eIF4A1 enhances LARP1-mediated translational repression during mTORC1 inhibition

Eukaryotic translation initiation factor (eIF)4A-a DEAD-box RNA-binding protein-plays an essential role in translation initiation. Recent reports have suggested helicase-dependent and helicase-independent functions for eIF4A, but the multifaceted roles of eIF4A have not been fully explored. Here we show that eIF4A1 enhances translational repression during the inhibition of mechanistic target of rapamycin complex 1 (mTORC1), an essential kinase complex controlling cell proliferation. RNA pulldown followed by sequencing revealed that eIF4A1 preferentially binds to mRNAs containing terminal oligopyrimidine (TOP) motifs, whose translation is rapidly repressed upon mTORC1 inhibition. This selective interaction depends on a La-related RNA-binding protein, LARP1. Ribosome profiling revealed that deletion of EIF4A1 attenuated the translational repression of TOP mRNAs upon mTORC1 inactivation. Moreover, eIF4A1 increases the interaction between TOP mRNAs and LARP1 and, thus, ensures stronger translational repression upon mTORC1 inhibition. Our data show the multimodality of eIF4A1 in modulating protein synthesis through an inhibitory binding partner and provide a unique example of the repressive role of a universal translational activator.

Assessment of Stress and Well-Being of Japanese Employees Using Wearable Devices for Sleep Monitoring Combined With Ecological Momentary Assessment: Pilot Observational Study

BACKGROUND

Poor sleep quality can elevate stress levels and diminish overall well-being. Japanese individuals often experience sleep deprivation, and workers have high levels of stress. Nevertheless, research examining the connection between objective sleep assessments and stress levels, as well as overall well-being, among Japanese workers is lacking.

OBJECTIVE

This study aims to investigate the correlation between physiological data, including sleep duration and heart rate variability (HRV), objectively measured through wearable devices, and 3 states (sleepiness, mood, and energy) assessed through ecological momentary assessment (EMA) and use of rating scales for stress and well-being.

METHODS

A total of 40 office workers (female, 20/40, 50%; mean age 40.4 years, SD 11.8 years) participated in the study. Participants were asked to wear a wearable wristband device for 8 consecutive weeks. EMA regarding sleepiness, mood, and energy levels was conducted via email messages sent by participants 4 times daily, with each session spaced 3 hours apart. This assessment occurred on 8 designated days within the 8-week timeframe. Participants' stress levels and perception of well-being were assessed using respective self-rating questionnaires. Subsequently, participants were categorized into quartiles based on their stress and well-being scores, and the sleep patterns and HRV indices recorded by the Fitbit Inspire 2 were compared among these groups. The Mann-Whitney U test was used to assess differences between the quartiles, with adjustments made for multiple comparisons using the Bonferroni correction. Furthermore, EMA results and the sleep and HRV indices were subjected to multilevel analysis for a comprehensive evaluation.

RESULTS

The EMA achieved a total response rate of 87.3%, while the Fitbit Inspire 2 wear rate reached 88.0%. When participants were grouped based on quartiles of well-being and stress-related scores, significant differences emerged. Specifically, individuals in the lowest stress quartile or highest subjective satisfaction quartile retired to bed earlier (P<.001 and P=.01, respectively), whereas those in the highest stress quartile exhibited greater variation in the midpoint of sleep (P<.001). A multilevel analysis unveiled notable relationships: intraindividual variability analysis indicated that higher energy levels were associated with lower deviation of heart rate during sleep on the preceding day (β=-.12, P<.001), and decreased sleepiness was observed on days following longer sleep durations (β=-.10, P<.001). Furthermore, interindividual variability analysis revealed that individuals with earlier midpoints of sleep tended to exhibit higher energy levels (β=-.26, P=.04).

CONCLUSIONS

Increased sleep variabilities, characterized by unstable bedtime or midpoint of sleep, were correlated with elevated stress levels and diminished well-being. Conversely, improved sleep indices (eg, lower heart rate during sleep and earlier average bedtime) were associated with heightened daytime energy levels. Further research with a larger sample size using these methodologies, particularly focusing on specific phenomena such as social jet lag, has the potential to yield valuable insights.

TRIAL REGISTRATION

UMIN-CTR UMIN000046858; https://center6.umin.ac.jp/cgi-open-bin/ctr/ctr_view.cgi?recptno=R000053392.

Assessment of glycemic variability and lifestyle behaviors in healthy nondiabetic individuals according to the categories of body mass index

BACKGROUND

There are limited data about the association between body mass index (BMI), glycemic variability (GV), and life-related factors in healthy nondiabetic adults.

METHODS

This cross-sectional study was carried out within our ethics committee-approved study called "Exploring the impact of nutrition advice on blood sugar and psychological status using continuous glucose monitoring (CGM) and wearable devices". Prediabetes was defined by the HbA1c level of 5.7-6.4% and /or fasting glucose level of 100-125 mg/dL. Glucose levels and daily steps were measured for 40 participants using Free Style Libre and Fitbit Inspire 2 under normal conditions for 14 days. Dietary intakes and eating behaviors were assessed using a brief-type self-administered dietary history questionnaire and a modified questionnaire from the Obesity Guidelines.

RESULTS

All indices of GV were higher in the prediabetes group than in the healthy group, but a significant difference was observed only in mean amplitude of glycemic excursions (MAGE). In the multivariate analysis, only the presence of prediabetes showed a significant association with the risk of higher than median MAGE (Odds, 6.786; 95% CI, 1.596-28.858; P = 0.010). Additionally, the underweight (BMI < 18.5) group had significantly higher value in standard deviation (23.7 ± 3.5 vs 19.8 ± 3.7 mg/dL, P = 0.038) and coefficient variability (22.6 ± 4.6 vs 18.4 ± 3.2%, P = 0.015), compared to the normal group. This GV can be partially attributed to irregularity of eating habits. On the contrary, the overweight (BMI ≥ 25) group had the longest time above the 140 or 180 mg/dL range, which may be due to eating style and taking fewer steps (6394 ± 2337 vs 9749 ± 2408 steps, P = 0.013).

CONCLUSIONS

Concurrent CGM with diet and activity monitoring could reduce postprandial hyperglycemia through assessment of diet and daily activity, especially in non- normal weight individuals.

METTL18-mediated histidine methylation of RPL3 modulates translation elongation for proteostasis maintenance

Protein methylation occurs predominantly on lysine and arginine residues, but histidine also serves as a methylation substrate. However, a limited number of enzymes responsible for this modification have been reported. Moreover, the biological role of histidine methylation has remained poorly understood to date. Here, we report that human METTL18 is a histidine methyltransferase for the ribosomal protein RPL3 and that the modification specifically slows ribosome traversal on Tyr codons, allowing the proper folding of synthesized proteins. By performing an in vitro methylation assay with a methyl donor analog and quantitative mass spectrometry, we found that His245 of RPL3 is methylated at the τ-N position by METTL18. Structural comparison of the modified and unmodified ribosomes showed stoichiometric modification and suggested a role in translation reactions. Indeed, genome-wide ribosome profiling and an in vitro translation assay revealed that translation elongation at Tyr codons was suppressed by RPL3 methylation. Because the slower elongation provides enough time for nascent protein folding, RPL3 methylation protects cells from the cellular aggregation of Tyr-rich proteins. Our results reveal histidine methylation as an example of a ribosome modification that ensures proteome integrity in cells.

A significant risk of metabolic dysfunction-associated fatty liver disease plus diabetes on subclinical atherosclerosis

BACKGROUND

This cross-sectional study aims to investigate the association between subclinical atherosclerosis and metabolic dysfunction-associated fatty liver disease (MAFLD) or non-alcoholic fatty liver disease (NAFLD), and a synergistic effect of diabetes mellitus (DM) and MAFLD on subclinical atherosclerosis.

