Yuki Miyata

Decreased accumulation of ultrasound contrast in the liver of nonalcoholic steatohepatitis rat model

AIM To investigate the diagnosis of nonalcoholic steatohepatitis (NASH) using contrast ultrasonography in the NASH rat model. METHODS The liver in methionine choline-deficient diet (MCDD) rats, a NASH model constructed by feeding an MCDD, was examined by contrast ultrasonography at weeks 2, 4, 8, 12 and 16, with late phase images of contrast ultrasonography (Kupffer imaging) in which contrast enhancement was achieved by incorporation of a contrast agent by Kupffer cells (KCs), and images were compared to those in rats taking a regular chow. RESULTS Decrease in contrast enhancement was observed first in MCDD rats at week 2. KCs were counted based on immunohistochemistry, but their numbers were not reduced and it was assumed that attenuation of contrast enhancement was attributable to reduced phagocytic activity of the KCs. CONCLUSION It is suggested that clinical application of contrast ultrasonography may be valuable for non-invasive diagnosis of NASH.

Restoration of natural killer cell activity by pegylated interferon-alpha/ribavirin therapy in chronic hepatitis C patient.

The combination therapy of pegylated interferon‐α and ribavirin (PEG IFN/RBV) is one of the effective treatments for chronic hepatitis C (CHC) patients. Natural killer (NK)‐cell activity was reported to be impaired in patients with hepatitis C virus (HCV). The aim of this study was to examine whether PEG IFN/RBV therapy could restore NK activity in CHC patients.

Flexible imaging color enhancement improves visibility of transnasal endoscopic images in diagnosing esophageal varices: a multicenter prospective blinded study.

To clarify the usefulness of transnasal esophagogastroduodenoscope (N‐EGD) with all flexible imaging color enhancement (FICE) patterns (0–9) for the diagnosis of esophageal varices (EV).

Branched-chain amino acid-enriched nutrient increases blood platelet count in patients after endoscopic injection sclerotherapy.

Protein and energy malnutrition is a severe problem for patients with liver cirrhosis (LC) and fasting often induces starvation which is a vitally important outcome. Dietary restriction is essential for endoscopic injection sclerotherapy (EIS) in patients with risky esophageal varices, thereby creating the possible exacerbation of nutritional state and inducing liver dysfunction. Whether EIS induces nutritional deficiency in LC patients and the effects of branched‐chain amino acid (BCAA)‐enriched nutrient are prospectively investigated.

Obliteration of gastric varices improves the arrival time of ultrasound contrast agents in hepatic artery and vein

Liver cirrhosis (LC) is accompanied by hepatic arterializations, intrahepatic shunts, and hyperdynamic circulations. These changes shorten the arrival time (AT) of ultrasound contrast agents to the hepatic vein (HV). Whether treatment of gastric fundal varices (GVs) by balloon‐occluded transvenous obliteration (B‐RTO) improves the AT in LC patients was prospectively investigated.

Usefulness of Transnasal Argon Plasma Coagulation for Esophageal Varices Compared with the Peroral Method: A Randomized and Prospective Clinical Study

Background: Argon plasma coagulation (APC) is very useful as a consolidation treatment for reducing the recurrence of esophageal varices (EVs). However, repeated sedation in endoscopic treatment has the risk of prolonging hepatic encephalopathy and affects the respiratory state of liver cirrhosis (LC) patients, in whom pulmonary arteriovenous shunts are observed. We evaluated prospectively whether transnasal endoscopic APC without sedation is more effective than peroral endoscopic APC with sedation. Patients and Methods: LC patients (n = 101), treated by endoscopic injection sclerotherapy to eradicate EVs, were randomly divided into a transnasal APC group (n = 50) and a peroral APC group (n = 51). The primary efficacy endpoint was the cumulative recurrence rate of EVs. The secondary endpoints were blood pressure (BP), heart rate, oxygen saturation during APC and complications. Results: There was no significant difference in the cumulative recurrence rate of EVs at 36 months between the transnasal APC and peroral APC groups (35.0 vs. 40.8%, p = 0.39, log-rank test), indicating that transnasal APC is not inferior to peroral APC. The transnasal APC group showed more stable intraoperative BP and oxygen saturation values, and a lower incidence of epigastralgia (56.0 vs. 74.5%, p = 0.04). Conclusion: The efficacy of reducing the recurrence of EVs in the transnasal APC group was not significantly different from that in the peroral APC group. Transnasal APC caused less distress and required no sedation. Therefore, this method was more advantageous for LC patients at risk of suffering from prolongation of hepatic encephalopathy.

Elucidation of Idiopathic Portal Hypertension Based on Liver and Spleen Stiffness Measurements by Virtual Touch Tissue Quantification and Peripheral Blood CD4+ CD25+ T Cytometry

[Introduction] Virtual Touch Tissue Quantification (VTTQ) is an ultrasound technique to quantify tissue stiffness based on measurement of the propagation velocity of elastic shearwaves (Vs) generated by acoustic radiation force impulses that cause tissue displacements. [Objective] To explore the usefulness of liver and spleen stiffness measurements by VTTQ for diagnostic differentiation between idiopathic portal hypertension (IPH) and portal hypertension caused by liver cirrhosis (LC). [Subjects] Thirteen patients with histologically diagnosed IPH and 18 patients with histologically diagnosed LC were recruited for this study. Eight normal subjects (NC) and 7 patients with chronic hepatitis (CH) were also included. [Methods] With the region of interest (ROI) set at a 3-cm depth from the body surface, the mean of 5 successful Vs measurements of the liver and spleen in each patient was determined. The percentage of peripheral blood CD4+ CD25+ T cells (Tregs) in the LC cases and IPH cases was analyzed by FACS, and the size of the spleen (SI) was also measured. [Results] The measured stiffness of the liver (NC: CH: LC: IPH = 1.14: 1.40: 2.50: 1.56 m/s) was greater in the LC patients (p < 0.001), and that of the spleen (2.03: 2.30: 3.12: 3.90) was greater in the patients with IPH (p < 0.001). Making each ROC curve, we set the cut-off values of liver stiffness by VTTQ as follows (CH: LC: IPH = 1.14: 1.54: 1.23 m/s). The sensitivities were (89.5: 94.7: 89.5%) and the specificities were (62.5: 100.0: 75.0%). Meanwhile, setting the cut-off values of spleen stiffness as follows (CH: LC: IPH = 2.44: 2.61: 2.88 m/s), the sensitivities were (66.7: 90.5: 90.5%) and the specificities were (87.5: 100.0: 100.0%). The stiffness measurements of both liver and spleen were proved to be useful in diagnosis. Furthermore, a lower peripheral blood Tregs frequency [(LC: IPH) = (19.0: 11.6%)] (p < 0.001) and a larger SI (22.5: 44.5) (p < 0.001) were recorded in the IPH patients. [Discussion] The IPH patient group showed a lower liver stiffness relative to the LC group and comparable liver stiffness to that in the CH group. Stiffness of the spleen, nevertheless, was markedly higher in the IPH group; thus, stiffness measurements of both the liver and spleen allowed ready diagnostic differentiation between portal hypertension associated with LC and IPH. The increased splenic stiffness with splenomegaly in IPH was considered to be attributable to a state of enhanced immune functions when viewed with reference to the reduced percentage of peripheral blood Tregs.