Effect of bile reflux on gastric juice microbiota in patients with different histology phenotypes

BACKGROUND/AIMS

Bile reflux (BR) can influence the gastric environment by altering gastric acidity and possibly the gastric microbiota composition. This study investigated the correlation between bile acids and microbial compositions in the gastric juice of 50 subjects with differing gastric pathologies.

METHODS

This study included 50 subjects, which were categorized into three groups based on the endoscopic BR grading system. The primary and secondary bile acid concentrations in gastric juice samples were measured, and microbiota profiling was conducted using 16 S rRNA gene sequencing.

RESULTS

Significant differences were observed in each bile acid level in the three endoscopic BR groups (P < 0.05). The Shannon index demonstrated a significant decrease in the higher BR groups (P < 0.05). Analysis of the β-diversity revealed that BR significantly altered the gastric microbiota composition. The presence of neoplastic lesions and the presence of H. pylori infection impacted the β-diversity of the gastric juice microbiota. The abundance of the Streptococcus and Lancefielfdella genera exhibited positive correlations for almost all bile acid components(P < 0.05). In addition, the abundance of Slobacterium, Veillonella, and Schaalia showed positive correlations with primary unconjugated bile acids (P < 0.05).

CONCLUSION

Changes in microbial diversity in the gastric juice were associated with BR presence in the stomach. This result suggests that the degree of BR should be considered when studying the gastric juice microbiome.

The impact of discontinuing single-room isolation of patients with vancomycin-resistant enterococci: a quasi-experimental single-centre study in South Korea

OBJECTIVES

There is limited data on the effects of discontinuing single-room isolation while maintaining contact precautions, such as the use of gowns and gloves. In April 2021, our hospital ceased single-room isolation for patients with vancomycin-resistant enterococci (VRE) because of single-room unavailability. This study assessed the impact of this policy by examining the incidence of hospital-acquired VRE bloodstream infections (HA-VRE BSI).

METHODS

This retrospective quasi-experimental study was conducted at a tertiary-care hospital in Seoul, South Korea. Time-series analysis was used to evaluate HA-VRE BSI incidence at the hospital level and in the haematology unit before (phase 1) and after (phase 2) the policy change.

RESULTS

At the hospital level, HA-VRE BSI incidence level (VRE BSI per 1000 patient-days per month) and trend did not change significantly between phase 1 and phase 2 (coefficient -0.015, 95% confidence interval (CI): -0.053 to 0.023, P=0.45 and 0.000, 95% CI: -0.002 to 0.002, P=0.84, respectively). Similarly, HA-VRE BSI incidence level and trend in the haematology unit (-0.285, 95% CI: -0.618 to 0.048, P=0.09 and -0.018, 95% CI: -0.036 to 0.000, P = 0.054, respectively) did not change significantly across the two phases.

CONCLUSIONS

Discontinuing single-room isolation of VRE-colonized or infected patients was not associated with an increase in the incidence of VRE BSI at the hospital level or among high-risk patients in the haematology unit. Horizontal intervention for multi-drug-resistant organisms, including measures such as enhanced hand hygiene and environmental cleaning, may be more effective at preventing VRE transmission.

Intracerebroventricular administration of TRH Agonist, RX-77368 alleviates visceral pain induced by colorectal distension in rats

Thyrotropin-releasing hormone (TRH) acts centrally to exert pleiotropic actions independently from its endocrine function, including antinociceptive effects against somatic pain in rodents. Whether exogenous or endogenous activation of TRH signaling in the brain modulates visceral pain is unknown. Adult male Sprague-Dawley rats received an intracerebroventricular (ICV) injection of the stable TRH analog, RX-77368 (10, 30 and 100 ng/rat) or saline (5 µl) or were semi-restrained and exposed to cold (4°C) for 45 min. The visceromotor response (VMR) to graded phasic colorectal distensions (CRD) was monitored using non-invasive intracolonic pressure manometry. Naloxone (1 mg/kg) was injected subcutaneously 10 min before ICV RX-77368 or saline. Fecal pellet output was monitored for 1 h after ICV injection. RX-77368 ICV (10, 30 and 100 ng/rat) reduced significantly the VMR by 56.7%, 67.1% and 81.1% at 40 mmHg and by 30.3%, 58.9% and 87.4% at 60 mmHg respectively vs ICV saline. Naloxone reduced RX-77368 (30 and 100 ng, ICV) analgesic response by 51% and 28% at 40 mmHg and by 30% and 33% at 60 mmHg respectively, but had no effect per se. The visceral analgesia was mimicked by the acute exposure to cold. At the doses of 30 and 100 ng, ICV RX-77368 induced defecation within 30 min. These data established the antinociceptive action of RX-77368 injected ICV in a model of visceral pain induced by colonic distension through recruitment of both opioid and non-opioid dependent mechanisms.

The Effects of Fermented Rice Drink With Lactiplantibacillus plantarum JSA22 in Overweight Irritable Bowel Syndrome Patients: A Randomized, Double-blind, Placebo-controlled Study

Background/Aims

This study aims to investigate the effect of a fermented rice drink with Lactiplantibacillus plantarum JSA22 on symptoms, blood tests, microbiomes, and fecal metabolites in patients with irritable bowel syndrome (IBS) who were overweight.

Methods

Sixty overweight (body mass index ≥ 23 kg/m2) patients aged between 20 and 65 with IBS were enrolled. Patients were divided into 2 groups and administered either a fermented rice drink or an nonfermented rice drink for a month. The symptom questionnaire, blood samples, and stool samples for microbiome and metabolite were collected before and after the month of rice drink administration. The primary efficacy variable was the subject's global assessment of IBS symptoms.

Results

In both groups, global IBS symptoms, including abdominal pain, bowel habit, urgency, and abdominal distension, improved significantly (P < 0.01). The abdominal bloating was more significantly improved in the fermented rice drink group than in the nonfermented rice drink group (P < 0.05). Significant changes were not observed in metabolic syndrome-related blood tests or fecal metabolites in either group. However, microbiome analysis showed significant differences in genus levels before and after consuming fermented rice drink, such as in Blautia in stool (P = 0.020) and Prevotella (P = 0.017) and Oribacterium (P = 0.018) in saliva.

Conclusions

The fermented rice drink with L. plantarum JSA22 showed a beneficial effect in reducing abdominal distension in IBS patients. Bacteria that reduce visceral fat accumulation increased in the stool and saliva of patients who consumed fermented rice drinks.

Progranulin haploinsufficiency mediates cytoplasmic TDP-43 aggregation with lysosomal abnormalities in human microglia

BACKGROUND

Progranulin (PGRN) haploinsufficiency due to progranulin gene (GRN) variants can cause frontotemporal dementia (FTD) with aberrant TAR DNA-binding protein 43 (TDP-43) accumulation. Despite microglial burden with TDP-43-related pathophysiology, direct microglial TDP-43 pathology has not been clarified yet, only emphasized in neuronal pathology. Thus, the objective of this study was to investigate TDP-43 pathology in microglia of patients with PGRN haploinsufficiency.

METHODS

To design a human microglial cell model with PGRN haploinsufficiency, monocyte-derived microglia (iMGs) were generated from FTD-GRN patients carrying pathogenic or likely pathogenic variants (p.M1? and p.W147*) and three healthy controls.