METHODS

Of 977 subjects who underwent health checkups with coronary artery calcification (CAC), carotid intima-media thickness, and brachial-ankle pulse wave velocity (ba-PWV), 890 were included in this study. They were classified as MAFLD, NAFLD, or Neither-FLD, and MAFLD was further categorized into three groups by three metabolic disorders (obesity, lean with metabolic dysregulation, DM), according to its new definition: Obesity-MAFLD, Lean-MAFLD and DM-MAFLD.

RESULTS

In a multivariable analysis, MAFLD and NAFLD were significantly associated with subclinical atherosclerosis, except for an association between ba-PWV and NAFLD. MAFLD had higher odds for CAC than NAFLD (for CAC score > 100, odds ratio (OR) = 2.599, 95% confidence interval (CI) = 1.625-4.157; OR = 1.795, 95%CI = 1.145-2.814, respectively). In a sub-analysis, DM-MAFLD had higher odds for CAC (for CAC score > 100, OR = 5.833, 95%CI = 3.047-11.164) than the other groups of MAFLD, when compared to Neither FLD as a reference. Moreover, DM-MAFLD had a higher level of homeostasis model assessment of insulin resistance and high sensitive C-reactive protein, compared to the other groups of MAFLD.

CONCLUSIONS

MAFLD was significantly associated with subclinical atherosclerosis in the general population. Additionally, DM-MAFLD could be a significant risk factor for cardiovascular disease through insulin resistance and low-grade inflammation and requires careful follow-up or appropriate intervention.

eIF2B-capturing viral protein NSs suppresses the integrated stress response

Various stressors such as viral infection lead to the suppression of cap-dependent translation and the activation of the integrated stress response (ISR), since the stress-induced phosphorylated eukaryotic translation initiation factor 2 [eIF2(αP)] tightly binds to eIF2B to prevent it from exchanging guanine nucleotide molecules on its substrate, unphosphorylated eIF2. Sandfly fever Sicilian virus (SFSV) evades this cap-dependent translation suppression through the interaction between its nonstructural protein NSs and host eIF2B. However, its precise mechanism has remained unclear. Here, our cryo-electron microscopy (cryo-EM) analysis reveals that SFSV NSs binds to the α-subunit of eIF2B in a competitive manner with eIF2(αP). Together with SFSV NSs, eIF2B retains nucleotide exchange activity even in the presence of eIF2(αP), in line with the cryo-EM structures of the eIF2B•SFSV NSs•unphosphorylated eIF2 complex. A genome-wide ribosome profiling analysis clarified that SFSV NSs expressed in cultured human cells attenuates the ISR triggered by thapsigargin, an endoplasmic reticulum stress inducer. Furthermore, SFSV NSs introduced in rat hippocampal neurons and human induced-pluripotent stem (iPS) cell-derived motor neurons exhibits neuroprotective effects against the ISR-inducing stress. Since ISR inhibition is beneficial in various neurological disease models, SFSV NSs may be a promising therapeutic ISR inhibitor.

New strategy for evaluating pancreatic tissue specimens from endoscopic ultrasound-guided fine needle aspiration and surgery

Background and Aim

Preoperative histological evaluation of pancreatic neoplasms is important for guiding the resection strategy and preventing postoperative adverse events. However, conventional endoscopic methods have technical limitations that reduce the accuracy of the histopathological examination. Probe electrospray ionization mass spectrometry (PESI‐MS) may be a useful technique for rapidly evaluating small specimens.

Methods

This single‐center prospective study included patients with pancreatic neoplasms between October 2018 and December 2019. Pancreatic ductal adenocarcinoma (PDAC) specimens were obtained via endoscopic ultrasound‐guided fine needle aspiration (EUS‐FNA) and non‐neoplastic tissue was obtained via surgery. Specimens were subjected to PESI‐MS and the mass spectra were analyzed using partial least squares regression‐discriminant analysis.

Results

The study included 40 patients with 20 nonneoplastic specimens and 19 PDAC specimens (1 case of neuroendocrine carcinoma was omitted). All nonneoplastic specimens were sufficient for PESI‐MS analysis, although only 7 of 19 PDAC specimens were sufficient for PESI‐MS analysis because of poor sample quality or insufficient quantity (<1 mg). Among the 27 analyzed cases, the mass spectra clearly differentiated between the PDAC and nonneoplastic specimens.

Conclusions

This study revealed that PESI‐MS could differentiate between PDAC and nonneoplastic specimens, even in cases where EUS‐FNA produced very small specimens.

A significant association of non-obese non-alcoholic fatty liver disease with osteosarcopenic obesity in females 50 years and older

BACKGROUND & AIMS

Osteosarcopenic obesity (OSO) encompassing obesity, sarcopenia and osteopenia, is due to redistribution or infiltration of fat into muscle and bone. This cross-sectional study evaluated the association between OSO and non-alcoholic fatty liver disease (NAFLD).

METHODS

Obesity, sarcopenia and osteopenia was defined using the percentage of body fat mass, reduced muscle mass, and the percentage of young adult mean < 80%, measured by dual-energy x-ray absorptiometry, respectively. Non-obese and obese NAFLD was diagnosed by ultrasound and body mass index cut-off point (25 kg/m²). A total of 619 subjects ≥ 50 years who completed health checkups were divided into obesity group including OSO and sarcopenic obesity (SO) alone phenotype, and non-obesity group that did not belong to any phenotype, including standard (St).

RESULTS

Overall osteopenia and OSO were detected in only 10% and 1% in males, compared with 45% and 9% in females, respectively. Multivariate analysis for females demonstrated a significant association of OSO with non-obese NAFLD (odds ratio = 3.737, 95% confidence interval = 1.365-10.233, P = 0.010), while the association between SO alone and non-obese NAFLD was equivocal. The OSO phenotype had a significantly higher proportion of slower walking speed and weaker grip strength, compared to the St phenotype. The proportion of OSO increased with age in contrast to constant prevalence of non-obese NAFLD.

CONCLUSION

Non-obese NAFLD had a significant association with OSO in females, independent of plausible confounders. These results suggest that non-obese NAFLD might be an independent risk factor for OSO.

Moderate alcohol consumption is not associated with subclinical cardiovascular damage but with hepatic fibrosis in non-alcoholic fatty liver disease

BACKGROUND

Moderate alcohol consumption is believed to be associated with reduced mortality from cardiovascular disease (CVD) in the general population. This cross-sectional study aimed to comprehensively examine the association between alcohol consumption and subclinical cardiovascular damage or hepatic fibrosis in non-alcoholic fatty liver disease (NAFLD).

METHODS

Subjects with NAFLD without a history of heart disease were extracted from 977 consecutive examinees who completed health checkups and optional cardiovascular examinations. Subclinical cardiovascular damage was assessed by coronary artery calcification (CAC), carotid artery ultrasound, and brachial-ankle pulse wave velocity (ba-PWV). CAC scores were classified into three grades (0, ≤100, and >100) by Agatston's method. Alcohol consumption was divided into three groups [Non-drinking (G0); Light (G1), 0.1-6.9 drinks/week; Moderate (G2), 7-20.9 drinks/week for men and 7-13.9 drinks/week for women]. Noninvasive markers (FIB-4, Fibrosis-4; NFS, NAFLD fibrosis score) were calculated for assessment of hepatic fibrosis and classified into low and intermediate-high grade.

RESULTS

The overall mean age was 60.2 years and males were 200 (74.6%) among 268 subjects with NAFLD. Number (%) of G0, G1, and G2 were 102 (38.1%), 103 (38.4%), and 63 (23.5%). Binary logistic regression analysis showed no significant difference between G0 and G1, or G0 and G2 in any of the above subclinical cardiovascular damages (CAC score >0, or CAC score >100, carotid plaque +, intima-media thickness ≥1.1 mm, and ba-PWV >1400 cm/s). However, only G2 had a significant association with intermediate-high grade of FIB-4 or NFS [odds ratio (95% confidence intervals), p value: 1.871 (1.209-2.893), p = 0.005; 2.910 (1.715-4.939), p = 0.000], compared to G0.

CONCLUSIONS

Non-heavy drinking might not reduce the risk of CVD in NAFLD subjects. On the contrary, even moderate drinking could promote hepatic fibrosis. Thus, NAFLD drinkers should not be recommended for even a moderate amount of alcohol.

