A. fumigatus, indicating that Vγ9Vδ2 T cells could be used for treating drug-resistant A. fumigatus. The antifungal activity of Vγ9Vδ2 T cells depended on cell-to-cell contact with A. fumigatus hyphae, and degranulation characterized by CD107a mobilization seems essential for this activity against A. fumigatus. Vγ9Vδ2 T cells could be developed as a novel modality for treating IA or mucormycosis.IMPORTANCEInvasive aspergillosis (IA) and mucormycosis are often resistant to treatment with conventional antifungal agents and have a high mortality rate. Additionally, effective antifungal treatment is hindered by drug toxicity, given that both fungal and human cells are eukaryotic, and antifungal agents are also likely to act on human cells, resulting in adverse effects. Therefore, the development of novel therapeutic agents specifically targeting fungi is challenging. This study demonstrated the antifungal activity of Vγ9Vδ2 T cells against various Aspergillus spp. and several Mucorales in vitro and discussed the mechanism underlying their antifungal activity. We indicate that adoptive immunotherapy using Vγ9Vδ2 T cells may offer a new therapeutic approach to IA.

Abstract Factors affecting the start date of the influenza epidemic season and total number of infected persons per 1,000,000 population in 47 prefectures of Japan were evaluated. This retrospective observational study (September 2014–August 2019; N = 472,740–883,804) evaluated data from a Japanese health insurance claims database. Single and multiple regression analyses evaluated the time to start of the epidemic or total infected persons per 1,000,000 population with time to absolute humidity (AH) or number of days with AH (≤ 5.5, ≤ 6.0, ≤ 6.5, and ≤ 7.0), total visitors (first epidemic month or per day), and total population. For the 2014/15, 2015/16, and 2016/17 seasons, a weak-to-moderate positive correlation (R2: 0.042–0.417) was observed between time to start of the epidemic and time to first day with AH below the cutoff values. Except in the 2016/17 season (R2: 0.089), a moderate correlation was reported between time to start of the epidemic and the total population (R2: 0.212–0.401). For all seasons, multiple regression analysis showed negative R2 for time to start of the epidemic and total visitors and population density (positive for time to AH ≤ 7.0). The earlier the climate becomes suitable for virus transmission and the higher the human mobility (more visitors and higher population density), the earlier the epidemic season tends to begin.

Objective Epidemiological information is essential in providing appropriate empiric antimicrobial therapy for pneumonia. This study aimed to clarify the epidemiology of community-acquired pneumonia (CAP) by conducting a systematic review of published studies in Japan.Design Systematic review.Data source PubMed and Ichushi web database (January 1970 to October 2022).Eligibility criteria Clinical studies describing pathogenic micro-organisms in CAP written in English or Japanese, excluding studies on pneumonia other than adult CAP, investigations limited to specific pathogens and case reports.Data extraction and synthesis Patient setting (inpatient vs outpatient), number of patients, concordance with the CAP guidelines, diagnostic criteria and methods for diagnosing pneumonia pathogens as well as the numbers of each isolate. A meta-analysis of various situations was performed to measure the frequency of each aetiological agent.Results Fifty-six studies were included and 17 095 cases of CAP were identified. Pathogens were undetectable in 44.1% (95% CI 39.7% to 48.5%). Streptococcus pneumoniae was the most common cause of CAP requiring hospitalisation or outpatient care (20.0% (95% CI 17.2% to 22.8%)), followed by Haemophilus influenzae (10.8% (95% CI 7.3% to 14.3%)) and Mycoplasma pneumoniae (7.5% (95% CI 4.6% to 10.4%)). However, when limited to CAP requiring hospitalisation, Staphylococcus aureus was the third most common at 4.9% (95% CI 3.9% to 5.8%). Pseudomonas aeruginosa was more frequent in hospitalised cases, while atypical pathogens were less common. Methicillin-resistant S. aureus accounted for 40.7% (95% CI 29.0% to 52.4%) of S. aureus cases. In studies that used PCR testing for pan-respiratory viral pathogens, human enterovirus/human rhinovirus (9.4% (95% CI 0% to 20.5%)) and several other respiratory pathogenic viruses were detected. The epidemiology varied depending on the methodology and situation.Conclusion The epidemiology of CAP varies depending on the situation, such as in the hospital versus outpatient setting. Viruses are more frequently detected by exhaustive genetic searches, resulting in a significant variation in epidemiology.

