Impact of clinical clerkship integrated with clinical ladder on attending physicians' teaching self-efficacy

BACKGROUND

Self-efficacy plays an important role in enhancing the teaching capabilities of attending physicians (APs). The clinical ladder (CL) is an educational approach developed in the field of nursing education that increases difficulty in an incremental manner. However, no previous study has confirmed the effectiveness of CL in medical education. Therefore, this study aimed to examine the effect of clinical clerkship integrated with clinical ladder (CC-CL) on the self-efficacy of APs.

METHODS

Sixth-year medical students participated in CC-CL for 6 months starting from April 2023, and the changes in the self-efficacy of APs were retrospectively evaluated. The students were trained by the APs concurrently, and the achievement levels of each student were shared. The primary outcome measure was the physician teaching self-efficacy questionnaire (PTSQ) score. The PTSQ scores before and after CC-CL were analyzed using the Wilcoxon matched-pair signed-rank test.

RESULTS

Fifteen APs from the Department of Pediatric and Child Neurology were included in this study. No significant difference was observed in the total PTSQ scores of the APs before and after CC-CL. However, a significant increase was observed in the PTSQ score of APs who participated for at least 2 h per week over a period of more than 3 months (n = 8) after CC-CL (p = 0.022). Furthermore, APs who had received their pediatrician certification < 10 years ago (n = 8) showed a significant increase in the total PTSQ score after CC-CL (p = 0.022).

CONCLUSIONS

CC-CL may play an important role in cultivating the self-efficacy of less experienced APs. Further comparative studies must be conducted in the future to validate the findings of this study.

Acceptability, Safety, and Feasibility of Transnasal and Peroral Ultrathin Endoscopy Using GAGLESS Mouthpieces: A Prospective Randomized Trial

BACKGROUND/AIM

Esophagogastroduodenoscopy (EGD) is an effective screening method for early detection of gastric cancer. The GAGLESS mouthpiece has a structure that widens the pharyngeal cavity and suppresses the pharyngeal reflex. This study aimed to investigate the acceptability, safety, and feasibility of transnasal and peroral ultrathin endoscopy using GAGLESS mouthpieces (Clinical Trial Number: UMIN000036922).

PATIENTS AND METHODS

This study was a multicenter, prospective, randomized, open-label trial performed using a questionnaire. The study included 101 consecutive patients who visited the participating medical institutions between June 2019 and March 2022 (median age=47 years, range=24-87 years; all male). Patients aged ≥20 years at the time of consent acquisition who were the first to undergo EGD were included in the study. The primary endpoint was the degree of distress during EGD, as determined using a visual analog scale (VAS).

RESULTS

The VAS score during endoscopic passage through the pharynx was significantly better in the transnasal endoscopy group than in the oral endoscopy group (2.420 vs. 4.092, p=0.001). There was no significant difference in the VAS scores between the two groups during anesthesia or throughout the examination. Compared with nasal endoscopy, oral endoscopy with a GAGLESS mouthpiece did not reduce the VAS score but did significantly improve gastric visibility.

CONCLUSION

For patients in whom there was difficulty in inserting a nasal endoscope, using a GAGLESS mouthpiece rather than a conventional mouthpiece may be more useful in reducing pain.

A Novel Monochromatic Light to Detect Target Specimens Within Endoscopic Ultrasonography-guided Fine-needle Aspiration Biopsy Samples

BACKGROUND/AIM

Endoscopic ultrasonography (EUS)-guided fine-needle aspiration biopsy (EUS-FNB) enhances the diagnostic capabilities of EUS by providing additional pathological samples. However, detecting the target specimens within the collected samples can be challenging. The aim of this study was to determine the optimal wavelength of light for detection of target specimens within EUS-FNB samples in an animal experiment.

MATERIALS AND METHODS

EUS-FNB pancreatic tissue samples were collected from a male beagle (weight, 10 kg), and the samples were illuminated with monochromatic light ranging from 430 to 700 nm in 5-nm intervals. The intensities of the target specimen and blood samples were analyzed using the densitometry of the images obtained through irradiation.

RESULTS

We found that transmitted monochromatic light of 605 nm most vividly enhanced the contrast between the target specimens and blood in the samples in the impression of appearance.

CONCLUSION

Thus, microscopical observations under transmitted light of 605 nm are optimal for target tissue identification within EUS-FNB samples.

A Strategic Translational Research System for Drug Discovery in Tottori University

The probability of successful drug discovery is declining, and research and development costs are increasing. To solve these problems, pharmaceutical companies tend to in-license seeds from venture companies and academia. Therefore, academia's role in drug discovery is extremely important. Tottori University started a "Next-Generation Research Support Project (Strategic Research Support Project)" in 2020, developing a translational research system to promote drug discovery. In this project, we established a research and development infrastructure, such as seed registration, construction of drug research and development support, and research fund allocation. The registered seed were converted into project, and the project implemented this research and development system, and evaluated and verified its results. Twenty-two seeds were converted into projects and portfolios were constructed. Research funds were allocated to eight prioritized projects. Each project raised the research and development stages. From the overall portfolio, one project with the Japan Agency for Medical Research and Development (AMED) Drug Discovery Booster Project, and three projects with Seeds A of the AMED Translational Research Strategic Promotion Program were adopted. Additionally, a new low-molecular weight chaperone drug against GM1-gangliosidosis was out-licensed to an overseas pharmaceutical company. The strength of this system was the strategic allocation of research funds and the accompanying support that leveraged internal and external resources with the PM and researchers at its core. This system achieved certain results in promoting drug discovery; however, resource optimization of specialized personnel needs to be strengthened in the future. In this report, we summarized the efforts of translational research in Japan and around the world. In addition, the translational research efforts of Japanese academia and Tottori University were compared and the current status was summarized.