ISRIB Blunts the Integrated Stress Response by Allosterically Antagonising the Inhibitory Effect of Phosphorylated eIF2 on eIF2B

The small molecule ISRIB antagonizes the activation of the integrated stress response (ISR) by phosphorylated translation initiation factor 2, eIF2(αP). ISRIB and eIF2(αP) bind distinct sites in their common target, eIF2B, a guanine nucleotide exchange factor for eIF2. We have found that ISRIB-mediated acceleration of eIF2B’s nucleotide exchange activity in vitro is observed preferentially in the presence of eIF2(αP) and is attenuated by mutations that desensitize eIF2B to the inhibitory effect of eIF2(αP). ISRIB’s efficacy as an ISR inhibitor in cells also depends on presence of eIF2(αP). Cryoelectron microscopy (cryo-EM) showed that engagement of both eIF2B regulatory sites by two eIF2(αP) molecules remodels both the ISRIB-binding pocket and the pockets that would engage eIF2α during active nucleotide exchange, thereby discouraging both binding events. In vitro, eIF2(αP) and ISRIB reciprocally opposed each other’s binding to eIF2B. These findings point to antagonistic allostery in ISRIB action on eIF2B, culminating in inhibition of the ISR.

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Mutually antagonistic binding of phosphorylated eIF2 and ISRIB to eIF2B

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Opposing structural rearrangement of eIF2B by binding ISRIB or phosphorylated eIF2

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Phosphorylated eIF2 exposes ISRIB’s ability to enhance eIF2B activity in vitro

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Weak ISR-inhibitory activity of ISRIB in cells lacking phosphorylated eIF2

Negative effect of fatty liver on visualization of pancreatic cystic lesions at screening transabdominal ultrasonography

RATIONALE, AIMS, AND OBJECTIVES

The aim of this observational study is to identify factors by which some pancreatic cystic lesions (PCLs) were undetectable at transabdominal ultrasonography (TAUS), using magnetic resonance imaging (MRI) as reference standard.

METHODS

The database for 781 consecutive subjects who underwent a health checkup including fat computed tomography and upper abdominal MRI as option was searched. The presence of fatty liver and fatty pancreas was diagnosed by TAUS, and atrophic pancreas was determined by reevaluating the image of the pancreas in the chest computed tomography for screening. Subjects with PCL detected and those undetected at TAUS were statistically compared in clinical characteristics.

RESULTS

The prevalence of PCL detected at MRI was 17.8% in the general population. Multivariate logistic regression analysis showed that fatty liver, body mass index, and the size of PCL were significantly associated with the factors influencing the visualization of PCL at TAUS (odds ratio [OR]: 0.337, 95% confidence interval [CI]: 0.154-0.734, P = 0.006; OR: 0.852, 95% CI: 0.737-0.985, P = 0.030; OR:1.120, 95% CI: 1.045-1.200, P = .001). Thirty-six PCLs (64.3%) in a total of 56 PCLs were undermeasured by TAUS. Additionally, nine (56%) out of 16 PCLs (≥ 15 mm) were undermeasured by 5 mm or more by TAUS, although a significantly higher detection rate was observed for PCLs (≥ 15 mm) in comparison with that for PCLs (< 15 mm) (80% vs 33.6%, P = .000).

CONCLUSIONS

It should be noted that coexisting fatty liver may lower the detection of PCL, and its size may be underestimated by TAUS.

Structural basis for eIF2B inhibition in integrated stress response

A core event in the integrated stress response, an adaptive pathway common to all eukaryotic cells in response to various stress stimuli, is the phosphorylation of eukaryotic translation initiation factor 2 (eIF2). Normally, unphosphorylated eIF2 transfers the methionylated initiator tRNA to the ribosome in a guanosine 5'-triphosphate-dependent manner. By contrast, phosphorylated eIF2 inhibits its specific guanine nucleotide exchange factor, eIF2B. To elucidate how the eIF2 phosphorylation status regulates the eIF2B activity, we determined cryo-electron microscopic and crystallographic structures of eIF2B in complex with unphosphorylated or phosphorylated eIF2. The unphosphorylated and phosphorylated forms of eIF2 bind to eIF2B in completely different manners: the nucleotide exchange-active and -inactive modes, respectively. These structures explain how phosphorylated eIF2 dominantly inhibits the nucleotide exchange activity of eIF2B.

Glial pathology in a novel spontaneous mutant mouse of the Eif2b5 gene: a vanishing white matter disease model

Vanishing white matter disease (VWM) is an autosomal recessive neurological disorder caused by mutation(s) in any subunit of eukaryotic translation initiation factor 2B (eIF2B), an activator of translation initiation factor eIF2. VWM occurs with mutation of the genes encoding eIF2B subunits (EIF2B1, EIF2B2, EIF2B3, EIF2B4, and EIF2B5). However, little is known regarding the underlying pathogenetic mechanisms or how to treat patients with VWM. Here we describe the identification and detailed analysis of a new spontaneous mutant mouse harboring a point mutation in the Eif2b5 gene (p.Ile98Met). Homozygous Eif2b5^I98M mutant mice exhibited a small body, abnormal gait, male and female infertility, epileptic seizures, and a shortened lifespan. Biochemical analyses indicated that the mutant eIF2B protein with the Eif2b5^I98M mutation decreased guanine nucleotide exchange activity on eIF2, and the level of the endoplasmic reticulum stress marker activating transcription factor 4 was elevated in the 1-month-old Eif2b5^I98M brain. Histological analyses indicated up-regulated glial fibrillary acidic protein immunoreactivity in the astrocytes of the Eif2b5^I98M forebrain and translocation of Bergmann glia in the Eif2b5^I98M cerebellum, as well as increased mRNA expression of an endoplasmic reticulum stress marker, C/EBP homologous protein. Disruption of myelin and clustering of oligodendrocyte progenitor cells were also indicated in the white matter of the Eif2b5^I98M spinal cord at 8 months old. Our data show that Eif2b5^I98M mutants are a good model for understanding VWM pathogenesis and therapy development. Cover Image for this issue: doi: 10.1111/jnc.14751.

P3365Relationship between early diastolic intra-ventricular pressure gradient shortly after aortic valve closure estimated by vector flow mapping and left ventricular diastolic untwisting rate in humans

Background

Early diastolic suction is an important determinant of early diastolic function. Previous studies using color Doppler M-mode and speckle-tracking echocardiography have shown left ventricular (LV) early diastolic LV untwisting rate is directly related to LV intra-ventricular pressure gradient (IVPG) between LV base and apex during early diastole. Recent introduction of vector flow mapping (VFM) using combination of color Doppler and speckle-tracking echocardiography provides noninvasive and feasible assessment of early diastolic IVPG shortly after aortic valve closure including isovolmic relaxation period (ED-IVPG) in humans. However, relationship between VFM–derived ED-IVPG and early diastolic LV untwisting rate has not been well investigated.

Purpose

The purpose of this study was to examine relationship between ED-IVPG estimated by VFM and LV untwisting rate by speckle-tracking echocardiography.

Methods

The study population consists of 66 patients without segmental wall motion abnormality, significant valvular diseases, and atrial fibrillation who underwent echocardiography for evaluation of LV function (age: 60±15 years, LVEF: 49±16%). From the apical long-axis views by color Doppler echocardiography, we analyzed peak ED-IVPG between LV base and apex just after aortic valve closure (figure) using commercially available VFM analysis software (DAS-RS1, Hitachi). We assessed peak early diastolic LV untwisting rate and LV torsion from LV basal and apical short-axis view by speckle-tracking echocardiography. We evaluated correlation between ED-IVPG and LV untwisting rate. We also evaluated correlation between ED-IVPG and peak systolic LV torsion, LV end-diastolic (EDV) and end-systolic volumes (ESV), ejection fraction (EF), early diastolic velocity (E) of LV inflow, average early diastolic velocity (e') of mitral annulus, and average E/e'.