Abstract Background Mixed neuroendocrine carcinoma (NEC) and hepatocellular carcinoma (HCC) is extremely rare, thus radiological features have not been fully clarified. Case A male patient (age: 70 years) visited our hospital due to a tumor in the liver. Examination using contrast‐enhanced computed tomography (CT) revealed a tumor (diameter: 5.0 cm) in hepatic segment 5, with early enhancement of the peripheral area and slight internal heterogeneous enhancement in the arterial and delayed phases, respectively. F‐18 fluorodeoxyglucose (FDG)‐positron emission tomography (PET)/CT revealed intratumoral heterogeneity, characterized by increased uptake (standardized uptake value, 12.10) in the corresponding low‐density area detected using enhanced CT relative to the surrounding areas of the tumor. On magnetic resonance imaging, diffusion‐weighted imaging also showed high intensity in the corresponding low‐density area detected using CT. Preoperatively, the patient was diagnosed with HCC and underwent anterior sectionectomy. Pathological findings revealed both HCC and NEC components, and the patient was diagnosed with mixed NEC and HCC. Comparison of component distribution with FDG‐PET/CT revealed an increased uptake area was congruent with the NEC component in the tumor. Conclusion In this case, the difference in tumor components affected the uptake in FDG‐PET/CT. Such heterogeneous uptake with an enhanced spot may be useful for suspecting the presence of mixed NEC and HCC in patients with atypical HCC.

Studies indicated potential harm from empirical broad-spectrum therapy. A recent study of hospitalizations for community-acquired pneumonia suggested that empirical anti-methicillin-resistant Staphylococcus aureus (MRSA) therapy was associated with an increased risk of death and other complications. However, limited evidence supports empirical anti-MRSA therapy for older patients with aspiration pneumonia. In a nationwide Japanese database, patients aged ≥65 years on admission with aspiration pneumonia were analyzed. Patients were divided based on presence of respiratory failure and further sub-categorized based on their condition within 3 days of hospital admission, either receiving a combination of anti-MRSA agents and other antibiotics, or not using MRSA agents. An inverse probability weighting method with estimated propensity scores was used. Out of 81,306 eligible patients, 55,098 had respiratory failure, and 26,208 did not. In the group with and without respiratory failure, 0.93% and 0.42% of the patients, respectively, received anti-MRSA agents. In patients with respiratory failure, in-hospital mortality (31.38% vs. 19.03%, p < 0.001), 30-day mortality, and 90-day mortality were significantly higher, and oxygen administration length was significantly longer in the anti-MRSA agent combination group. Anti-MRSA agent combination use did not improve the outcomes in older patients with aspiration pneumonia and respiratory failure, and should be carefully and comprehensively considered.

Outbreaks of invasive infections, with high mortality rates, caused by multidrug-resistant Candida auris have been reported worldwide. Although hotspot mutations in FKS1 are an established cause of echinocandin resistance, the actual contribution of these mutations to echinocandin resistance remains unknown. Here, we sequenced the FKS1 gene of a caspofungin-resistant clinical isolate (clade I) and identified a novel resistance mutation (G4061A inducing R1354H). We applied the clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9 system to generate a recovered strain (H1354R) in which only this single nucleotide mutation was reverted to its wild-type sequence. We also generated mutant strains with only the R1354H mutation introduced into C. auris wild-type strains (clade I and II) and analyzed their antifungal susceptibility. Compared to their parental strains, the R1354H mutants exhibited a 4- to 16-fold increase in caspofungin minimum inhibitory concentration (MIC) while the H1354R reverted strain exhibited a 4-fold decrease in caspofungin MIC. In a mouse model of disseminated candidiasis, the in vivo therapeutic effect of caspofungin was more closely related to the FKS1 R1354H mutation and the virulence of the strain than its in vitro MIC. The CRISPR-Cas9 system could thus aid in elucidating the mechanism underlying drug resistance in C. auris.

Summary: SARS-CoV-2, the etiologic agent of COVID-19, uses ACE2 as a cell entry receptor. Soluble ACE2 has been shown to have neutralizing antiviral activity but has a short half-life and no active transport mechanism from the circulation into the alveolar spaces of the lung. To overcome this, we constructed an ACE2-human IgG1 fusion protein with mutations in the catalytic domain of ACE2. A mutation in the catalytic domain of ACE2, MDR504, significantly increased binding to SARS-CoV-2 spike protein, as well as to a spike variant, in vitro with more potent viral neutralization in plaque assays. Parental administration of the protein showed stable serum concentrations with excellent bioavailability in the epithelial lining fluid of the lung, and ameliorated lung SARS-CoV-2 infection in vivo. These data support that the MDR504 hACE2-Fc is an excellent candidate for treatment or prophylaxis of COVID-19 and potentially emerging variants.