Examining the reliability and validity of a self-regulated learning strategy scale for undergraduate nursing students and effective factors of self-regulated learning strategies

BACKGROUND

Self-regulated learning in higher education has increasingly attracted attention in recent years. This study involved a survey of nursing students using an originally developed tool called the Self-regulated Learning Strategy Scale for Undergraduate Nursing Students (SRLSS-NS).

OBJECTIVES

We aimed to elucidate factors relating to the promotion of self-regulated learning while confirming the reliability and validity of the novel scale.

DESIGN

A cross-sectional survey design was adopted.

SETTING

School of Health Science, Faculty of Medicine.

PARTICIPANTS

Participants included first- to fourth-year undergraduate nursing students.

METHODS

Descriptive statistics were used to ascertain participant characteristics. We confirmed the criterion-related validity of the survey through exploratory factor analysis and Pearson's product-moment coefficient with external criteria. Reliability was calculated using Cronbach's α coefficient. To examine stability, we confirmed the correlation between the first and second surveys. Multiple regression analysis was performed using the SRLSS-NS score as the objective variable and basic attributes/individual factors, learning-related factors, and cognitive factors as explanatory variables. The statistical significance level was defined as 5 %.

RESULTS

The scale consisted of 12 items related to three factors-construct validity, internal consistency, and stability-which were confirmed. Regarding factors related to the SRLS of undergraduate nursing students, the SRLSS-NS score was greater for items such as, "I feel that university education gives me confidence in learning" (β = 0.255, p < 0.001), "I like/find interest in things I am learning" (β = 0.228, p < 0.001), "I feel that university education teaches me how to learn" (β = 0.198, p = 0.003), and "Self-esteem as a professional" (β = 0.143, p = 0.023).

CONCLUSION

As more efforts are made to improve undergraduate nursing students' SRLS, the importance of education for increasing confidence, promoting intrinsic motivation, teaching learning methods, and fostering occupational identity is emphasized.

Evaluation of the Hemoglobin Concentration in Drainage Fluid After Surgery by Absorbance Spectrophotometry Using an Optical Sensor

Background

A drain is often placed in the abdominal cavity for postoperative monitoring and early detection of complications such as rebleeding and pancreatic or bile leaks. Since determining the color of the drainage fluid is subjective, an objective method of judging color is needed.

Methods

The hemoglobin concentration of the drainage fluid after gastrointestinal surgery was measured using the Hemato Check Module, a newly developed instrument capable of absorbance analysis with an optical sensor. The correlation between the results and those measured by an existing blood count measuring device (XN3000) was investigated.

Results

A total of 215 specimens were analyzed in 43 patients. For the correlation analysis, there was a strong positive correlation with a correlation coefficient of 0.884 (P < 0.001). The Hemato Check Module showed a clear proportional error compared to the XN3000.

Conclusion

The Hemato Check Module was a convenient and accurate instrument for measuring hemoglobin concentration in waste fluid to determine the presence of blood.

Newly Invented Micellized Vitamin K2 Recovered Prolonged Prothrombin Time under Obstructive Jaundice in Rats with Bile Duct Ligation

In cholestatic liver diseases, coagulopathy is induced by malabsorption of vitamin K. Supplementation of vitamin K has previously been shown to prevent coagulopathy. In this study, we tested the efficacy of a newly invented micellized vitamin K2 (m-vitK2) in treating coagulopathy, using a rat bile duct ligation (BDL) model. Experiment 1: m-vitK2 (0.3 mg/kg) or m-vitK2 (0.3 mg/kg) mixed with taurocholic acid (TA) (10 mg/body) was orally administrated every day for 7 d from the fourth day after BDL (n=6 for each). Experiment 2: To evaluate absorption, m-vitK2 (0.3 mg/kg) with or without TA (10 mg/body) was orally administered on the fourth day after BDL and compared with the untreated control BDL (n=2 for each). These data were compared with sham-operated (n=6) and untreated control BDL rats (n=6). The m-vitK2 recovered prothrombin time (PT) in Experiment 1 (control 42.7±5.7 s vs. m-vitK2 24.0±9.3 s, p<0.05). Experiment 2 demonstrated that the mixture of m-vitK2 and TA enhanced absorption compared to m-vitK2 alone. Moreover, in Experiment 1, m-vitK2 mixed with TA completely recovered PT (control 42.7±5.7 s vs. m-vitK2+TA 14.9±1.2 s, p<0.01). Micelle sizes decreased with the m-vitK2 and TA treatment (m-vitK2 86.3±5.6 nm vs. m-vitK2+TA 71.9±4.7 nm, p<0.05). Orally administered, newly invented m-vitK2 recovered coagulopathy even under obstructive jaundice. TA decreased the mean micelle size and improved m-vitK2 absorption.

Creating an LMS ePortfolio Building System That Enhances the Quality of College Life from One That Supports Self-Regulated Learning

During the recent coronavirus disease 2019 (COVID-19) pandemic, the ability to be a self-regulated learner has become more important with the introduction of online classes. These changes mean that students are now required to review their learning strategies and self-manage their learning time. We have developed a new "ePortfolio system" with the aim of building a system that fosters self-regulated learners and can visualize students' learning outcomes. This paper introduces the concepts of our ePortfolio system as a Learning Management System ePortfolio building system that will provide enhanced functions and become a university-wide initiative.