Results

In all the study patients, ED-IVPG was successfully and quickly evaluated. 1) ED-IVPG correlated well with peak LV untwisting rate (r=0.64, p<0.0001). 2) ED-IVPG significantly correlated with LV torsion, LVEDV, LVESV, and LVEF (r=0.47, r=−0.48, r=−0.46, and r=0.48, respectively, p<0.001). 3) There were no significant correlations between ED-IVPG and other indexes including E, average e', and average E/e'. According to receiver operating characteristic analysis, the best cut-off value of ED-IVPG for determining impaired LV untwisting rate (<80 degrees/s) was found at 0.42 mmHg (sensitivity 81%, specificity 76%, and area under the curve 0.86)

ED-IVPG measurement by VFM

Conclusions

The present results showed that noninvasive VFM-derived peak ED-IVPG shortly after aortic valve closure is related to early diastolic peak LV untwisting rate. ED-IVPG easily and quickly estimated by VFM may be used as an additional index for LV diastolic function.

Pancreatic fat content may increase the risk of imaging progression in low-risk branch duct intraductal papillary mucinous neoplasm

OBJECTIVE

To identify risk factors of imaging progression (increase in cyst size or main pancreatic duct size, or a new mural nodule) in low-risk branch duct intraductal papillary mucinous neoplasm (BD-IPMN), including obesity-related factors such as pancreatic fat content.

METHODS

Our hospital databases were searched for patients who had completed health checkup, including upper abdominal magnetic resonance imaging (MRI) over 48 months (August 2012 to July 2016). Individuals with BD-IPMN without worrisome features and high-risk stigmata who underwent surveillance with at least one follow-up MRI, irrespective of the follow-up period, were included. Pancreatic computed tomography attenuation indexes were defined as the difference between the pancreas and spleen attenuation (P - S) and the pancreas to spleen attenuation ratio (P/S).

RESULTS

Among 75 patients diagnosed as having low-risk BD-IPMN, during a median follow-up of 36 months, 11 (15%) had imaging progression in cyst size, including two with worrisome features. A multivariate logistic analysis showed that the initial cyst size and both indexes (P - S, or P/S) were significantly associated with imaging progression in IPMN, respectively (Model 1: odds ratio [OR] 1.188, 95% confidence interval [CI] 1.060-1.331, P = 0.003; OR 0.871, 95% CI 0.776-0.977, P = 0.019; Model 2: OR 1.186, 95% CI 1.064-1.322, P = 0.002; OR 0.002, 95% CI 0.000-0.970, P = 0.049).

CONCLUSIONS

Pancreatic fat content and initial cyst size were significantly associated with imaging progression in low-risk BD-IPMN. Revisions of international consensus Fukuoka guidelines might be customized based on initial cyst size and pancreatic fat content.

A Remote Operating Slit Lamp Microscope System

Objectives: To develop a remote-operating slit lamp microscope system (the remote slit lamp) as the core for highly specialized ophthalmology diagnoses, and to compare the utility of this system with the conventional slit lamp microscope system (the conventional slit lamp) in making a diagnosis.

Methods: The remote slit lamp system was developed. Three factors were evaluated in comparison to the conventional slit lamp. The ability to acquire skills was investigated using a task loading system among specialists and residents in ophthalmology. Participants repeated a task up to ten times and the time required for each task was analyzed. The consistency of the two systems in making a diagnosis was investigated using eyes of patients with ocular diseases as well as healthy volunteers.

Results: The remote slit lamp is composed of a patient’s unit and ophthalmologist’s unit connected by high-speed internet. The two units share images acquired by the slit lamp in addition to the images and voices of patients and ophthalmologists. Both ophthalmology specialists and residents could minimize the completion times after several trials. The remote slit lamp took more time than the conventional slit lamp. Both systems showed a high consistency in evaluations among eyes with healthy eyes or those with ocular diseases.

Conclusions: The remote slit lamp has a similar diagnostic ability, but required more examination time in comparison to the conventional slit lamp. The currently developed remote slit lamp has the potential to be employed for telemedicine purposes in the field of ophthalmology.

The impact of visceral adipose tissue as best predictor for difficult colonoscopy and the clinical utility of a long small-caliber scope as rescue

BACKGROUND

There have been many reports about a variety of factors associated with incomplete colonoscopy or difficult colonoscopy with long cecal intubation time (CIT). The aim of this retrospective study was to analyze the factors related to difficult colonoscopy under conscious sedation and demonstrate the clinical utility of a small-caliber scope as rescue by using the data from a large number of subjects who underwent health check-ups.

METHODS

Consecutive 1036 cases over a 12-month period (April 2015 to March 2016) were enrolled and 619 subjects were divided into two groups: Easy colonoscopy (CS) Group (CIT ≤ 10 min); Difficult CS Group (CIT > 10 min or incomplete colonoscopy by a standard scope). The two groups were compared by subjects and colonoscopy characteristics with univariate analysis followed by multivariate logistic regression analysis. Reasons for incomplete colonoscopy were also assessed.

RESULTS

Cecal intubation rate increased from 97.9% to 99.9% (1007/1008) by the rescue scope. Main reasons for incomplete colonoscopy were tortuosity in the left hemicolon (38%), redundancy in the right hemicolon (29%), pain (19%) and fixation (14%). Moreover, 95% (20/21) of rescue colonoscopies were completed without additional sedation. Higher BMI (21 kg/m2 ≤ BMI) and intermediate visceral adipose tissue (VAT) (75 cm2 ≤ VAT < 150 cm2) were significantly associated with easy CS (80.7% vs 19.3%, P = 0.004; 56.3% vs 43.7%, P = 0.001) by univariate analysis. Age, gender, and VAT, not BMI, were independently associated with difficult colonoscopy by multivariate analysis (OR (95% CI), P: 0.964 (0.942, 0.985), 0.001; 1.845 (1.101, 3.091), 0.020; 2.347 (1.395, 3.951), 0.001). Subgroup analysis by gender also showed VAT as the best predictor for both genders.

CONCLUSION

Difficult colonoscopy was significantly associated with advancing age, female gender and, lower (< 75 cm2) or higher (150 cm2 ≤) VAT. These subjects may benefit from having complete and more comfortable colonoscopy examinations by using the small-caliber scope rather than the standard scope.

Limited Identification of Dual-time-point Positron Emission Tomography/Computed Tomography in Advanced Colorectal Neoplasms

Objective We investigated whether dual-time-point 18-Fluorodeoxyglucose (¹⁸FDG) positron emission tomography/computed tomography (PET/CT) could improve the positive predictive value for detecting advanced colorectal neoplasms (cancer, adenoma ≥10 mm or adenoma with high-grade dysplasia). Methods We retrospectively searched for consecutive patients with a known primary cancer, who had a colonic ¹⁸FDG uptake incidentally found by PET/CT, followed by colonoscopy between January 2013 and August 2014. The clinical characteristics including the maximum standardized uptake value (SUVmax) were compared between advanced colorectal neoplasms and non-advanced lesions. Results Forty-eight patients had 51 foci with an incidental focal colorectal uptake of ¹⁸FDG. Among these 51 foci, 28 foci were judged as being advanced neoplasms, whereas 23 foci identified as non-advanced lesions. Four cases were missed by PET/CT: two laterally spreading tumors (LSTs) with intramucosal cancer and two severe adenomas (<10 mm). The positive predictive value for the detection of advanced neoplasms was 55%. The per-spot performance of PET/CT showed that SUVmax was significantly higher in advanced neoplasms than in non-advanced lesions for the early-phase (10.1±4.9 vs. 6.5±3.2, p=0.029) and the delayed-phase (12.0±6.0 vs. 7.4±4.0, p=0.022). However, more importantly, there was a significant overlap of the SUVmax and no significant difference was found in the retention index (19.2±20.1 vs. 16.6±29.4, p=0.767). Conclusion Dual-time-point PET/CT was found to have limited impact for identifying advanced colorectal neoplasms in spite of its high sensitivity and it might therefore not be able to identify either LSTs or small advanced neoplasms.

