A Cysteine Residue of Human Cytomegalovirus vMIA Protein Plays a Crucial Role in Viperin Trafficking to Control Viral Infectivity.

Viperin is a multifunctional interferon-inducible protein that is directly induced in cells by human cytomegalovirus (HCMV) infection. The viral mitochondrion-localized inhibitor of apoptosis (vMIA) interacts with viperin at the early stages of infection and translocates it from the endoplasmic reticulum to the mitochondria, where viperin modulates the cellular metabolism to increase viral infectivity. Viperin finally relocalizes to the viral assembly compartment (AC) at late stages of infection. Despite the importance of vMIA interactions with viperin during viral infection, their interacting residues are unknown. In the present study, we showed that cysteine residue 44 (Cys44) of vMIA and the N-terminal domain (amino acids [aa] 1 to 42) of viperin are necessary for their interaction and for the mitochondrial localization of viperin. In addition, the N-terminal domain of mouse viperin, which is structurally similar to that of human viperin, interacted with vMIA. This indicates that the structure, rather than the sequence composition, of the N-terminal domain of viperin, is required for the interaction with vMIA. Recombinant HCMV, in which Cys44 of vMIA was replaced by an alanine residue, failed to translocate viperin to the mitochondria at the early stages of infection and inefficiently relocalized it to the AC at late stages of infection, resulting in the impairment of viperin-mediated lipid synthesis and a reduction in viral replication. These data indicate that Cys44 of vMIA is therefore essential for the intracellular trafficking and function of viperin to increase viral replication. Our findings also suggest that the interacting residues of these two proteins are potential therapeutic targets for HCMV-associated diseases. IMPORTANCE Viperin traffics to the endoplasmic reticulum (ER), mitochondria, and viral assembly compartment (AC) during human cytomegalovirus (HCMV) infection. Viperin has antiviral activity at the ER and regulates cellular metabolism at the mitochondria. Here, we show that Cys44 of HCMV vMIA protein and the N-terminal domain (aa 1 to 42) of viperin are necessary for their interaction. Cys44 of vMIA also has a critical role for viperin trafficking from the ER to the AC via the mitochondria during viral infection. Recombinant HCMV expressing a mutant vMIA Cys44 has impaired lipid synthesis and viral infectivity, which are attributed to mislocalization of viperin. Cys44 of vMIA is essential for the trafficking and function of viperin and may be a therapeutic target for HCMV-associated diseases.

Murine Coronavirus Disease 2019 Lethality Is Characterized by Lymphoid Depletion Associated with Suppressed Antigen-Presenting Cell Functionality.

The disease severity of coronavirus disease 2019 (COVID-19) varies considerably from asymptomatic to serious, with fatal complications associated with dysregulation of innate and adaptive immunity. Lymphoid depletion in lymphoid tissues and lymphocytopenia have both been associated with poor disease outcomes in patients with COVID-19, but the mechanisms involved remain elusive. In this study, human angiotensin-converting enzyme 2 (hACE2) transgenic mouse models susceptible to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection were used to investigate the characteristics and determinants of lethality associated with the lymphoid depletion observed in SARS-CoV-2 infection. The lethality of Wuhan SARS-CoV-2 infection in K18-hACE2 mice was characterized by severe lymphoid depletion and apoptosis in lymphoid tissues related to fatal neuroinvasion. The lymphoid depletion was associated with a decreased number of antigen-presenting cells (APCs) and their suppressed functionality below basal levels. Lymphoid depletion with reduced APC function was a specific feature observed in SARS-CoV-2 infection but not in influenza A infection and had the greatest prognostic value for disease severity in murine COVID-19. Comparison of transgenic mouse models resistant and susceptible to SARS-CoV-2 infection revealed that suppressed APC function could be determined by the hACE2 expression pattern and interferon-related signaling. Thus, we demonstrated that lymphoid depletion associated with suppressed APC function characterizes the lethality of COVID-19 mouse models. Our data also suggest a potential therapeutic approach to prevent the severe progression of COVID-19 by enhancing APC functionality.