Abstract Background Rapid diagnosis and appropriate treatment of Munchausen syndrome is important not only for the patient but also for health care workers because a delay in diagnosis can worsen patients’ clinical outcomes, and result in a substantial medical cost. Case presentation A young and previously healthy 24-year-old Japanese woman, a nurse, presented with complaints of refractory abscess on her left upper limb for 3 months. A physical examination on admission revealed low-grade fever and a subcutaneous abscess in her left forearm. Laboratory data suggested mild systemic inflammation and liver dysfunction, but no abnormalities of the immune system, including changes in the number of lymphocytes and neutrophils, neutrophil phagocytic capacity, and natural killer (NK) cell activity, were observed. A human immunodeficiency virus test was also negative. Multiple modalities, including positron emission tomography-computed tomography, failed to detect any cause and focus of infection except her left upper limb. Streptococcus mitis and Prevotella buccae were detected from the wound, but no microorganisms were detected in a blood culture. The cellulitis promptly resolved; however, exacerbation of the subcutaneous abscess with polymicrobial bacteremia repeatedly occurred unexpectedly. Because of this puzzling clinical course, the possibility of self-injury was finally suspected. Three syringes with needles, with a turbid liquid, were found in our patient’s bag. Enterobacter cloacae and Enterococcus faecalis were detected in the liquid, and an analysis via repetitive element sequence-based polymerase chain reaction determined that Enterococcus faecalis in the wound and syringe contents were genetically identical. She was diagnosed as having Munchausen syndrome and treated with the collaboration of a psychiatrist. She finally confessed that she had injected her own saliva and toilet water into the drip line and wound. Conclusions This case report is valuable in that it is the first case in which this syndrome was diagnosed by a genetic method. Munchausen syndrome should not be neglected as a possible cause of refractory and recurrent infection.

Severe fever with thrombocytopenia syndrome (SFTS) and Japanese spotted fever (JSF; a spotted fever group rickettsiosis) are tick-borne zoonoses that are becoming a significant public health threat in Japan and East Asia. Strategies for treatment and infection control differ between the two; therefore, initial differential diagnosis is important. We aimed to compare the clinical characteristics of SFTS and JSF based on symptomology, physical examination, laboratory data, and radiography findings at admission. This retrospective study included patients with SFTS and JSF treated at five hospitals in Nagasaki Prefecture, western Japan, between 2013 and 2020. Data from 23 patients with SFTS and 38 patients with JSF were examined for differentiating factors and were divided by 7:3 into a training cohort and a validation cohort. Decision tree analysis revealed leukopenia (white blood cell [WBC] < 4000/μL) and altered mental status as the best differentiating factors (AUC 1.000) with 100% sensitivity and 100% specificity. Using only physical examination factors, absence of skin rash and altered mental status resulted in the best differentiating factors with AUC 0.871, 71.4% sensitivity, and 90.0% specificity. When treating patients with suspected tick-borne infection, WBC < 4000/µL, absence of skin rash, and altered mental status are very useful to differentiate SFTS from JSF.

Although, free fascia lata autografts can be used to reconstruct various anatomical structures, little information is available about the status of such autografts several years after the procedure, especially in a clinical setting. Here, we describe our experience with a patient who underwent relaparotomy two years after incisional hernia repair using a fascia lata graft. A 79-year-old man underwent open hepatectomy for hepatocellular carcinoma. One year later, abdominal computed tomography revealed a locally recurrent tumor 1.5 cm in diameter and a giant incisional hernia measuring approximately 15×6 cm on the supraumbilical midline. After repeat hepatectomy, the incisional hernia was repaired using a free fascia lata patch as an interpositional graft. Two years later, the patient was readmitted because of recurrent tumors in the liver, and repeat hepatectomy was performed. During surgery, the fascia lata graft had survived well and become incorporated into the native fascia. We incised this fascia lata graft in the same way as for a normal laparotomy. After hepatectomy, the fascia lata graft was closed in layers with interrupted sutures. The patient was discharged on postoperative day 11 with no wound-related morbidity.

