COVID-19 severity is associated with the risk of gastrointestinal bleeding.

OBJECTIVE: The association between the severity of COVID-19 and gastrointestinal (GI) bleeding is unknown. This study aimed to determine whether the severity of COVID-19 is a risk factor for GI bleeding. DESIGN: A multicentre, retrospective cohort study was conducted on hospitalised patients with COVID-19 between January 2020 and December 2021. The severity of COVID-19 was classified according to the National Institute of Health severity classification. The primary outcome was the occurrence of GI bleeding during hospitalisation. The main analysis compared the relationship between the severity of COVID-19 and the occurrence of GI bleeding. Multivariable logistic regression analysis was performed to evaluate the association between the severity of COVID-19 and the occurrence of GI bleeding. RESULTS: 12 044 patients were included. 4165 (34.6%) and 1257 (10.4%) patients had severe and critical COVID-19, respectively, and 55 (0.5%) experienced GI bleeding. Multivariable analysis showed that patients with severe COVID-19 had a significantly higher risk of GI bleeding than patients with non-severe COVID-19 (OR: 3.013, 95% CI: 1.222 to 7.427). Patients with critical COVID-19 also had a significantly higher risk of GI bleeding (OR: 15.632, 95% CI: 6.581 to 37.130). Patients with severe COVID-19 had a significantly increased risk of lower GI bleeding (OR: 10.349, 95% CI: 1.253 to 85.463), but the risk of upper GI bleeding was unchanged (OR: 1.875, 95% CI: 0.658 to 5.342). CONCLUSION: The severity of COVID-19 is associated with GI bleeding, and especially lower GI bleeding was associated with the severity of COVID-19. Patients with severe or critical COVID-19 should be treated with caution as they are at higher risk for GI bleeding.

Molecular Evolutionary Analyses of the Spike Protein Gene and Spike Protein in the SARS-CoV-2 Omicron Subvariants.

To better understand the evolution of the SARS-CoV-2 Omicron subvariants, we performed molecular evolutionary analyses of the spike (S) protein gene/S protein using advanced bioinformatics technologies. First, time-scaled phylogenetic analysis estimated that a common ancestor of the Wuhan, Alpha, Beta, Delta variants, and Omicron variants/subvariants diverged in May 2020. After that, a common ancestor of the Omicron variant generated various Omicron subvariants over one year. Furthermore, a chimeric virus between the BM.1.1.1 and BJ.1 subvariants, known as XBB, diverged in July 2021, leading to the emergence of the prevalent subvariants XBB.1.5 and XBB.1.16. Next, similarity plot (SimPlot) data estimated that the recombination point (breakpoint) corresponded to nucleotide position 1373. As a result, XBB.1.5 subvariants had the 5' nucleotide side from the breakpoint as a strain with a BJ.1 sequence and the 3' nucleotide side as a strain with a BM.1.1.1 sequence. Genome network data showed that Omicron subvariants were genetically linked with the common ancestors of the Wuhan and Delta variants, resulting in many amino acid mutations. Selective pressure analysis estimated that the prevalent subvariants, XBB.1.5 and XBB.1.16, had specific amino acid mutations, such as V445P, G446S, N460K, and F486P, located in the RBD when compared with the BA.4 and BA.5 subvariants. Moreover, some representative immunogenicity-associated amino acid mutations, including L452R, F486V, R493Q, and V490S, were also found in these subvariants. These substitutions were involved in the conformational epitopes, implying that these mutations affect immunogenicity and vaccine evasion. Furthermore, these mutations were identified as positive selection sites. These results suggest that the S gene/S protein Omicron subvariants rapidly evolved, and mutations observed in the conformational epitopes may reduce the effectiveness of the current vaccine, including bivalent vaccines such as mRNA vaccines containing the BA.4/BA.5 subvariants.

Molecular Evolutionary Analyses of the RNA-Dependent RNA Polymerase (RdRp) Region and VP1 Gene in Human Norovirus Genotypes GII.P6-GII.6 and GII.P7-GII.6.

