Successful Fistula Closure After Treatment with Colostomy and Infliximab in a Patient with Ulcerative Colitis Complicated by Rectovaginal Fistula.

The patient was a 50-year-old Japanese woman who was diagnosed with total-colitis-type ulcerative colitis (UC) at the age of 26 years. She was treated with mesalazine and azathioprine, and her disease activity was well controlled. At the age of 50 years, the patient was experiencing fever, abdominal pain, diarrhea, bloody stool, and anal pain, which led to a diagnosis of a relapse of UC. Although steroid therapy was administered and tended to improve her symptoms, fecaloid vaginal discharge occurred, and rectovaginal fistula (RVF) was confirmed. Colostomy was performed, and infliximab was initiated as maintenance therapy for UC. All symptoms improved, and RVF closure was confirmed 6 months after the initiation of infliximab. To date, she has been free from relapse of UC. There have been only a few reports of UC complicated by RVF, and this condition is often difficult to treat. To the best of our knowledge, no other case of UC complicated by RVF in which the fistula was closed after treatment with colostomy and infliximab has been previously reported; thus, our report of the present case is valuable to the literature.

One-Pot Synthesis of Useful S-Substituted-l-cysteine Sulfoxides Using Genetically Engineered Escherichia coli.

S-Substituted-l-cysteine sulfoxides are valuable compounds that are contained in plants. Particularly, (+)-alliin and its degraded products have gained significant attention because of their human health benefits. However, (+)-alliin production has been limited to extraction from plants and chemical synthesis; both methods have drawbacks in terms of stability and safety. Here, we proposed the enzymatic cascade reaction for synthesizing (+)-alliin from readily available substrates. To achieve a one-pot (+)-alliin production, we constructed Escherichia coli coexpressing the genes encoding tryptophan synthase from Aeromonas hydrophila ssp. hydrophila NBRC 3820 and l-isoleucine hydroxylase from Bacillus thuringiensis 2e2 for the biocatalyst. Deletion of tryptophanase gene in E. coli increased the yield about 2-fold. Under optimized conditions, (+)-alliin accumulation reached 110 mM, which is the highest productivity thus far. Moreover, natural and unnatural S-substituted-l-cysteine sulfoxides were synthesized by applying various thiols to the cascade reaction. These results indicate that the developed bioprocess would enable the supply of diverse S-substituted-l-cysteine sulfoxides.

An ACE2, SARS-CoV-2 spike protein binding protein, -like enzyme isolated from food-related microorganisms.

Angiotensin-converting enzyme 2 (ACE2) is a binding target of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike protein. An ACE2-like enzyme, such as bacterial M32-carboxypeptidase (M32-CAP), is assumed to be a potential therapeutic candidate for coronavirus disease 2019 (COVID-19). Here, we screened bacteria with an ACE2-like enzyme activity from Japanese fermented food and dietary products using the fluorogenic substrate for rapid screening. The strain showing the highest activity, Enterobacter sp. 200527-13, produced an enzyme with the same hydrolytic activity as ACE2 on Angiotensin II (Ang II). The enzymatic analysis using the heterologously-expressed enzyme in Escherichia coli revealed that the enzyme catalyzes the same reaction with that of ACE2, Ang II hydrolysis to Ang 1-7, and phenylalanine. The gene sequence information showed that the enzyme belongs to the M32-CAP family. These results suggested that the selected enzyme, M32-CAP (EntCP), from Enterobacter sp. 200527-13 was identified as an ACE2-like enzyme.

Identification of tryptophanase from Escherichia coli for the synthesis of S-allyl-l-cysteine and related S-substituted cysteine derivatives.

A wide variety of S-substituted cysteine derivatives occur in plant metabolites. For example, S-allyl-l-cysteine (SAC), mainly contained in garlic, gathers huge interest because of its favorable bioactivities for human health. However, conventional methods for preparing SAC suffer from several drawbacks with regard to efficiency and toxicity, which highlights the need for improved processes for SAC synthesis. This study aims to develop a novel bioprocess to produce SAC by microbial enzymes from easily available substrates. We found that Escherichia coli had the ability to synthesize SAC from allyl mercaptan, pyruvic acid, and ammonium sulfate. An enzyme purification through 3-step column chromatography, followed by determination of the N-terminal amino acid sequence revealed that tryptophanase (TnaA) was the enzyme responsible for SAC formation. Although the enzyme catalyzed the reversible reaction for synthesizing and degrading SAC, the degradation proceeded significantly faster than the synthesis. Interestingly, TnaA catalyzed the synthesis of a wide range of S-substituted cysteines with alkyl chains or aromatic rings, some of which are present in Allium and Petiveria plants. Our results showed a novel substrate specificity of TnaA toward various S-substituted cysteine. TnaA is a promising biocatalyst for developing a new process to supply various valuable S-substituted cysteine derivatives for medicinal and health-promoting applications.