RESULTS

iMGs from FTD-GRN patients with PGRN deficiency exhibited severe neuroinflammation phenotype and failure to maintain their homeostatic molecular signatures, along with impaired phagocytosis. In FTD-GRN patients-derived iMGs, significant cytoplasmic TDP-43 aggregation and accumulation of lipid droplets with profound lysosomal abnormalities were observed. These pathomechanisms were mediated by complement C1q activation and upregulation of pro-inflammatory cytokines.

CONCLUSIONS

Our study provides considerable cellular and molecular evidence that loss-of-function variants of GRN in human microglia can cause microglial dysfunction with abnormal TDP-43 aggregation induced by inflammatory milieu as well as the impaired lysosome. Elucidating the role of microglial TDP-43 pathology in intensifying neuroinflammation in individuals with FTD due to PGRN deficiency and examining consequential effects on microglial dysfunction might yield novel insights into the mechanisms underlying FTD and neurodegenerative disorders.

Masculinity, Rather Than Biological Sex, Is Associated With Psychological Comorbidities in Patients With Irritable Bowel Syndrome

Background/Aims

Irritable bowel syndrome (IBS) generally shows sex differences, and psychiatric comorbidities play an important role in its pathogenesis. We aim to measure the levels of gender roles and investigate their relationship with psychiatric factors in patients with IBS versus healthy controls.

Methods

Patients diagnosed with IBS by Rome III and whose colonoscopy findings were normal were enrolled at multiple sites in Korea. The participants completed the Korean Sex Role Inventory-Short Form (KSRI-SF) to assess masculinity and femininity, the stress questionnaire, the Hospital Anxiety Depression Scale (HADS), and the 36-item Short Form Health Survey questionnaire to assess the quality of life (QOL).

Results

In total, 102 patients with IBS (male:female = 35:67; mean age 42.6 ± 16.7 years) and 55 controls (male:female = 20:35; mean age 42.4 ± 11.1 years) were recruited. IBS patients had higher stress (9.69 ± 8.23 vs 4.56 ± 8.31, P < 0.001) and HADS scores (16.12 ± 7.17 vs 10.22 ± 5.74, P < 0.001) than the control group, but showed no significant difference in KSRI-SF scores. No significant differences in HADS and KSRI-SF scores were found between males and females. However, IBS patients whose symptoms worsened due to stress and patients with anxiety or depression had significantly lower masculinity. QOL was poorer in IBS patients than in controls. In stepwise multivariate analyses, the anxiety score, depression score, and the degree of daily life disturbance, not masculinity, were associated with the QOL of IBS patients.

Conclusions

IBS patients had higher stress, more psychiatric comorbidities, and lower QOL than controls. Low masculinity, rather than sex, was associated with stress and psychological comorbidities, which deteriorated the QOL in IBS patients.

Disease burden of bacteraemia with extended-spectrum beta-lactamase-producing and carbapenem-resistant Enterobacterales in Korea

BACKGROUND

Despite the significant impact of multi-drug-resistant bacteraemia, especially extended-spectrum beta-lactamase-producing Enterobacterales (ESBL-E) and carbapenem-resistant Enterobacterales (CRE), the burden of disease has not been investigated thoroughly.

AIM

To evaluate the clinical outcomes and socio-economic burden of ESBL-E and CRE bacteraemia nationwide in the Republic of Korea.

METHODS

A search was undertaken for all cases of ESBL-E and CRE bacteraemia and matched controls in 10 hospitals in the Republic of Korea over 6 months. Patients with ESBL-E or CRE bacteraemia were classified as the R group, and matched controls with antibiotic-susceptible bacteraemia and without infection were classified as the S and N groups, respectively. Patients' clinical data were collected, and the economic burden was estimated based on medical expenses, loss of productivity and total costs.

FINDINGS

In total, 795 patients were identified, including 265 patients with ESBL-E or CRE bacteraemia and their matched controls. The mean total length of stay for patients with ESBL-E and CRE in the R group was 1.53 and 1.90 times that of patients in the S group, respectively. The 90-day mortality rates for ESBL-E in the R and S groups were 12.1% and 5.6%, respectively, and the corresponding figures for CRE were 28.6% and 12.0%. There were significant differences in the total costs between the R, S and N groups for both ESBL-E and CRE (ESBL-E: $11,151 vs $8712 vs $6063, P=0.004; CRE: $40,464 vs $8748 vs $7279, P=0.024).

CONCLUSION

The clinical and economic burden imposed by ESBL-E or CRE bacteraemia was extremely high. These findings suggest that efforts to control resistant bacteraemia are necessary to reduce this burden.

An analysis of variants in TARDBP in the Korean population with amyotrophic lateral sclerosis: comparison with previous data

The TARDBP gene variant is a known major cause of amyotrophic lateral sclerosis (ALS), with limited reports of Korean patients with ALS harboring the variants in TARDBP. This large cohort study introduces four ALS patients who share the p.M337V variant of the TARDBP, allowing for an investigation of clinical characteristics and prognosis by analyzing previously reported cases with the same variant. From November 2014 to August 2022, participants were recruited from two tertiary hospitals in Seoul, Korea. Clinical characteristics of patients diagnosed with ALS carrying the variant in TARDBP were evaluated. Previous articles demonstrating subjects' characteristics were reviewed. Four patients were identified with the pathogenic missense variant (c.1009A>G; p.M337V) in the TARDBP. The mean age of onset was 55 years old, and none of the patients showed severe cognitive impairment. Sixty-three patients carrying the p.M337V variant in TARDBP from this study and previous reports delineated young age of onset (51.6 years), high frequency of bulbar onset patients (61.9%), and low comorbidity of frontotemporal dementia. This study reveals the presence of pathogenic variant of TARDBP in Korea and emphasizes the importance of genetic screening of the TARDBP gene, in diagnosing ALS and evaluating prognosis among familial and simplex ALS patients in Korea.

Evaluation of Usefulness of Yeast-Based Biological Phantom and Preliminary Study for Verification of Hypoxic Effect of Flash Radiotherapy

PURPOSE/OBJECTIVE(S)

As a basic hypothesis for the effectiveness of flash radiation therapy, the effect of preserving normal tissue during flash radiation is due to the instantaneous chemical depletion of oxygen. A yeast-based biological phantom was created to verify the hypoxic effect of flash radiation therapy. A study to upgrade the previously developed X-Band LINAC to a flash irradiation mode is in progress, and a preceding study is conducted to evaluate the usefulness of a yeast-based biological phantom manufactured by analyzing the change in oxygen by irradiating a high dose in a general radiation therapy device.

MATERIALS/METHODS

Freeze-dried yeast sample (Saccharomyces cerevisiae, S288C) is activated and sub-cultured. For mass production of yeast samples, yeast culture medium is prepared by adding yeast colonies to the ypd medium. This study was conducted to verify the hypoxic effect among the biological mechanisms that occur during flash radiation therapy at the basic stage, and the oxygen concentration change during general radiation irradiation was measured in real time using a DO (Dissolved oxygen) meter and fiber optic sensor designed to do that. To prevent scatter, which is a concern during flash irradiation, the fiber form was used, and precise experiments are possible as a non-invasive oxygen concentration measurement method. Based on 10MV of general radiation therapy device, high-dose radiation of 500-10,000 cGy is irradiated to measure real-time oxygen concentration change.

RESULTS

As a result of irradiation with high-dose (500-10,000 cGy) radiation of general LINAC, it was confirmed that the oxygen concentration of the yeast culture medium decreased by 5.7-63.2%, and the usefulness of the biological phantom fabricated based on the yeast culture medium was evaluated.

