Novel anti-reflux biliary metal stent with a distal tapered end for distal malignant biliary obstruction: a feasibility study

Background and study aims  We developed a self-expandable metallic stent (SEMS) with a distal tapered end to reproduce the physiological bile flow with a pressure gradient due to the difference in the diameter. We aimed to evaluate the safety and efficacy of the newly developed distal tapered covered metal stent (TMS) for distal malignant biliary obstruction (DMBO). Patients and methods  This single-center, prospective, single-arm study was conducted in patients with DMBO. The primary endpoint was time to recurrent biliary obstruction (TRBO), and the secondary endpoints were the survival time and incidence of adverse events (AEs). Results  Thirty-five patients (15 men, 20 women; median age, 81 years [range: 53-92]) were enrolled between December 2017 and December 2019. The primary diseases were pancreatic head cancer in 25 cases, bile duct cancer in eight cases, and ampullary cancer in two cases. TMS was successfully placed in all cases. Acute cholecystitis occurred as an early AE (within 30 days) in two cases (5.7 %). The median TRBO was 503 days, median survival time was 239 days. RBO was observed in 10 cases (28.6 %), and the causes were distal migration in six cases, proximal migration in two cases, biliary sludge in one case, and tumor overgrowth in one case. Conclusions  Endoscopic placement of the newly developed TMS in patients with DMBO is technically feasible and safe, and the TRBO was remarkably long. The anti-reflux mechanism based on the difference in diameter may be effective, and a randomized controlled trial with a conventional SEMS is required.

Histological improvement in chronic hepatitis C-autoimmune hepatitis overlap syndrome by glecaprevir and pibrentasvir

A 60-year-old man with type-2 diabetes and chronic hepatitis C (HCV) was diagnosed with single hepatocellular carcinoma (HCC) of 67 mm in the hepatic posterior right lobe. Lenvatinib 8 mg was initiated but discontinued because of grade 3 liver injury. The patient continued to have prolonged liver injury and persistently high immunoglobulin G levels. Antinuclear antibody titer increased from 1:40 to 1:320. Histopathological examination of a liver biopsy specimen revealed interface hepatitis with lymphocyte and plasma cell infiltration, rosette formation, and emperipolesis, suggesting the possibility of autoimmune hepatitis (AIH). First, treatment with prednisolone was initiated; however, the response was poor. After starting glecaprevir/pibrentasvir (GLE/PIB) as direct-acting antivirals (DAA), HCV RNA rapidly disappeared, and serological liver function improved. After confirmation of sustained virological response 24, HCC recurrence was observed, and partial hepatectomy was performed. Background liver findings showed that liver parenchymal inflammation improved compared with that before DAA treatment. This is the first case of HCV-AIH overlap syndrome treated with DAA using GLE/PIB. Liver function improved within a short treatment period of 8 weeks, as confirmed using serology and histology.

Disseminated Bone Marrow Carcinomatosis Due to Malignant Melanoma of Unknown Primary Origin

An 80-year-old woman was admitted to our hospital due to appetite loss and vomiting. A blood examination showed liver disorder with disseminated intravascular coagulation. All tumor markers and hepatitis virus markers were negative. Contrast-enhanced computed tomography did not show tumor lesions, bone lesions, lymphadenopathies, or thrombosis. A bone marrow biopsy revealed large, atypical cells with brown pigmentation and positive immunostaining for HMB-45, S100 proteins, and CD79a without myeloid or lymphoid markers. We experienced a case of disseminated carcinomatosis of the bone marrow due to malignant melanoma of unknown primary origin.

Chemotherapy with gemcitabine for unresectable intrahepatic cholangiocarcinoma in a patient undergoing maintenance hemodialysis