COVID-19 After Treatment With Direct-acting Antivirals for HCV Infection and Decompensated Cirrhosis: A Case Report.

BACKGROUND: Eradication of hepatitis C virus (HCV) from chronic HCV-infected patients could improve liver function and prevent hepatocarcinogenesis in the long term. Eradication of HCV by direct-acting antivirals (DAAs) also leads to dynamic immunological changes. We report a case of recurrent coronavirus disease 2019 (COVID-19) that developed immediately after combination treatment with DAAs for HCV infection and decompensated cirrhosis. CASE REPORT: A 55-year-old male was started on a 12-week treatment with combination of HCV NS5A inhibitor velpatasvir and HCV NS5B polymerase inhibitor sofosbuvir. HCV RNA became undetectable after six weeks of treatment and was undetectable at the end of the treatment (EOT). Twelve days after the EOT, we diagnosed the patient with COVID-19 pneumonia, admitted him to our hospital and he was discharged two weeks later. One week after his discharge, he visited our hospital again, was diagnosed with recurrent COVID-19 pneumonia readmitted for a second time. Four days after second admission, cardiac arrest occurred, however, he recovered from severe COVID-19 and achieved sustained virological response and his liver function improved. CONCLUSION: In the COVID-19 era, while attention should be paid to the occurrence or exacerbation of infection, including COVID-19, interferon-free DAA combination therapy should be performed for HCV-infected individuals.

l-Tryptophan-starved cultivation enhances S-allyl-l-cysteine synthesis in various food-related microorganisms.

S-Allyl-l-cysteine (SAC) has received much interest due to its beneficial effects on human health. To satisfy the increasing demand for SAC, this study aims to develop a valuable culturing method for microbial screening synthesizing SAC from readily available materials. Although tryptophan synthase is a promising enzyme for SAC synthesis, its expression in microorganisms is strictly regulated by environmental l-tryptophan. Thus, we constructed a semisynthetic medium lacking l-tryptophan using casamino acids. This medium successfully enhanced the SAC-synthesizing activity of Lactococcus lactis ssp. cremoris NBRC 100676. In addition, microorganisms with high SAC-synthesizing activity were screened by the same medium. Food-related Klebsiella pneumoniae K-15 and Pantoea agglomerans P-3 were found to have a significantly increased SAC-synthesizing activity. The SAC-producing process established in this study is shorter in duration than the conventional garlic aging method. Furthermore, this study proposes a promising alternative strategy for producing food-grade SAC by microorganisms.

Left Gastric Vein Width Is an Important Risk Factor for Exacerbation of Esophageal Varices Post Balloon-Occluded Retrograde Transvenous Obliteration for Gastric Varices in Cirrhotic Patients.

Background and Objectives: Balloon-occluded retrograde transvenous obliteration (BRTO) could be currently one of the best therapies for patients with gastric varices. This study examined the exacerbation rates for esophageal varices following BRTO for gastric varices in patients with hepatic cirrhosis. Materials and Methods: We enrolled 91 cirrhotic patients who underwent BRTO for gastric varices. In total, 50 patients were examined for exacerbation rates of esophageal varices following BRTO. Esophageal varices and their associated exacerbation were evaluated by upper gastrointestinal endoscopy. Patients were allocated into two groups according to the main inflow tract for gastric varices: (1) 37 patients in the left gastric vein (LGV) group with an LGV width of more than 3.55 mm, and (2) 13 patients in the non-LGV group who had short gastric vein or posterior gastric vein. Moreover, treatment outcomes were retrospectively analyzed. Results: LGV width (p < 0.01) was the major risk factor for the deterioration of esophageal varices post BRTO. In addition, LGV was the most common inflow tract, and the LGV group contained 74% (37/50) of patients. The exacerbation rates of esophageal varices at 1, 2, 3, and 4 years post BRTO were 40%, 62%, 65%, and 68%, respectively. The comparison of the exacerbation rates for esophageal varices following BRTO according to inflow tract showed that the exacerbation rates were significantly higher in the LGV group than those of the non-LGV group (p = 0.03). In more than half of the subjects, LGV was the main inflow tract for gastric varices, and this group experienced more frequent exacerbations of esophageal varices following BRTO compared to patients with different inflow tract sources. Conclusion: Careful attention should be paid to the LGV width when BRTO is performed for gastric varices.