CONCLUSION

Prior to the analysis of oxygen concentration change in yeast cells during X-Band LINAC flash irradiation, a preliminary study was conducted at a high dose in a general LINAC to obtain a significant result of oxygen concentration change and confirm the usefulness of the yeast-based biological phantom. Prior research was conducted and verified as a general irradiation experiment using a yeast-based biological phantom manufactured based on a DO meter and a fiber optic oxygen sensor. After irradiation with high-dose radiation, the oxygen concentration of the yeast culture medium was measured 5 times, and it was confirmed that there was a change in oxygen concentration of 5.7-63.2%, verifying the usefulness and stability of the biological phantom. The usefulness of the yeast-based biological phantom for high doses was confirmed, and it is expected that the usefulness of the biological phantom for flash radiation can be verified by additionally measuring the change in oxygen concentration of the biological phantom according to the high dose rate in the future.

Definitive Radiotherapy in Patients with Clinical T1N0M0 Esophageal Squamous Cell Carcinoma: A Multicenter Retrospective Study

PURPOSE/OBJECTIVE(S)

In this study, we aimed to assess the failure pattern and survival outcomes and to analyze the optimal treatment field of definitive RT for T1N0M0 esophageal squamous cell carcinoma (ESCC).

MATERIALS/METHODS

We performed a retrospective analysis in a multi-institutional cohort of patients with histologically confirmed T1N0M0 ESCC. We included patients who underwent RT with definitive aim from 2010 to 2019. Patterns of failure were demonstrated as in-field locoregional, out-field locoregional and distant metastasis. In the survival analysis, freedom from locoregional recurrence and their association with clinicopathologic risk factors were analyzed. We performed a propensity score matching in the cT1b patients to adjust for the heterogeneity of radiation technique, radiation dose and the use of concurrent chemotherapy.

RESULTS

A total of 168 patients were included with a median follow-up of 34.0 months, and there were 20 cT1a, 94 cT1b and 24 cT1x, (cT1, not otherwise specified) patients. The rates of all and locoregional failure were 26.9% and 23.1% for cT1a and 25.0% and 22.4% for cT1b patients. 10 (10.6%) patients experienced grade ≥ 3 adverse events. Among 116 cT1b patients, 69 patients received elective nodal irradiation (ENI) and 47 patients received involved field irradiation (IFI). After propensity score matching, the 3-year FFLRR rate was 84.5% (95% Confidence Interval, 71.0 - 92.1%). There was no significant difference between the ENI and IFI patients in FFLRR (Log-rank P = 0.831). In the multivariate analysis, the use of concurrent chemotherapy was the only factor marginally associated with FFLRR (Hazard ratio, 0.17; 95% CI, 0.02 - 1.13; P = 0.067).

CONCLUSION

cT1a patients who cannot receive endoscopic resection, showed similar rates of failure compared with cT1b patients, which questioned the accuracy of the staging and raised the need for through treatment such as chemoradiotherapy. In cT1b patients, IFI using dose of 50 to 60 Gy with concurrent chemotherapy could be a reasonable treatment option.

Epigenetic Activation of Tensin 4 Promotes Gastric Cancer Progression

Gastric cancer (GC) is a complex disease influenced by multiple genetic and epigenetic factors. Chronic inflammation caused by Helicobacter pylori infection and dietary risk factors can result in the accumulation of aberrant DNA methylation in gastric mucosa, which promotes GC development. Tensin 4 (TNS4), a member of the Tensin family of proteins, is localized to focal adhesion sites, which connect the extracellular matrix and cytoskeletal network. We identified upregulation of TNS4 in GC using quantitative reverse transcription PCR with 174 paired samples of GC tumors and adjacent normal tissues. Transcriptional activation of TNS4 occurred even during the early stage of tumor development. TNS4 depletion in GC cell lines that expressed high to moderate levels of TNS4, i.e., SNU-601, KATO III, and MKN74, reduced cell proliferation and migration, whereas ectopic expression of TNS4 in those lines that expressed lower levels of TNS4, i.e., SNU-638, MKN1, and MKN45 increased colony formation and cell migration. The promoter region of TNS4 was hypomethylated in GC cell lines that showed upregulation of TNS4. We also found a significant negative correlation between TNS4 expression and CpG methylation in 250 GC tumors based on The Cancer Genome Atlas (TCGA) data. This study elucidates the epigenetic mechanism of TNS4 activation and functional roles of TNS4 in GC development and progression and suggests a possible approach for future GC treatments.

[Brain-Gut-Microbiota Axis]

Patients frequently report that stress causes or exacerbates gastrointestinal (GI) symptoms, indicating a functional relationship between the brain and the GI tract. The brain and GI tract are closely related embryologically and functionally, interacting in various ways. The concept of the brain-gut axis was originally established in the 19th and early 20th centuries based on physiological observations and experiments conducted in animals and humans. In recent years, with the growing recognition that gut microbiota plays a vital role in human health and disease, this concept has been expanded to the brain-gut-microbiota axis. The brain influences the motility, secretion, and immunity of the GI tract, with consequent effects on the composition and function of the gut microbiota. On the other hand, gut microbiota plays an essential role in the development and function of the brain and enteric nervous system. Although knowledge of the mechanisms through which the gut microbiota influences distant brain function is incomplete, studies have demonstrated communication between these organs through the neuronal, immune, and endocrine systems. The brain-gut-microbiota axis is an essential aspect of the pathophysiology of functional GI disorders such as irritable bowel syndrome, and is also involved in other GI diseases, including inflammatory bowel disease. This review summarizes the evolving concept of the brain-gut-microbiota axis and its implications for GI diseases, providing clinicians with new knowledge to apply in clinical practice.

Multi-omics data of gastric cancer cell lines

OBJECTIVES

Gastric cancer (GC) is the fourth most common cancer worldwide, with the highest incidence and mortality regardless of sex. Despite technological advances in diagnosing and treating gastric cancer, GC still has high incidence and mortality rates. Therefore, continuous research is needed to overcome GC. In various studies, cell lines are used to find and verify the cause of specific diseases. Large-scale genomic studies such as ENCODE and Roadmap epigenomic projects provide multiomics data from various organisms and samples. However, few multi-omics data for gastric tissues and cell lines have been generated. Therefore, we performed RNA-seq, Exome-seq, and ChIP-seq with several gastric cell lines to generate a multi-omics data set in gastric cancer.

DATA DESCRIPTION

Multiomic data, such as RNA-seq, Exome-seq, and ChIP-seq, were produced in gastric cancer and normal cell lines. RNA-seq data were generated from nine GC and one normal gastric cell line, mapped to a human reference genome (hg38) using the STAR alignment tool, and quantified with HTseq. Exome sequence data were produced in nine GC and two normal gastric lines. Sequenced reads were mapped and processed using BWA-MEM and GATK, variants were called by stralka2, and annotation was performed using ANNOVAR. Finally, for the ChIP-seq, nine GC cell lines and four GC cell lines were used in two experimental sets; chip-seq was performed to confirm changes in H3K4me3 and H3K27me3. Data was mapped to human reference hg38 with BWA-MEM, and peak calling and annotation were performed using the Homer tool. Since these data provide multi-omics data for GC cell lines, it will be useful for researchers who use the GC cell lines to study.