Efficacy and safety of MC-003 solution for endoscopic mucosal or submucosal resection: a prospective, multicenter, randomized, triple-blinded, parallel-group, phase III study.

BACKGROUND AND AIMS: The safety and efficacy of solutions for submucosal injection are critical for endoscopic resection of gastric adenomas or early gastric cancers. Although several injectable solutions have been introduced for endoscopic resection, they have some limitations. We aimed to compare the efficacy of the new sodium alginate-based solution MC-003 with that of normal saline (NS; 0.9% sodium chloride). METHODS: In this randomized, triple-blind study, 70 patients were initially enrolled for EMR or endoscopic submucosal dissection (ESD). The main outcomes included the need for additional injections, completion of en bloc resection, and occurrence of adverse events. RESULTS: Each group ultimately included 34 patients. Complete en bloc resections were achieved in all patients (P = 1.000). The MC-003 group had more peri-neoplasm tissue fibrosis (P = .056) and needed fewer additional injections for lesions >15 mm (P = .037), located in the distal portion of the stomach (P = .007), and during ESD procedures (P = .001). The adverse event rate was comparable in both groups. CONCLUSIONS: MC-003 outperformed NS in reducing the need for additional injections during en bloc resection, particularly in larger lesions located in the distal portion of the stomach (where most lesions were found) during ESD procedures, without increasing the incidence of serious adverse events. MC-003 is a promising submucosal injectable solution in real-world clinical settings.

Factors influencing re-bleeding after trans-arterial embolization for endoscopically unmanageable peptic ulcer bleeding.

BACKGROUND/AIMS: Acute peptic ulcer bleeding is the most common cause of non-variceal upper gastrointestinal bleeding (NVUGIB). Endoscopic hemostasis is the standard treatment. However, various conditions complicate endoscopic hemostasis. Transarterial visceral embolization (TAE) may be helpful as a rescue therapy. This study aimed to investigate the factors associated with rebleeding after TAE. METHODS: We retrospectively investigated the records of 156 patients treated with TAE between January 2007 and December 2021. Rebleeding was defined as the presence of melena, hematemesis, or hematochezia, with a fall (>2.0 g/dl) in hemoglobin level or shock after TAE. The primary outcomes were rebleeding rate and 30-day mortality. RESULTS: Seventy patients with peptic ulcer bleeding were selected, and rebleeding within a month after TAE occurred in 15 patients (21.4%). Among the patients included in rebleeding group, significant increases were observed in the prevalence of thrombocytopenia (73.3% vs. 16.4%, p<.001) and ulcers >1 cm (93.3% vs 54.5%, p = .014). The mean AIMS65 (albumin, international normalized ratio, mental status, systolic blood pressure, age >65 years) score (2.3 vs 1.4, p = .009) was significantly higher in the rebleeding group. Multivariate logistic analysis revealed that thrombocytopenia (odds ratio 31.92, 95% confidence interval 6.24-270.6, p<.001) and larger ulcer size (odds ratio 27.19, 95% confidence interval 3.27-677.7, p=.010) significantly increased the risk of rebleeding after TAE. CONCLUSION: TAE was effective in the treatment of patients with high-risk peptic ulcer bleeding. AIMS65 score was a significant predictor of rebleeding after TAE, and thrombocytopenia and larger ulcer size increased the risk of rebleeding after TAE.

Endoscopic resection and laparoscopic lymph node dissection for early gastric cancer beyond conventional endoscopic treatment indications: a 10-year outcome study.

