Separation of the diastereomers of phosphorothioated siRNAs by anion-exchange chromatography under non-denaturing conditions

In recent years, several small interfering RNA (siRNA) therapeutics have been approved, and most of them are phosphorothioate (PS)-modified for improving nuclease resistance. This chemical modification induces chirality in the phosphorus atom, leading to the formation of diastereomers. Recent studies have revealed that Sp and Rp configurations of PS modifications of siRNAs have different biological properties, such as nuclease resistance and RNA-induced silencing complex (RISC) loading. These results highlight the importance of determining diastereomeric distribution in quality control. Although various analytical approaches have been used to separate diastereomers (mainly single-stranded oligonucleotides), it becomes more difficult to separate all of them as the number of PS modifications increases. Despite siRNA exhibits efficacy in the double-stranded form, few reports have examined the separation of diastereomers in the double-stranded form. In this study, we investigated the applicability of non-denaturing anion-exchange chromatography (AEX) for the separation of PS-modified siRNA diastereomers. Separation of the four isomers of the two PS bonds tended to improve in the double-stranded form compared to the single-stranded form. In addition, the effects of the analytical conditions and PS-modified position on the separation were evaluated. Moreover, the elution order of the Sp and Rp configurations was confirmed, and the steric difference between them, i.e., the direction of the anionic sulfur atom, appeared to be important for the separation mechanism in non-denaturing AEX. Consequently, all 16 peak tops of the four PS modifications were detected in one sequence, and approximately 30 peak tops were detected out of 64 isomers of six PS bonds, indicating that non-denaturing AEX is a useful technique for the quality control of PS-modified siRNA therapeutics.

Diagnosis by combination of endoscopic findings helps differentiate non-Helicobacter pylori Helicobacter-infected gastritis from Helicobacter pylori-infected gastritis

BACKGROUND

The characteristic endoscopic findings of non-Helicobacter pylori Helicobacter (NHPH) gastritis, including white marbled appearance and crack-like mucosa, have been reported. However, these findings can also manifest in H. pylori (HP)-infected gastritis. This study compared NHPH gastritis and mild atrophic HP gastritis to identify features that may enhance NHPH diagnosis.

MATERIALS AND METHODS

A total of 2087 patients underwent upper gastrointestinal endoscopy and were histologically evaluated by multiple gastric mucosal biopsies according to the updated Sydney System (USS) at Shinshu University Hospital between 2005 and 2023. Among them, nine patients were classified into the NHPH group and 134 patients with HP infection and mild atrophy were classified into the HP group for retrospective comparisons of endoscopic findings and clinicopathological characteristics.

RESULTS

All nine patients in the NHPH group (eight males [89%], median ± standard deviation [SD] age: 49 ± 13.0 years) were infected with H. suis. The 134 patients in the HP group contained 70 men (52%) and had a median ± SD age of 35 ± 19.9 years. Endoscopic findings were statistically comparable for white marbled appearance (three patients [33%] in the NHPH group and 37 patients [31%] in the HP group) and crack-like mucosa (three patients [33%] and 27 patients [20%], respectively). Diffuse redness was significantly less frequent in the NHPH group (one patient [14%] vs. 97 patients [72%], p < 0.001). White marbled appearance or crack-like mucosa without diffuse redness was significantly more common in the NHPH group (56% vs. 13%, p = 0.004), with a sensitivity and specificity of 56% and 87%, respectively. Mean USS neutrophil infiltration and Helicobacter density scores were significantly higher in the HP group (both p < 0.01), which might have influenced the endoscopic findings of diffuse redness.

CONCLUSIONS

When endoscopic findings of white marbled appearance or cracked-like mucosa are present, evaluation for diffuse redness may contribute to a more accurate diagnosis of NHPH gastritis.

First Detection of Chimeric β-Lactamase CTX-M-64-Producing Salmonella Typhimurium from a Domestic Source in Japan

Salmonella enterica subsp. enterica serovar Typhimurium has recently emerged worldwide as a producer of extended-spectrum β-lactamase (ESBL). However, drug-resistant clinical isolates are rare in Japan. The common types of ESBLs found are the CTX-M-type β-lactamases, including novel β-lactamases such as CTX-M-64. CTX-M-64 has a chimeric structure comprising a combination of the CTX-M-1 and CTX-M-9 groups. In 2017, S. Typhimurium was isolated from stool, blood, and urine cultures of an 82-year-old man. Herein, we describe the discovery of a clinical isolate of S. Typhimurium in Japan. Antimicrobial susceptibility testing revealed that the isolate was resistant to third- and fourth-generation cephalosporins, including ceftazidime and monobactam. The minimum inhibitory concentrations of ceftazidime and ceftriaxone were restored by administration of clavulanic acid. Whole-genome sequencing analysis revealed that the isolate harbored the blaCTX-M-64 gene on an IncHI2/IncHI2A-type plasmid, with an assembly length of 174,477 bp. The genetic structure of the region surrounding the blaCTX-M-64 gene, ISKpn26-ΔISEcp1-blaCTX-M-64-orf477, was shared only with the chromosome sequence of S. Typhimurium detected in food-producing chickens in Guangdong, China. Although rare, S. Typhimurium can induce bloodstream infections and produce ESBL. To our knowledge, this is the first report of a CTX-M-64-producing Enterobacterales clinical isolate of domestic origin in Japan.

External quality control survey on identification of microorganisms using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry（ MALDI-TOF MS） is a bacterial typing tool that was approved as a medical device in 2011. However, external accuracy control examination of bacterial typing using mass spectrometry is still only performed on a small scale. In this study, E. faecium and S. maltophilia were selected and tested according to established procedures using Score Values at 228 institutions. The Score Values for MALDI Biotyper were 2.43±0.08 for E. faecium and 2.38±0.08 for S. maltophilia; and those for VITEK MS/PRIME were 99.9±0.0 for E. faecium and S. maltophilia. These results suggest that it is useful to evaluate external accuracy control with Score Values using the procedures we have developed.

Visceral hypersensitivity induced by mild traumatic brain injury via the corticotropin-releasing hormone receptor: An animal model

BACKGROUND

Mild blast-induced traumatic brain injury (bTBI) induces various gut symptoms resembling human irritable bowel syndrome (IBS) as one of mental and behavioral disorders. However, the underlying mechanisms remain unclear. We investigated whether the extremely localized brain impact extracranially induced by laser-induced shock wave (LISW) evoked IBS-like phenomenon including visceral hypersensitivity and intestinal hyperpermeability in rats.

METHODS

The rats were subjected to LISW on the scalp to shock the entire brain. Visceral hypersensitivity was evaluated by the threshold pressure of abdominal withdrawal reflex (AWR) using a colorectal distension test. Permeability was evaluated by the concentration of penetrating FITC-dextran from intestine and the mRNA expression levels of tight junction family proteins. Involvement of corticotropin-releasing factor receptor (CRFR) 1 and 2 was examined by evaluating mRNA expression and modulating CRFR function with agonist, recombinant CRF (10 μg/kg), and antagonist, astressin (33 μg/kg). High-throughput sequencing of the gut microbiota was performed by MiSeqIII instrument and QIIME tool.