Association of Dietary Antioxidant Vitamin Intake and Gastric Cancer Risk According to Smoking Status and Histological Subtypes of Gastric Cancer: A Case-Control Study in Korea

Smoking is a risk factor for gastric cancer (GC) and causes oxidative stress. Antioxidant vitamins may protect against oxidative stress. This study aimed to determine the association between dietary antioxidant vitamin intake and GC risk according to smoking status and the histological subtype. This case-control study included 286 pairs of patients with GC and controls aged 20-79 years enrolled at two hospitals from 2002 to 2006, matched by age (± 2 years), sex, hospital, and participation period (± 1 years). Dietary information was collected using a quantitative food frequency questionnaire (FFQ). When stratified by smoking status, increased intake of vitamin C (OR = 0.38; 95% CI = 0.17-0.84 for highest vs. lowest; P for trend = 0.033) and folate (OR = 0.28; 95% CI = 0.12-0.64 for highest vs. lowest; P for trend = 0.003) decreased GC risk in nonsmokers. Vitamin C (P for interaction = 0.043) and folate (P for interaction =0.015) levels were significantly associated with smoking status. Similar results were observed in nonsmokers with diffuse and mixed types of GC, but not in those with intestinal type of GC. Therefore, we found an inverse association between higher intake of dietary vitamin C and folate with the risk of GC among nonsmokers. These protective associations were strong in nonsmokers with diffuse and mixed types of GC.

Association between soy products, fruits, vegetables, and dairy products and gastric cancer risk in Helicobacter pylori-infected subjects: a case-control study in Korea

BACKGROUND/OBJECTIVES

Consumption of certain protective foods may help inhibit Helicobacter pylori (H. pylori) associated gastric pathologies. However, studies conducted to assess the efficacy of protective foods in H. pylori-infected subjects are either limited or inconsistent. This study evaluated the association of individual or a combination of protective foods on the incidence of gastric cancer (GC) in H. pylori-positive subjects through a case-control study.

MATERIALS/METHODS

Subjects aged 20-79 years were selected from 2 hospitals between December 2002 and September 2006. In total, 134 patients and 212 controls tested positive for H. pylori infection. Among these, we included 82 pairs of cases and controls matched by sex, age (± 5 years), enrollment period (± 1 years), and hospital.

RESULTS

A higher intake of soy products was associated with a significantly lower risk of GC than a lower intake of soy products (odds ratio [OR] = 0.37, 95% confidence interval [CI] = 0.14-0.96). Additionally, a higher fruit intake resulted in a significantly lower risk of GC than a lower fruit intake (OR = 0.35, 95% CI = 0.13-0.94). A combination of food groups was evaluated, and a lower risk of GC was observed with a high intake of both soy products and fruits (OR = 0.20, 95% CI = 0.06-0.67), high intake of soy and dairy products (OR = 0.28, 95% CI = 0.10-0.78) and high intake of fruits and dairy products (OR = 0.28, 95% CI = 0.09-0.83).

CONCLUSIONS

A high intake of soy products or fruits was associated with a lower risk of GC. A combination of soy products or fruits with dairy products was associated with a lower risk of GC. A balanced intake of soy products, fruits, and dairy products may help reduce GC risk.

Dietary zinc intake and mortality in patients with intestinal-type gastric cancer: A prospective cohort study in Korea

Purpose

Current evidence regarding the association between zinc intake and gastric cancer (GC)-specific survival in patients with intestinal-type GC is lacking. Therefore, this cohort study investigated the association between zinc intake and GC mortality through follow-up on GC death among patients with intestinal-type GC and whether these effects differ according to the source of zinc intake.

Methods

A total of 185 patients with intestinal-type GC were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephone surveys.

Results

A total of 178 patients were included and analyzed. The median follow-up period was 7.3 years. In the fully adjusted models, the highest tertile of total zinc intake showed a significantly lower GC mortality than the lowest tertile (hazard ratio, 0.22; 95% confidence interval: 0.08–0.64). In addition, the tertile of total zinc intake showed a dose-response association with GC mortality (p=0.015). Analysis of the source of zinc intake revealed that when zinc intake from staples (rice and noodles), animal, and plant food sources were combined, the results were similar to those of total zinc intake and GC mortality.

Conclusion

Zinc intake through various foods may be effective in reducing GC mortality by achieving balance with other nutrients. Our results suggest that zinc improves the survival of patients with intestinal-type GC in Korea.

Genomic and transcriptomic analysis of Korean colorectal cancer patients

Background

Colorectal cancer (CRC) is the third most common type of diagnosed cancer in the world and has the second-highest mortality rate. Meanwhile, South Korea has the second-highest incidence rate for CRC in the world.

Objective

To assess the possible influence of ethnicity on the molecular profile of colorectal cancer, we compared genomic and transcriptomic features of South Korean CRCs with European CRCs.

Methods

We assembled a genomic and transcriptomic dataset of South Korean CRC patients (KOCRC; n = 126) from previous studies and European cases (EUCRC; n = 245) selected from The Cancer Genome Atlas (TCGA). Then, we compared the two datasets in terms of clinical data, driver genes, mutational signature, gene sets, consensus molecular subtype, and fusion genes.

Results

These two cohorts showed similar profiles in driver mutations but differences in the mutation frequencies of some driver genes (including APC, TP53, PABPC1, FAT4, MUC7, HSPG2, GNAS, DENND5B, and BRAF). Analysis of hallmark pathways using genomic data sets revealed further differences between these populations in the WNT, TP53, and NOTCH signaling pathways. In consensus molecular subtype (CMS) analyses of the study cases, no BRAF mutations were found in the CMS1 subtype of KOCRC, which contrasts with previous findings. Fusion gene analysis identified oncogenic fusion of PTPRK-RSPO3 in a subset of KOCRC patients without APC mutations.

Conclusions

This study presents insights into the genomic landscape of KOCRCs and reveals some similarities and differences with EUCRCs at the molecular level.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13258-022-01275-4.

Prokinetic Agents

Gastrointestinal (GI) prokinetic agents are drugs that increase GI motility and promote the movement of contents in the GI tract by amplifying and controlling the contraction of GI smooth muscle. Currently used prokinetics increase GI motility by acting as a dopamine D₂ receptor antagonist (e.g., metoclopramide, domperidone, levosulpiride) and 5-HT₄ receptor agonist (e.g., mosapride, prucalopride). Some prokinetics also have a cholinesterase inhibitory property (e.g., itopride), and herb-derived prokinetics (e.g., motilitone) affect multiple receptors. Depending on the type and distribution of receptors on which the prokinetics bind, the effect(s) may be regional or throughout the GI tract. Most prokinetics have been used for functional dyspepsia and gastroparesis because they mainly affect upper GI motility. However, prucalopride, a highly selective 5-HT₄ receptor agonist, is used primarily to treat chronic constipation and pseudo-obstruction. Dopamine D₂ receptor antagonists also inhibit the D₂ receptor in the medulla oblongata chemoreceptor trigger zone; therefore, they can treat nausea and vomiting. However, short term use of dopamine D₂ antagonists at an appropriate dose is recommended because of their potential for central nervous system side effects by penetrating the blood-brain barrier. It is necessary to know the mechanism of action, each clinical trial’s characteristics, and the side effects of prokinetics to obtain the best clinical outcomes. This article aims to summarize the results of clinical studies related to the impact of currently available prokinetic agents in Korea on GI motility.