BACKGROUND: Endoscopic full-thickness gastric resection (EFTGR) with laparoscopic regional lymph node dissection (LLND) and endoscopic submucosal dissection (ESD) with LLND have been investigated as treatment options for early gastric cancer beyond the absolute indications for ESD. However, comparative studies on the long-term outcomes of these procedures are lacking. This study aimed to analyze and compare the 10-year outcomes of both procedures in a real clinical setting. METHODS: Between January 2009 and December 2013, 28 and 37 patients diagnosed with EGC beyond the absolute indications for ESD were treated with EFTGR with LLND and ESD with LLND, respectively. In both procedures, the dye was injected into the tumor. However, after injection and LLND, EFTGR was performed immediately in the EFTGR with LLND group, whereas LLND was followed by ESD in the ESD with LLND group. The primary endpoint was the 10-year survival rate. RESULTS: The EFTGR with LLND group had one case of local recurrence (3.6%) and mortality (3.6%) each, while the ESD with LLND group had none (0.0% for both); however, the differences were not statistically significant (P = 0.247 for each). Furthermore, there was no significant difference in complications such as ischemia and anastomosis leakage between the groups (P = 0.247). CONCLUSIONS: When the procedures were properly applied, EFTGR with LLND and ESD with LLND did not increase the 10-year mortality in patients with EGC beyond the absolute ESD indications compared with conventional radical gastrectomy.

Da Vinci robot-assisted endoscopic full-thickness gastric resection with regional lymph node dissection using a 3D near-infrared video system: a single-center 5-year clinical outcome.

BACKGROUND: Endoscopic full-thickness gastric resection (EFTGR) with regional lymph node dissection (LND) has been used for early gastric cancer (EGC) exceeding the indications for endoscopic submucosal dissection (ESD). The extent of the dissected lymph nodes is crucial. A 3D near-infrared (NIR) video robot system significantly enhances visualization of the lymphatic system. However, this system has not been used in EFTGR with LND. Thus, this study assessed the benefits of the 3D NIR video robot system in a clinical setting. METHODS: Between February 2015 and September 2018, 24 patients with EGC exceeding the indications for ESD were treated with EFTGR and LND using a 3D NIR video system with the da Vinci surgical robot. Indocyanine green (ICG) was injected endoscopically around the tumor, and basin node (BN) dissection around the nodes was examined using the 3D NIR video system of the da Vinci Si surgical robot. Subsequently, robot-assisted EFTGR was performed. The primary outcome was the 5-year survival rate. RESULT: During a 5-year follow-up of all 24 patients, an 80-year-old patient with an ulcer and T2 invasion was lost to follow-up. Among the remaining 23 patients, no mortality or recurrence was observed. CONCLUSION: No metastasis or mortality occurred using the da Vinci robot-assisted EFTGR with LLND and a 3D NIR video system for patients who required radical gastrectomy for EGC in over 5 years. Hence, this may be a safe and effective method for radical gastrectomy; further studies are required confirming its effectiveness.

Establishment of multicenter COVID-19 therapeutics preclinical test system in Republic of Korea.

Throughout the recent COVID-19 pandemic, South Korea led national efforts to develop vaccines and therapeutics for SARS-CoV-2. The project proceeded as follows: 1) evaluation system setup (including Animal Biosafety Level 3 (ABSL3) facility alliance, standardized nonclinical evaluation protocol, and laboratory information management system), 2) application (including committee review and selection), and 3) evaluation (including expert judgment and reporting). After receiving 101 applications, the selection committee reviewed pharmacokinetics, toxicity, and efficacy data and selected 32 final candidates. In the nonclinical efficacy test, we used golden Syrian hamsters and human angiotensin-converting enzyme 2 transgenic mice under a cytokeratin 18 promoter to evaluate mortality, clinical signs, body weight, viral titer, neutralizing antibody presence, and histopathology. These data indicated eight new drugs and one repositioned drug having significant efficacy for COVID-19. Three vaccine and four antiviral drugs exerted significant protective activities against SARS-CoV-2 pathogenesis. Additionally, two anti-inflammatory drugs showed therapeutic effects on lung lesions and weight loss through their mechanism of action but did not affect viral replication. Along with systematic verification of COVID-19 animal models through large-scale studies, our findings suggest that ABSL3 multicenter alliance and nonclinical evaluation protocol standardization can promote reliable efficacy testing against COVID-19, thus expediting medical product development.