KEY RESULTS

The thresholds of the AWR were significantly lowered after LISW. Permeability was increased in small intestine by LISW along with decreased expression of tight junction ZO-1. LISW significantly increased CRFR1 expression and decreased CRFR2 expression. Visceral hypersensitivity was significantly aggravated by CRFR agonist and suppressed by CRFR antagonist. The α- and β-diversity of the fecal microbiota was altered after LISW.

CONCLUSIONS AND INFERENCES

LISW provoked visceral hypersensitivity, small intestinal hyperpermeability, altered expression of CRFRs and changes in the microbiota, suggesting that genuine bTBI caused by LISW can induce a pathophysiology comparable to that of human IBS.

Probiotic Yeast from Miso Ameliorates Stress-Induced Visceral Hypersensitivity by Modulating the Gut Microbiota in a Rat Model of Irritable Bowel Syndrome

Background/Aims

Recent studies indicate that probiotics, which have attracted attention as a treatment for irritable bowel syndrome, affect intestinal homeostasis. In this study, we investigated whether Zygosaccharomyces sapae (strain I-6), a probiotic yeast isolated from miso (a traditional Japanese fermented food), could improve irritable bowel syndrome symptoms.

Methods

Male Wistar rats were exposed to water avoidance stress (WAS). The number of defecations during WAS and the visceral hypersensitivity before and after WAS were evaluated using colorectal distension. Tight junction changes were assessed by Western blotting. Some rats were fed with strain I-6 or β-glucan from strain I-6. Changes in the intestinal microbiota were analyzed. The effect of fecal microbiota transplantation after WAS was evaluated similarly. Caco-2 cells were stimulated with interleukin-1β and tight junction changes were investigated after coculture with strain I-6.

Results

The increased number of stool pellets and visceral hypersensitivity induced by WAS were suppressed by administering strain I-6. The decrease in tight junction protein occludin by WAS was reversed by the administration of strain I-6. β-Glucan from strain I-6 also suppressed those changes induced by WAS. In the rat intestinal microbiota, treatment with strain I-6 altered the β-diversity and induced changes in bacterial occupancy. Upon fecal microbiota transplantation, some symptoms caused by WAS were ameliorated.

Conclusions

These results suggest that traditional fermented foods such as miso in Japan are valuable sources of probiotic yeast candidates, which may be useful for preventing and treating stress-induced visceral hypersensitivity.

Transgenerational impacts of oral probiotic administration in pregnant mice on offspring gut immune cells and colitis susceptibility

BACKGROUND AND AIM

The study of the impact of environmental factors during pregnancy on fetal development has so far been focused primarily on those negatively affecting human health; however, little is known about the effects of probiotic treatment during pregnancy on inflammatory bowel diseases (IBD). In this study, we investigated whether oral administration of heat-killed probiotics isolated from fermented foods decreased the vulnerability of offspring to IBD.

METHODS

Probiotics were administered to the pregnant mice until the birth of pups, after which the parent mice were maintained with autoclaved water. Partial pups were evaluated for dextran sodium sulfate-induced colitis. The influence of CD11c⁺ CD103⁺ dendritic cells (DCs) and regulatory T cells (Tregs) in mesenteric lymph nodes of parent mice and their pups was analyzed.

RESULTS

Oral administration of heat-killed probiotics to pregnant dams significantly decreased inflammation induced by dextran sodium sulfate in pups. Probiotic treatment increased the number of CD103⁺ DCs, and the expression of β8-integrin in CD103⁺ DCs and Tregs in mesenteric lymph nodes, not only in dams themselves but also in their offspring.

CONCLUSIONS

Oral administration of probiotics during gestation induced transgenerational immunomodulatory effects on the gut-associated immune system and resilience to experimental colitis in the offspring. Our results suggest that consumption of fermented foods during pregnancy can be effective in preventing inflammatory diseases such as IBD beyond generation.

Proinflammatory role of basophils in oxazolone-induced chronic intestinal inflammation

BACKGROUND AND AIM

The functions of basophils have not been elucidated until recently because of their rarity. However, with recent developments in basophil-specific antibodies and basophil-deficient animals, the roles of basophils in various diseases related to chronic inflammation have been clarified. In this study, we aimed to investigate the roles of basophils in human ulcerative colitis (UC) and oxazolone (OXA) colitis using genetically engineered Mcpt8^DTR mice.

METHODS

Immunohistochemical staining of human colon specimens was performed to examine the involvement of basophils in the pathogenesis of UC. We examined the correlation between the number of infiltrating basophils and the UC endoscopic index of severity (UCEIS), Mayo score, and Matts score. We also examined the correlation between eosinophil count and basophil infiltration. In murine experiments, we examined whether basophil infiltration was involved in OXA-induced colitis and whether basophil depletion improved inflammation in Mcpt8^DTR mice.

RESULTS

Colonic basophil infiltration was significantly increased in patients with UC. There were significant correlations between UCEIS, Mayo score, Matts score, and the number of infiltrating basophils. In murine OXA-induced colitis, a significant increase in basophil infiltration was observed. When basophils were depleted by diphtheria toxin in Mcpt8^DTR mice, inflammation improved significantly and mRNA expression of some proinflammatory cytokines, including Tnf-α and Ifn-γ decreased significantly.

CONCLUSION

Basophil infiltration correlated with endoscopic, clinical, and pathological scores in human UC independently of eosinophil infiltration, and depletion of basophils ameliorated mucosal inflammation in murine OXA-induced colitis, collectively suggesting that basophils exert a proinflammatory role in chronic intestinal inflammation such as UC.

Immunoglobulin G4‐related disease accompanying a small intestinal ulcer: A case

Immunoglobulin (Ig)G4‐related disease (IgG4‐RD) is a systemic condition associated with fibroinflammatory lesions and is characterized by elevated serum IgG4 levels and IgG4‐positive cell infiltration into the affected tissues. It has been reported that IgG4‐RD affects a variety of organs but uncommonly affects the gastrointestinal tract. In particular, there are few cases of lesions in the small intestine, except for sclerosing mesenteritis, which were mostly diagnosed from surgical specimens. Herein, we describe the case of a 70‐year‐old man who initially presented with abdominal pain, headache, later cognitive decline, and gait disturbance caused by IgG4‐RD. Colonoscopy revealed irregular ulcers in the terminal ileum, and computed tomography of the head showed hypertrophic pachymeningitis. Numerous IgG4‐positive cells were detected in the ileal and dural biopsies. We diagnosed the patient with IgG4‐RD and started steroid pulse therapy. After initiation of treatment, the symptoms quickly improved. The patient was discharged from the hospital after starting oral prednisolone treatment (30 mg). The dosage was gradually reduced to 10 mg. A follow‐up colonoscopy revealed scarring of the ileal ulcers. This case may provide valuable information regarding the endoscopic findings of small intestinal lesions in IgG4‐RD.