Gastric Cancer Risk Was Associated with Dietary Factors Irritating the Stomach Wall: A Case-Control Study in Korea

The incidence of gastric cancer is high in Korea, and dietary factors are important risk factors for gastric cancer. This study examined whether gastric cancer risk was related to dietary factors that directly irritate the stomach wall. This case−control study consisted of 308 matched pairs of gastric cancer cases and controls recruited from 2002 to 2006 at two hospitals in Korea. Dietary assessments were completed using a food frequency questionnaire and a dietary habit questionnaire. Gastric cancer risk was increased for high meal frequency of >3 vs. low meal frequency of ≤3 times per day, overeating vs. not overeating, and preferred vs. not preferred spicy or salty foods. Furthermore, participants with dietary factors of high meal frequency, overeating, and preference for spicy or salty foods elevated the risk of gastric cancer compared to those with low meal frequency, not overeating, and not preferring spicy or salty foods, simultaneously. In conclusion, gastric cancer risk was significantly increased in people with dietary factors that irritate the stomach wall, such as high meal frequency, overeating, and preference for spicy or salty foods.

Response After Repeated Ketamine Injections in a Rat Model of Neuropathic Pain

Ketamine, an N-methyl-D-aspartate antagonist, reduces pain by decreasing central sensitization and pain windup. However, chronic ketamine use can cause tolerance, dependency, impaired consciousness, urinary symptoms, and abdominal pain. This study aimed to investigate the effects of repeated ketamine injections and ketamine readministration after discontinuation in a rat model of neuropathic pain. To induce neuropathic pain, partial sciatic nerve ligation (PSNL) was performed in 15 male Wistar rats, and these animals were divided into three groups: PSNL (control), PSNL + ketamine 5 mg/kg (K5), and PSNL + ketamine 10 mg/kg (K10; n=5 each). Ketamine was injected intraperitoneally daily for 4 weeks, discontinued for 2 weeks, and then readministered for 1 week. Following PSNL, the mechanical withdrawal threshold was determined weekly using the Von Frey. The K10 group showed a significant increase in the mechanical withdrawal threshold, presented here as the target force (in g), at 21 and 28 days compared to the time point before ketamine injection (mean±SE, 276.0±24.0 vs. 21.6±2.7 and 300.0±0.0 vs. 21.6±2.7, respectively; P<0.01) and at 14, 21, and 28 days compared to the control group (108.2±51.2 vs. 2.7±1.3, 276.0±24.0 vs. 2.5±1.5, and 300.0±0.0 vs. 4.0±0.0, respectively; P<0.05). However, in the K10 group, the ketamine effects decreased significantly at 7 days after readministration compared to those after 28 days of repeated injections (P<0.05). In the K10 group, repeated ketamine injections showed a significant increase in antinociceptive effect for >2 weeks, but this ketamine effect decreased after drug readministration.

Dietary Intake of Soy Products, Vegetables, and Dairy Products and Gastric Cancer Survival according to Histological Subtype: a Long-term Prospective Cohort Study

PURPOSE

Owing to differences in the general characteristics of gastric cancer (GC) according to histological type, the association of GC risk factors, such as diet, may also differ depending on the histological type. We investigated the associations between individual and combined intake of soy products, vegetables, and dairy products and GC mortality by following up cases of death among Korean GC cases and whether these associations differ according to the histological type.

MATERIALS AND METHODS

A total of 508 GC cases were enrolled from two hospitals between 2002 and 2006. Their survival or death was prospectively followed up until December 31, 2016, through a review of medical records and telephonic surveys. Finally, 300 GC cases classified as intestinal- or diffuse-type GC cases were included. The median follow-up period was 7.1 years.

RESULTS

In the fully adjusted model, a high intake of soy products (hazard ratio [HR], 0.43; 95% confidence interval [CI], 0.19-0.96) and the combination of soy products and vegetables (HR, 0.34; 95% CI, 0.12-0.96) or soy products and dairy products (HR, 0.37; 95% CI, 0.14-0.98) decreased the mortality from intestinal-type GC. In particular, patients consuming various potentially protective foods (HR, 0.23; 95% CI, 0.06-0.83) showed a highly significant association with a lower mortality from intestinal-type GC. However, no significant association was found with diffuse-type GC.

CONCLUSIONS

High intake of potentially protective foods, including soy products, vegetables, and dairy products, may help increase survival in intestinal-type GC.

Effect of Combination Therapy of Oral Famotidine with Mosapride on Intragastric pH and Gastric Emptying in Rats

Background/Aims: Studies in healthy humans have reported that the addition of mosapride to acid suppressants resulted in higher intragastric pH than acid suppressant administration alone. We investigated the effect of the addition of mosapride to famotidine on the intragastric pH and gastric emptying rate (GER) in rats.Materials and Methods: Sixty male Wistar rats were used in this study. Experimental groups were divided into control, famotidine-only, mosapride-only, and famotidine with mosapride (combination). The first experiment was performed in non-stressed rats. Mosapride was administered by oral gavage 1 hour before the meal, and famotidine was administered just before the meal. The rats were provided with food for 30 minutes. The intragastric pH was measured under isoflurane anesthesia, and the GER was measured after harvesting the stomach. In the stress experiment, rats were exposed to 1-hour restraint stress immediately after mosapride administration and subjected to the same process as in the experiment with the non-stressed rats.Results: The famotidine-only and combination groups showed significantly higher gastric pH levels than the control group in non-stressed (P<0.01 and P<0.001, respectively) and stressed (P<0.001 and P<0.001, respectively) rats. The combination group also showed significantly higher intragastric pH levels than the famotidine-only group in non-stressed (P<0.01) and stressed (P<0.05) rats. Additionally, combination groups showed a significantly higher GER than the famotidine-only group in non-stressed (P<0.001) and stressed (P<0.01) rats.Conclusions: The combination of mosapride with famotidine significantly increased intragastric pH compared to famotidine alone in the non-stressed and stressed rats.

Helicobacter pylori Eradication Therapy-associated Diarrhea

Eradication of Helicobacter pylori has contributed to the treatment of peptic ulcers and mucosa-associated lymphoid tissue lymphoma. Moreover, it has possibly decreased the prevalence of gastric cancer. However, eradication therapy is associated with various adverse effects, of which diarrhea is the most common. The incidence of diarrhea after eradication treatment varies from 8% to 48%. In particular, the incidence is higher in patients who receive first-line standard triple therapy compared with those who receive second-line therapy. Both antibiotics and proton pump inhibitors, components of eradication therapy, have short-term and long-term impacts on gut microbiota. The alterations of gut microbiota may not recover until 1 year after eradication therapy. Most cases of diarrhea that occur after eradication therapy are antibiotic-associated diarrhea caused by the destruction of the normal gut microbiota. In some cases, Clostridioides difficile-associated diarrhea occurs after eradication therapy. If bloody diarrhea occurs after eradication therapy and the Clostridioides difficile toxin is not detected, antibiotic-associated hemorrhagic colitis associated with Klebsiella oxytoca infection should be suspected. It is crucial to explain the possibility of diarrhea before initiating eradication therapy to increase compliance. Furthermore, probiotics may be administered to reduce diarrhea. If severe diarrhea or symptoms other than the usual antibiotic-associated diarrhea occur during or after eradication therapy, antibiotics should be discontinued. In addition, appropriate tests to determine the cause of diarrhea should be performed. This review summarizes the alteration of the gut microbiota, the causes of diarrhea after Helicobacter pylori eradication therapy, and its management.

Clinically Applicable Serum Biomarkers Among 14 Candidates Associated With Recurrence of Stage II and III Colorectal Cancer

BACKGROUND/AIM

We evaluated the predictive value of candidate serum biomarkers for recurrence in stage II and III colorectal cancer (CRC) after curative surgery.