Efficacy of Glecaprevir/Pibrentasvir for Real-World HCV Infected Patients in the Northern Part of Tokyo, Japan.

Hepatis virus C (HCV) infection causes liver cirrhosis and hepatocellular carcinoma (HCC) worldwide. The objective of our study was to examine the effects of the HCV nonstructural protein (NS) 3/4A inhibitor glecaprevir/NS5A inhibitor pibrentasvir on real-world HCV patients in the northern part of Tokyo, Japan. Although 106 patients were consecutively included, a total of 102 HCV-infected patients with chronic hepatitis or compensated cirrhosis, who received 8- or 12-week combination treatment with glecaprevir/pibrentasvir and were followed up to week 12 after the end of treatment were analyzed retrospectively. Only three patients discontinued treatment due to adverse events; however, they achieved a sustained virologic response at 12 weeks (SVR12). Finally, SVR rates were 99.0% (101/102). Only one patient without liver cirrhosis was a treatment relapser who received hepatic resection for HCC approximately two years after commencement of the 8-week combination treatment with glecaprevir/pibrentasvir. After the exclusion of patients with HCV genotype 1b and P32 deletion in the HCV NS5A region, a 12-week combination of glecaprevir/pibrentasvir led to SVR12 in all nine direct-acting antiviral-experienced patients. Glecaprevir/pibrentasvir had a high efficacy and an acceptable safety profile for real-world HCV patients in a single hospital in Japan.

Immune Checkpoint Inhibitor as a Therapeutic Choice for Double Cancer: A Case Series.

BACKGROUND: Hepatocellular carcinoma (HCC) occasionally presents with simultaneous or metachronous primary malignancies of other organs. Despite the limited scope of cytocidal anticancer drugs or molecular targeted agents, immune checkpoint inhibitors (ICIs) can still be used for various malignancies. Here, we present cases of double cancers including HCC treated with ICIs. CASE REPORT: Case 1: A 70-year-old man with lung cancer and 80-mm HCC underwent nivolumab therapy. The sizes of both cancers remained constant for nine months. Case 2: A 58-year-old man with pharyngeal cancer and HCC. Nivolumab was administered, but was withdrawn after one session because of progressive disease. Case 3: A 71-year-old man with a 5 cm HCC invading the inferior vena cava, and early esophageal cancer. HCC showed a significant volume reduction and esophageal cancer demonstrated slight improvement by atezolizumab and bevacizumab therapy. CONCLUSION: A combination therapy including ICI is a promising treatment option for HCC with concurrent malignancies.

Olmesartan-associated sprue-like enteropathy diagnosed by capsule endoscopy and double balloon endoscopy.

Sprue-like enteropathy associated with olmesartan is characterized by villous atrophy in the duodenum. We report the case of an 81-year-old woman diagnosed with olmesartan-associated sprue-like enteropathy with no villous atrophy in the duodenum. The patient had been taking olmesartan for 10 years and complained of diarrhea and weight loss. Despite undergoing general treatment for 2 months, her symptoms showed no improvement. Gastrointestinal endoscopy and pathological findings showed no villous atrophy in the duodenum. However, villous atrophy was observed in the small intestine by capsule endoscopy. Pathological biopsy with double balloon endoscopy provided a definitive diagnosis. Diarrhea improved with the discontinuation of olmesartan and weight increased within a week of withdrawal. After the improvement of clinical symptoms, both endoscopic and pathological findings of villous atrophy in small intestine showed improvement.

Follow-Up of Patients Who Achieved Sustained Virologic Response after Interferon-Free Treatment against Hepatitis C Virus: Focus on Older Patients.

Background and Objectives: Direct-acting antiviral agents (DAAs) have improved sustained virologic response (SVR) rates in patients with chronic hepatitis C virus (HCV) infection. Our aim was to elucidate the occurrence of hepatocellular carcinoma (HCC) and to compare the outcomes of patients aged 75 years or older (older group) with those of patients younger than 75 years (younger group) after SVR. Materials and Methods: Among 441 patients treated with interferon-free DAA combinations, a total of 409 SVR patients were analyzed. We compared the two age groups in terms of HCC incidence and mortality rates. Results: Older and younger groups consisted of 68 and 341 patients, respectively. Occurrence of HCC after SVR did not differ between the two groups of patients with a history of HCC. Occurrence of HCC after SVR was observed more in younger patients without a history of HCC (p < 0.01). Although older patients without a history of HCC had a higher mortality rate (p < 0.01), their causes of death were not associated with liver diseases. Among younger patients without a history of HCC, none died. Conclusions: After SVR, liver disease may not be a prognostic factor in older HCV patients without a history of HCC.