Clinical outcomes of Dieulafoy's lesion compared with peptic ulcer in upper gastrointestinal bleeding.

BACKGROUND AND AIM: Although Dieulafoy's lesion (DL) is an important cause of nonvariceal upper gastrointestinal (GI) bleeding, few studies have investigated the clinico-epidemiological outcomes due to its rarity. Here, we investigated clinical features of upper GI bleeding caused by peptic ulcer (PU) or DL and compared endoscopic treatment outcomes. METHODS: Patients with upper GI bleeding resulting from PU or DL who visited emergency room between January 2013 and December 2017 were eligible. Clinical features and treatment outcomes were retrospectively investigated. RESULTS: Overall, 728 patients with upper GI bleeding due to PU (n = 669) and DL (n = 59) were enrolled. The median age was 64 years (interquartile range [IQR], 56-75 years), and 74.3% were male. Endoscopic intervention was performed in 53.7% (n = 359) and 98.3% (n = 58) of the PU and DL groups, respectively (P < 0.0001). Patients were matched by sex, age, body mass index, comorbidity, and past medical history, and 190 PU and 52 DL were finally selected. The rebleeding rates within 7 (7.37% vs 17.31%, P = 0.037) and 30 (7.37% vs 26.92%, P < 0.001) days after initial endoscopy were significantly lower in the PU than in the DL group after propensity score matching. During the median follow-up period of 52 months (IQR, 34-70 months), there was no difference in overall survival rate (67.9% vs 82.7%, P = 0.518). CONCLUSIONS: Although DL is a rare cause of upper GI bleeding, it requires endoscopic hemostasis more frequently and has a higher rate of rebleeding than PU even after therapeutic endoscopy. Endoscopists should pay attention and perform active endoscopic hemostasis for DL bleeding.

Clinical outcomes of marginal ulcer bleeding compared with those of peptic ulcer bleeding.

BACKGROUND: Marginal ulcer bleeding (MUB) is a complication that can occur following several types of surgery. However, few studies exist on it. Therefore, this study aimed to compare the clinical outcomes of MUB with those of peptic ulcer bleeding (PUB). METHODS: Between January 2013 and December 2017, 5,076 patients underwent emergent esophagogastroduodenoscopy for suspected upper gastrointestinal bleeding. We retrospectively reviewed and analyzed the medical records of MUB and PUB patients and developed a propensity score matching (PSM) method to adjust for between-group differences in baseline characteristics with 1:2 ratios. Sex, age, body mass index (BMI), underlying diseases, and drugs were included as matching factors. RESULTS: A total of 64 and 678 patients were diagnosed with MUB and PUB, respectively, on emergent esophagogastroduodenoscopy, and 62 and 124 patients with MUB and PUB, respectively, were selected after PSM. Rebleeding was significantly higher in patients with MUB than in those with PUB (57.8% vs 9.1%, p < 0.001). Mortality caused by bleeding was higher in patients with MUB than in those with PUB (4.7% vs. 0.4%, p < 0.001). Multivariate analysis revealed that proton pump inhibitor (PPI) administration (odds ratio [OR], 0.14; 95% confidence interval [CI], 0.03-0.56; p = 0.011) after first bleeding was inversely correlated with MUB rebleeding. Large ulcer size (> 1 cm) (OR, 6.69; 95% CI, 1.95-27.94; p = 0.005) and surgery covering pancreas (OR, 3.97; 95% CI, 1.19-15.04) were independent risk factors for MUB rebleeding. CONCLUSIONS: MUB showed a severe clinical course than PUB. Therefore, MUB should be managed more cautiously, especially for large ulcers and pancreatic surgery. Prophylactic PPI administration may be helpful in reducing rebleeding in MUB.

Broad humoral and cellular immunity elicited by one-dose mRNA vaccination 18 months after SARS-CoV-2 infection.