A 56-year-old man with chronic renal failure due to diabetic nephropathy had received maintenance dialysis (every 4 h, three times/week). A hypoechoic tumor measuring 67 × 50 mm in the right lobe of the liver was discovered following routine abdominal ultrasonography. Dynamic computed tomography showed a low-density liver tumor, enlarged hilar lymph node, and a small nodule on the dorsal side of the lower lobe of the left lung. Histopathological examination of the liver tumor revealed intrahepatic cholangiocarcinoma. We developed a chemotherapy treatment plan with gemcitabine, which can be performed concurrently with hemodialysis. Gemcitabine (1000 mg/m², three times/cycle) was administered on Friday afternoon, and hemodialysis was performed on Tuesday, Thursday, and Saturday. Anemia and hypotension occurred after gemcitabine administration. Therefore, the dose of darbepoetin alpha was increased, and packed red blood cells were transfused. The patient was treated with gemcitabine for approximately 5 and a half months until computed tomography findings showed progressive disease; the survival time after treatment start was 8 months. Chemotherapy using gemcitabine has not been established in dialysis patients and has little evidence. We report a case of unresectable intrahepatic cholangiocarcinoma that developed during maintenance dialysis and was treated using gemcitabine chemotherapy.

Immunohistochemical detection of procalcitonin in fibrolamellar hepatocellular carcinoma

A 25-year-old woman with fever and epigastric pain was referred to our hospital. Blood examination showed significant liver dysfunction, markedly high C-reactive protein (CRP 19.1 mg/dL) and procalcitonin (48.3 ng/mL) levels. Dynamic computed tomography showed a tumor approximately 120 mm in size in the right lobe of the liver, but with no abscess formation. The patient was hospitalized and started on antibiotics; her CRP level improved, but the procalcitonin level did not decrease. Histopathological examination of the liver tumor biopsy revealed fibrolamellar hepatocellular carcinoma (FLC). Positive staining of the FLC with an anti-procalcitonin antibody suggested the production of procalcitonin.

Distinguishing coagulase-negative Staphylococcus bacteremia from contamination using blood-culture positive bottle detection pattern and time to positivity

AIM

Detection of coagulase-negative Staphylococcus in blood culture may be a result of either bacteremia or contamination. This often leads to diagnostic uncertainly. Our objective was to develop a method for differentiating whether a coagulase-negative Staphylococcus sp. positive blood culture represents bacteremia or contamination based on positive bottle detection pattern and time to positivity (TTP).

METHODS

This study included 155 and 51 adults with positive blood cultures for Staphylococcus epidermidis and Staphylococcus hominis, respectively, over a three-year period from 2016 to 2018. Positive blood culture cases were categorized as either bacteremia or contamination based on the clinically available information, and the detection pattern and TTP in each category were investigated.

RESULTS

A total of 57, 92, and 6 S. epidermidis positive blood cultures were categorized as bacteremia, contamination, and undetermined, respectively, whereas 15 and 36 S. hominis positive blood cultures were categorized as bacteremia and contamination, respectively. For positive blood cultures categorized as bacteremia, all four bottles in two sets of blood cultures were positive in 47/47 S. epidermidis and 14/14 S. hominis, respectively, whereas either one bottle in each of two sets or three bottles in two sets were positive in 10/19 S. epidermidis and 1/4 S. hominis, respectively; most of those TTPs were <48 h. Among them, the TTP in catheter-related blood stream infection was <24 h.

CONCLUSION

Although clinical assessment is crucial to differentiate between bacteremia and contamination, a combination of positive bottle detection pattern and TTP is a valuable diagnostic auxiliary tool.

Fructo-oligosaccharides ameliorate steatohepatitis, visceral adiposity, and associated chronic inflammation via increased production of short-chain fatty acids in a mouse model of non-alcoholic steatohepatitis

Background

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome. Within the spectrum of NAFLD, non-alcoholic steatohepatitis (NASH) in combination with hepatic inflammation and fibrosis can lead to liver cirrhosis and hepatocellular carcinoma. Dysbiosis was reported to contribute to NASH pathogenesis. This study aimed to determine the effects of fructo-oligosaccharides (FOS) on steatohepatitis and visceral adiposity in an obese mouse model of NASH.

Methods

Twelve newborn C57BL/6 J male mice were subcutaneously injected with monosodium glutamate (MSG) to induce obesity on a conventional diet. Six mice were also administered 5% FOS via drinking water from 10 weeks of age. At 18 weeks, histological characteristics of the liver and epididymal fat were compared between the groups. Hepatic mRNA expression of lipid metabolism enzymes and SCFA in feces and sera were measured.