PATIENTS AND METHODS

A total of 33 and 120 patients with CRC with or without recurrence at 5 years after curative surgery were included in the training set and the validation set, respectively. Possible serum biomarkers were examined for associations with CRC recurrence using receiver operating characteristics (ROC) curve analysis.

RESULTS

In the training set, the expression levels of the 14 biomarkers were compared according to recurrence. Among them, five biomarkers that had significantly different expression levels were validated in 60 patients with recurrence at 5 years after curative surgery and 60 patients without. Multivariate analysis showed that natural log-transformed values of carcinoembryonic antigen (CEA), cyclin-dependent kinase regulatory subunit 2 (CKS2), 2'-5'-oligoadenylate synthetase 2 (OAS2), and autophagy-related gene 5 (ATG5) in preoperative serum were significantly related to recurrence. ROC analysis showed that these biomarkers were able to discriminate patients with recurrence from those without (area under the curve=0.828, 95% confidence interval=0.755-0.990).

CONCLUSION

Preoperative serum levels of CEA, CKS2, OAS2 and ATG5 were independent risk factors for recurrence. A combination of serum CEA, CKS2, OAS2 and ATG5 predicted tumor recurrence well in patients with stage II and III CRC.

P–205 Epothilone D as an actin cytoskeleton stabilizer improved mitochondria bioenergenesis and blastocyst formation of mouse preimplantation embryo

Study question

What is primary factor of bioenergetics product activity between microtubule instability and the functional activity of mitochondria in embryo?

Summary answer

The actin cytoskeleton instability is presumably the primary cause for the bioenergenesis of mitochondrial function to the preimplantation embryo development.

What is known already

Mitochondria are cellular organelles dynamically moving and morphological changes. It provides for homeostatic energy to the cell. The dynamic property of the mitochondria is associated with the microtubule network in the cell. However, the stability of the microtubule was clearly identified for preimplantation embryo development.

Study design, size, duration

This study is designed to assess the ATP productivity of the mitochondria, and specifically to observe what its primary factor is in terms of providing microtubule stability in mammalian cells. Additionally, we investigated the relationship between blastocyst formation and actin cytoskeleton stabilization by EpD with 2-cell mice.

Participants/materials, setting, methods

We prepared the microtubule stability regulation model with the HEK293 cell line by using the microtubule stabilizer as an Epothilone D (EpD). Then we analyzed the metabolic activity of the cells through oxidative phosphorylation (OXP) ratios analysis. Also, we performed confocal live imaging to observe mitochondria morphology depending on the cells’ microtubule. Next, we treated EpD to 2-cell culture media for the analysis of blastocyst development ratios.

Main results and the role of chance

EpD significantly increased fusion form. Also, EpD enhance bioenergy ratios like OXP in the mitochondria and functional activity related marker, like mTOR compared with the control. These results suggest that microtubule stabilization enhances mitochondrial metabolism by increasing oxygen consumption. Also, EpD in 2-cell culture media led to a significant increase in the speed of development and 50% higher hatched out blastocyst formation ratios compared to the control group.

Limitations, reasons for caution

This study had limited animal experiments. For the next study, we are planning with an aim to improve the quality and development ratios of human embryos by EpD.

Wider implications of the findings: Microtubule stabilizer has a possibility to recover the mitochondria’s functional activity in the preimplantation embryo development. Mitochondrial functional activity along the actin cytoskeleton may play a pivotal role in determining the embryo quality and development ratios for archive pregnancy.

Trial registration number

non-clinical trials

P–657 Prostaglandin D2 is correlated with follicles development and a reliable marker of ovarian reserve of poor ovarian responder patients

Study question

Is the prostaglandin D2 (PGD2) associated with growing follicles and ovarian reserve of poor ovarian responders?

Summary answer

PGD2 is correlated with ovarian stimulation activity and follicle growth. Especially, poor ovarian responders show a significant decrease in the level of follicular fluid.

What is known already

Prostaglandins (PGs) are involved in the female reproductive process, mainly ovulation, fertilization, and implantation.

Study design, size, duration

We investigated the PGD2 level in the follicular fluid of poor ovarian responders. The collection of human follicular fluid was approved by the Institutional Research and Ethical Committees of CHA University (approval number: 1044308–201611-BR–027–04) from January to December 2019. Follicular fluid was collected from patients with normal ovarian response and patients with POR.

Participants/materials, setting, methods

We studied whether prostaglandin has related to POR in the clinical key factor by measuring human follicular fluid. Follicular fluid was collected from patients with normal ovarian response and patients with POR. The concentration of PGD2 in follicular fluid was determined with ELISA kits following the manufacturer’s protocol.

Main results and the role of chance

We analyzed the level of PGD2 in the follicular fluid of patients with normal ovarian response and patients with POR using an ELISA. The PGD2 concentration was significantly lower in the follicular fluid of patients with POR than in the follicular fluid of young and old patients with normal ovarian response.

Limitations, reasons for caution

This study has an identification of biomarker of the clinical samples as POR criteria patients. Therefore, further investigations aimed at specific recovery of low PGD2 metabolic activity in the CCs during control ovarian stimulation.

Wider implications of the findings: Until now there is no specific biomarker of POR. AMH is just an ovary reserve marker for an indication of ovary function. PGD2 is one of the metabolites in steroid metabolism in the ovary. Therefore, we can find some cure through further study for improved PGD2 production to POR patients.

Trial registration number

none

P–658 Lovastatin promotes the expression of LDL receptor and enhances E2 production in the cumulus cells

Study question

Lovastatin enhanced E2 productive ratios in the cumulus cells through promoted expression of Low-density lipoprotein receptor (LDLR).

Summary answer

Lovastatin up-regulated gene expression of LDLR in the CCs. And the high expression of LDLR promoted E2 productive ratios from CCs.

What is known already

We already reported that the up-regulation of LDLR correlated with clinical pregnancy. Therefore, we found lovastatin as an up-regulator of LDLR expression of clinical pregnancy.

Study design, size, duration

This is an expended study of LDLR to enhance steroidogenesis regarding the effect of lovastatin in the CCs. The collection of human cumulus cells was approved by the Institutional Research and Ethical Committees of CHA University (approval number: 1044308–201611-BR–027–04) from January to December 2019. The CCs were collected from 12 patients with normal ovarian response after oocyte denudation for ICSI.

Participants/materials, setting, methods

We studied whether lovastatin has up-regulated LDLR expression in human CCs. Cumulus cells were collected from patients with young (∼ 36) and old aged patients (37 ∼). After culturing human CCs, they were treated lovastatin for one day. The concentration of E2 in culture medium was measured using Chemiluminescence immunoassay. The mRNA isolated from CCs was analyzed gene expression level through real time-PCR.

Main results and the role of chance

The concentration of E2 was significantly increased in the culture medium treated with lovastatin. The CCs treated with lovastatin increased the expression of LDLR and StAR which are components of the steroidogenesis pathway.

Limitations, reasons for caution

We have found that the role of lovastatin promotes the E2 production by increasing the ldlr gene of CCs. Therefore, further investigations aimed at lovastatin effect on human oocytes embryo whether enhanced quality of oocytes or not.

Wider implications of the findings: Previous data show that high activation of LDLR and StAR was associated with embryo quality and clinical pregnancy in infertile women. Our data suggest that lovastatin is stimulated LDLR expression to enhanced pregnancy ratios of IVF patients.