BACKGROUND: Practical guidance is needed regarding the vaccination of coronavirus disease 2019 (COVID-19) convalescent individuals in resource-limited countries. It includes the number of vaccine doses that should be given to unvaccinated patients who experienced COVID-19 early in the pandemic. METHODS: We recruited COVID-19 convalescent individuals who received one or two doses of an mRNA vaccine within 6 or around 18 months after a diagnosis of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection. Their samples were assessed for IgG-binding or neutralizing activity and cell-mediated immune responses against SARS-CoV-2 wild-type and variants of concern. RESULTS: A total of 43 COVID-19 convalescent individuals were analyzed in the present study. The results showed that humoral and cellular immune responses against SARS-CoV-2 wild-type and variants of concern, including the Omicron variant, were comparable among patients vaccinated within 6 versus around 18 months. A second dose of vaccine did not significantly increase immune responses. CONCLUSION: One dose of mRNA vaccine should be considered sufficient to elicit a broad immune response even around 18 months after a COVID-19 diagnosis.

Intrinsic expression of viperin regulates thermogenesis in adipose tissues.

Viperin is an interferon (IFN)-inducible multifunctional protein. Recent evidence from high-throughput analyses indicates that most IFN-inducible proteins, including viperin, are intrinsically expressed in specific tissues; however, the respective intrinsic functions are unknown. Here we show that the intrinsic expression of viperin regulates adipose tissue thermogenesis, which is known to counter metabolic disease and contribute to the febrile response to pathogen invasion. Viperin knockout mice exhibit increased heat production, resulting in a reduction of fat mass, improvement of high-fat diet (HFD)-induced glucose tolerance, and enhancement of cold tolerance. These thermogenic phenotypes are attributed to an adipocyte-autonomous mechanism that regulates fatty acid ß-oxidation. Under an HFD, viperin expression is increased, and its function is enhanced. Our findings reveal the intrinsic function of viperin as a novel mechanism regulating thermogenesis in adipose tissues, suggesting that viperin represents a molecular target for thermoregulation in clinical contexts.

The implications of clinical risk factors, CAR index, and compositional changes of immune cells on hyperprogressive disease in non-small cell lung cancer patients receiving immunotherapy.

BACKGROUND: Immune checkpoint blockades (ICBs) are characterized by a durable clinical response and better tolerability in patients with a variety of advanced solid tumors. However, we not infrequently encounter patients with hyperprogressive disease (HPD) exhibiting paradoxically accelerated tumor growth with poor clinical outcomes. This study aimed to investigate implications of clinical factors and immune cell composition on different tumor responses to immunotherapy in patients with non-small cell lung cancer (NSCLC). METHODS: This study evaluated 231 NSCLC patients receiving ICBs between January 2014 and May 2018. HPD was defined as a > 2-fold tumor growth kinetics ratio during ICB therapy and time-to-treatment failure of ≤2 months. We analyzed clinical data, imaging studies, periodic serologic indexes, and immune cell compositions in tumors and stromata using multiplex immunohistochemistry. RESULTS: Of 231 NSCLC patients, PR/CR and SD were observed in 50 (21.6%) and 79 (34.2%) patients, respectively and 26 (11.3%) patients met the criteria for HPD. Median overall survival in poor response groups (HPD and non-HPD PD) was extremely shorter than disease-controlled group (SD and PR/CR) (5.5 and 6.1 months vs. 16.2 and 18.3 months, respectively, P = 0.000). In multivariate analysis, HPD were significantly associated with heavy smoker (p = 0.0072), PD-L1 expression ≤1% (p = 0.0355), and number of metastatic site ≥3 (p = 0.0297). Among the serologic indexes including NLR, PLR, CAR, and LDH, only CAR had constantly significant correlations with HPD at the beginning of prior treatment and immunotherapy, and at the 1st tumor assessment. The number of CD4+ effector T cells and CD8+ cytotoxic T cells, and CD8+/PD-1+ tumor-infiltrating lymphocytes (TIL) tended to be smaller, especially in stromata of HPD group. More M2-type macrophages expressing CD14, CD68 and CD163 in the stromal area and markedly fewer CD56+ NK cells in the intratumoral area were observed in HPD group. CONCLUSIONS: Our study suggests that not only clinical factors including heavy smoker, very low PD-L1 expression, multiple metastasis, and CAR index, but also fewer CD8+/PD-1+ TIL and more M2 macrophages in the tumor microenvironment are significantly associated with the occurrence of HPD in the patients with advanced/metastatic NSCLC receiving immunotherapy.