Efficacy and Safety of a Novel Mouthpiece for Esophagogastroduodenoscopy: A Multi-Center, Randomized Study

This randomized trial aimed to compare the safety and efficacy of the GAGLESS mouthpiece for esophagogastroduodenoscopy (EGD) with that of the conventional mouthpiece. In all, 90 participants were divided into the GAGLESS mouthpiece and conventional mouthpiece groups. The primary endpoint was the severity of pain using the visual analog scale (VAS), and secondary endpoints were examination time, past history of endoscopy, success of the procedure, systolic (SBP) and diastolic (DBP) blood pressure, oxygen saturation, pulse rate before and after EGD, and adverse events. Endoscopy was completed in all cases, and no complications were observed. VAS, when passing the scope through the pharynx, was 2.5 ± 2.4 and 2.0 ± 1.9 cm (p = 0.24) in the conventional and GAGLESS groups, respectively, and that, throughout the examination, was 2.5 ± 2.4 and 1.7 ± 1.5 cm (p = 0.06), respectively. The difference in blood pressure between the GAGLESS and conventional groups was not significant for SBP (p = 0.08) and significant for DBP (p = 0.03). The post-EGD difference in DBP was significantly lower in the GAGLESS group than in the conventional group. The results indicate that GAGLESS mouthpieces had a lower VAS during endoscopy than the conventional mouthpieces, and the changes in blood pressure were smaller with the GAGLESS mouthpiece.

Novel mouthpiece for reducing the gag reflex during esophagogastroduodenoscopy

BACKGROUND AND AIM

Discomfort associated with the gag reflex during transoral endoscopy can be troublesome. To overcome this problem during esophagogastroduodenoscopy (EGD), we recently developed a novel mouthpiece. The aim of the present study was to compare acceptance and tolerability of transoral EGD with conventional and new mouthpieces in unsedated patients and analyze the effects of the new mouthpiece.

METHODS

This study consisted of two phases of cephalometric and EGD examinations to analyze the effects of the new mouthpiece. Cephalometry was carried out in six subjects to evaluate differences in the size of the pharynx (anteroposterior diameter of the oropharynx and longitudinal diameter of the oral cavity) when subjects held the conventional mouthpiece (MAJ674) or the new mouthpiece in their mouths. EGD was done in 10 subjects using the conventional or new mouthpiece to evaluate the number of times the gag reflex occurred, examinee discomfort, and endoscope operability during EGD using a visual analogue scale (VAS).

RESULTS

Anteroposterior diameter of the oropharynx and longitudinal diameter of the oral cavity were significantly larger with the new mouthpiece than with the conventional mouthpiece (oropharynx: P = 0.03; oral cavity: P = 0.03). With the new mouthpiece during EGD, subjects had significantly fewer instances of the gag reflex (P = 0.01); VAS score for discomfort was significantly lower (P < 0.01) and score for endoscope operability was significantly higher (P = 0.04).

CONCLUSION

The new mouthpiece we developed reduced the gag reflex during EGD by extending the pharynx, thus decreasing examinee discomfort and increasing endoscopic operability.

Thermal damage of osteocytes during pig bone drilling: an in vivo comparative study of currently available and modified drills

OBJECTIVES

The Gekkou-drill® is an industrial drill that is highly efficient due to reduced cutting resistance resulting from its characteristic drill point shape. In this experiment, we compared the degree of thermal damage to bone tissue caused by conventional medical drills and these same drills with Gekkou modifications.

METHODS

Holes were created in the tibias of living pigs using two different 3.2-mm diameter drills and their modified versions. Regarding the drilling parameters, the thrust force was 10 N and the drilling speeds were 800 revolutions per minute (rpm) and 1500 rpm. We compared the original and modified drills in terms of the bone temperature around the drill bit and the total time necessary to create each hole, the latter calculated using imaging data captured during drilling. In histopathological examination, the percentages of empty lacunae in osteocytes of the cortical bone beneath the periosteum were evaluated at 400 × magnification with an optical microscope.

RESULTS

Compared to the original drills, the modified drills required significantly less time to create each hole and caused a significantly lower temperature rise during bone drilling. With the modified drills, the percentages of empty lacunae around the drilling holes were about 1/2-1/3 of those with the original drills, and were significantly lower for both drilling speeds.

CONCLUSIONS

Gekkou-modified medical drills shortened drilling times despite low thrust force, and histopathological assessment demonstrated a significant reduction in osteocyte damage.

A Computer-Based Glucose Management System Reduces the Incidence of Forgotten Glucose Measurements: A Retrospective Observational Study

INTRODUCTION

Frequent glucose measurements are needed for good blood glucose control in hospitals; however, this requirement means that measurements can be forgotten. We developed a novel glucose management system using an iPod^® and electronic health records.

METHODS

A time schedule system for glucose measurement was developed using point-of-care testing, an iPod^®, and electronic health records. The system contains the glucose measurement schedule and an alarm sounds if a measurement is forgotten. The number of times measurements were forgotten was analyzed.

RESULTS

Approximately 7000 glucose measurements were recorded per month. Before implementation of the system, the average number of times measurements were forgotten was 4.8 times per month. This significantly decreased to 2.6 times per month after the system started. We also analyzed the incidence of forgotten glucose measurements as a proportion of the total number of measurements for each period and found a significant difference between the two 9-month periods (43/64,049-24/65,870, P = 0.014, chi-squared test).

CONCLUSIONS

This computer-based blood glucose monitoring system is useful for the management of glucose monitoring in hospitals.

FUNDING

Johnson & Johnson Japan.