Trial registration number

none

A Nationwide Cohort Study Shows a Sex-Dependent Change in the Trend of Peptic Ulcer Bleeding Incidence in Korea between 2006 and 2015

Background/Aims

The incidence of peptic ulcer disease has decreased in past decades; however, the trends in peptic ulcer bleeding (PUB) are inconsistent among regions. This study aimed to investigate the trends in PUB incidence and the effect of risk factors on PUB in Korea.

Methods

The records of patients hospitalized with PUB from 2006 to 2015 were retrieved from the Korean National Health Insurance Service Database. Standardized incidences of PUB were calculated, and the clinical characteristics such as age, sex, Helicobacterpylori infection, drug exposure, comorbidities, and mortality were obtained.

Results

In total, 151,507 hospitalizations with PUB were identified. The overall annual hospitalization rate was 34.98 per 100,000 person-years. The incidence of PUB showed no significant change from 2006 to 2008 and decreased from 2008 to 2015, with an annual change of –2.7% (p<0.05); however, this change was only significant in men. The incidence of PUB was higher in men than in women between 40 and 70 years old and higher in women than in men older than 80 years. From 2006 to 2015, the H. pylori infection rate increased significantly in patients with PUB; however, there was no significant change in exposure to nonsteroidal anti-inflammatory drugs or other drugs that increase the risk of PUB.

Conclusions

Over the past decade, the incidence of PUB has decreased in a sex-specific manner. There has been a decreasing trend in the H. pylori infection rate and no change in exposure to drugs that increase the risk of PUB in Korea.

Diagnostic test accuracy of 18F-FDG PET/CT for prediction of programmed death ligand 1 (PD-L1) expression in solid tumours: a meta-analysis

AIM

To investigate the predictive value of integrated 2-[¹⁸F]-fluoro-2-deoxy-d-glucose (¹⁸F-FDG) positron-emission tomography/computed tomography (PET/CT) for the prediction of programmed death ligand 1 (PD-L1) expression in solid tumours via a systematic review and meta-analysis.

MATERIALS AND METHODS

The PubMed, Cochrane, and EMBASE databases, from the earliest available date of indexing through 31 October 2020, were searched for studies evaluating the diagnostic performance of ¹⁸F-FDG PET/CT for prediction of PD-L1 expression in solid tumours other than lung cancer.

RESULTS

Across seven studies (473 patients), the pooled sensitivity for ¹⁸F-FDG PET/CT was 0.75 (95% confidence interval [CI]: 0.65-0.82) without heterogeneity (I² = 47.2, p=0.08) and a pooled specificity of 0.73 (95% CI: 0.64-0.81) with heterogeneity (I² = 53.8, p=0.04). Likelihood ratio (LR) syntheses gave an overall positive likelihood ratio (LR+) of 2.8 (95% CI: 2.1-3.7) and negative likelihood ratio (LR-) of 0.35 (95% CI: 0.26-0.47). The pooled diagnostic odds ratio (DOR) was 8 (95% CI: 5-13). Hierarchical summary receiver operating characteristic (ROC) curve and indicates that the area under the curve was 0.80 (95% CI: 0.77-0.84).

CONCLUSION

The current meta-analysis showed a moderate sensitivity and specificity of ¹⁸F-FDG PET/CT for the prediction of PD-L1 expression in solid tumours. At present, the literature regarding the use of ¹⁸F-FDG PET/CT for the prediction of PD-L1 expression in solid tumours still limited; thus, further large multicentre studies would be necessary to substantiate the diagnostic accuracy of ¹⁸F-FDG PET/CT for prediction of PD-L1 expression in solid tumours.

Methylation of the CDX2 promoter in Helicobacter pylori-infected gastric mucosa increases with age and its rapid demethylation in gastric tumors is associated with upregulated gene expression

Pathological changes in the epigenetic landscape of chromatin are hallmarks of cancer. The caudal-type homeobox gene CDX2 is not expressed in normal gastric epithelia but rather in adult intestinal epithelia, and it is overexpressed in intestinal metaplasia (IM). However, it remains unclear how CDX2 transcription is suppressed in normal gastric epithelial cells and overexpressed in IM. Here, we demonstrate that methylation of the CDX2 promoter increases with age in Helicobacter pylori-positive, noncancerous gastric tissue, whereas the promoter is demethylated in paired gastric tumors in which CDX2 is upregulated. Moreover, we also found that the CDX2 promoter is demethylated in IM as well as gastric tumor. Immunohistochemistry revealed that CDX2 is present in foci of parts of the gastric mucosae but highly expressed in IM as well as in gastric tumors, suggesting that the elevated level of CDX2 in IM and gastric tumors may be attributable to promoter demethylation. Our data suggest that CDX2 repression may be associated with promoter methylation in noncancerous H. pylori-positive mucosa but its upregulation might be attributable to increased promoter activity mediated by chromatin remodeling during gastric carcinogenesis.

[Identification of the side population associated with ATP-binding cassette transporters activity using imaging flow cytometry]

DyeCycle Violet efflux, caused by ATP-binding cassette transporters activity, was analyzed in human colorectal adenocarcinoma cell lines SW480, HT-29, Caco-2 by neans of FACSAria III flow cytometer and ImageStreamX Mk II imaging flow cytometer. Along with similarity of cytometry data obtained on the two instruments, the use of imaging flow cytometry made it possible to characterize the morphology of side population cells, as well as morphology of other cell populations differing in the degree of dye accumulation. The population of cells, which are smaller than the side population cells and practically do not take the dye, is of the special interest. Probably, this population may contribute to the tumor resistance to chemotherapy.

High-Fat Foods and FODMAPs Containing Gluten Foods Primarily Contribute to Symptoms of Irritable Bowel Syndrome in Korean Adults

Dietary control plays an important role in the treatment of irritable bowel syndrome (IBS). However, few studies have examined the relationship between dietary intake and symptoms of IBS in Koreans. The current cross-sectional study aimed to examine the diet in food consumption and nutrient intake in Korean adults aged 20 to 40 with IBS. The data collected were completed by 857 subjects using a community-based web survey. The questionnaire covered functional bowel disorders based on Rome III, the semi-quantitative Food Frequency Questionnaire (SQ-FFQ), and the food items causing symptoms. In total, 186 of 857 subjects (21.7%) were diagnosed with IBS. The non-IBS group had a fat intake of 76.9 ± 47.9 g/day, while the IBS group had a fat intake of 86.6 ± 55.1 g/day (p = 0.014). The non-IBS group had a total fermentable oligosaccharide, disaccharide, monosaccharide, and polyol (FODMAP) intake of 12.6 ± 9.7 g/day, whereas the IBS group had a total FODMAP intake of 13.9 ± 9.9 g/day (p = 0.030). Foods that contributed to the onset of symptoms in the IBS group were instant noodles (70.8%), Chinese noodles with vegetables and seafood (68.7%), pizza (67.2%), and black bean sauce noodles (66.3%) which are mostly classified as high fat and high gluten foods. The dietary intake of IBS patients differs from that of non-IBS subjects. Increased intake of gluten-containing or high-fat foods due to the westernized diet caused more IBS symptoms than high FODMAPs and dairy products in Korean adults in their 20 s to 40 s.

Subepithelial neutrophil infiltration as a predictor of the surgical outcome of chronic rhinosinusitis with nasal polyps

BACKGROUND

Neutrophils present as major inflammatory cells in refractory chronic rhinosinusitis with nasal polyps (CRSwNP), regardless of the endotype. However, their role in the pathophysiology of CRSwNP remains poorly understood. We investigated factors predicting the surgical outcomes of CRSwNP patients with focus on neutrophilic localization.