Changes in Colonic Inflammation Related with Takayasu Arteritis during a 10-year Observation Period

Takayasu arteritis (TA) sometimes presents with colitis, which may be diagnosed as inflammatory bowel disease unclassified (IBDU) because of atypical or mixed findings of ulcerative colitis (UC) and Crohn's disease. We herein report an 18-year-old girl presenting with colitis with an occasional high fever eventually diagnosed as TA with IBDU. Colonic inflammation was initially discontinuous and stronger in the proximal colon, atypical of UC. However, over 10-year observation, the distribution of colonic inflammation varied and became UC-like. Variations in TA-related colonic inflammations over time have been unclear. Our long-term observation might help clarify the details of TA-related colonic inflammation.

Acesulfame potassium induces dysbiosis and intestinal injury with enhanced lymphocyte migration to intestinal mucosa

BACKGROUND AND AIM

The artificial sweetener acesulfame potassium (ACK) is officially approved as safe for intake and has been used in processed foods. However, ACKs have been reported to induce metabolic syndrome, along with alteration of the gut microbiota in mice. In recent years, studies have suggested that this artificial sweetener promotes myeloperoxidase reactivity in Crohn's disease-like ileitis. We aimed to investigate the effect of ACK on the intestinal mucosa and gut microbiota of normal mice.

METHODS

Acesulfame potassium was administered to C57BL/6J mice (8 weeks old) via free drinking. Intestinal damage was evaluated histologically, and messenger RNA (mRNA) levels of TNF-α, IFN-γ, IL1-β, MAdCAM-1, GLP1R, and GLP2R were determined with quantitative reverse transcription polymerase chain reaction (qRT-PCR). Immunohistochemistry was performed to examine the expression of MAdCAM-1 in the small intestine. The composition of gut microbiota was assessed using high-throughput sequencing. We performed intravital microscopic observation to examine if ACK altered lymphocyte migration to the intestinal microvessels.

RESULTS

Acesulfame potassium increased the expression of proinflammatory cytokines, decreased the expression of GLP-1R and GLP-2R, and induced small intestinal injury with an increase in intestinal permeability, and ACK treatment induced microbial changes, but the transfer of feces alone from ACK mice did not reproduce intestinal damage in recipient mice. ACK treatment significantly increased the migration of lymphocytes to intestinal microvessels.

CONCLUSION

Acesulfame potassium induces dysbiosis and intestinal injury with enhanced lymphocyte migration to intestinal mucosa. Massive use of non-caloric artificial sweeteners may not be as safe as we think.

Antibiotic resistance and the presence of bla CfxA and bla CSP genes in β-lactamase-producing clinical Capnocytophaga isolates from a university hospital in Japan

Introduction . Capnocytophaga species are common inhabitants of the oral cavity and can be responsible for systemic diseases in immunocompromised patients with granulocytopenia. Furthermore, it has been reported that some clinical isolates of Capnocytophaga species produce extended-spectrum β-lactamases (ESBLs).Gap statement. Information is lacking about the types of β-lactamase genes possessed by Capnocytophaga spp. and the antimicrobial susceptibility of Capnocytophaga spp. possessing each β-lactamase gene.Aim. The aim of this study was to investigate the presence of β-lactamase genes in clinical strains of β-lactamase-producing Capnocytophaga species isolated from clinical samples acquired at Shinshu University Hospital and examine the antimicrobial susceptibility of those strains.Methodology. The β-lactamase-producing Capnocytophaga species (n=49) were obtained from clinical specimens. PCR assays were used to detect bla _CfxA, bla _CSP, bla _TEM, bla _CepA/CblA and transposon Tn4555 genes. Southern hybridization assays were used to detect bla _CfxA and bla _CSP. The minimum inhibitory concentration of some β-lactams was determined using the E-test method.Results. PCR analysis indicated that the bla _CfxA gene was present in 15 (30.6 %) and the bla _CSP gene in 35 (69.3 %) of the 49 Capnocytophaga strains investigated, . Both bla _CfxA and bla _CSP genes were detected in a Capnocytophaga gingivalis strain. The PCR results were confirmed by Southern hybridization assays. Transposon Tn4555 was only detected in Capnocytophaga spp. harbouring the bla _CfxA gene. All the β-lactamase-producing Capnocytophaga isolates were susceptible to ceftazidime-clavulanic acid, cefoxitin and imipenem. In contrast, most of the isolates were resistant to amoxicillin.Conclusions. The clinical isolates of Capnocytophaga spp. showed a high prevalence of the bla _CSP gene in Japan. The presence of the bla _CSP gene was distributed in Capnocytophaga sputigena as well as other Capnocytophaga spp. These results seem to suggest the dissemination of bla _CfxA and bla _CSP β-lactamase genes among Capnocytophaga species.

Indirect Potentiometric pH Detection of Weak Acids with Absolute Quantitation by a Theoretical Approach

A fast response potentiometric flow-through pH sensor was applied for organic acid determination. The analyte response with the pH sensor was obtained by eluent pH modification following ion exclusion chromatography with HClO₄ as an eluent. The response characteristics depend on the adjusted baseline pH. The baseline pH adjustment was successfully done with an ammonia permeation device without solution mixing, which may cause analyte dilution, dispersion, and mixing noise. After pH adjustment, the pH response was universal to the equivalent of introduced analyte acids because the pH response was obtained by the titration of the permeant ammonia by the analytes. The average of limit of detections (S/N = 3) was 0.06 mM for seven target organic acids. Furthermore, the pH response follows the theoretical pH calculation with the concentrations of the eluent, pH modifier, and analyte. Thus, the analyte concentration in the sample can be theoretically calculated from the pH response without calibration by the analyte standard. Predicted concentrations of injected standards were within 5% of the actual standard concentration. Additionally, analysis of real samples was performed and compared with the conventional post-column reaction with a bromothymol blue (BTB) method. The results obtained with the present system (absolute quantification with theoretical calculation) and conventional BTB method agreed within 10% of errors.

Deoxycholic acid enhancement of lymphocyte migration through direct interaction with the intestinal vascular endothelium

BACKGROUND AND AIM

The small intestine plays a central role in gut immunity, and enhanced lymphocyte migration is involved in the pathophysiology of various enteropathy. Bile acid (BA) is closely related to lipid metabolism and gut microbiota and essential for gut homeostasis. However, the effects of BA on gut immunity have not been studied in detail, especially on the small intestine and lymphocyte migration. Therefore, we aimed to investigate the effect of BA on small intestinal lymphocyte microcirculation.

METHODS

The effect of deoxycholic acid (DCA), taurocholic acid (tCA), or cholic acid (CA) on the indomethacin (IND)-induced small intestinal enteropathy in mice was investigated. Lymphocyte movements were evaluated after exposure to BA using intravital microscopy. The effects of BA on surface expression of adhesion molecules on the vascular endothelium and lymphocytes through BA receptors were examined in vitro.