Endocytoscopic classification can be predictive for relapse in ulcerative colitis

The present study was conducted to explore the association of endocytoscopy (EC) classification with microscopic inflammatory features of ulcerative colitis (UC) and disease relapse.EC was performed for mild-to-moderate UC 32 cases from January 2010 to August 2016. EC appearance was stratified into 4 categories: EC-A, regular arrangement of round to oval pits; EC-B, irregular arrangement with/without enlarged spaces between regular pits; EC-C, deformed pits with distorted crypt lumen which are unordered in arrangement but not disrupted; and EC-D, disruptive or disappeared pits. We evaluated the association of EC classification with Mayo endoscopic subscores (MES) and the clinically active state. Microscopic features including the severity in mucosal inflammatory infiltrates the presence of crypt abscess and goblet cell depletion were assessed by an experienced pathologist who was blinded to clinical and endoscopic information. Clinical follow-up was provided for treating 22 UC patients more than 60 months after EC.There were 15 cases in EC-A, 8 in EC-B, 5 in EC-C, and 4 in EC-D. Interobserver agreement was excellent with κ value of 0.77. There were 13 patients in active disease stage, while 19 in remission. Each EC-A case was in clinically remission stage, while all the EC-C and EC-D cases were in the active stage. There were 4 and 4 EC-B cases in remission and active stage, respectively. The EC-A group consisted of 11 MES0 and 4 MES1 cases, whereas the EC-B group consisted of 2 MES0 and 6 MES1 cases. There were no cases of MES0 in the EC-C and -D groups. The EC stratification was significantly associated with pathognomonic microscopic features for UC. There were significant differences in the remission rate among the EC groups. None had relapse in the EC-A group during the follow-up period.EC stratification could be predictive for relapse in UC. Moreover, EC is reliable to assess UC specific microscopic features.

A panel study of airborne particulate matter composition versus concentration: Potential for inflammatory response and impaired pulmonary function in children

BACKGROUND

The relationship between airborne particulate matter (PM) and pulmonary function in children has not been consistent among studies, potentially owing to differences in the inflammatory response to PM, based on PM types and sources. The objective of this study was to investigate the effect of airborne PM on pulmonary function in schoolchildren and its potential for an inflammatory response.

METHODS

Daily morning peak expiratory flow (PEF) was measured in 339 schoolchildren in February 2015. Interleukin (IL)-8 production was assessed in THP1 cells stimulated by airborne PM collected every day during the study period, and these IL-8 concentrations are described as the daily IL-8 levels. A linear mixed model was used to estimate the association between PEF values and the daily levels of suspended PM (SPM), PM diameters smaller than 2.5 μm (PM_2.5), and IL-8.

RESULTS

The daily IL-8 levels were significantly associated with those of SPM and PM_2.5. A 0.83 μg/mL increase in IL-8 levels was significantly associated with a -1.07 L/min (95% confidence interval, -2.05 to -0.08) decrease in PEF. A 12.0 μg/m³ increase in SPM and a 10.0 μg/m³ increase in PM_2.5 were associated with a -1.36 L/min (-2.93 to 0.22) and -1.72 L/min (-3.82 to 0.36) decreases in PEF, respectively. There were no significant relationships between PEF, SPM, and PM_2.5.

CONCLUSIONS

These findings suggest that the effects of airborne PM on pulmonary function in schoolchildren might depend more on the pro-inflammatory response than the mass concentration of the PM.

Role of the preoperative usefulness of the pathological diagnosis of pancreatic diseases

Pancreatic cancer is the fifth leading cause of cancer death and has the lowest survival rate of any solid cancer. Endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNA) is currently capable of providing a cytopathological diagnosis of pancreatic malignancies with a higher diagnostic power, with a sensitivity and specificity of 85%-89% and 98%-99%, compared to pancreatic juice cytology (PJC), whose sensitivity and specificity are only 33.3%-93% and 83.3%-100%. However, EUS-FNA is not effective in the cases of carcinoma in situ and minimally invasive carcinoma because both are undetectable by endoscopic ultrasonography, although PJC is able to detect them. As for the frequency of complications such as post endoscopic retrograde cholangiopancreatography pancreatitis, EUS-FNA is safer than PJC. To diagnose pancreatic cancer appropriately, it is necessary for us to master both procedures so that we can select the best methods of sampling tissues while considering the patient’s safety and condition.

Transurethral En Bloc Resection of Bladder Tumor Using an Endoscopic Submucosal Dissection Technique: Preliminary Results in an Animal Model

BACKGROUND

Transurethral resection of bladder tumor (TURBT) technique has been considered the routine method for removing most bladder tumors for decades. In contrast, endoscopic submucosal dissection (ESD) is the gold-standard treatment for gastrointestinal superficial tumors. We investigated the effectiveness and applicability of a new technique for en bloc bladder tumor resection using ESD procedure.

METHODS

Four Landrace Large White Duroc female pigs were anesthetized with isoflurane prior endoscopic resection using a large-caliber prototype fiber bronchoscope. After local infiltration of the submucosa with sodium hyaluronate using an injector needle, a section of the target area (1.0-2.0 cm diameter circular area) was cut with the Dual Knife.

RESULTS

In total, seven target sections were resected from the pigs. The median size of the resected sections was 1.8 cm (range 1.0-2.5 cm) and the median time taken to perform the resection of one section was 20 min (range 4-35 min). These target sections were completely resected en bloc. Although the small bladder perforations occurred on two occasions, no other short-term complications such as uncontrollable bleeding were observed.

CONCLUSION

This procedure is a slightly difficult in the pigs with thin bladder walls. However, this procedure with the slim flexible cystoscope may allow us to be able to remove bladder tumors using only light sedation, especially for cases when small tumor recurrence is observed during routine cystoscopy for the patients with non-muscle invasive bladder cancer.