To understand the evolution of GII.P6-GII.6 and GII.P7-GII.6 strains, the prevalent human norovirus genotypes, we analysed both the RdRp region and VP1 gene in globally collected strains using authentic bioinformatics technologies. A common ancestor of the P6- and P7-type RdRp region emerged approximately 50 years ago and a common ancestor of the P6- and P7-type VP1 gene emerged approximately 110 years ago. Subsequently, the RdRp region and VP1 gene evolved. Moreover, the evolutionary rates were significantly faster for the P6-type RdRp region and VP1 gene than for the P7-type RdRp region and VP1 genes. Large genetic divergence was observed in the P7-type RdRp region and VP1 gene compared with the P6-type RdRp region and VP1 gene. The phylodynamics of the RdRp region and VP1 gene fluctuated after the year 2000. Positive selection sites in VP1 proteins were located in the antigenicity-related protruding 2 domain, and these sites overlapped with conformational epitopes. These results suggest that the GII.6 VP1 gene and VP1 proteins evolved uniquely due to recombination between the P6- and P7-type RdRp regions in the HuNoV GII.P6-GII.6 and GII.P7-GII.6 virus strains.

Molecular evolutionary analyses of the fusion protein gene in human respirovirus 1.

Few evolutionary studies of the human respiratory virus (HRV) have been conducted, but most of them have focused on HRV3. In this study, the full-length fusion (F) genes in HRV1 strains collected from various countries were subjected to time-scaled phylogenetic, genome population size, and selective pressure analyses. Antigenicity analysis was performed on the F protein. The time-scaled phylogenetic tree using the Bayesian Markov Chain Monte Carlo method estimated that the common ancestor of the HRV1 F gene diverged in 1957 and eventually formed three lineages. Phylodynamic analyses showed that the genome population size of the F gene has doubled over approximately 80 years. Phylogenetic distances between the strains were short (< 0.02). No positive selection sites were detected for the F protein, whereas many negative selection sites were identified. Almost all conformational epitopes of the F protein, except one in each monomer, did not correspond to the neutralising antibody (NT-Ab) binding sites. These results suggest that the HRV1 F gene has constantly evolved over many years, infecting humans, while the gene may be relatively conserved. Mismatches between computationally predicted epitopes and NT-Ab binding sites may be partially responsible for HRV1 reinfection and other viruses such as HRV3 and respiratory syncytial virus.

Rhinovirus Infection and Virus-Induced Asthma.

While the aetiology of asthma is unclear, the onset and/or exacerbation of asthma may be associated with respiratory infections. Virus-induced asthma is also known as virus-associated/triggered asthma, and the reported main causative agent is rhinovirus (RV). Understanding the relationship between viral infections and asthma may overcome the gaps in deferential immunity between viral infections and allergies. Moreover, understanding the complicated cytokine networks involved in RV infection may be necessary. Therefore, the complexity of RV-induced asthma is not only owing to the response of airway and immune cells against viral infection, but also to allergic immune responses caused by the wide variety of cytokines produced by these cells. To better understand RV-induced asthma, it is necessary to elucidate the nature RV infections and the corresponding host defence mechanisms. In this review, we attempt to organise the complexity of RV-induced asthma to make it easily understandable for readers.

Detailed Molecular Interactions between Respiratory Syncytial Virus Fusion Protein and the TLR4/MD-2 Complex In Silico.

Molecular interactions between respiratory syncytial virus (RSV) fusion protein (F protein) and the cellular receptor Toll-like receptor 4 (TLR4) and myeloid differentiation factor-2 (MD-2) protein complex are unknown. Thus, to reveal the detailed molecular interactions between them, in silico analyses were performed using various bioinformatics techniques. The present simulation data showed that the neutralizing antibody (NT-Ab) binding sites in both prefusion and postfusion proteins at sites II and IV were involved in the interactions between them and the TLR4 molecule. Moreover, the binding affinity between postfusion proteins and the TLR4/MD-2 complex was higher than that between prefusion proteins and the TLR4/MD-2 complex. This increased binding affinity due to conformational changes in the F protein may be able to form syncytium in RSV-infected cells. These results may contribute to better understand the infectivity and pathogenicity (syncytium formation) of RSV.

FOLFOX as First-line Therapy for Gastric Cancer with Severe Peritoneal Metastasis.