RESULTS

IND-induced small intestinal enteropathy was histologically aggravated by DCA treatment alone. The expression of adhesion molecules ICAM-1 and VCAM-1 was significantly enhanced by DCA. Exposure to DCA increased lymphocyte adhesion in the microvessels of the ileum, which was partially blocked by anti-α4β1 integrin antibody in vivo. The expression of ICAM-1 and VCAM-1 was significantly enhanced by DCA in vitro, which was partially suppressed by the sphingosine-1-phosphate receptor 2 (S1PR2) antagonist. The S1PR2 antagonist significantly ameliorated IND-induced and DCA-exaggerated small intestinal injury.

CONCLUSION

DCA exacerbated IND-induced small intestinal enteropathy. DCA directly acts on the vascular endothelium and enhances the expression levels of adhesion molecules partially via S1PR2, leading to enhanced small intestinal lymphocyte migration.

Acute gastric mucosal lesions caused by acute infection of non-Helicobacter pylori Helicobacter: a case report

BACKGROUND

Non-Helicobacter pylori Helicobacter (NHPH) is not widely recognized as a cause of acute gastric mucosal lesions (AGML), as only a few cases of AGML caused by NHPH have been reported. We present here one case and examine the species and eradication of NHPH together with the three previously reported cases.

CASE PRESENTATION

A 52-year-old woman presented with a two-day history of severe epigastric pain, nausea, and vomiting. An esophagogastroduodenoscopy showed mucosal edema, multiple erosions, and ulcerations in the antrum. Biopsy specimens taken from the antrum revealed long spiral-shaped organisms, suggesting NHPH. As both serum anti-Helicobacter pylori (H. pylori) antibody and H. pylori stool antigen test were negative, this case was diagnosed as AGML caused by NHPH. After the administration of esomeprazole 20 mg for 14 days and the interval of the following 12 days, AGML was deemed to have been cured endoscopically. In addition, microscopic examination and PCR analysis confirmed the success of NHPH eradication.

CONCLUSIONS

NHPH should be considered a probable cause of AGML in cases that are not attributed to the other causes already recognized. Taking probability of spontaneous eradication into consideration, it is appropriate to start eradication therapy after confirming the chronicity of NHPH infection.

Prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings of non-Helicobacter pylori Helicobacter infection: A study of 50 cases at a single facility in Japan

BACKGROUND AND AIM

There are only a few reports of non-Helicobacter pylori Helicobacter (NHPH) gastritis in Japanese patients. We aimed to examine its prevalence, clinical features, and esophagogastroduodenoscopy (EGD) findings based on 50 patients encountered in one facility.

MATERIALS AND METHODS

Subjects were all patients who had undergone gastric mucosal biopsy endoscopically at Kenwakai Hospital for approximately 10 years. NHPH infection was diagnosed by microscopic findings of Giemsa staining performed on all specimens. PCR analysis of urease genes was performed to detect and identify NHPH, when informed consent was obtained. Helicobacter pylori-diagnostic tests were also performed. NHPH-infected patients were questioned about symptoms and animal contact.

RESULTS

NHPH gastritis was found in 50 of 3847 patients (1.30%). The percentage increased to 3.35% (30 of 896 patients) in the latter 2 years and 4 months with increasing recognition of its characteristic endoscopic findings by endoscopists. PCR analysis, performed in 30 patients, detected NHPH in 28 patients: 26 as Helicobacter suis and 2 as Helicobacter heilmanii/Helicobacter ailurogastricus. Helicobacter pylori-diagnostic tests were almost negative. However, anti-H. pylori antibody showed high-negative titer (3.0-9.9 U/ml) in 12. Of 50 patients (consisting of 49 men and 1 woman), almost all were asymptomatic, and 25 were keeping pets. Regarding EGD findings, in all 50 patients, "crack-like mucosa" and/or nodular gastritis was noted in gastric antrum, and regular arrangement of collecting venules (RAC) was noted in gastric corpus. None of the patients infected with NHPH were co-infected with H. pylori.

CONCLUSIONS

The prevalence was finally estimated to be approximately 3.35%. Helicobacter suis was the most common NHPH species. "Crack-like mucosa" and/or nodular gastritis in gastric antrum, RAC in gastric corpus, and H. pylori-negativity by H. pylori-diagnostic tests especially containing a high-negative titer of anti-H. pylori antibody may indicate NHPH infection.

Angiopoietin-like protein 4 deficiency augments liver fibrosis in liver diseases such as nonalcoholic steatohepatitis in mice through enhanced free cholesterol accumulation in hepatic stellate cells

AIM

We recently reported that lipoprotein lipase (LPL)-mediated free cholesterol (FC) accumulation in hepatic stellate cells (HSCs) augmented liver fibrosis in non-alcoholic steatohepatitis (NASH). The aim of the present study was to explore the role of angiopoietin-like protein 4 (Angptl4), an LPL inhibitor, in the pathogenesis of liver fibrosis in NASH.

METHODS

Angptl4-deficient or wild-type mice were used to investigate the role of Angptl4 in the pathogenesis of NASH induced by feeding a methionine- and choline-deficient diet. We also examined the effect of Angptl4 on FC accumulation in HSCs, and the subsequent activation of HSCs, using Angptl4-deficient HSCs.

RESULTS

In the NASH model, Angptl4-deficient mice had significantly aggravated liver fibrosis and activated HSCs without enhancement of hepatocellular injury, liver inflammation, or liver angiogenesis. FC levels were significantly higher in HSCs from Angptl4-deficient mice than in those from wild-type mice. Treatment with Angptl4 reversed low-density lipoprotein-induced FC accumulation in HSCs through the inhibition of LPL. The Angptl4 deficiency-induced FC accumulation in HSCs suppressed HSC expression of the transforming growth factor-β (TGF-ß) pseudoreceptor, bone morphogenetic protein, and activin membrane-bound inhibitor, and sensitized HSCs to TGF-β-induced activation in vivo and in vitro.

CONCLUSIONS

Angptl4 plays an important role in the pathogenesis of FC accumulation in HSCs. In addition, regulation of FC levels in HSCs by Angptl4 plays a critical role in the pathogenesis of liver fibrosis in NASH. Thus, Angptl4 could represent a novel therapeutic option for NASH.

Intestinal inflammations increase efflux of innate lymphoid cells from the intestinal mucosa to the mesenteric lymph nodes through lymph-collecting ducts

INTRODUCTION

Innate lymphoid cells (ILCs) are abundant in the intestinal mucosa, forming boundaries externally. Herein, ILCs were directly obtained from intestinal lymph using a lymph fistula rat model and analyzed under physiological and pathological conditions.

METHODS

Thoracic duct (TD) lymphocytes were collected by cannulation with/without preceded mesenteric lymphadenectomy, which were comparable to lymphocytes flowing through mesenteric lymphatic vessels (MLVs) or TD, respectively. The collected ILCs were classified according to gene transcription factors and analyzed by flow cytometry. The effect of IL-25 or indomethacin was studied.