Automated stride assistance device improved the gait parameters and energy cost during walking of healthy middle-aged females but not those of young controls

[Purpose] The aim of this study was to clarify the effects of an automated stride assistance device on gait parameters and energy cost during walking performed by healthy middle-aged and young females. [Subjects and Methods] Ten middle-aged females and 10 young females were recruited as case and control participants, respectively. The participants walked for 3 minutes continuously under two different experimental conditions: with the device and without the device. Walking distance, mean walking speed, mean step length, cadence, walk ratio and the physiological cost index during the 3-minutes walk were measured. [Results] When walking with the stride assistance device, the step length and walk ratio of the middle-aged group were significantly higher than without it. Also, during walking without assistance from the device, the physiological cost index of the middle-aged group significantly increased; whereas during walking with assistance, there was no change. The intergroup comparison in the middle-aged group showed the physiological cost index was lower under the experimental condition with assistance provided, as opposed to the condition without the provision of assistance. [Conclusion] The results of this study show that the stride assistance device improved the gait parameters of the middle-aged group but not those of young controls.

Development of a device for detecting target specimens from EUS-guided FNA samples

BACKGROUND AND STUDY AIMS

Specimens collected by fine needle are microscopic and contain blood; therefore, the presence of a target specimen within a sample is often difficult to confirm. Although rapid on-site evaluation (ROSE) during endoscopic ultrasound-guided fine needle aspiration biopsy (EUS-FNA) is beneficial, many health care facilities are unable to apply this technique due to a lack of cytopathologists. The aim of this study was to develop and validate a device that detects the target specimen within pancreatic tumor EUS-FNA samples.

PATIENTS AND METHODS

Fifty-eight consecutive patients with solid pancreatic masses were studied for a preliminary case series at a tertiary-care university hospital (Tottori University Hospital, Yonago, Japan). The material collected was checked with a target sample check illuminator (TSCI) and was evaluated by one cytopathologist.

RESULTS

The agreement rate between the TSCI and histopathology was 93.7 %. Further testing procedures were not needed in 91.4 % of patients, and the mean number of needle punctures was 1.2 after a single pass using TSCI. No adverse events were encountered with the procedure.

CONCLUSIONS

With the introduction of the TSCI in EUS-FNA, it became possible to both collect the minimum necessary target samples by EUS-FNA and to end further procedures, even without performing ROSE.

Therapeutic effects of the direct renin inhibitor, aliskiren, on non-alcoholic steatohepatitis in fatty liver Shionogi ob/ob male mice

AIM

Non-alcoholic steatohepatitis (NASH) is a manifestation of metabolic syndrome in the liver that is characterized by hepatic fat accumulation, inflammation and varying degrees of fibrosis. The renin-angiotensin system (RAS) appears to play important roles in NASH. Direct renin inhibitors (DRI) reduce plasma renin activity (PRA) through interaction with the active site of the enzyme and reduce the formation of angiotensin-II (AT-II). Therefore, the DRI aliskiren may further suppress the RAS. This study examined the effects of aliskiren on NASH in fatty liver Shionogi (FLS)-ob/ob male mice that are the closest animal model of metabolic syndrome-related NASH in humans.

METHODS

Aliskiren (100 mg/kg per day, aliskiren group) or a placebo (control group) was p.o. administrated to eight FLS-ob/ob mice each for 16 weeks and factors including steatosis, fibrosis, inflammation and oxidative stress were compared between the two groups.

RESULTS

Amounts of hepatic fibrosis were significantly lower in the aliskiren group than in the control group. Areas of α-smooth muscle actin positivity, the numbers of F4/80 positive, 8-hydroxy-2-deoxyguanosine positive cells and immunohistochemical staining of 4-hydroxynonenal were also significantly decreased in the aliskiren group. Levels of RNA expression for transforming growth factor-β1, connective tissue growth factor and monocyte chemoattractant protein-1 were significantly lower in the aliskiren group.

CONCLUSION

Aliskiren attenuated the progression of hepatic fibrosis by inhibiting the activation of hepatic stellate and Kupffer cells and by reducing oxidative stress.

Hepatitis B and C virus infection is a risk factor for the development of cholangiocarcinoma

OBJECTIVE

Chronic hepatitis B virus (HBV) and hepatitis C virus (HCV) infection may be involved in the development of cholangiocarcinoma. The prevalence of HBV and HCV infection was examined in patients with intrahepatic cholangiocarcinoma (ICC) and extrahepatic cholangiocarcinoma (ECC).

METHODS

The levels of HBV surface antigens (HBsAg), antibodies against HBV core antigens (HBcAb) and hepatitis C virus antibodies (HCV-Ab) were determined in sera obtained from 145 consecutive patients (50 patients with ICC, 95 patients with ECC).

RESULTS

The seroprevalence of HBsAg was 10% in the ICC patients and 4.2% in the ECC patients. The prevalence of HCV-Ab was 20% in the ICC patients and 7.4% in the ECC patients.

CONCLUSION

The prevalence of HBsAg and HCV-Ab is 0.8-2.2% and 1-2%, respectively, in the Japanese population living in the Tottori area. Furthermore, HBV and HCV infection is a possible risk factor for the development of cholangiocarcinoma. Therefore, the surveillance of ICC and ECC is needed in HBV and HCV carriers.

Fatty liver Shionogi-ob/ob mouse: A new candidate for a non-alcoholic steatohepatitis model

AIM

The fatty liver Shionogi (FLS) mouse develops hereditary fatty liver without obesity. The FLS-ob/ob mouse made by transferring the leptin(ob) gene demonstrates several metabolic disorders and marked fat deposition in the liver. The aim was to evaluate which mouse model, the FLS or FLS-ob/ob, is more useful for non-alcoholic steatohepatitis research.