Results

Hepatic steatosis, inflammatory cell infiltration, and hepatocyte ballooning in the liver and increased hepatic mRNA expression of fatty acid synthase and glycerol-3-phosphate acyltransferase were observed in the MSG-treated mice. FOS treatment improved the liver pathology and blunted the increases in the mRNA expression levels of lipid metabolism enzymes. In addition, FOS inhibited adipocyte enlargement and formation of crown-like structures and reduced the M1 macrophage frequency in the epididymal fat of the MSG mice (39.4% ± 3.0% vs. 22.8% ± 0.7%; P = 0.001). FOS increased not only the fecal concentrations of n-butyric acid (0.04 ± 0.01 vs. 0.38 ± 0.14 mg/g, P = 0.02), propionic acid (0.09 ± 0.03 vs. 0.42 ± 0.16 mg/g, P = 0.02), and acetic acid (0.65 ± 0.16 vs. 1.48 ± 0.29 mg/g, P = 0.03) but also the serum concentration of propionic acid (3.9 ± 0.5 vs. 8.2 ± 0.5 μmol/L, P = 0.001).

Conclusions

FOS ameliorates steatohepatitis, visceral adiposity, and chronic inflammation by increasing SCFA production.

Immunoglobulin G4-related Liver Disease Overlapping with Non-alcoholic Steatohepatitis That Was Diagnosed Simultaneously with Autoimmune Pancreatitis: A Case Report and Review of the Literature

A 70-year-old woman was referred to our hospital due to symptoms of dry eyes, dry mouth, and epigastric pain. Computed tomography showed distal pancreatic swelling, liver edge dullness and surface irregularities. Serum anti-nuclear antibody titers, immunoglobulin G and IgG4 levels were elevated. Autoimmune pancreatitis (AIP) was diagnosed based on endoscopic findings and a histopathological examination. Her AIP improved after starting prednisolone treatment. A liver biopsy revealed interface hepatitis with lymphoplasmacyte and IgG4-positive plasma cell infiltration. In addition, non-alcoholic steatohepatitis (NASH) was diagnosed based on the presence of parenchymal steatosis, ballooning hepatocytes, and pericellular fibrosis. We experienced a unique liver disease case showing IgG4-related liver disease overlapping with NASH.

Detection of Anti-mitochondrial Antibodies Accompanied by Drug-induced Hepatic Injury due to Atorvastatin

A 44-year-old Japanese woman was admitted to our hospital with fatigue and an altered liver function. She had been receiving atorvastatin treatment for 10 months. Although no jaundice was seen, the patient's serum alkaline phosphatase and γ-glutamyl transpeptidase levels were markedly elevated. Based on the results of a drug-induced lymphocyte-stimulation test, her liver disease was diagnosed as atorvastatin-induced hepatic injury. Subsequently, anti-mitochondrial antibodies (AMAs) were detected in her serum; however, a liver biopsy specimen did not show the characteristic features of primary biliary cholangitis. We herein report the detection of AMAs accompanied by drug-induced hepatic injury caused by atorvastatin.

Usefulness of training using animal models for colorectal endoscopic submucosal dissection: is experience performing gastric ESD really needed?

BACKGROUND AND STUDY AIMS

Despite the clinical advantages of colorectal endoscopic submucosal dissection (ESD), an effective training system, especially for Western endoscopists, has been challenging to establish. Herein, we propose a novel training program using ex vivo animal models and evaluate the learning curve of colorectal ESD trainees without gastric ESD experience.

PATIENTS AND METHODS

A total of 80 colorectal lesions were prospectively collected and removed by two novice operators. Before human ESD procedures, they received ESD training using an ex vivo porcine "proximal colon" model, which simulates a lumen with many folds and flexions. To assess the validity of our training system, the self-completion and en bloc R0 resection rates, the operation time, and prevalence of complications were compared between the first and latter period. Moreover the factors associated with prolonged operation time were evaluated.

RESULTS

The overall rates of self-completion and en bloc R0 resection were 98 % (78/80) and 100 % (80/80), respectively. The operation time during the first period was significantly longer than that during the latter period (86 ± 50 minutes vs. 60 ± 36 minutes, P = 0.01). Regarding complications, only two cases of perforations and delayed hemorrhage were observed during the first period; however, all of the complications were successfully managed endoscopically. The presence of fibrosis was identified as a significant independent predictor of a prolonged operation time during the first period (coefficient, 5.90; 95 %CI, 2.36 - 9.44, P = 0.002).