[Three-dimensional Structure of eIF2B: A Clue to Understanding the Pathogenesis of CACH/VWM Disease]

CACH/VWM (childhood ataxia with central nervous system hypomyelination/vanishing white matter) disease is caused by mutations in the genes encoding the subunits of eukaryotic initiation factor 2B (eIF2B), but its etiology is poorly understood. Here, we attempt to provide an explanation for the pathogenic mechanism of this disease, based on the crystal structure of eIF2B.

Crystal structure of eIF2B and insights into eIF2-eIF2B interactions

Eukaryotic translation initiation factor 2B (eIF2B), a heterodecameric complex of two sets of the α, β, γ, δ, and ε subunits, is the guanine nucleotide exchange factor (GEF) specific for eIF2, a heterotrimeric G protein consisting of the α, β, and γ subunits. The eIF2 protein binds GTP on the γ subunits and delivers an initiator methionyl-tRNA (Met-tRNA_i^Met ) to the ribosome. The GEF activity of eIF2B is inhibited by stress-induced phosphorylation of Ser51 in the α subunit of eIF2, which leads to lower amounts of active eIF2 and a limited quantity of Met-tRNA_i^Met for the ribosome, resulting in global repression of translation. However, the structural mechanism of the GEF activity inhibition remained enigmatic, and therefore the three-dimensional structure of the entire eIF2B molecule had been awaited. Recently, we determined the crystal structure of Schizosaccharomyces pombe eIF2B. In this Structural Snapshot, we present the structural features of eIF2B and the mechanism underlying the GEF activity inhibition by the phosphorylation of eIF2α, elucidated from structure-based in vitro analyses.

Prospective, randomized, placebo-controlled trial evaluating the efficacy and safety of propofol sedation by anesthesiologists and gastroenterologist-led teams using computer-assisted personalized sedation during upper and lower gastrointestinal endoscopy

BACKGROUND AND AIM

No randomized controlled studies comparing propofol versus no sedation have been reported. Comparative data demonstrating the efficacy and safety of propofol sedation by anesthesiologists (ANES), and gastroenterologist-led teams (GLT) using computer-assisted personalized sedation (CAPS), during routine gastrointestinal (GI) endoscopy in Japan do not exist. We aimed to demonstrate the safety and efficacy of propofol sedation versus no sedation (PLCB) when propofol is given by ANES or GLT, during routine GI endoscopy.

METHODS

Two hundred and seventy two American Society of Anesthesiologists (ASA) class I or II adults were prospectively enrolled in this multicenter study and randomized into three groups (PLCB, ANES, GLT). Ability to maintain moderate sedation, defined as MOAA/S scores of 2-4 for ≥50% of all MOAA/S measurements from scope-in to scope-out, was the primary endpoint. Secondary endpoints included patient (PSSI) and clinician (CSSI) satisfaction.

RESULTS

Proportion of subjects maintained in moderate sedation by ANES (88.1%) and GLT (94.5%) was significantly higher than PLCB (21.6%; P < 0.001); there was no difference between the ANES and GLT groups (P = 0.116). Mean PSSI scores for subjects sedated by ANES (81.2 ± 12.5) and GLT (80.8 ± 14.1) were significantly higher than PLCB (65.3 ± 19.7; P < 0.001) and mean CSSI scores were also significantly higher in both active treatment groups (75.5 ± 10.2, 77.9 ± 10.3) than PLCB (60.8 ± 18.6; P < 0.001).

CONCLUSION

Moderate sedation can be achieved and maintained with propofol, improving both patient and physician satisfaction, when propofol is given by an anesthesiologist or a gastroenterologist-led team using CAPS.

Expression, purification, and crystallization of Schizosaccharomyces pombe eIF2B

Tight control of protein synthesis is necessary for cells to respond and adapt to environmental changes rapidly. Eukaryotic translation initiation factor (eIF) 2B, the guanine nucleotide exchange factor for eIF2, is a key target of translation control at the initiation step. The nucleotide exchange activity of eIF2B is inhibited by the stress-induced phosphorylation of eIF2. As a result, the level of active GTP-bound eIF2 is lowered, and protein synthesis is attenuated. eIF2B is a large multi-subunit complex composed of five different subunits, and all five of the subunits are the gene products responsible for the neurodegenerative disease, leukoencephalopathy with vanishing white matter. However, the overall structure of eIF2B has remained unresolved, due to the difficulty in preparing a sufficient amount of the eIF2B complex. To overcome this problem, we established the recombinant expression and purification method for eIF2B from the fission yeast Schizosaccharomyces pombe. All five of the eIF2B subunits were co-expressed and reconstructed into the complex in Escherichia coli cells. The complex was successfully purified with a high yield. This recombinant eIF2B complex contains each subunit in an equimolar ratio, and the size exclusion chromatography analysis suggests it forms a heterodecamer, consistent with recent reports. This eIF2B increased protein synthesis in the reconstituted in vitro human translation system. In addition, disease-linked mutations led to subunit dissociation. Furthermore, we crystallized this functional recombinant eIF2B, and the crystals diffracted to 3.0 Å resolution.

Percutaneous endoscopic gastrostomy under steady pressure automatically controlled endoscopy: First clinical series

AIM: To elucidate the safety of percutaneous endoscopic gastrostomy (PEG) under steady pressure automatically controlled endoscopy (SPACE) using carbon dioxide (CO₂).

METHODS: Nine patients underwent PEG with a modified introducer method under conscious sedation. A T-tube was attached to the channel of an endoscope connected to an automatic surgical insufflator. The stomach was inflated under the SPACE system. The intragastric pressure was kept between 4-8 mmHg with a flow of CO₂ at 35 L/min. Median procedure time, intragastric pressure, median systolic blood pressure, partial pressure of CO₂, abdominal girth before and immediately after PEG, and free gas and small intestinal gas on abdominal X-ray before and after PEG were recorded.

RESULTS: PEG was completed under stable pneumostomach in all patients, with a median procedural time of 22 min. Median intragastric pressure was 6.9 mmHg and median arterial CO₂ pressure before and after PEG was 42.1 and 45.5 Torr (NS). The median abdominal girth before and after PEG was 68.1 and 69.6 cm (NS). A mild free gas image after PEG was observed in two patients, and faint abdominal gas in the downstream bowel was documented in two patients.

CONCLUSION: SPACE might enable standardized pneumostomach and modified introducer procedure of PEG.

Surveillance using trimodal imaging endoscopy after endoscopic submucosal dissection for superficial gastric neoplasia

AIM: To evaluate the effectiveness of trimodal imaging endoscopy (TME) to detect another lesion after endoscopic submucosal dissection (ESD) for superficial gastric neoplasia (SGN).

METHODS: Surveillance esophagogastroduodenoscopy (EGD) using a TME was conducted in 182 patients that had undergone ESD for SGN. Autofluorescence imaging (AFI) was conducted after white-light imaging (WLI). When SGN was suspicious, magnifying endoscopy with narrow-band imaging (ME-NBI) was conducted. Final diagnoses were made by histopathologic findings of biopsy specimens. The detection rates of lesions in WLI, AFI, and NBI, and the characteristics of lesions detected by WLI and ones missed by WLI but detected by AFI were examined. The sensitivity, specificity, and accuracy of endoscopic diagnosis using WLI, AFI and ME-NBI were evaluated.

RESULTS: In 242 surveillance EGDs, 27 lesions were determined pathologically to be neoplasias. Sixteen early gastric cancers and 6 gastric adenomas could be detected by WLI. Sixteen lesions were reddish and 6 were whitish. Five gastric neoplasias were missed by WLI but were detected by AFI, and all were whitish and protruded gastric adenomas. There was a significant difference in color and pathology between the two groups (P = 0.006). Sensitivity, specificity and accuracy in ME-NBI were higher than those in both WLI and AFI. Specificity and accuracy in AFI were lower than those in WLI.

CONCLUSION: Surveillance using trimodal imaging endoscopy might be useful for detecting another lesion after endoscopic submucosal dissection for superficial gastric neoplasia.

