The overexpression and misfolding of viral proteins in the endoplasmic reticulum (ER) may cause cellular stress, thereby inducing a cytoprotective, proteostatic host response involving phosphorylation of eukaryotic translation initiation factor 2 subunit alpha (eIF2α). Here, we show that hepatitis A virus, a positive-strand RNA virus responsible for infectious hepatitis, adopts a stress-resistant, eIF2α-independent mechanism of translation to ensure the synthesis of viral proteins within the infected liver. Cap-independent translation directed by the hepatovirus internal ribosome entry site and productive hepatovirus infection of mice both require platelet-derived growth factor subunit A (PDGFA)-associated protein 1 (PDAP1), a small phosphoprotein of unknown function with eIF4E-binding activity.
View Article and Find Full Text PDFAn 81-year-old woman presented to our hospital with dyspnea. She had been treated with trastuzumab for nine years. Chest radiography revealed pleural effusion.
View Article and Find Full Text PDFType III interferons (IFN-λ) are antiviral and immunomodulatory cytokines that have been best characterized in respiratory and gastrointestinal infections, but the effects of IFN-λ against skin infections have not been extensively investigated. We sought to define the skin-specific effects of IFN-λ against the highly prevalent human pathogen, herpes simplex virus (HSV). We infected mice lacking the IFN-λ receptor (), both the IFN-λ and the IFN-α/β receptors (), or IFN-λ cytokines () and found that IFN-λ restricts the severity of HSV-1 and HSV-2 skin lesions without affecting viral loads.
View Article and Find Full Text PDFZoonotic arenavirus infections can result in viral hemorrhagic disease, characterized by platelet loss, petechia, and multi-organ injury. The mechanisms governing these outcomes are likely impacted by virus strain and infection dose, as well as an individual's genetic background and immune constitution. To better understand the processes leading to severe pathogenesis, we compared two strains of inbred mice, C57BL/6J (B6) and FVB/NJ (FVB), that have diametrically opposed outcomes during disseminated lymphocytic choriomeningitis virus (LCMV) infection.
View Article and Find Full Text PDFType III interferons (IFN-λ) are antiviral and immunomodulatory cytokines that have been best characterized in respiratory and gastrointestinal infections, but the effects of IFN-λ against skin infections have not been extensively investigated. We sought to define the skin-specific effects of IFN-λ against the highly prevalent human pathogen herpes simplex virus (HSV). We infected mice lacking the IFN-λ receptor (), both the IFN-λ and the IFN-αβ receptor ( ), or IFN-λ cytokines () and found that IFN-λ restricts the severity of HSV-1 and HSV-2 skin lesions, independent of a direct effect on viral load.
View Article and Find Full Text PDFUnlabelled: A 69-year-old woman was admitted our hospital due to acute cerebral infarction. Transthoracic echocardiography showed massive left ventricular (LV) hypertrophy with small ventricles and normal LV ejection fraction. Apical 4-chamber and longitudinal images showed mild LV obstruction.
View Article and Find Full Text PDFUnlabelled: An 82-year-old woman with parkinsonism and Lewy body dementia was re-admitted to our hospital due to convulsions and the recurrence of cerebral infarction. Parasternal transthoracic echocardiography showed normal left ventricular wall thickness and wall motion. To treat marked bradycardia and hypotension, she underwent temporary pacing.
View Article and Find Full Text PDFA 93-year-old woman was transferred to our hospital for lightheadedness. She had had Takotsubo cardiomyopathy for seven years. Transthoracic apical four-chamber echocardiography showed a large apical aneurysm.
View Article and Find Full Text PDFBackground & Aims: Consistent with its relatively narrow host species range, hepatitis A virus (HAV) cannot infect C57BL/6 mice. However, in Mavs mice with genetic deficiency of the innate immune signaling adaptor MAVS, HAV replicates robustly in the absence of disease. The HAV 3ABC protease cleaves MAVS in human cells, thereby disrupting virus-induced IFN responses, but it cannot cleave murine MAVS (mMAVS) due to sequence differences at the site of scission.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
July 2022
Despite excellent vaccines, resurgent outbreaks of hepatitis A have caused thousands of hospitalizations and hundreds of deaths within the United States in recent years. There is no effective antiviral therapy for hepatitis A, and many aspects of the hepatitis A virus (HAV) replication cycle remain to be elucidated. Replication requires the zinc finger protein ZCCHC14 and noncanonical TENT4 poly(A) polymerases with which it associates, but the underlying mechanism is unknown.