Distinct functional domains within the acidic cluster of tegument protein pp28 required for trafficking and cytoplasmic envelopment of human cytomegalovirus.

Human cytomegalovirus UL99-encoded tegument protein pp28 contains a 16 aa acidic cluster that is required for pp28 trafficking to the assembly compartment (AC) and the virus assembly. However, functional signals within the acidic cluster of pp28 remain undefined. Here, we demonstrated that an acidic cluster rather than specific sorting signals was required for trafficking to the AC. Recombinant viruses with chimeric pp28 proteins expressing non-native acidic clusters exhibited delayed viral growth kinetics and decreased production of infectious virus, indicating that the native acidic cluster of pp28 was essential for wild-type virus assembly. These results suggested that the acidic cluster of pp28 has distinct functional domains required for trafficking and for efficient virus assembly. The first half (aa 44-50) of the acidic cluster was sufficient for pp28 trafficking, whereas the native acidic cluster consisting of aa 51-59 was required for the assembly of wild-type levels of infectious virus.

Targeting ODC1 inhibits tumor growth through reduction of lipid metabolism in human hepatocellular carcinoma.

Ornithine decarboxylase 1 (ODC1), a metabolic enzyme critically involved in the polyamine biosynthesis, is commonly upregulated in hepatocellular carcinoma (HCC). Despite its altered expression in human HCC tissues, the molecular mechanism by which ODC1 alters the course of HCC progression and functions in HCC cell survival is unknown. Here we identified that silencing of ODC1 expression with small interfering (si) RNA causes inhibition of HCC cell growth through blockade of cell cycle progression and induction of apoptosis. Next, to obtain insights into the molecular changes in response to ODC1 knockdown, global changes in gene expression were examined using RNA sequencing. It revealed that 119 genes show same directional regulation (76 up- and 43 down-regulated) in both Huh1 and Huh7 cells and were considered as a common ODC1 knockdown signature. Particularly, we found through a network analysis that KLF2, which is known to inhibit PPARγ expression and adipogenesis, was commonly up-regulated. Subsequent Western blotting affirmed that the downregulation of ODC1 was accompanied by a decrease in the levels of PPARγ as well as of PARP-1, cyclin E1 and pro-caspase 9 delaying cell cycle progression and accelerating apoptotic signaling. Following the down-regulation of PPARγ expression, ODC1 silencing resulted in a strong inhibition in the expression of important regulators of glucose transport and lipid biogenesis, and caused a marked decrease in lipid droplet accumulation. In addition, ODC1 silencing significantly inhibited the growth of human HCC xenografts in nude mice. These findings indicate that the function of ODC1 is correlated with HCC lipogenesis and suggest that targeting ODC1 could be an attractive option for molecular therapy of HCC.

Viperin regulates cellular lipid metabolism during human cytomegalovirus infection.

Human cytomegalovirus (HCMV) has been shown to induce increased lipogenesis in infected cells, and this is believed to be required for proper virion envelopment. We show here that this increase is a consequence of the virus-induced redistribution of the host protein viperin to mitochondria and its capacity to interact with and block the function of the mitochondrial trifunctional protein (TFP), the enzyme that mediates fatty acid-ß-oxidation. The resulting decrease in cellular ATP levels activates the enzyme AMP-activated protein kinase (AMPK), which induces expression of the glucose transporter GLUT4, resulting in increased glucose import and translocation to the nucleus of the glucose-regulated transcription factor ChREBP. This induces increased transcription of genes encoding lipogenic enzymes, increased lipid synthesis and lipid droplet accumulation, and generation of the viral envelope. Viperin-dependent lipogenesis is required for optimal production of infectious virus. We show that all of these metabolic outcomes can be replicated by direct targeting of viperin to mitochondria in the absence of HCMV infection, and that the motif responsible for Fe-S cluster binding by viperin is essential. The data indicate that viperin is the major effector underlying the ability of HCMV to regulate cellular lipid metabolism.