METHODS

We employed machine-learning methods such as the decision tree and random forest models to predict the surgical outcomes of CRSwNP. Immunofluorescence analysis was conducted to detect human neutrophil elastase (HNE), Bcl-2, and Ki-67 in NP tissues. We counted the immunofluorescence-positive cells and divided them into three groups based on the infiltrated area, namely, epithelial, subepithelial, and perivascular groups.

RESULTS

On machine learning, the decision tree algorithm demonstrated that the number of subepithelial HNE-positive cells, Lund-Mackay (LM) scores, and endotype (eosinophilic or non-eosinophilic) were the most important predictors of surgical outcomes in CRSwNP patients. Additionally, the random forest algorithm showed that, after ranking the mean decrease in the Gini index or the accuracy of each factor, the top three ranking factors associated with surgical outcomes were the LM score, age, and number of subepithelial HNE-positive cells. In terms of cellular proliferation, immunofluorescence analysis revealed that Ki-67/HNE-double positive and Bcl-2/HNE-double positive cells were significantly increased in the subepithelial area in refractory CRSwNP.

CONCLUSION

Our machine-learning approach and immunofluorescence analysis demonstrated that subepithelial neutrophils in NP tissues had a high expression of Ki-67 and could serve as a cellular biomarker for predicting surgical outcomes in CRSwNP patients.

A compact and stable incidence-plane-rotating second harmonics detector

We describe a compact and stable setup for detecting the optical second harmonics, in which the incident plane rotates with respect to the sample. The setup is composed of rotating Fresnel rhomb optics and a femtosecond ytterbium-doped fiber laser source operating at the repetition frequency of 10 MHz. The setup including the laser source occupies an area of 1 m² and is stable so that the intensity fluctuation of the laser harmonics can be less than 0.2% for 4 h. We present the isotropic harmonic signal of a gold mirror of 0.5 pW and demonstrate the integrity and sensitivity of the setup. We also show the polarization-dependent six-fold pattern of the harmonics of a few-layer WSe₂, from which we infer the degree of local-field effects. Finally, we describe the extensibility of the setup to investigate the samples in various conditions such as cryogenic, strained, ultrafast non-equilibrium, and high magnetic fields.

The sex-specific effect of the apolipoprotein E allele and methylenetetrahydrofolate reductase gene polymorphism on the biochemical, anatomical, and cognitive profiles of patients clinically diagnosed with probable Alzheimer's disease

OBJECTIVES

We aimed to evaluate the sex-specific effect of apolipoprotein E (APOE) alleles and methylenetetrahydrofolate reductase (MTHFR) C677T polymorphism on the biochemical, anatomical, and cognitive profiles of Alzheimer's disease (AD) patients.

METHODS

The patient (followed-up for at least 2 years) medical records, which comprised of data on plasma homocysteine and folate levels, lipid profile, HbA1c, MTHFR C677T genotype, APOE allele type, mini-mental state examination (MMSE) and clinical dementia rating (CDR) scores, and brain scans, were retrospectively analyzed. Two trained neurologists scored the white matter lesions (Fazekas scale), medial temporal lobe atrophy (MTA), and microbleeds using brain magnetic resonance imaging scans.

RESULTS

This study included 574 patients clinically diagnosed with probable AD (average age, 73.2 years; mean MMSE score, 10.05). The effect of sex on all parameters was evaluated. The triglyceride (TG) and homocysteine levels and the MTA and Fazekas scores were higher in female APOE-ε4/ε4 carriers than in women without APOE-ε4. The TG and homocysteine levels were lower in men with the MTHFR CC allele than in those with the MTHFR TT allele. In contrast, MTHFR polymorphism and APOE-ε4 alleles were not significantly correlated with anatomical lesions and rate of decline in the MMSE and CDR scores.

CONCLUSIONS

We demonstrated the sex-specific effect of the APOE allele and MTHFR polymorphism on the serological and anatomical biomarkers in AD patients. The APOE allele and MTHFR mutations did not directly affect cognitive progression, but differentially affected other biochemical factors, between the sexes. These findings will aid in devising novel preventive and therapeutic strategies.

Multi-chord IR-visible two-color interferometer on KSTAR

Major parts of an IR-visible two-color interferometer (TCI) on KSTAR have been upgraded for the multi-chord operation: (1) a diode-pumped-solid-state (DPSS) laser (660 nm) replacing the former HeNe laser (633 nm), (2) vacuum-compatible vibration isolator with titanium retro-reflectors, and (3) full digital phase comparator for multi-chord real-time density signals. The commercial compact DPSS laser suits the multiple chord configuration with its strong beam power (500 mW) and long coherent length (>100 m). Ti retro-reflectors are mounted on vacuum-compatible vibration isolators. The isolators are essential for the visible beams to avoid any fringe skips due to their short wavelength, considering the speed of the mechanical vibration (up to hundreds of μm). Field-programmable-gate-array (FPGA) modules count the entire fringes fast enough with a signal output rate up to 1.25 MHz, solving the fringe skip issues. The FPGA module enables the full digital processing of the phase comparator with a CORDIC algorithm after the sampling rate of 160 MS/s for the 40 MHz intermediate frequency of each beam. The full digital signals are transferred to the main plasma control system in real-time. Stable single-input-single-output operation of the KSTAR density control was demonstrated with the TCI. The real-time density profile control is also promising in the near future, with multiple actuators such as pellets and gas puffings.

[How to Study the Sex and Gender Effect in Biomedical Research?]

Men and women are different, but this difference has not been well reflected in clinical trials and preclinical studies of biomedical science. Gender medicine, which systematically analyzes research results according to sex and gender, has been emphasized to overcome this problem. On the other hand, researchers still have difficulty in applying gender medicine to their research. To perform rigorous gender medicine, using correct terms, a thorough literature review during research planning, appropriate statistical analysis and reporting, and cautious interpretation of the results are necessary. Applying gender medicine will increase the reproducibility of studies, promote discoveries, expand the study relevance, and ultimately improve patient care in both men and women. Here, this study reviewed the practical issues on applying gender medicine to both preclinical and clinical studies in the field of biomedical science.

Compositional and Functional Changes in the Gut Microbiota in Irritable Bowel Syndrome Patients

Background/Aims

This study aimed to characterize the changes in the gut microbiota of irritable bowel syndrome (IBS) patients and to investigate the consequent alterations in bacterial functions.

Methods

We performed 16S rRNA metagenomic sequencing and a phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) analyses using fecal samples from control (n=12) and diarrhea-dominant IBS patients (n=7).

Results

The samples were clustered by the principal coordinates analysis depending on the presence of IBS (p=0.003). In the IBS patients, the abundances of Acidaminococcaceae, Sutterellaceae, and Desulfovibrionaceae were significantly increased, while those of Enterococcaceae, Leuconostocaceae, Clostridiaceae, Peptostreptococcaceae, and Lachnospiraceae were significantly decreased. The PICRUSt results indicated that two orthologues involved in secondary bile acid biosynthesis were significantly decreased in IBS patients. Modules involved in multidrug resistance, lipopolysaccharide biosynthesis, the reductive citrate cycle, and the citrate cycle were significantly increased in the IBS patients. In contrast, modules involved in cationic antimicrobial peptide resistance, and some transport systems were more abundant in controls than in IBS patients.

Conclusions

Changes in the gut microbiota composition in IBS patients lead to alterations in bacterial functions, such as bile acid transformation and the induction of inflammation, which is a known pathophysiological mechanism of IBS.