Despite a considerable number of reports of Mirizzi syndrome, none have described the process of its development from simple cholecystolithiasis. We report an extremely rare case of Mirizzi syndrome in which it was possible to observe the process of development of cholecystobiliary fistula from asymptomatic cholecystolithiasis until unavoidable surgical intervention 4 years later. A 68-year-old woman presented at our hospital with right upper quadrant pain. She had been diagnosed as having asymptomatic cholecystolithiasis 4 years previously. Diagnostic abdominal computed tomography (CT) had revealed a 1.9 cm radiopaque stone, and thereafter, the patient had been monitored by imaging alone. CT conducted 6 months before the present admission revealed that the gallbladder stone was compressing the common hepatic duct, although the patient remained asymptomatic. On admission, abdominal CT showed that the gallbladder stone was obstructing the common bile duct with dilatation of the intrahepatic duct. Endoscopic retrograde cholangiopancreatography revealed a round filling defect at the confluence of the common bile duct and the image of the cystic duct; therefore, the patient was categorized as having Mirizzi syndrome type III, according to the Csendes classification. Intraoperative findings revealed a cholecystobiliary fistula involving up to two-thirds of the circumference of the common bile duct.

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by the SFTS virus. It involves multiple organ systems, including the lungs. However, the significance of the lung involvement in SFTS remains unclear. In the present study, we aimed to investigate the relationship between the clinical findings and abnormalities noted in the chest computed tomography (CT) of patients with SFTS. The medical records of 22 confirmed SFTS patients hospitalized in five hospitals in Nagasaki, Japan, between April 2013 and September 2019, were reviewed retrospectively. Interstitial septal thickening and ground-glass opacity (GGO) were the most common findings in 15 (68.1%) and 12 (54.5%) patients, respectively, and lung GGOs were associated with fatalities. The SFTS patients with a GGO pattern were elderly, had a disturbance of the conscious and tachycardia, and had higher c-reactive protein levels at admission (p = 0.009, 0.006, 0.002, and 0.038, respectively). These results suggested that the GGO pattern in patients with SFTS displayed disseminated inflammation in multiple organs and that cardiac stress was linked to higher mortality. Chest CT evaluations may be useful for hospitalized patients with SFTS to predict their severity and as early triage for the need of intensive care.

Background: The aim of this study was to evaluate the effectiveness of a modified reconstruction technique-anchored straight stomach reconstruction-in reducing the incidence of delayed gastric emptying (DGE) after pancreaticoduodenectomy (PD) and its impact on postoperative nutritional recovery. Methods: A case series analysis of 125 consecutive PD patients was conducted: 104 of them had undergone anchored straight stomach reconstruction (SSR group) and the remaining 21 without (Non-SSR group). The incidence of DGE and the change in postoperative nutritional status (body weight and serum albumin level during 12 months post-surgery) were compared. Results: The incidence of DGE in the SSR group (13%) was significantly lower than that in the Non-SSR group (33%) (P = .018); further the significant DGE (grade B or C) was only 5%. Comparison of nutritional status showed that SSR facilitated a prompt recovery of body weight and serum albumin level at 6 months after PD. At 12 months after surgery, body weight gain was significantly better in the SSR group than in the Non-SSR group (P = .006), and albumin level tended to be higher in the SSR group (P = .071). Conclusion: Straight stomach reconstruction is able to reduce DGE in patients after PD and also improves their postoperative nutritional recovery. [ABSTRACT FROM AUTHOR]

Background: Cryptococcal meningitis (CM) is an invasive fungal infection with a poor prognosis that often occurs in both healthy individuals and compromised hosts, such as patients infected with human immunodeficiency virus (HIV). Unlike CM in HIV patients, evidence regarding CM in non-HIV patients is limited to small retrospective studies. Objective: To identify the pretreatment prognostic factors for CM in non-HIV patients. Methods: We conducted a large retrospective analysis of CM in non-HIV patients using data from a nationwide Japanese database. The study included hospitalized patients diagnosed with CM between 1 April 2010 and 31 March 2017. All-cause mortality was compared between patients with CM with and without HIV infection. Poor diagnostic factors were analysed in the non-HIV CM group. Results: Overall, 533 (64 HIV and 469 non-HIV) patients met the criteria. The mortality rate at 90 days was significantly lower in the HIV group (6.3% vs. 25.4% p = .0002). In a logistic regression analysis of the non-HIV group, age = 65 y (odds ratio [OR] 2.37, 95% CI 1.17-4.78), impaired consciousness (Japan Coma Scale =1) (OR 2.25, 95% CI 1.29-3.93), haemodialysis (OR 3.53, 95% CI 1.12-11.20) and previous corticosteroid usage (OR 2.40, 95% CI 1.37-4.19) were associated with poor prognosis at 30 days after diagnosis. Conclusion: More caution is suggested when treating non-HIV with CM in older patients with impaired consciousness, previous corticosteroid usage and haemodialysis. [ABSTRACT FROM AUTHOR]