RESULTS

The proportion of total ILCs in the MLVs (MLV-ILCs) was significantly higher than that in TD (TD-ILCs, 0.01% vs. 0.003%, respectively). Physiologically, there were several significant differences in the MLV-ILCs compared with TD-ILCs, including the proportion of ILC2 (42.3% vs. 70.9%) and ILC3 (33.3% vs. 13.8%), and the proportion of α4-integrin-positive cells (36.8% vs. 0.3%). IL-25 significantly increased the proportion of MLV-ILC2 after 3 days. Indomethacin-induced intestinal injury increased the proportion of MLV-ILC3 in the early phase within 12 h.

CONCLUSION

Intestinal ILCs were found to migrate through MLVs. The altered mobilization of MLV-ILCs after stimuli suggests that ILCs play an important role in regulating the immune responses at the secondary lymph nodes.

Examination of conditions for regular internal quality control in identification of microorganisms using MALDI-TOF MS

Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) was approved for medical use in 2011, and is currently used as a rapid, accurate and low-cost technique for bacterial identification. Microbiological testing and internal accuracy control in Japan are mainly implemented in accordance with the standards of the Clinical and Laboratory Standards Institute (CLSI). However, few facilities perform internal accuracy control of bacterial identification by MALDI-TOF MS. Therefore, we examined the procedures for internal accuracy control of bacterial identification using MALDI-TOF MS in daily work at clinical laboratories in the seven hospitals.

Sarcopenia-derived exosomal micro-RNA 16-5p exerts the cardio-repair disturbance via pro-apoptotic mechanism in myocardial infarction of mice

Background

Sarcopenia is a pathophysiological malfunction induced by skeletal muscle atrophy, and several studies reported an association between sarcopenia-induced cardiac cachexia and poor prognosis in heart disease. Since only a few established animal models are recently available, the underlying mechanism of disturbed cardiac repair accompanied with sarcopenia remains poorly understood.

Purpose

We hypothesized that specific microRNAs in sarcopenia-derived exosomes play crucial roles in disturbed cardiac repair with sarcopenia, and these microRNAs directly exacerbate cardiomyocyte injury following cardiac ischemia and reperfusion.

Methods

We developed a novel sarcopenia-induced cardiac repair disturbance mouse model that is induced by tail suspension (TS) 7 days after a 45-min coronary occlusion of cardiac ischemia and reperfusion (I/R). The reduction of the left ventricular ejection fraction (LVEF) after I/R was compared in mice with TS [I/R-TS(+), n=14] and without [I/R-TS(−), n=12] by echocardiography. To investigate the exosomal mechanism of cardiac repair disturbance, a comprehensive analysis of extracted exosomal microRNAs from mice serum was performed in the 2 groups at day 8. Then, we investigated the impact of the identified candidate microRNA in neonatal rat cardiomyocytes (NRVMs). After 4 days in primary culture, candidate microRNA was transfected into NRVMs under hypoxic culture conditions. TUNEL analysis and quantitative PCR analysis of apoptosis-related genes were performed on the NRVMs.

Results

At day 8 after I/R, the LVEF of I/R-TS(+) was not significantly ameliorated compared to that of I/R-TS(−) (ΔLVEF; 1.59±6.92 vs. 8.04±7.71% p=0.034). Four candidate microRNAs obtained from I/R mice serum were identified in the microRNA array analysis. The re-analysis of these candidate micro-RNAs using all I/R mice demonstrated that the level of mir-16-5p in I/R-TS(+) was raised by approximately nine-fold than that in I/R-TS(−) (9.67±13.35 vs. 0.99±1.41, p&lt;0.05). Next, an in vitro experimental model using a microRNA mimic revealed that apoptosis in NRVMs was greatly enhanced by the transfection of a mir-16-5p mimic in hypoxic culture conditions (mir-16-5p vs. control = 5.77±2.84 vs. 1.72±0.55%, p&lt;0.01). Furthermore, by qRT-PCR analysis, the expression of CASP3 and TRP53 were upregulated in NRVMs treated with a mir-16-5p mimic than in control NRVMs.

Conclusion

Myocardial I/R injury in sarcopenia ended in cardiac repair disturbance accompanying with the enhanced expression of exosomal-mir-16-5p. A pro-apoptotic effect of mir-16-5p may exacerbate myocardial I/R injury and thus can be a novel therapeutic target for cardiac repair disturbance in sarcopenia.

Funding Acknowledgement

Type of funding source: Public grant(s) – National budget only. Main funding source(s): Japan Society for the Promotion of Science

Microscopic Observation of Lymphocyte Dynamics in Rat Peyer's Patches

Naïve lymphocytes recirculate from the blood to the lymphoid tissues under physiological condition and it is commonly recognized as an important phenomenon in the gut immunity. The stroma of secondary lymphoid organs, such as Peyer's patches (PPs) or mesenteric lymph nodes, are where naïve lymphocytes sense antigens. Naïve lymphocytes circulate through the bloodstream to reach high endothelial venules, the portal of entry into PPs. Some immunomodulators are estimated to influence lymphocyte migration, but the precise evaluation of microcirculation dynamics is very difficult, and establishing a method to observe lymphocyte migration in vivo can contribute to the clarification of the precise mechanisms. We refined the method of collecting lymphocytes from the lymph duct and observing the detailed dynamics of gut-tropic lymphocytes in rat PPs. We chose confocal laser scanning microscopy to observe rat PPs in vivo and recorded it using time-lapse photography. We can now obtain clear images that can contribute to the analysis of lymphocyte dynamics.

Predictors of Cerebral Aneurysm Rupture after Coil Embolization: Single-Center Experience with Recanalized Aneurysms

BACKGROUND AND PURPOSE

Recanalization after coil embolization is widely studied. However, there are limited data on how recanalized aneurysms rupture. Herein, we describe our experience with the rupture of recanalized aneurysms and discuss the type of recanalized aneurysms at greatest rupture risk.

MATERIALS AND METHODS

A total of 426 unruptured aneurysms and 169 ruptured aneurysms underwent coil embolization in our institution between January 2009 and December 2017. Recanalization occurred in 38 (8.9%) of 426 unruptured aneurysms (unruptured group) and 37 (21.9%) of 169 ruptured aneurysms (ruptured group). The Modified Raymond-Roy classification on DSA was used to categorize the recanalization type. Follow-up DSA was scheduled until 6 months after treatment, and follow-up MRA was scheduled yearly. If recanalization was suspected on MRA, DSA was performed.

RESULTS

In the unruptured group, the median follow-up term was 74.0 months. Retreatment for recanalization was performed in 18 aneurysms. Four of 20 untreated recanalized aneurysms (0.94% of total coiled aneurysms) ruptured. In untreated recanalized aneurysms, class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .025). In the ruptured group, the median follow-up term was 28.0 months. Retreatment for recanalization was performed in 16 aneurysms. Four of 21 untreated recanalized aneurysms (2.37% of total coiled aneurysms) ruptured. Class IIIb aneurysms ruptured significantly more frequently than class II and IIIa (P = .02).