BACKGROUND/AIM: Severe peritoneal metastasis (PM) from advanced gastric cancer (AGC) causes massive ascites and inadequate oral intake. Because patients with severe PM are often not included in clinical trials, little is known regarding the efficacy and safety of oxaliplatin with l-leucovorin and bolus/continuous infusion of 5-fluorouracil (FOLFOX) for them. PATIENTS AND METHODS: We retrospectively studied AGC patients with massive ascites and/or inadequate oral intake due to severe PM treated with FOLFOX as the first-line treatment. RESULTS: Only 39 (10%) of 378 AGC patients had severe PM; 10 received FOLFOX. The median progression-free and overall survivals were 7.5 and 13.2 months, respectively. Ascites decreased in seven of nine patients with ascites, and oral intake improved in four of seven patients with an inadequate oral intake. Common grade 3-4 adverse events included neutropenia and anemia. CONCLUSION: This study suggests that FOLFOX is effective and manageable for AGC patients with severe PM.

[Self-expanding antireflux stents for malignant esophageal stenosis - a report of three cases].

Use of a standard open stent or self-expanding metal stent for patients with malignant dysphagia is associated with a risk of gastroesophageal reflux especially when placed across the esophagogastric junction. We report 3 cases of malignant esophageal stenosis treated with a long cover-type Niti-STM stent with an antireflux mechanism. Case 1: A 87-year-old man presented with dysphagia due to esophageal cancer at the middle thoracic esophagus. Two months after surgery using a standard open stent, the dysphagia relapsed because of tissue overgrowth. Case 2: A 73-year-old woman presented with lung cancer and severe dysphagia due to enlarged mediastinal lymph nodes. Case 3: A 66-year-old man presented with dysphagia due to esophageal cancer at the lower thoracic esophagus. All 3 patients received an antireflux stent across the esophagogastric junction. In cases 1 and 2, dysphagia was relieved immediately without complications. In case 3, the patient experienced severe reflux and chest pain associated with stent placement and could not ingest any solid food. We conclude that the antireflux stent may be useful for palliation in patients with severe malignant esophageal obstruction; however, patients should be informed about the risk of failure to prevent reflux.

[A case of Carboplatin and pemetrexed combination chemotherapy for synchronous double cancers of hepatocellular carcinoma and primary lung cancer].

A 78-year-old man presented to our hospital with lung abnormality on his chest radiograph. Computed tomography (CT) showed a mass and obstructive pneumonia in the right upper lobe of the lung. The mass was diagnosed as a pulmonary adenocarcinoma with a bronchoscopy (cT4N2M0, Stage IIIB). CT also revealed multiple hepatic tumors, which were diagnosed as hepatocellular carcinoma (HCC) by dynamic CT and gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid enhanced magnetic resonance imaging(EOB-MRI). First, we treated the lung cancer with a combination of cisplatin and pemetrexed (PEM), but it caused renal dysfunction. Carboplatin (CBDCA) and PEM combination chemotherapy was administered, and not only the lung cancer but also the HCCs decreased in size. There are few reports of synchronous double cancers of HCC and primary lung cancer, and the treatment is not established. We report that platinum-containing anticancer drugs such as CBDCA may be effective against synchronous double cancers of HCC and lung cancer.

[A case of primary peritoneal carcinoma successfully treated using Paclitaxel and Carboplatin chemotherapy].

BACKGROUND: A standard treatment for primary peritoneal carcinoma has not been established to date. We describe a case in which this cancer was successfully treated by use of paclitaxel and carboplatin chemotherapy. CASE: An 80-year-old woman who presented with abdominal distension and right upper abdominal pain was diagnosed with massive ascites and an omentum tumor via abdominal computed tomography and magnetic resonance imaging (MRI); her ovaries were normal-sized. Serum levels of the tumor marker CA125 were above normal (170 U/mL), and aspiration cytology showed the presence of adenocarcinoma cells. Despite several examinations, the primary tumor was not detected. The patient underwent exploratory laparotomy and was diagnosed with primary peritoneal carcinoma. She received combination chemotherapy consisting of paclitaxel and carboplatin. Serum CA125 levels returned to normal, and an MRI showed no evidence ofa tumor. CONCLUSION: Paclitaxel and carboplatin combination chemotherapy is effective for treatment of primary peritoneal adenocarcinomas.

[Insertion of percutaneous transhepatic biliary endoprosthesis for unresectable lower cholangiocellular carcinoma following cholangitis due to endoscopic biliary plastic stent obstruction].