Occurrence of hepatitis in an elderly woman during the treatment of pembrolizumab for right advanced renal pelvis, ureteral cancer, and bladder cancer.

Recently, the use of immune checkpoint inhibitors (ICIs) with or without chemotherapeutic agents has been increasing in the treatment for advanced cancer. Here, we report the occurrence of liver failure after the use of pembrolizumab in an 82-year-old woman with metastatic liver disease derived from right advanced renal pelvis, ureteral cancer, and bladder cancer. She was successfully treated with 0.6 mg/kg daily prednisolone. In patients treated with ICIs, ICI-induced hepatitis is occasionally observed. Even if patients are older, it appears important to diagnose and treat ICI-induced hepatitis earlier by multidisciplinary therapies including steroid treatment. This is a first report of pembrolizumab-induced liver failure in elder patient with age over 80 years. Even if patients are older, it appears important to diagnose and treat ICI-induced hepatitis earlier by multidisciplinary therapies including steroid treatment.

Male-Dominant Hepatitis A Outbreak Observed among Non-HIV-Infected Persons in the Northern Part of Tokyo, Japan.

Recently, we experienced an outbreak of acute hepatitis A virus (HAV) infection between 2018 and 2020. Herein, we describe this male-dominant HAV infection outbreak observed among non-human immunodeficiency virus (HIV)-infected persons in the northern part of Tokyo, Japan. Clinical information was collected from patient interviews and from medical record descriptions. In the present study, 21 patients were retrospectively analyzed. A total of 90.4 and 33.3% of patients were males, and men who have sex with men (MSM), respectively. The total bilirubin levels and platelet counts tended to be lower in the MSM group than in the non-MSM group. C-reactive protein (CRP) levels tended to be higher in acute liver failure (ALF) patients than in non-ALF patients. Prolonged cholestasis was observed in one patient (4.8%). We also found that 18 HAV isolates belonged to HAV subgenotype IA/subgroup 13 (S13), which clustered with the HAV isolate (KX151459) that was derived from an outbreak of HAV infection among MSM in Taiwan in 2015. Our results suggest that the application of antivirals against HAV, as well as HAV vaccines, would be useful for the treatment and prevention of severe HAV infection.

Japanese Man with HCV Genotype 4 Infection and Cirrhosis Who Was Successfully Treated by the Combination of Glecaprevir and Pibrentasvir.

A 74-year-old man with a history of transfusion at 35 years old in Egypt was referred to our hospital. He was infected with hepatitis C virus (HCV) genotype 4 (GT4), which is a rare HCV GT in Japan, and was also diagnosed with hepatic compensated cirrhosis. We safely treated the patient for 12 weeks with the combination of glecaprevir and pibrentasvir, and a sustained virologic response (SVR) was achieved. This is the first report of HCV GT4 infection in a treatment-naïve Japanese patient with cirrhosis in whom SVR was achieved with the combination treatment of glecaprevir and pibrentasvir.

Novel FXR agonist nelumal A suppresses colitis and inflammation-related colorectal carcinogenesis.

FXR is a member of the nuclear receptor superfamily and bile acids are endogenous ligands of FXR. FXR activation has recently been reported to inhibit intestinal inflammation and tumour development. This study aimed to investigate whether the novel FXR agonist nelumal A, the active compound of the plant Ligularia nelumbifolia, can prevent colitis and colorectal carcinogenesis. In a mouse colitis model, dextran sodium sulfate-induced colonic mucosal ulcer and the inflammation grade in the colon significantly reduced in mice fed diets containing nelumal A. In an azoxymethane/dextran sodium sulfate-induced mouse inflammation-related colorectal carcinogenesis model, the mice showed decreased incidence of colonic mucosal ulcers and adenocarcinomas in nelumal A-treated group. Administration of nelumal A also induced tight junctions, antioxidant enzymes, and FXR target gene expression in the intestine, while it decreased the gene expression of bile acid synthesis in the liver. These findings suggest that nelumal A effectively attenuates colonic inflammation and suppresses colitis-related carcinogenesis, presumably through reduction of bile acid synthesis and oxidative damage. This agent may be potentially useful for treatment of inflammatory bowel diseases as well as their related colorectal cancer chemoprevention.

Skeletal Muscle Depletion: A Risk Factor for Pneumonia following Gastric Endoscopic Submucosal Dissection in Elderly Patients.