Serial magnetic resonance imaging study of posterior cruciate ligament reconstruction or augmentation using hamstring tendons

PURPOSE

The purpose of this study was to analyze serial changes in the magnetic resonance imaging (MRI) signals of autograft hamstrings single bundle posterior cruciate ligament (PCL) reconstruction and the effects of remnant preservation (augmentation).

MATERIAL AND METHODS

Twenty-two isolated PCL injuries were arthroscopically reconstructed or augmented with hamstring tendons. MRI scans were obtained at 3, 6, and 12 months, and prior to the second-look arthroscopy (average 20.7 months). The patients were divided into 2 groups by remnant preservation: five PCL reconstructions after PCL remnant resection (Group Rec) (23%), and 17 reconstructions preserving the remnant (Group Aug) (77%). The 22 patients were also divided in two groups depending on the location of the PCL tear. There were 9 knees with proximal tear (Type P) (41%) and 13 knees with distal tear (Type D) (59%). The signal intensity and fiber continuity of 4 zones (proximal, middle, distal intra-articular and tibial tunnel zones) were evaluated by the Mariani score.

RESULTS

The average MRI evaluation score gradually increased from 6 months through the final MRI. The intra-articular part of the graft exhibited slower maturation (12 months - final scan) as compared with the tibial tunnel (6-12 months). The distal zone underwent better maturation than the proximal or middle zones at all points. In the proximal zone, the score for Group Aug was significantly higher than Group Rec. In the proximal zone, the Type D score with a proximally-preserved remnant was significantly higher than Type P without a proximal remnant.

CONCLUSIONS

The hamstring tendons require more than 1 year to achieve low-signal intensity. PCL remnant has a beneficial effect on the maturation of the hamstring graft.

LEVEL OF EVIDENCE IV

therapeutic case series.

Modified bowel preparation regimen for use in second-generation colon capsule endoscopy in patients with ulcerative colitis

BACKGROUND AND AIM

We have reported that second-generation colon capsule endoscopy (CCE-2) might be feasible for assessing the severity of mucosal inflammation in ulcerative colitis (UC). However, because of the low rate (69%) of complete evaluation of the colon and owing to inadequate cleansing. We believe that the method of bowel preparation could be improved by reducing volume. In the present study, we attempted to improve the colon-cleansing regimen in order to optimize the usefulness of CCE-2 in the management of UC patients.

METHODS

Twenty patients with histologically confirmed UC were enrolled. Patients took a maximum 2.2 L lavage solution (polyethylene glycol solution and magnesium citrate) in two or three divided doses. To assess the effectiveness of the modified bowel preparation regimen, we evaluated the rate of total colonobservation, the effectiveness of bowel cleansing, andinterobserver agreement in assessing UC disease activity. We used a four-point grading scale (poor, fair, good, and excellent) for evaluating the quality of bowel cleansing. Matts' endoscopic score was used to evaluate disease activity.

RESULTS

The rate of total colon observation was 85%, and 15 patients (75%) excreted the CCE-2 within 8 h. The proportion of excellent plus good cleansing was approximately 60%. There was a substantial interobserver agreement (κ = 0.777) in assessment of overall cleansing, which was still substantial at the fair cleansing level (κ = 0.700).

CONCLUSION

Using CCE-2, the modified bowel preparation regimen, with reduced volume has the potential to succeed in the evaluation of mucosal severity in UC.

Structural insight into the eIF2-eIF2B interaction

eIF2B (eukaryotic initiation factor 2B) is a key regulator of translation initiation. It catalyzes guanine nucleotide exchange on eIF2, which delivers the methionylated initiator tRNA to the 40S ribosomal subunit. This exchange reaction is inhibited by the stress-induced phosphorylation of the eIF2 alpha subunit, which leads to global repression of cellular protein synthesis. eIF2B is composed of five subunits. The catalytic gamma/epsilon subcomplex is responsible for nucleotide exchange, while the regulatory alpha/beta/delta subcomplex discriminates the phosphorylation status of the eIF2 alpha subunit. We established a bacterial expression system for eIF2B, and determined its crystal structure at 3.2 Å resolution. The crystal structure revealed that eIF2B is a decamer containing two molecules of each subunit. The hexameric regulatory subcomplex is formed by the trimerization of one alpha-alpha homodimer unit and two beta-delta heterodimer units, and two catalytic subcomplexes are individually connected to the regulatory subcomplex through two beta-delta heterodimer units. Photo-cross-linking analyses showed that the N-terminal domain of the eIF2 alpha subunit, which bears the phosphorylation site, is recognized by a composite surface formed by the eIF2B alpha, beta, and delta subunits. Based on these results, we report structural insights into the interaction between eIF2 and eIF2B.

Advanced endoscopic submucosal dissection with traction

Endoscopic submucosal dissection (ESD) has been established as a standard treatment for early stage gastric cancer (EGC) in Japan and has spread worldwide. ESD has been used not only for EGC but also for early esophageal and colonic cancers. However, ESD is associated with several adverse events, such as bleeding and perforation, which requires more skill. Adequate tissue tension and clear visibility of the tissue to be dissected are important for effective and safe dissection. Many ESD methods using traction have been developed, such as clip-with-line method, percutaneous traction method, sinker-assisted method, magnetic anchor method, external forceps method, internal-traction method, double-channel-scope method, outerroute method, double-scope method, endoscopic-surgical-platform, and robot-assisted method. Each method has both advantages and disadvantages. Robotic endoscopy, enabling ESD with a traction method, will become more common due to advances in technology. In the near future, simple, noninvasive, and effective ESD using traction is expected to be developed and become established as a worldwide standard treatment for superficial gastrointestinal neoplasias.

Crystal structure of the eukaryotic translation initiation factor 2A from Schizosaccharomyces pombe

The eukaryotic translation initiation factor 2A (eIF2A) was identified as a factor that stimulates the binding of methionylated initiator tRNA (Met-tRNA_i^Met) to the 40S ribosomal subunit, but its physiological role remains poorly defined. Recently, eIF2A was shown to be involved in unconventional translation initiation from CUG codons and in viral protein synthesis under stress conditions where eIF2 is inactivated. We determined the crystal structure of the WD-repeat domain of Schizosaccharomyces pombe eIF2A at 2.5 Å resolution. The structure adopts a novel nine-bladed β-propeller fold. In contrast to the usual β-propeller proteins, the central channel of the molecule has the narrower opening on the bottom of the protein and the wider opening on the top. Highly conserved residues are concentrated in the positively-charged top face, suggesting the importance of this face for interactions with nucleic acids or other initiation factors.

Continuous low-dose irradiation by I-125 seeds induces apoptosis of gastric cancer cells regardless of histological origin

The efficacy of conventional radiation therapy for gastric cancer is controversial. In this study, we evaluated the in vitro and in vivo effects of continuous low-dose-rate irradiation by I-125 seeds on different histological types of gastric cancer cell lines. Three human gastric cancer cell lines (MKN74, MKN45, and NUGC4) were treated with or without continuous low-dose irradiation by I-125 seeds in vitro and in vivo. Cell viability, apoptosis, caspase-3 assay, and cell-cycle distribution were examined in vitro. Body weight and tumor volumes of BALB/c nude mice bearing MKN74, MKN45, and NUGC4 gastric cancer xenografts were measured, and in vivo cell proliferation and apoptosis assays were performed by Ki67 and TUNEL staining, respectively. Continuous low-dose-rate irradiation by I-125 seeds reduced cell viability and induced cell apoptosis through the activation of caspase-3, and led to the accumulation of cells in the G 2/M phase in vitro. It also suppressed the growth of gastric cancer xenografts in nude mice, while inhibiting cell proliferation and inducing apoptosis as demonstrated by Ki67 and TUNEL staining. Therefore, our data suggest that continuous low-dose-rate irradiation by I-125 seeds could be a promising new option for gastric cancer treatment, regardless of histological origin.