Predicting Helicobacter pylori infection from endoscopic features.

BACKGROUND: Helicobacter pylori infection, prevalent in more than half of the global population, is associated with various gastrointestinal diseases, including peptic ulcers and gastric cancer. The effectiveness of early diagnosis and treatment in preventing gastric cancer highlights the need for improved diagnostic methods. This study aimed to develop a simple scoring system based on endoscopic findings to predict H. pylori infection. METHODS: A retrospective analysis was conducted on 1,007 patients who underwent upper gastrointestinal endoscopy at Asan Medical Center from January 2019 to December 2021. Exclusion criteria included prior H. pylori treatment, gastric surgery, or gastric malignancies. Diagnostic techniques included rapid urease and 13C-urea breath tests, H. pylori culture, and assessment of endoscopic features following the Kyoto gastritis classification. A new scoring system based on endoscopic findings including regular arrangement of collecting venules (RAC), nodularity, and diffuse or spotty redness was developed for predicting H. pylori infection, utilizing logistic regression analysis in the development set. RESULTS: The scoring system demonstrated high predictive accuracy for H. pylori infection in the validation set. Scores of 2 and 3 were associated with 96% and 99% infection risk, respectively. Additionally, there was a higher prevalence of diffuse redness and sticky mucus in cases where the initial H. pylori eradication treatment failed. CONCLUSION: Our scoring system showed potential for improving diagnostic accuracy in H. pylori infection. H. pylori testing should be considered upon spotty redness, diffuse redness, nodularity, and RAC absence on endoscopic findings as determined by the predictive scoring system.

A longitudinal molecular and cellular lung atlas of lethal SARS-CoV-2 infection in K18-hACE2 transgenic mice.

BACKGROUND: The global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to approximately 500 million cases and 6 million deaths worldwide. Previous investigations into the pathophysiology of SARS-CoV-2 primarily focused on peripheral blood mononuclear cells from patients, lacking detailed mechanistic insights into the virus's impact on inflamed tissue. Existing animal models, such as hamster and ferret, do not faithfully replicate the severe SARS-CoV-2 infection seen in patients, underscoring the need for more relevant animal system-based research. METHODS: In this study, we employed single-cell RNA sequencing (scRNA-seq) with lung tissues from K18-hACE2 transgenic (TG) mice during SARS-CoV-2 infection. This approach allowed for a comprehensive examination of the molecular and cellular responses to the virus in lung tissue. FINDINGS: Upon SARS-CoV-2 infection, K18-hACE2 TG mice exhibited severe lung pathologies, including acute pneumonia, alveolar collapse, and immune cell infiltration. Through scRNA-seq, we identified 36 different types of cells dynamically orchestrating SARS-CoV-2-induced pathologies. Notably, SPP1+ macrophages in the myeloid compartment emerged as key drivers of severe lung inflammation and fibrosis in K18-hACE2 TG mice. Dynamic receptor-ligand interactions, involving various cell types such as immunological and bronchial cells, defined an enhanced TGFß signaling pathway linked to delayed tissue regeneration, severe lung injury, and fibrotic processes. INTERPRETATION: Our study provides a comprehensive understanding of SARS-CoV-2 pathogenesis in lung tissue, surpassing previous limitations in investigating inflamed tissues. The identified SPP1+ macrophages and the dysregulated TGFß signaling pathway offer potential targets for therapeutic intervention. Insights from this research may contribute to the development of innovative diagnostics and therapies for COVID-19. FUNDING: This research was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (2020M3A9I2109027, 2021R1A2C2004501).