CONCLUSIONS

The types of recanalization after coil embolization may be predictors of rupture. Coiled aneurysms with class IIIb recanalization should undergo early retreatment because of an increased rupture risk.

Depression Promotes the Onset of Irritable Bowel Syndrome through Unique Dysbiosis in Rats

Background/Aims

Although studies using conventional animal models have shown that specific stressors cause irritable bowel syndrome (IBS), it is unclear whether depression itself causes IBS. Our aim was to establish a rat model to determine if depression itself promotes the onset of IBS and to elucidate the role of gut microbiota in brain-gut axis pathogenesis during coincident depression and IBS.

Methods

Rat models of depression were induced using our shuttle box method of learned helplessness. Visceral hypersensitivity was evaluated by colorectal distension (CRD) to diagnose IBS. Gut microbiota compositions were analyzed using high-throughput sequencing. In the subanalysis of rats without depression-like symptoms, rats with posttraumatic stress disorder (PTSD) were also examined.

Results

The threshold value of CRD in depressed rats was significantly lower than that in control rats. Microbial community analysis of cecal microbiota showed that the relative abundance of Clostridiales incertae sedis, the most prevalent microbe, was significantly lower in depressed rats than in control rats. The distribution pattern of the microbiota clearly differed between depressed rats and control rats. Neither visceral hypersensitivity nor the composition of gut microbiota was altered in rats with PTSD-like phenotypes.

Conclusions

Our rat model of depression is useful for clarifying the effect of depression on IBS and suggests that depression itself, rather than specific stressors, promotes the onset of IBS. Further, we provided evidence that various psychiatric diseases, viz., depression and PTSD, are associated with unique gut microbiota profiles, which could differentially affect the onset and progression of coincident IBS.

Dietary emulsifier polysorbate-80-induced small-intestinal vulnerability to indomethacin-induced lesions via dysbiosis

BACKGROUND AND AIM

Dietary emulsifiers are widely used in processed foods and officially approved as safe for intake. However, recent studies have demonstrated that some emulsifiers alter the colonic microbiota, leading to colonic low-grade inflammation, in mice. The effect of dietary emulsifiers on small-intestinal microbiota, which is important for gut immunity, has not been studied. We aimed to investigate the effect of a representative dietary emulsifier, polysorbate-80 (P80), on the small-intestinal microbiota in normal mice.

METHODS

Some mice were pretreated with P80 for 8 weeks with or without indomethacin administration on the last 2 days, and intestinal damage was evaluated histologically. The ileal and colonic microbiota composition was assessed using 16S rRNA polymerase chain reaction.

RESULTS

Polysorbate-80 increased the Gammaproteobacteria abundance and decreased the α-diversity in the small intestine. No decrease in α-diversity was observed in the colon. P80 pretreatment exacerbated the indomethacin-induced small-intestinal lesions and significantly increased the interleukin-1β expression. Culture of ileal content on deoxycholate hydrogen sulfide lactose agar showed that P80 significantly increased the colonies of the sulfide-producing bacteria Proteus spp. (genetically identified as Proteus mirabilis). Antibiotic pretreatment abolished the P80-induced aggravation of indomethacin-induced ileitis. Motility assay in semisolid agar showed that adding 0.02% P80 to the agar significantly increased the diameter of P. mirabilis colonies but not that of Escherichia coli colonies.

CONCLUSIONS

Polysorbate-80 enhances the vulnerability of the small intestine to indomethacin-induced injury by inducing ileal dysbiosis. Direct enhancement of the motility of specific flagellated microbiota by P80 might be related to dysbiosis and intestinal injury.

Detection of Acinetobacter pittii ST220 co-producing NDM-1 and OXA-820 carbapenemases from a hospital sink in a non-endemic country of NDM

OBJECTIVES

NDM-1 is by far one of the most commonly prevalent carbapenemases in Enterobacteriaceae and Acinetobacter baumannii. This study presented an Acinetobacter pittii (A. pittii) isolate co-harboring bla_NDM-1 and bla_OXA-820 from a university hospital sink, where New Delhi metallo-β-lactamase (NDM) producers have not been found in either patients or their environments.

METHODS

Whole-genome sequencing was performed on the HiSeq 4000 platform, and the reads were de novo assembled using the A5-miSeq Assembly pipeline. Annotation of the resulting scaffolds were performed by using the DDBJ Fast Annotation and Submission Tool (DFAST). The bla_NDM-1-carrying plasmid was determined.

RESULTS

The A. pittii ST220 strain SU1805 detected from a sink strainer in the treatment room was resistant to imipenem and meropenem. Antimicrobial resistance genes bla_NDM-1, bla_OXA-820, bla_ADC-43, and aphA6 were found in this strain. The bla_NDM-1 was found to be located downstream of an ISAba125 element on a plasmid pSU1805NDM with a size of 41,022 bp, and GC content of 38.3% harbouring 48 protein-coding genes. The aphA6 gene was also located upstream of the ISAba125 on the same plasmid. The A. pittii intrinsic bla_OXA-213-like gene bla_OXA-820 was located between fxsA and yncA genes in the chromosome. The strain also harboured biofilm-associated genes such as ompA, the csu operon and their regulating genes bfmRS.

CONCLUSION

This study described the first isolation of NDM-1-producing A. pittii in Japan, and highlighted the importance of proper implementation of measures against AMR for sink drainage systems, since NDM producers may have already been hidden in such environments in a non-endemic country of NDM.

Chitinase 3-like 1 deficiency ameliorates liver fibrosis by promoting hepatic macrophage apoptosis

AIM

Chitinase 3-like 1 (CHI3L1), an 18-glycosyl hydrolase-related molecule, is a member of the enzymatically inactive chitinase-like protein family. Serum levels of CHI3L1 are strongly correlated with hepatic fibrosis progression during many liver diseases. Therefore, this protein could be involved in the development of hepatic fibrosis pathology; however, its role has not been elucidated. We aimed to elucidate its role in the pathophysiology of liver fibrosis.

METHODS

Chitinase 3-like 1-deficient (Chi3l1^-/- ) mice were given carbon tetrachloride twice per week for 4 weeks or fed a methionine choline-deficient diet for 12 weeks to generate mouse liver fibrosis models. Human fibrotic liver tissues were also examined immunohistochemically.

RESULTS

In human and mouse fibrotic livers, CHI3L1 expression was mainly localized to hepatic macrophages, and the intrahepatic accumulation of CHI3L1⁺ macrophages was significantly enhanced compared to that in control livers. In the two mouse models, hepatic fibrosis was significantly ameliorated in Chi3l1^-/- mice compared to that in wild-type mice, which was dependent on hepatic macrophages. The accumulation and activation of hepatic macrophages was also significantly suppressed in Chi3l1^-/- mice compared to that in wild-type mice. Furthermore, apoptotic hepatic macrophages were significantly increased in Chi3l1^-/- mice. Chitinase 3-like 1 was found to inhibit hepatic macrophage apoptosis by suppressing Fas expression and activating Akt signaling in an autocrine manner, which resulted in hepatic macrophage accumulation and activation, exaggerating liver fibrosis.