Applicability of second-generation colon capsule endoscope to ulcerative colitis: a clinical feasibility study

BACKGROUND AND AIM

Colon capsule endoscopy has already been used for colon visualization and detection of polyps but its applicability to inflammatory bowel disease is still unconfirmed. The aim of this study was to assess the feasibility of evaluating the severity of mucosal inflammation in patients with ulcerative colitis (UC) using a second-generation colon capsule endoscope (CCE-2).

METHODS

Forty patients with histological confirmed diagnosis of UC were enrolled. Low-volume (2 L) polyethylene glycol solution with prokinetics (mosapride citrate and metoclopramide) regimen was used for the bowel preparation. In Phase 1, consisting of 10 patients, to confirm appropriate CCE-2 bowel preparation for UC. In Phase 2, consisting of 30 patients, CCE-2 was performed with a fixed bowel preparation regimen. CCE-2 findings were recorded for 8 h starting from capsule ingestion and conventional colonoscopy was subsequently performed on the same day. CCE-2 procedure completion rate and the colon cleansing level with a 4-point grading scale (poor, fair, good, and excellent) were evaluated in Phase 2. Correlations between Matts endoscopic scores as judged by CCE-2 and conventional colonoscopy were calculated.

RESULTS

CCE-2 procedure was completed within 8 h in 69% of the patients. The proportion of patients with good or excellent cleansing level was below 50%. However, Matts endoscopic scores determined by CCE-2 showed a strong correlation with scores obtained by conventional colonoscopy (average ρ = 0.797).

CONCLUSIONS

Although modifications in bowel preparation are needed, CCE-2 might be feasible for assessing the severity of mucosal inflammation in patients with UC.

Association study of genetic variants on chromosome 7q31 with susceptibility to normal tension glaucoma in a Japanese population

The caveolin 1 to caveolin 2 (CAV1-CAV2) gene region on chromosome 7q31 has been reported to be associated with susceptibility to primary open angle glaucoma (POAG) and normal tension glaucoma (NTG) in previous studies. We investigated whether genetic variants in the CAV1-CAV2 region are associated with NTG in Japanese patients. Two hundred and ninety-two Japanese patients with NTG and 352 Japanese healthy controls were recruited. We genotyped three single-nucleotide polymorphisms; that is, rs1052990, rs4236601, and rs7795356, in the CAV1-CAV2 gene region and assessed the allelic diversity among cases and controls. The frequency of the minor allele (G) of rs1052990 was significantly decreased in NTG cases compared with controls (P=0.014, OR=0.71), whereas NTG or POAG cases had a significantly higher frequency of the allele than controls in previous studies. Conversely, rs7795356 did not show any significant association with NTG cases, and rs4236601 was monomorphic in the Japanese study population. Our findings did not correspond with previous positive results, suggesting that CAV1-CAV2 variants studied in the present study are not important risk factors for NTG susceptibility in all populations. Further studies are needed to elucidate the possible contribution of the CAV1-CAV2 region to the development of glaucoma.

Novel technique of endoscopic submucosal dissection by using external forceps for early rectal cancer (with videos)

BACKGROUND

Endoscopic submucosal dissection (ESD) is more difficult for rectal cancer than for gastric cancer.

OBJECTIVE

To evaluate the feasibility and safety of an ESD procedure by using external forceps for early rectal cancer.

DESIGN

A case series.

SETTING

A tertiary medical center.

PATIENTS

Thirteen patients with early-stage rectal cancer were enrolled. Twelve of the 13 lesions were granular-type laterally spreading tumors and 1 was a protruding tumor.

INTERVENTIONS

After circumferential incision around the lesion with a dual-knife or a flex-knife, bendable external forceps were introduced with the help of grasping forceps inserted through the accessory channel and anchored at the anal margin of the lesion. After the forceps were bent, they were locked. With gentle anal traction and bending applied with the forceps, the lesion was elevated, the submucosal layer was opened, and the submucosal layer was dissected from the grasped side, facilitating dissection of the submucosal layer under direct vision.

MAIN OUTCOME MEASUREMENTS

Technical success, complication rates.

RESULTS

The mean lesion size was 33.0 mm (range 20-80 mm), and the mean operating time was 60 minutes (range 20-150 minutes). All lesions could be resected en bloc with tumor-free margins. Major bleeding after ESD occurred in only 1 patient (7.7%), who did not require blood transfusion. Perforation did not occur in any patient.

LIMITATIONS

Single-center experience, small number of patients.

CONCLUSION

This ESD procedure using external forceps for early-stage rectal cancers is feasible and safe.

The Enhancing Effect of -Cyclodextrin Inclusion on -Tocotrienol-dependent Negative Growth Control of Mesothelioma Cells in a Xenograft Model

Background: Malignant mesothelioma is an aggressive cancer with no effective treatment options. Of phytochemicals, tocotrienol (T3), a member of vitamin E, is one of the most potent anti-mesothelioma agents, but the effectiveness in vivo is quite limited, due to its low bioavailability. In this study, we investigated if the oral treatment of -T3 inclusion with -cyclodextrin (CD) could improve the bioavailability and anticancer activity of the T3.Findings: Using nude mice bearing MSTO-211H cells (a human malignant mesothelioma cell line), the effect of -T3 inclusion with -CD on -T3 level in tumor tissues, tumor growth, and its related mRNA levels were examined. The difference of tumor growth between the two groups had no statistical significance, but the latter showed a lower tendency compared with the former. In linked with this observation, the level of vascular endothelial growth factor mRNA required for in vivo tumor growth in -T3 inclusion with -CD group was lower than that in -T3 group, on the contrary, the level of -T3 level showed an opposite tendency.Conclusion: Our study demonstrated that the bioavailability of -T3 was improved by an oral administration of a novel -T3 inclusion complex with CD. Furthermore, the improvement of the bioavailability contributed to the increase of anticancer activity of -T3 in vivo.Key words: Anti-cancer agent, bioavailability, cyclodextrin, mesothelioma, tocotrienol.

Comparing approaches to screening for angle closure in older Chinese adults

AIMS

Primary angle-closure glaucoma is expected to account for nearly 50% of bilateral glaucoma blindness by 2020. This study was conducted to assess the performance of the scanning peripheral anterior chamber depth analyzer (SPAC) and limbal anterior chamber depth (LACD) as screening methods for angle closure.

METHODS

This study assessed two clinical populations to compare SPAC, LACD, and gonioscopy: the Zhongshan Angle-closure Prevention Trial, from which 370 patients were eligible as closed-angle participants and the Liwan Eye Study, from which 72 patients were selected as open-angle controls. Eligible participants were assessed by SPAC, LACD, and gonioscopy.

RESULTS

Angle status was defined by gonioscopy. Area under the receiver operating characteristic curve (AUROC) for SPAC was 0.92 (0.89-0.95) whereas AUROC for LACD was 0.94 (0.92-0.97). Using conventional cutoff points, sensitivity/specificity was 93.0%/70.8% for SPAC and 94.1%/87.5% for LACD. Sequential testing using both SPAC and LACD increased the specificity to 94.4% and decreased the sensitivity to 87.0%.

CONCLUSION

SPAC has significantly lower specificity than LACD measurement using conventional cutoffs but interpretation of the findings can be performed by modestly trained personnel.

Clinical results of observation of the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope

BACKGROUND AND AIM

Esophagogastroduodenoscopy through the oral cavity of patients who have undergone percutaneous endoscopic gastrostomy (PEG) causes some distress and puts these patients at risk of aspiration pneumonia. The aim of this study was to evaluate results for the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope.

METHODS

The study subjects were 43 patients, who underwent exchange of a PEG button or tube, 20-French or more in diameter. After PEG buttons or tubes were extracted from the gastrostomy tract, an ultrathin endoscope was inserted through the gastrostomy tract. The stomach and the duodenal bulb were observed and the esophagus was observed in retrograde passage. A new PEG button or tube was then inserted. The rate of successful insertion into the esophagus and duodenal bulb, the observation of the gastrostomy site in retroversion in the stomach, and the endoscopic findings were analyzed.