METHODS

FLS (n = 40) and FLS-ob/ob (n = 40) mice were fed a standard diet for 12, 24, 36 and 48 weeks, and then killed. The degree of fat deposition, oxidative stress, fibrosis and apoptosis were analyzed in the liver. Hepatic mRNA expression of fibrogenic and pro-inflammatory cytokines was measured.

RESULTS

FLS mice developed hepatic steatosis and slight fibrosis without obesity between 12 and 48 weeks of age. Conversely, FLS-ob/ob mice developed severe steatosis at 12 weeks of age, and steatohepatitis with increased oxidative stress and advanced fibrosis between 24 and 36 weeks of age. At 48 weeks of age, some FLS-ob/ob but not FLS mice, progressed to cirrhosis. Transforming growth factor-β1, connective tissue growth factor and tumor necrosis factor-α mRNA expression levels were greater in FLS-ob/ob than FLS mice between 24 and 48 weeks of age. The number of apoptotic cells in the liver was greater at 12 weeks of age in FLS mice and at 48 weeks of age in FLS-ob/ob mice.

CONCLUSION

FLS-ob/ob mice developed more severe steatohepatitis with fibrosis than FLS mice, and had increased oxidative stress and apoptosis. These findings indicate that the FLS-ob/ob mouse is a more useful model for steatohepatitis research.

Extracellular matrix metabolism-related gene expression in bile duct-ligated rats

Bile duct-ligated rats have been widely used as a model of cholestatic liver fibrosis. The aim of this study was to analyze the sequential expression of extracellular matrix (ECM) metabolism-related genes in these rats. We analyzed the intrahepatic messenger RNA (mRNA) expression of several ECM metabolism-related genes: transforming growth factor β1 (TGF-β1), connective tissue growth factor (CTGF), procollagen-α1 (collagen-I), matrix metalloproteinase (MMP)-2, MMP-13 and tissue inhibitor of metalloproteinases (TIMP)-1 on days 10, 21 and 42 after bile duct ligation (BDL). A DNA microarray was used to evaluate the expression of genes related to early fibrogenesis on day 10 following BDL; the grade of hepatic fibrosis was found to gradually progress from day 10 to 42. Collagen-I mRNA expression significantly increased from day 10 to day 42, as did TGF-β1 and CTGF mRNA. On the other hand, MMP-13 and -2 mRNA expression increased maximally from day 10 to 21, but tended to decrease by day 42. TIMP-1 mRNA expression was significant on day 21 and was sustained until day 42. The DNA microarray revealed genes significantly increased on day 10, including calgranulin B, solute carrier family 34, thymosin and tubulin, but not fibrogenesis-related cytokines or MMPs/TIMPs. In conclusion, the enhanced gene expression of collagen-I, TGF-β1, CTGF and TIMP-1 and the decreased gene expression of MMP-13 and -2 was noted on day 42 in BDL-induced liver fibrosis.

Therapeutic effects of angiotensin II type 1 receptor blocker, irbesartan, on non-alcoholic steatohepatitis using FLS-ob/ob male mice

Non-alcoholic steatohepatitis (NASH) is the hepatic manifestation of a metabolic syndrome characterized by accumulation of hepatic fat, inflammation and varying degrees of fibrosis. Angiotensin (AT)-II has been reported to play a role in the establishment of NASH. This study examined the effects of an AT-II receptor blocker, irbesartan, on NASH using fatty liver Shionogi (FLS)-ob/ob male mice as the closest animal model of human metabolic syndrome-related NASH. Irbesartan (30 mg/kg/day) was orally administered to FLS-ob/ob mice for 12 weeks (irbesartan group). The effects of irbesartan on steatohepatitis were examined using factors including steatosis, fibrosis, inflammation and oxidative stress. The areas of hepatic fibrosis and hepatic hydroxyproline content were significantly lower in the irbesartan group compared to controls. The areas of α-smooth muscle actin-positivity and F4/80-positive cells were significantly decreased in the irbesartan group. The percentage of 8-hydroxy-2-deoxyguanosine (8-OHdG)-positive cells and 8-OHdG DNA content were significantly decreased in the irbesartan group compared to controls. Levels of RNA expression for procollagen I, transforming growth factor β1, tumor necrosis factor-α, sterol regulatory element-binding protein 1c and fatty acid synthase were significantly lower in the irbesartan group compared to controls. In contrast, the gene expression of peroxisome proliferator activated receptor-α was significantly higher in the irbesartan group compared to controls. Irbesartan administration improved hepatic steatosis and attenuated the progression of hepatic fibrosis by inhibiting the activation of hepatic stellate cells and Kupffer cells and reducing oxidative stress.

Therapeutic effects of ezetimibe for non-alcoholic steatohepatitis in fatty liver shionogi-ob/ob mice

AIM

  An effective therapy for non-alcoholic steatohepatitis has yet to be defined. This study examined the therapeutic effects of ezetimibe, a lipid-lowering medication, on steatosis and hepatic fibrosis in fatty liver Shionogi ob/ob (FLS-ob) mice.

METHODS

  Low-dose (0.2 mg/kg body weight) and high-dose (1.0 mg/kg body weight) of ezetimibe were administered to FLS-ob mice orally for 12 weeks.

RESULTS

  Administration of ezetimibe significantly and dose-dependently decreased liver cholesterol content. The area of hepatic fibrosis and hepatic hydroxyproline content in the low- and high-dose groups were significantly decreased compared with controls. Areas of α-smooth muscle actin positivity and F4/80 positivity were significantly decreased in a dose-dependent manner. Percentages of 8-hydroxy-2-deoxyguanosine-positive cells in low- and high-dose groups were significantly decreased compared with those in controls, and 8-hydroxy-2-deoxyguanosine DNA content and thiobarbituric acid reactive substances in the high-dose group was also significantly decreased compared to controls. Gene expression levels of procollagen I and transforming growth factor β1 mRNA levels were lower in the low- and high-dose groups than in controls. Tumor necrosis factor-α and sterol regulatory element-binding protein 1c mRNA levels were also lower in the low- and high-dose groups than in controls.