CONCLUSIONS

Chitinase 3-like 1 exacerbates liver fibrosis progression by suppressing apoptosis in hepatic macrophages. Therefore, this might be a potential therapeutic target for the treatment of liver fibrosis.

Three-Dimensional Aerial Image Interface, 3DAII

In this paper, we introduce the three-dimensional aerial image interface, 3DAII. This interface reconstructs and aerially projects a three-dimensional object image, which can be simultaneously observed from various viewpoints or by multiple users with the naked eye. A pyramid reflector is used to reconstruct the object image, and a pair of parabolic mirrors is used to aerially project the image. A user can directly manipulate the three-dimensional object image by superimposing a user’s hand-finger or a rod on the image. A motion capture sensor detects the user’s hand-finger that manipulates the projected image, and the system immediately exhibits some reaction such as deformation, displacement, and discoloration of the object image, including sound effects. A performance test is executed to confirm the functions of 3DAII. The execution time of the end-tip positioning of a robotic arm has been compared among four operating devices: touchscreen, gamepad, joystick, and 3DAII. The results exhibit the advantages of 3DAII; we can directly instruct the movement direction and movement speed of the end-tip of the robotic arm, using the three-dimensional Euclidean vector outputs of 3DAII in which we can intuitively make the end-tip of the robotic arm move in three-dimensional space. Therefore, 3DAII would be one important alternative to an intuitive spatial user interface, e.g., an operation device of aerial robots, a center console of automobiles, and a 3D modelling system. A survey has been conducted to evaluatecomfortandfatiguebased on ISO/TS 9241-411 andease of learningandsatisfactionbased on the USE questionnaire. We have identified several challenges related to visibility, workspace, and sensory feedback to users that we would like to address in the future.

P4144Pericyte-specific deletion of ninjurin1 induces abnormal vasa vasorum formation and persistent inflammation and enhances intimal hyperplasia of injured vasculature

Introduction

Atherosclerosis is fundamental pathological condition inducing severe ischemic diseases such as ischemic heart disease and stroke. New concept has been proposed that adventitial abnormalities including enhanced malformation of adventitial microvessel, vasa vasorum are associated with development and vulnerability of atherosclerotic plaque. However, the role of vasa vasorum malformation in vascular remodelling has not been fully clarified. We recently reported that Ninjurin1 (Ninj1) is critical adhesion molecule to associate pericytes (PCs) with endothelial (EC) tubes to form stabilized mature neovessels. The purpose of this study is to examine if formation of adventitial microvessels affects the vascular remodelling of injured vessels using PCs-specific Ninj1 deletion mouse model.

Methods and results

Deletion of Ninj1 gene in NG2-positive PCs was induced by tamoxifen (Tam)-treated NG2-CreER/Ninj1loxp mice (Ninj1KO, n=9). Tam-treated-NG2-CreER (n=4) or Tam-nontreated NG2-CreER/Ninj1loxp (n=5) mice were used as Control (Ct1 and Ct2 respectively). Femoral arteries were injured by insertion of coiled wire. After 4 weeks of surgery, blood vessels were stained by venous injection of FITC-lectin. Isolated femoral arteries were fixed with paraformaldehyde and decolorized with CUBIC reagent. Wire-mediated vessel injury induced intimal hyperplasia, as assessed by intima/media (I/M) ratio and accordingly grew microvessels in adventitia. Intimal hyperplasia in Ninj1KO were significantly enhanced compared to Controls. Although there was no significant difference in total length of adventitial microvessels among three groups, extravasation of FITC-lectin from adventitial microvessels were significantly enhanced in Ninj1KO. The number of infiltrated macrophages in adventitia were increased in Ninj1KO.

Conclusion

Deletion of Ninj1 in PCs contributes to formation of immature microvessels in adventitia of injured vasculature and to adventitial microbleeding, and subsequently enhances intimal hyperplasia. Ninj1 is an attractive target to normalize microvessels for anti-atherosclerotic therapy.

Crohn's Disease Accompanied with Small Intestinal Extramedullary Plasmacytoma

We herein present the case of an immunocompetent 63-year-old man who had previously undergone resection of Crohn's disease (CD)-related small intestinal obstruction more than 30 years ago. He had not been receiving any medication for many years, but had recently started to suffer from ileus. A stenosed site of ileo-cecal anastomosis was identified and therefore was surgically resected, which was diagnosed as CD with small intestinal extramedullary plasmacytoma (EMP). The subsequent progression of CD was successfully controlled by anti-TNFα agents without any recurrence of EMP for over 3 years, implying the clinical benefit and safety of the biological therapy. This was the first known case of a patient who received anti-TNFα agents after a resection of small intestinal EMP accompanied with CD.

A case of cervical subcutaneous abscess due to Bordetella hinzii

We present a case of subcutaneous infection caused by Bordetella hinzii in a healthy male. The isolate was successfully identified by gyrB gene sequencing. B. hinzii cannot be distinctively identified using 16S rRNA gene sequencing or by biochemical methods. The number of cases infected with B. hinzii might be underestimated owing to the difficulty in accurate identification, which can be achieved by gyrB gene sequencing to gain knowledge about the species.

Lipoprotein Lipase Up-regulation in Hepatic Stellate Cells Exacerbates Liver Fibrosis in Nonalcoholic Steatohepatitis in Mice

Lipoprotein lipase (LPL) plays a central role in incorporating plasma lipids into tissues and regulates lipid metabolism and energy balance in the human body. Conversely, LPL expression is almost absent in normal adult livers. Therefore, its physiological role in the liver remains unknown. We aimed to elucidate the role of LPL in the pathophysiology of nonalcoholic steatohepatitis (NASH), a hepatic manifestation of obesity. Hepatic stellate cell (HSC)–specific LPL‐knockout (Lpl^HSC‐KO) mice, LPL‐floxed (Lpl^fl/fl) mice, or double‐mutant toll‐like receptor 4–deficient (Tlr4^−/−) Lpl^HSC‐KO mice were fed a high‐fat/high‐cholesterol diet for 4 weeks to establish the nonalcoholic fatty liver model or an high‐fat/high‐cholesterol diet for 24 weeks to establish the NASH model. Human samples, derived from patients with nonalcoholic fatty liver disease, were also examined. In human and mouse NASH livers, serum obesity‐related factors, such as free fatty acid, leptin, and interleukin‐6, dramatically increased the expression of LPL, specifically in HSCs through signal transducer and activator of transcription 3 signaling, as opposed to that in hepatocytes or hepatic macrophages. In the NASH mouse model, liver fibrosis was significantly reduced in Lpl^HSC‐KO mice compared with that in Lpl^fl/fl mice. Nonenzymatic LPL‐mediated cholesterol uptake from serum lipoproteins enhanced the accumulation of free cholesterol in HSCs, which amplified TLR4 signaling, resulting in the activation of HSCs and progression of hepatic fibrosis in NASH. Conclusion: The present study reveals the pathophysiological role of LPL in the liver, and furthermore, clarifies the pathophysiology in which obesity, as a background factor, exacerbates NASH. The LPL‐mediated HSC activation pathway could be a promising therapeutic target for treating liver fibrosis in NASH.