RESULTS

Ninety-nine examinations were carried out. The esophagus could be observed in 95 (96.0%), the duodenum in 92 (92.9%) and the gastrostomy site in the stomach in all. Gastric polyps were detected in four patients, gastric erosions in two, reflux esophagitis in two, polypoid lesion at the gastrostomy tract in two, gastric ulcer scar in one, duodenal ulcer scar in one, early gastric cancer in one and recurrent esophageal cancer in one. Neither discomfort nor complications occurred during transgastrostomic endoscopy.

CONCLUSIONS

Observation of the upper gastrointestinal tract by transgastrostomic endoscopy using an ultrathin endoscope during a gastrostomy button or tube replacement may be useful and safe.

Autofluorescence videoendoscopy system using the SAFE-3000 for assessing superficial gastric neoplasia

BACKGROUND

Autofluorescence (AF) videoendoscopy has an advantage over ordinary videoendoscopy in the diagnosis of gastric neoplasias, and the aim of the present study was to evaluate the effectiveness of using the SAFE-3000 videoendoscopy system to diagnose superficial gastric neoplasias.

METHODS

Ordinary videoendoscopy, AF videoendoscopy, and chromoendoscopy (CE) were used to diagnose the tumor existence and extent in 14 patients with gastric adenoma, 40 patients with intestinal-type early gastric cancer (EGC) (10 protruded, and 30 depressed), and nine patients with diffuse-type EGC. The diagnostic accuracies of the three kinds of images were evaluated by comparison with the results of histopathological assessment of resected specimens.

RESULTS

For gastric adenomas the diagnostic accuracy between the AF images and white light (WL) images did not differ significantly, and for protruded intestinal-type EGCs and diffuse-type EGCs the diagnostic accuracy did not differ significantly between any of the types of images. For depressed intestinal-type EGCs, the diagnostic accuracy of AF images tended to be higher than that of the WL images (P < 0.05) and it was not significantly different from that of the CE images. The detection rate of pink or orange color in AF images was significantly higher for protruded intestinal-type EGCs than gastric adenomas (P = 0.005), depressed intestinal-type EGCs (P < 0.001), and diffuse-type EGCs (P = 0.027).

CONCLUSIONS

Autofluorescence videoendoscopy using the SAFE-3000 system for gastric neoplasias might be useful for diagnosing depressed intestinal-type early gastric cancers. The detection of orange or pink color in AF images may be efficacious in discriminating protruded intestinal-type early gastric cancers from gastric adenomas.

Autofluorescence videoendoscopy system using the SAFE-3000 for assessing superficial gastric neoplasia

BACKGROUND

Autofluorescence (AF) videoendoscopy has an advantage over ordinary videoendoscopy in the diagnosis of gastric neoplasias, and the aim of the present study was to evaluate the effectiveness of using the SAFE-3000 videoendoscopy system to diagnose superficial gastric neoplasias.

METHODS

Ordinary videoendoscopy, AF videoendoscopy, and chromoendoscopy (CE) were used to diagnose the tumor existence and extent in 14 patients with gastric adenoma, 40 patients with intestinal-type early gastric cancer (EGC) (10 protruded, and 30 depressed), and nine patients with diffuse-type EGC. The diagnostic accuracies of the three kinds of images were evaluated by comparison with the results of histopathological assessment of resected specimens.

RESULTS

For gastric adenomas the diagnostic accuracy between the AF images and white light (WL) images did not differ significantly, and for protruded intestinal-type EGCs and diffuse-type EGCs the diagnostic accuracy did not differ significantly between any of the types of images. For depressed intestinal-type EGCs, the diagnostic accuracy of AF images tended to be higher than that of the WL images (P < 0.05) and it was not significantly different from that of the CE images. The detection rate of pink or orange color in AF images was significantly higher for protruded intestinal-type EGCs than gastric adenomas (P = 0.005), depressed intestinal-type EGCs (P < 0.001), and diffuse-type EGCs (P = 0.027).

CONCLUSIONS

Autofluorescence videoendoscopy using the SAFE-3000 system for gastric neoplasias might be useful for diagnosing depressed intestinal-type early gastric cancers. The detection of orange or pink color in AF images may be efficacious in discriminating protruded intestinal-type early gastric cancers from gastric adenomas.

Investigation of the association between the GLC3A locus and normal tension glaucoma in Japanese patients by microsatellite analysis

Purpose:

To investigate whether the GLC3A locus harboring the CYP1B1 gene is associated with normal tension glaucoma (NTG) in Japanese patients.

Materials and Methods:

One hundred forty-two Japanese patients with NTG and 101 Japanese healthy controls were recruited. Patients exhibiting a comparatively early onset were selected as this suggests that genetic factors may show stronger involvement. Genotyping and assessment of allelic diversity was performed on 13 highly polymorphic microsatellite markers in and around the GLC3A locus.

Results:

There were decreased frequencies of the 444 allele of D2S0416i and the 258 allele of D2S0425i in cases compared to controls (P = 0.022 and P = 0.034, respectively). However, this statistical significance disappeared when corrected (Pc > 0.05). We did not find any significant association between the remaining 11 microsatellite markers, including D2S177, which may be associated with CYP1B1, and NTG (P > 0.05).

Conclusions:

Our study showed no association between the GLCA3 locus and NTG, suggesting that the CYP1B1 gene, which is reportedly involved in a range of glaucoma phenotypes, may not be an associated factor in the pathogenesis of NTG.

Novel technique of endoscopic submucosal dissection using an external grasping forceps for superficial gastric neoplasia

Endoscopic submucosal dissection (ESD) for early stage gastric cancer (EGC) has improved the success rate of en bloc resection but results in perforation more often than does endoscopic mucosal resection. We report a novel technique of ESD using an external grasping forceps. A total of 265 lesions with EGC or gastric adenoma were enrolled in this study. Sixteen lesions were located in the upper third portion of the stomach, 114 in the middle third portion, and 135 in the lower third portion. After submucosal injection followed by circumcision of the lesions with a flex knife, the external grasping forceps was introduced with the help of a second grasping forceps and anchored at the margin of the lesion. Oral traction applied with this forceps could elevate the lesion and make the submucosal layer wider and more visible, thereby facilitating dissection of the submucosal layer under direct vision. The mean lesion size was 15.0 mm (range: 5-50 mm). All but 11 lesions (95.8%) could be resected en bloc with free margins. Mean procedure time was 45 min (range: 20-180 min). It was difficult to carry out this procedure when the lesions were located in the cardia, lesser curvature, or posterior wall of the upper third of the gastric body. Bleeding after ESD occurred in 10 patients (3.8%) and perforation occurred in one patient (0.4%). The endoscopic submucosal dissection using an external grasping forceps for superficial gastric neoplasia is efficacious and safe.

Clinical results of endoscopic hemostasis using a short transparent hood and short hemoclips for non-variceal upper gastrointestinal bleeding

AIM

Endoscopic hemostasis using hemoclips is useful, but there are technical difficulties because the angle of the approach is tangential. A transparent hood facilitates the observation and treatment of these lesions, and a shorter hood provides a wider visible field. Endoscopic hemoclipping of hard lesions with hemoclips of the conventional size does not reliably result in sustained hemostasis because the clips slip. Short clips, however, can be easily clamped on protruded visible vessels without slip. The aim of the present study was to evaluate the efficacy of endoscopic hemostasis with a short transparent hood and short clips.

METHODS

Subjects were 198 patients with 214 lesions of non-variceal upper gastrointestinal bleeding at Keio University Hospital. We used a video endoscope with a short transparent hood attached to its distal tip and carried out hemostasis using short hemoclips.

RESULTS

The short transparent hood provided a good visual field. If the lesions were in the tangential, the short hood made it possible to observe them in the frontal view and made clip hemostasis much easier. The short clip could be securely clamped against protruded visible vessels. Of 214 lesion, 211 (98.6%) had temporal hemostasis. Rebleeding occurred in 13 of 211 lesions (6.2%), and 205 of 214 lesions (95.8%) had permanent hemostasis. Nine cases were endoscopically difficult.

CONCLUSION

Endoscopic hemostasis with a short transparent hood and short clips is useful for non-variceal upper gastrointestinal bleeding.