Immune Cells Are Differentially Affected by SARS-CoV-2 Viral Loads in K18-hACE2 Mice.

Viral load and the duration of viral shedding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) are important determinants of the transmission of coronavirus disease 2019. In this study, we examined the effects of viral doses on the lung and spleen of K18-hACE2 transgenic mice by temporal histological and transcriptional analyses. Approximately, 1×105 plaque-forming units (PFU) of SARS-CoV-2 induced strong host responses in the lungs from 2 days post inoculation (dpi) which did not recover until the mice died, whereas responses to the virus were obvious at 5 days, recovering to the basal state by 14 dpi at 1×102 PFU. Further, flow cytometry showed that number of CD8+ T cells continuously increased in 1×102 PFU-virus-infected lungs from 2 dpi, but not in 1×105 PFU-virus-infected lungs. In spleens, responses to the virus were prominent from 2 dpi, and number of B cells was significantly decreased at 1×105 PFU; however, 1×102 PFU of virus induced very weak responses from 2 dpi which recovered by 10 dpi. Although the defense responses returned to normal and the mice survived, lung histology showed evidence of fibrosis, suggesting sequelae of SARS-CoV-2 infection. Our findings indicate that specific effectors of the immune response in the lung and spleen were either increased or depleted in response to doses of SARS-CoV-2. This study demonstrated that the response of local and systemic immune effectors to a viral infection varies with viral dose, which either exacerbates the severity of the infection or accelerates its elimination.

Differential Diagnosis of Thickened Gastric Wall between Hypertrophic Gastritis and Borrmann Type 4 Advanced Gastric Cancer.

Background/Aims: : Accurately diagnosing diffuse gastric wall thickening is challenging. Hypertrophic gastritis (HG), while benign, mimics the morphology of Borrmann type 4 advanced gastric cancer (AGC B-4). We compared the features of endoscopy and endoscopic ultrasonography (EUS) between them. Methods: : We retrospectively reviewed patients who underwent EUS for gastric wall thickening between 2000 and 2021, selecting HG and pathologically confirmed advanced gastric cancer cases. Ulceration and antral wall thickening were determined via endoscopy, while EUS assessed the 5-layered gastric wall structure, measuring the proper muscle (PM) layer and total wall thickness. Results: : Male dominance was observed in AGC B-4, and the hemoglobin and albumin levels were significantly lower. The rate of antral wall thickening and presence of ulceration were significantly higher in AGC B-4 cases. Destruction of the PM layers was observed only in AGC B-4 cases, and the PM was significantly thicker in AGC B-4 cases. Forceps biopsy had an excellent success rate in ulcer-present AGC B-4 cases, but only a 42.6% success rate was observed for cases without ulcers, necessitating additional diagnostic modalities. A PM thickness of 2.39 mm distinguished between AGC B-4 and HG effectively. The multivariable analysis showed that a thickened PM layer and the presence of ulceration were significant risk factors for the diagnosis of AGC B-4. Conclusions: : Endoscopic findings of a thickened gastric wall, including antral involvement, and presence of ulcer were significant risk factors for the diagnosis of AGC B-4. EUS findings of destroyed wall layers and a thickened PM of >2.39 mm were the key points of differentiation between HG and AGC B-4.

Small Bowel Variceal Bleeding in Patients with Liver Cirrhosis Treated with Transarterial Embolization: Case Series.

Small bowel variceal bleeding is a rare cause of gastrointestinal hemorrhage, with clinical manifestations ranging from asymptomatic incidental findings to life-threatening conditions. The diagnosis and management of small bowel bleeding are challenging because of the localization of the lesion and the difficulty of the procedure. Trans-arterial embolization (TAE) is a secure and straightforward method for treating ectopic varices. On the other hand, there have been limited local studies on the outcomes of TAE for patients with small bowel variceal hemorrhage. This paper reports patients diagnosed with small bowel variceal bleeding and treated with TAE.