Abstract OT2-02-01: A confirmation study of omitting axillary dissection in patients with breast cancer and positive sentinel nodes

Background

The omission of axillary dissection for positive sentinel-node breast cancer is considered the standard treatment for patients who undergo breast conserving surgery and radiation therapy, according to the results of ACOSOG-Z0011 and AMAROS trials. On the other hand, some surgeons still think that the surgical stress of axillary dissection is minimal, and dissection is permitted. Furthermore, Z0011 contains several problems, such as insufficient number of entry cases and lack of radiation field unity. Thus, we planned a prospective trial to confirm the safety of omitting axillary dissection in patients with breast cancer and positive sentinel nodes.

Trial design

This is a single arm, confirmation study of three medical centers. Prior to surgery, informed consent is obtained, and patients are registered primarily. After surgery, patients with 1 to 2 positive sentinel nodes, for whom axillary dissection was omitted, are finally included in this trial at final registration.

Eligibility criteria

Patients with histologically-diagnosed breast cancer, Tis–2, N0 based on a core needle biopsy, will be included in this trial. Eligible patients must be between 20 and 80 years of age, with a performance status of 0–2 and adequate organ function. They must not have undergone any prior operation, radiation therapy, chemotherapy, endocrine therapy, or immunotherapy.

Specific aims

The primary endpoint is 5-year (y) axillary recurrence rate. Secondary endpoints are 5-y overall survival, 5-y recurrence-free survival, 5-y local recurrence-free survival, the rate of upper-limb lymphedema, quality of life, and comparison of axillary recurrence rates between patients with two or more dissected nodes and those with only one positive node.

Statistical methods

The expected rate of axillary recurrence is 2.0%, and non-inferiority is defined as an axillary recurrence lesser than or equal to 5% in the axillary radiotherapy group. The sample size was calculated with a study power of 80% and type I error of 10% (two-sided). The required number of patients is estimated to be 189.

Present and target accrual

Patient accrual from the three medical centers was initiated in July 2016. We plan to enroll a total of 189 patients at final registration in this trial.

Citation Format: Jibiki N, Hirano A, Ochi T, Sakamoto A, Horiuchi K, Noguchi E, Omi Y, Ogura K, Inoue H, Kamio T, Naritaka Y, Fujibayashi M, Hiroshima K, Nagashima Y, Sakai S, Karasawa K, Okamoto T. A confirmation study of omitting axillary dissection in patients with breast cancer and positive sentinel nodes [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr OT2-02-01.

Atypical Clinical Presentation of Crohn's Disease with Superior Mesenteric Vein Obstruction and Protein-losing Enteropathy

We herein report a 44-year-old man suffering from systemic edema due to protein-losing enteropathy (PLE) with superior mesenteric vein (SMV) obstruction and development of collateral veins, which subsequently proved to be a chronic result of thrombosis and a complication of Crohn's disease (CD). PLE was supposedly induced by both intestinal erosion and thrombosis-related lymphangiectasia, which was histologically proven in his surgically-resected ileal stenosis. Elemental diet and anti-TNFα agent improved his hypoalbuminemia after surgery. The rarity of the simultaneous coexistence of SMV obstruction and PLE and the precedence of these complications over typical abdominal symptoms of CD made the clinical course complex.

Cholesterol-α-glucosyltransferase gene is present in most Helicobacter species including gastric non-Helicobacter pylori helicobacters obtained from Japanese patients

BACKGROUND

Non-Helicobacter pylori helicobacters (NHPHs) besides H. pylori infect human stomachs and cause chronic gastritis and mucosa-associated lymphoid tissue lymphoma. Cholesteryl-α-glucosides have been identified as unique glycolipids present in H. pylori and some Helicobacter species. Cholesterol-α-glucosyltransferase (αCgT), a key enzyme for the biosynthesis of cholesteryl-α-glucosides, plays crucial roles in the pathogenicity of H. pylori. Therefore, it is important to examine αCgTs of NHPHs.

MATERIALS AND METHODS

Six gastric NHPHs were isolated from Japanese patients and maintained in mouse stomachs. The αCgT genes were amplified by PCR and inverse PCR. We retrieved the αCgT genes of other Helicobacter species by BLAST searches in GenBank.

RESULTS

αCgT genes were present in most Helicobacter species and in all Japanese isolates examined. However, we could find no candidate gene for αCgT in the whole genome of Helicobacter cinaedi and several enterohepatic species. Phylogenic analysis demonstrated that the αCgT genes of all Japanese isolates show high similarities to that of a zoonotic group of gastric NHPHs including Helicobacter suis, Helicobacter heilmannii, and Helicobacter ailurogastricus. Of 6 Japanese isolates, the αCgT genes of 4 isolates were identical to that of H. suis, and that of another 2 isolates were similar to that of H. heilmannii and H. ailurogastricus.

CONCLUSIONS

All gastric NHPHs examined showed presence of αCgT genes, indicating that αCgT may be beneficial for these helicobacters to infect human and possibly animal stomachs. Our study indicated that NHPHs could be classified into 2 groups, NHPHs with αCgT genes and NHPHs without αCgT genes.

Characterization of clinically isolated thymidine-dependent small-colony variants of Escherichia coli producing extended-spectrum β-lactamase

PURPOSE

Thymidine-dependent small-colony variants (TD-SCVs) are difficult to detect or test for antimicrobial susceptibility. We investigated the characteristics of clonal TD-SCVs of Escherichia coli, both with and without blaCTX-M-3, isolated from a patient.

METHODOLOGY

Mutation in the thyA gene was analysed by sequencing, and morphological abnormalities in the colonies and cells of the isolates were examined. Additionally, conjugational transfer experiments were performed to prove the horizontal transferability of plasmids harbouring resistance genes.

RESULTS

The TD-SCVs contained a single nucleotide substitution in the thyA gene, c.62G>A, corresponding to p.Arg21His. Morphologically, their colonies were more translucent and flattened than those of the wild-type strain. In addition, cells of the TD-SCVs were swollen and elongated, sometimes with abnormal and incomplete divisions; a large amount of cell debris was also observed. Changing c.62G>A back to the wild-type sequence reversed these abnormalities. Conjugational transfer experiments showed that the TD-SCV of E. coli with blaCTX-M-3 failed to transfer blaCTX-M-3 to E. coli CSH2. However, the TD-SCV of E. coli without blaCTX-M-3 experimentally received the plasmid encoding blaSHV-18 from Klebsiella pneumoniae ATCC 700603 and transferred it to E. coli CSH2.

CONCLUSION

Mutation in the thyA gene causes morphological abnormalities in the colonies and cells of E. coli, as well as inducing thymidine auxotrophy. In addition, TD-SCVs horizontally transmit plasmids encoding resistance genes. It is important to detect TD-SCVs based on their characteristics because they serve as reservoirs of transferable antibiotic resistance plasmids.