The patient was an 87-year-old woman who was diagnosed with atrial fibrillation, which was treated with an anticoagulant, and with chronic kidney disease. The patient was diagnosed as having liver dysfunction and lower cholangiocellular carcinoma (cStage I) on ultrasonography and magnetic resonance cholangiopancreatography. Since it was impossible to perform curative resection owing to the patient's decreased cardiac and renal function, we performed palliative endoscopic retrograde biliary drainage (ERBD) with a plastic stent (PS), and the patient was discharged 11 days later. However, the patient was readmitted because of fever (>38.0°C) and vomiting 124 days after ERBD. We assumed that the patient had developed cholangitis due to PS obstruction. Moreover, her blood culture was positive for Klebsiella pneumoniae. We were unable to replace the PS as the tumor had increased in size and hemorrhage from the papilla of Vater continued after the stent had been removed. The signs of inflammation improved after treatment of sepsis with antibiotics and immunoglobulins, and we performed percutaneous transhepatic cholangio drainage( PTCD) and eventually inserted a percutaneous transhepatic biliary endoprosthesis (PTBE) with an expandable metallic stent (EMS). The patient died 2 months later; no stent occlusion was observed. Our experience suggests that endoscopic biliary stents should be selected bearing in mind the patency of the stent and the prognosis.

[A case of advanced gastric cancer with carcinomatous lymphangitis of the lung treated with docetaxel and S-1 combination chemotherapy].

A 67-year-old woman with complaints of cough and dyspnea was admitted; her chest radiographs and computed tomography (CT) scans revealed pulmonary carcinomatous lymphangitis. Endoscopic examination revealed advanced gastric cancer and the patient was treated with a combination of 40 mg/m2 docetaxel, administered on day 1, and S-1 100 mg/body/day, administered for 14 days followed by a 7-day interval, as 1 course despite her performance status( PS) being grade 3. After 2 courses of chemotherapy, CT showed that the carcinomatous lymphangitis had improved, and the patient was discharged with PS of grade 0. We report that combination chemotherapy with docetaxel and S-1 might be effective for the treatment of advanced gastric cancer with carcinomatous lymphangitis of the lung in patients with a poor systemic condition.

[A case of drug-induced liver injury caused by entecavir for treatment of hepatitis B virus reactivation during RCHOP in a patient with non-Hodgkin lymphoma].

A 49-year-old-man, a healthy carrier of hepatitis B virus (HBV), received chemotherapy with a rituximab/cyclo- phosphamide/doxorubicin/vincristine/prednisolone (R-CHOP) regimen for non-Hodgkin's lymphoma. At the first course of chemotherapy, not only the liver function but the HBV DNA level was elevated. These symptoms were diagnosed as hepatic injury induced by HBV reactivation, and, therefore, entecavir (ETV) was started. As a result, although the treatment with ETV decreased the HBV DNA level, liver function values were remarkably elevated again (over 3 times the levels before beginning ETV). ETV was discontinued because of suspicion regarding the onset of hepatic injury it caused. After switching to lamivudine (LVD), the liver function quickly improved and no problems were observed with renewal of the R-CHOP regimen. In addition, the HBV DNA level decreased and 3 courses of R-CHOP were performed successfully. In our case, the hepatic injury was induced by ETV, although anti-HBV medicine was used for the treatment of HBV reactivation according to the guideline. Therefore, the medical staff must carefully and consistently observe patients with HBV infection after chemotherapy.

Co-translational involvement of the chaperonin GroEL in the folding of newly translated polypeptides.

A large fraction of the newly translated polypeptides emerging from the ribosome require certain proteins, the so-called molecular chaperones, to assist in their folding. In Escherichia coli, three major chaperone systems are considered to contribute to the folding of newly synthesized cytosolic polypeptides. Trigger factor (TF), a ribosome-tethered chaperone, and DnaK are known to exhibit overlapping co-translational roles, whereas the cage-shaped GroEL, with the aid of the co-chaperonin, GroES, and ATP, is believed to be implicated in folding only after the polypeptides are released from the ribosome. However, the recent finding that GroEL-GroES overproduction permits the growth of E. coli cells lacking both TF and DnaK raised questions regarding the separate roles of these chaperones. Here, we report the puromycin-sensitive association of GroEL-GroES with translating ribosomes in vivo. Further experiments in vitro, using a reconstituted cell-free translation system, clearly demonstrate that GroEL associates with the translation complex and accomplishes proper folding by encapsulating the newly translated polypeptides in the central cavity formed by GroES. Therefore, we propose that GroEL is a versatile chaperone, which participates in the folding pathway co-translationally and also achieves correct folding post-translationally.