View Article and Find Full Text PDFAn 83-year-old man suddenly lost consciousness, and his blood pressure dropped. Results of blood analysis were within normal range. A chest radiograph showed enlargement of the left mediastinum.
View Article and Find Full Text PDFUnlabelled: A 59-year-old man with systemic sclerosis and interstitial pneumonia was referred to our department because he developed dyspnea and leg edema after receiving a first shot of coronavirus disease 2019 (COVID-19) vaccine. Transthoracic echocardiography showed moderate pericardial effusion with conspicuous fibrin deposition. Prednisolone was increased from 6 mg/day for systemic sclerosis to 20 mg/day.
View Article and Find Full Text PDFBackground: In recent years, transthyretin amyloid cardiomyopathy (ATTR-CM) has received increasing attention; however, the epidemiology of ATTR-CM in Japan is not yet understood. In the Kumamoto Cardiac Amyloid Survey, we evaluated the current incidence, clinical characteristics, diagnostic approaches, and treatment strategies for ATTR-CM and compared tafamidis-prescription hospitals with regional hospitals.
Methods: We conducted a retrospective multicenter observational cohort study.
A 33-year-old woman visited our hospital due to visual loss. Her BP was 280/150 mm Hg and pulse rate was 111 beats per minute. A urinalysis showed protein in urine, suggesting kidney injury.
View Article and Find Full Text PDFHAV-infected Ifnar1-/- mice recapitulate many of the cardinal features of hepatitis A in humans, including serum alanine aminotransferase (ALT) elevation, hepatocellular apoptosis, and liver inflammation. Previous studies implicate MAVS-IRF3 signaling in pathogenesis, but leave unresolved the role of IRF3-mediated transcription versus the non-transcriptional, pro-apoptotic activity of ubiquitylated IRF3. Here, we compare the intrahepatic transcriptomes of infected versus naïve Mavs-/- and Ifnar1-/- mice using high-throughput sequencing, and identify IRF3-mediated transcriptional responses associated with hepatocyte apoptosis and liver inflammation.
View Article and Find Full Text PDFThere are few reports on the current awareness and status of venous ultrasonography, including the number of specialists who perform this procedure, in a specific regional area in Japan. This cross-sectional survey study was conducted in Kumamoto Prefecture from October 2018 to March 2019. Of the 366 medical institutions providing cardiology services in Kumamoto Prefecture, 259 (101 general hospitals, 158 small clinics) responded to our questionnaire.
View Article and Find Full Text PDFBackground & Aims: Hepatitis A virus (HAV) is a common cause of enterically transmitted viral hepatitis. In non-immune individuals, infection results in typically transient but occasionally fulminant and fatal inflammatory liver injury. Virus-specific T cell frequencies peak when liver damage is at its zenith, leading to the prevalent notion that T cells exacerbate liver disease, as suspected for other hepatotropic virus infections.
View Article and Find Full Text PDFA 78-year-old woman was referred to our hospital because of repetitive suppurative arthritis at the artificial left knee joint. Her plasma brain natriuretic peptide level was 122 pg/mL. A 12-lead electrocardiogram showed a QS pattern in the inferior leads.
View Article and Find Full Text PDFIminosugar compounds are monosaccharide mimetics with broad but generally weak antiviral activities related to inhibition of enzymes involved in glycobiology. Miglustat (-butyl-1-deoxynojirimycin), which is approved for the treatment of lipid storage diseases in humans, and UV-4 [-(9-methoxynonyl)-1-deoxynojirimycin] inhibit the replication of hepatitis A virus (HAV) in cell culture (50% inhibitory concentrations [ICs] of 32.13 μM and 8.
View Article and Find Full Text PDFA 73-year-old man visited our hospital due to dyspnea and epigastralgia. His plasma brain natriuretic peptide level was 1,205 pg/mL. A 12-lead electrocardiogram showed ST segment depression in leads I, V5, and V6.
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