INTRODUCTION: Endoscopic submucosal dissection (ESD) is an effective treatment for gastric neoplasms in elderly patients; however, it involves several adverse events, including pneumonia. This study aimed to investigate whether skeletal muscle depletion (SMD) was associated with the development of pneumonia in elderly patients who underwent gastric ESD. METHODS: This retrospective observational cohort study included 157 patients (≥80 years) who had undergone gastric ESD. The skeletal muscle cross-sectional area was measured by CT, and the value of the third lumbar vertebra skeletal muscle index (L3 SMI) was evaluated. The SMD was defined as an L3 SMI value ≤38.0 cm2/m2 for women and ≤42.0 cm2/m2 for men. Pneumonia was also diagnosed using CT to identify all included patients. RESULTS: Among 157 patients, 66 (42.0%) showed SMD. In the SMD group, the incidence of pneumonia was 21.2%, whereas it was 7.7% in the non-SMD group (p = 0.018). The longest hospitalization duration was 19 days. Antibiotics were administered in 61.9% of the patients. Procedure time was not significantly different between the groups (72 ± 54 min vs. 62 ± 44 min, p = 0.201). On multivariate analysis, SMD was an independent risk factor for the development of pneumonia (odds ratio = 3.16, 95% confidence interval, 1.18-8.50, p = 0.023). CONCLUSIONS: SMD was not a rare entity in patients aged ≥80 years with gastric neoplasms. SMD was a significant risk factor for pneumonia related to gastric ESD in elderly patients.

Co-Occurrence of Hepatitis A Infection and Chronic Liver Disease.

Hepatitis A virus (HAV) infection occasionally leads to a critical condition in patients with or without chronic liver diseases. Acute-on-chronic liver disease includes acute-on-chronic liver failure (ACLF) and non-ACLF. In this review, we searched the literature concerning the association between HAV infection and chronic liver diseases in PubMed. Chronic liver diseases, such as metabolic associated fatty liver disease and alcoholic liver disease, coinfection with other viruses, and host genetic factors may be associated with severe hepatitis A. It is important to understand these conditions and mechanisms. There may be no etiological correlation between liver failure and HAV infection, but there is an association between the level of chronic liver damage and the severity of acute-on-chronic liver disease. While the application of an HAV vaccination is important for preventing HAV infection, the development of antivirals against HAV may be important for preventing the development of ACLF with HAV infection as an acute insult. The latter is all the more urgent given that the lives of patients with HAV infection and a chronic liver disease of another etiology may be at immediate risk.

Advanced appendiceal goblet cell carcinoids with intestinal obstruction: two case reports.

A goblet cell carcinoid is quite rare and has features, wherein, a carcinoid-like image and an adenocarcinoma-like image coexist. We encountered two cases of rare goblet cell carcinoid originating in the appendix. Case 1 is that of a 48-year-old man with a chief complaint of abdominal distension and case 2 is that of a 64-year-old woman with a chief complaint of constipation. At the time of diagnosis, both cases had already metastasized to the peritoneum and other organs, and no radical surgical treatment could be administered in either case. Chemotherapies were performed according to the regimen for colon cancer, and they were effective to a certain extent. During the course of treatment, however, both cases developed intestinal obstruction, presumably due to peritoneal dissemination, which led to worse condition and death several months afterwards. Chemotherapy for goblet cell carcinoids has not yet reached a consensus, and further studies and establishment of therapeutic strategy are desired in the future.

Low Levels of Serum Tryptophan Underlie Skeletal Muscle Atrophy.

Sarcopenia is a poor prognosis factor in some cancer patients, but little is known about the mechanisms by which malignant tumors cause skeletal muscle atrophy. Tryptophan metabolism mediated by indoleamine 2,3-dioxygenase is one of the most important amino acid changes associated with cancer progression. Herein, we demonstrate the relationship between skeletal muscles and low levels of tryptophan. A positive correlation was observed between the volume of skeletal muscles and serum tryptophan levels in patients with diffuse large B-cell lymphoma. Low levels of tryptophan reduced C2C12 myoblast cell proliferation and differentiation. Fiber diameters in the tibialis anterior of C57BL/6 mice fed a tryptophan-deficient diet were smaller than those in mice fed a standard diet. Metabolomics analysis revealed that tryptophan-deficient diet downregulated glycolysis in the gastrocnemius and upregulated the concentrations of amino acids associated with the tricarboxylic acid cycle. The weights and muscle fiber diameters of mice fed the tryptophan-deficient diet recovered after switching to the standard diet. Our data showed a critical role for tryptophan in regulating skeletal muscle mass. Thus, the tryptophan metabolism pathway may be a promising target for preventing or treating skeletal muscle atrophies.