CONCLUSIONS

  Ezetimibe attenuated steatosis and liver fibrosis by reducing oxidative stress and lipid peroxidation and suppressing activated hepatic stellate cells and Kupffer cells.

Assessment of the ablated area after radiofrequency ablation by the spread of bubbles: comparison with virtual sonography with magnetic navigation

BACKGROUND/AIMS

The purpose of this study was to investigate whether bubble images after radiofrequency ablation (RFA) can predict the ablated area.

METHODOLOGY

The spread of bubbles 5 minutes after RFA were compared with the unenhanced area of virtual sonography with magnetic navigation in two RFA methods: expandable needle and cool-tip needle.

RESULTS

Thirty-one hepatocellular carcinoma nodules were treated by RFA with either an expandable needle or cool-tip needle (n=14 and n=17, respectively) and examined. In the 14 nodules treated by expandable needle, bubble images (puncture direction; r=0.833, p=0.0002, perpendicular direction; r=0.803, p=0.0005) were closely correlated with the unenhanced area of virtual sonography. On the other hand, in 17 nodules treated by cool-tip needle, there was no correlation between the bubble images and virtual sonography (puncture direction; r=0.590, p=0.0127, perpendicular direction; r=0.342, p=0.180).

CONCLUSIONS

The observation of bubbles with the expandable needle can accurately predict the ablated area and is helpful for assessing local control of RFA.

Assessment of ablative margin after radiofrequency ablation for hepatocellular carcinoma; comparison between magnetic resonance imaging with ferucarbotran and enhanced CT with iodized oil deposition

BACKGROUND AND PURPOSE

Our aim was to investigate whether magnetic resonance imaging (MRI) with ferucarbotran administered prior to radiofrequency ablation could accurately assess ablative margin when compared with enhanced computed tomography (CT) with iodized oil marking.

MATERIALS AND METHODS

We enrolled 27 patients with 32 hepatocellular carcinomas in which iodized oil deposits were visible throughout the nodule after transcatheter arterial chemoembolization. For these nodules, radiofrequency ablation was performed after ferucarbotran administration. We then performed T2-weighted MRI after 1 week and enhanced CT after 1 month. T2-weighted MRI demonstrated the ablative margin as a low-intensity rim. We classified the margin into three grades; margin (+): high-intensity area with a continuous low-intensity rim; margin zero: high-intensity area with a discontinuous low-intensity rim; and margin (-): high-intensity area extending beyond the low-intensity rim.

RESULTS

In 28 (86%) of 32 nodules, there was agreement between MRI and CT. The overall agreement between for the two modalities in the assessment of ablative margin was good (κ=0.759, 95% confidence interval: 0.480-1.000, p<0.001). In four nodules, ablative margins on MRI were underestimated by one grade compared with CT.

CONCLUSION

MRI using ferucarbotran is less invasive and allows earlier assessment than CT. The MRI technique performed similarly to enhanced CT with iodized oil marking in evaluating the ablative margin after radiofrequency ablation.

Assessment of ablative margin by MRI with ferucarbotran in radiofrequency ablation for liver cancer: comparison with enhanced CT

OBJECTIVES

Our aim was to determine whether ablated liver parenchyma surrounding a tumour can be assessed by MRI with ferucarbotran administered prior to radiofrequency ablation (RFA) compared with enhanced CT.

METHODS

55 hepatocellular carcinomas (HCCs) in 42 patients and 5 metastatic liver cancers in 3 patients were treated by RFA after ferucarbotran administration. We then performed T(2)* weighted MRI after 1 week and enhanced CT after 1 month. T(2)* weighted MRI demonstrated the ablated parenchyma as a low-intensity rim around the high intensity of the ablated tumour in these cases. The assessment was allocated to one of three grades: margin (+), high-intensity area with continuous low-intensity rim; margin zero, high-intensity area with discontinuous low-intensity rim; and margin (-), high-intensity area extending beyond the low-intensity rim.

RESULTS

Margin (+), margin zero and margin (-) were found in 17, 35 and 5 nodules, respectively. All 17 nodules with margin (+) and 13 of those with margin zero were assessed as having sufficient ablative margins on CT. The remaining 22 nodules with margin zero had insufficient margins on CT. The overall agreement between MRI and CT for the diagnosis of the ablative margin was moderate (κ = 0.507, p < 0.001). No local recurrence was found in 15 HCC nodules with margin (+), whereas local recurrence was found in 4 (11.8%) out of 34 HCC nodules with margin zero.

CONCLUSION

Administration of ferucarbotran before RFA enables the ablative margin to be visualised as a low-intensity rim, and also enables the evaluation of the ablative margin to be made earlier and more easily than with enhanced CT.

Cowden syndrome complicated with hepatocellular carcinoma possibly originating from non-alcoholic steatohepatitis (NASH)

There is currently no report that has documented hepatocellular carcinoma (HCC) in a case of Cowden syndrome. Here, we present the first reported case of HCC in a 60-year-old female patient with Cowden syndrome. We diagnosed the patient using a pathognomonic criterion of the International Cowden Consortium Operational Diagnostic Criteria and performed genetic analysis. Enhanced computed tomography demonstrated a hypervascular tumor in segment VII of the liver. The patient was diagnosed with Cowden syndrome because her mucocutaneous lesions met the pathognomonic criterion. Mutational analysis confirmed a heterozygous germ line TGT→TAT transition at nucleotide 407 in exon 5 of the phosphatase and tensin homolog detected on the chromosome 10 (PTEN) gene. Needle biopsy showed a poorly differentiated HCC. We also diagnosed non-alcoholic steatohepatitis (NASH) from hepatic histological findings of Mallory's bodies and ballooning cells. PTEN-deficient mice reportedly develop HCC through NASH. This is the first reported case of Cowden syndrome complicated with HCC possibly originating from NASH.