CONCLUSIONS

Our trainees achieved high rates of self-completion and R0 resection without severe complications even during the first 20 cases, suggesting that our training programs using ex vivo animal models are useful for trainees without gastric ESD experience.

STUDY REGISTRATION

UMIN000013566.

Accumulated myeloid-derived suppressor cells demonstrate distinct phenotypes and functions in two non-alcoholic steatohepatitis mouse models

BACKGROUND

To examine the steady state of hepatic myeloid-derived suppressor cells (MDSCs) and the lipid accumulation and inflammation-related changes in these cells, we analyzed the presence and functions of hepatic MDSCs in the following two non-alcoholic steatohepatitis (NASH) mouse models.

METHODS

Monosodium glutamate (MSG) model; MSG was subcutaneously injected into neonatal male C57BL/6J mice that were fed with normal diet up to 18 weeks of age. Methionine/choline-deficient diet (MCD) model; 16-week-old male C57BL/6J mice were fed with an MCD for 2 weeks. Those hepatic MDSCs were evaluated by flow cytometry and immunohistochemically.

RESULTS

Both MSG and MCD mice exhibited greater numbers of hepatic lipid droplets than 18-week-old male control mice. Hepatocellular ballooning was obvious in MSG, whereas inflammatory cell infiltration were apparent in MCD mice. CD11b, CD115, and Gr-1-positive hepatic MDSCs were increased in both models but higher in MCD mice, and demonstrated higher expression of an M2 macrophage marker CD206 mean fluorescence intensity (MFI) in MSG compared to MCD mice. Degree of reactive oxygen species production was evaluated using the DCFDA MFI values, which were significantly elevated in hepatic MDSCs from MCD mice. MSG mouse livers demonstrated Gr-1 positive cell accumulation around lipid droplets, mimicking crown-like structures in adipose tissues. In contrast, hepatic Gr-1 positive cells were primarily located in inflammatory cell aggregates in MCD mice.

CONCLUSIONS

These results suggest that hepatic fatty changes promote MDSC accumulation, and inflammatory changes induce phenotypic and functional alteration in hepatic MDSCs in NASH mouse models.

Splenic lymph follicles generate immunoglobulin M-producing B cells in primary biliary cirrhosis

AIM

To reveal the site of immunoglobulin (Ig)M production in primary biliary cirrhosis (PBC) we performed immunohistochemical analysis on spleens collected from patients with PBC.

METHODS

Splenic tissue samples were collected at the time of the autopsy from patients with hepatic failure. Immunostaining for IgM, CD21 and CXCL13 were performed using the splenic tissue samples.

RESULTS

The samples from five out of eight cases with PBC but not in eight cases of chronic hepatitis C virus infection showed accumulation of IgM positive cells in CD21 positive lymph follicles. The CXCL13 positive cells also accumulated in the center of the lymph follicles where the IgM positive cells accumulated.

CONCLUSION

The present results suggest that excess IgM is produced from the spleen of PBC. Furthermore, it was suggested that CXCL13 positive follicular dendritic cells possibly contribute to this process.

NIRS-based neurofeedback learning systems for controlling activity of the prefrontal cortex

The aim of this study was to develop a NIRS-based neurofeedback system to modulate activity in the prefrontal cortex (PFC). We evaluated the effectiveness of the system in terms of separability of changes in oxy-Hb and its derivative. Training with neurofeedback resulted in higher separability than training without neurofeedback or no training, suggesting that the neurofeedback system could enhance self-control of PFC activity. Interestingly, the dorsolateral PFC exhibited enhanced activity and high separability after neurofeedback training. These observations suggest that the neurofeedback system might be useful for training subjects to regulate emotions by self-control of dorsolateral PFC activity.

NIRS-based neurofeedback learning systems for controlling activity of the prefrontal cortex

The aim of this study was to develop a NIRS-based neurofeedback system to modulate activity in the prefrontal cortex (PFC). We evaluated the effectiveness of the system in terms of separability of changes in oxy-Hb and its derivative. Training with neurofeedback resulted in higher separability than training without neurofeedback or no training, suggesting that the neurofeedback system could enhance self-control of PFC activity. Interestingly, the dorsolateral PFC exhibited enhanced activity and high separability after neurofeedback training. These observations suggest that the neurofeedback system might be useful for training subjects to regulate emotions by self-control of dorsolateral PFC activity.