Assessment of hepatocellular carcinoma by contrast-enhanced ultrasound with perfluorobutane microbubbles: comparison with dynamic CT

OBJECTIVE

The aim of this study was to evaluate tumour vascularity and Kupffer cell imaging in hepatocellular carcinoma (HCC) using contrast-enhanced ultrasonography (CEUS) with Sonazoid (perfluorobutane) and to compare performance with dynamic CT.

METHODS

We studied 118 nodules in 88 patients with HCC. HCC was diagnosed as a hyperenhancement lesion in the arterial phase with washout in the portal phase on dynamic CT or by percutaneous biopsy. We observed tumour vascularity at the early vascular phase (10-30 s after contrast injection) and Kupffer imaging at the post-vascular phase (after 10 min).

RESULTS

Detection of vascularity at the early vascular phase was 88% in nodules that were found to be hypervascular on dynamic CT and 28% in hypo-/isovascular nodules; the detection of local recurrence nodules was 92%. The detection of vascularity was significantly lower in nodules >9 cm deep than in those ≤9 cm deep, but was not affected by tumour size. The detection of tumours at the post-vascular phase on CEUS was 83% in nodules with low density in the portal phase on dynamic CT and 82% in nodules with isodensity. The rate did not depend on the severity of underlying liver disease; rates decreased in nodules deeper than 9 cm, those smaller than 2 cm in diameter and in iso-enhancing nodules at the early vascular phase of CEUS.

CONCLUSION

CEUS with Sonazoid is a useful tool for assessing the vascularity of HCC and is equal to that of dynamic CT; however, the detectability of HCC vascularity is affected by location.

The effects of the selective mineralocorticoid receptor antagonist eplerenone on hepatic fibrosis induced by bile duct ligation in rat

The aim of this study was to examine the effects of eplerenone on hepatic fibrosis induced by bile duct ligation (BDL) in rat. Low- (1.0 mg/kg body weight, BW) and high- (4.0 mg/kg BW) dose eplerenone was administered orally for 21 days immediately following BDL. Fibrosis was assessed by measuring the fibrotic area after Sirius red staining. Immunostaining for alpha-smooth muscle actin (SMA), 4-hydroxy-2-nonenal (4-HNE) and 8-hydroxy-2-deoxyguanosine (8-OHdG) was also carried out. Gene expression levels of procollagen-I, transforming growth factor-beta1 (TGF-beta1), connective tissue growth factor (CTGF), tissue inhibitor of metalloproteinases-1 (TIMP-1) and matrix metalloproteinase-13 (MMP-13) in the liver were examined by real-time reverse transcriptase polymerase chain reaction. Plasma angiotensin II (ATII) concentration was measured via radioimmunoassay. The area of hepatic fibrosis and alpha-SMA positivity in the high-dose group was significantly decreased compared with that in the BDL group, but not in the low-dose group. 8-OHdG-positive cells in the low- and high-dose groups were significantly decreased compared with those in the BDL group. Immunostaining of 4-HNE in the high-dose group was significantly lower compared with that in the BDL group. Furthermore, TIMP-1 mRNA levels in the low- and high-dose groups were lower than that in the BDL group. The expression of TGF-beta1, CTGF, procollagen-1 and MMP-13 showed no differences. Plasma ATII concentration in the high-dose group was significantly decreased. Eplerenone attenuated the development of BDL-induced hepatic fibrosis by reducing oxidative stress, suppressing activated hepatic stellate cells and decreasing plasma ATII levels. Eplerenone may prove useful as an alternative treatment for antifibrosis therapy.

Measurement of activities in two different angiotensin II generating systems, chymase and angiotensin-converting enzyme, in the vitreous fluid of vitreoretinal diseases: A possible involvement of chymase in the pathogenesis of macular hole patients

PURPOSE

To investigate possible involvement of chymase and angiotensin-converting enzyme (ACE) in the pathogenesis of vitreoretinal diseases, both of which are related to the production of angiotensin II.

METHODS

We measured chymase and ACE activities in the vitreous in the 54 affected eyes of 54 patients who had undergone vitreous surgery for idiopathic macular holes (MH, n = 14), proliferative diabetic retinopathy (PDR, n = 14), idiopathic epiretinal membranes (ERM, n = 13), and rhegmatogenous retinal detachment (RRD, n = 13).

RESULTS

Chymase activities in the vitreous from patients with MH, PDR, ERM, and RRD were 1.87 +/- 0.53, 0.06 +/- 0.04, 0.40 +/- 0.12, and 0.08 +/- 0.03 (mean +/- SE) mU/mg protein, respectively, and ACE activities in the vitreous humor were 0.18 +/- 0.09, 0.30 +/- 0.07, 0.01 +/- 0.01, and 0.03 +/- 0.02 (mean +/- SE) mU/mg protein, respectively. Chymase activity was significantly elevated in MH among these diseases (p < 0.01, Scheffe), and ACE was significantly activated in PDR compared to ERM and RRD (p < 0.05, Scheffe).

CONCLUSIONS

Our results suggest that two different angiotensin II generating systems are activated in human vitreous humor; an increased activity of chymase may play a possible role in the formation of macular holes.