CD23+IgG1+ memory B cells are poised to switch to pathogenic IgE production in food allergy

Food allergy is caused by allergen-specific immunoglobulin E (IgE) antibodies, but little is known about the B cell memory of persistent IgE responses. Here, we describe, in human pediatric peanut allergy, a population of CD23+IgG1+ memory B cells arising in type 2 immune responses that contain high-affinity peanut-specific clones and generate IgE-producing cells upon activation. The frequency of CD23+IgG1+ memory B cells correlated with circulating concentrations of IgE in children with peanut allergy. A corresponding population of "type 2-marked" IgG1+ memory B cells was identified in single-cell RNA sequencing experiments. These cells differentially expressed interleukin-4 (IL-4)- and IL-13-regulated genes, such as FCER2/CD23+, IL4R, and germline IGHE, and carried highly mutated B cell receptors (BCRs). In children with high concentrations of serum peanut-specific IgE, high-affinity B cells that bind the main peanut allergen Ara h 2 mapped to the population of "type 2-marked" IgG1+ memory B cells and included clones with convergent BCRs across different individuals. Our findings indicate that CD23+IgG1+ memory B cells transcribing germline IGHE are a unique memory population containing precursors of high-affinity pathogenic IgE-producing cells that are likely to be involved in the long-term persistence of peanut allergy.

Organocatalyzed ring-opening reactions of γ-carbonyl-substituted ε-caprolactones

Side-chain-functionalized aliphatic polyesters are promising as functional biodegradable polymers. We have investigated ring-opening reactions of γ-carbonyl-substituted ε-caprolactones (gCCLs) to obtain poly(ε-caprolactone) (PCL) analogues. Organic catalysts and Sn(Oct)2 often used for the ring-opening polymerization (ROP) of ε-caprolactone (CL) have been explored to find the conditions for the formation of polymeric products of gCCLs. We confirmed the consumption of gCCLs in all catalyzed reactions. However, chain propagation hardly occurs, as the propagating species are preferentially transformed to α-substituted five-membered lactones when the substituents are linked by ester or not sterically hindered. Intramolecular cyclization to form thermodynamically stable five-membered lactones releases alcohols and amines, serving as nucleophiles for the subsequent ring opening of other gCCLs. Thus, apparent chain reactions are realized for continuous consumption of gCCLs. The reaction preference remains unchanged independent of the catalysts, although the reactions of the amide-linked gCCLs by acidic catalysts are slightly mitigated. Finally, copolymerization of CL and a gCCL catalyzed by diphenyl phosphate has been investigated, which enables the chain propagation reaction to yield the linear oligomers of PCL analogues containing up to 16 mol% of gCCL units. This study contributes to understanding the chemistry of ring-opening reactions of substituted lactones for designing functional degradable polymers.

Extracellular volume fraction using contrast-enhanced CT is useful in differentiating intrahepatic cholangiocellular carcinoma from hepatocellular carcinoma

Objectives

To evaluate whether tumor extracellular volume fraction (fECV) on contrast-enhanced computed tomography (CT) aids in the differentiation between intrahepatic cholangiocarcinoma (ICC) and hepatocellular carcinoma (HCC).

Methods

In this retrospective study, 113 patients with pathologically confirmed ICC (n = 39) or HCC (n = 74) who had undergone preoperative contrast-enhanced CT were enrolled. Enhancement values of the tumor (Etumor) and aorta (Eaorta) were obtained in the precontrast and equilibrium phase CT images. fECV was calculated using the following equation: fECV [%] = Etumor/Eaorta × (100 - hematocrit [%]). fECV values were compared between the ICC and HCC groups using Welch's t-test. The diagnostic performance of fECV for differentiating ICC and HCC was assessed using receiver-operating characteristic (ROC) analysis. fECV and the CT imaging features of tumors were evaluated by two radiologists. Multivariate logistic regression analysis was performed to identify factors predicting a diagnosis of ICC.

Results

Mean fECV was significantly higher in ICCs (43.8% ± 13.2%) than that in HCCs (31.6% ± 9.0%, p < 0.001). The area under the curve for differentiating ICC from HCC was 0.763 when the cutoff value of fECV was 41.5%. The multivariate analysis identified fECV (unit OR: 1.10; 95% CI: 1.01-1.21; p < 0.05), peripheral rim enhancement during the arterial phase (OR: 17.0; 95% CI: 1.29-225; p < 0.05), and absence of washout pattern (OR: 235; 95% CI: 14.03-3933; p < 0.001) as independent CT features for differentiating between the two tumor types.

Conclusions

A high value of fECV, peripheral rim enhancement during the arterial phase, and absence of washout pattern were independent factors in the differentiation of ICC from HCC.

Fusion of the molecular adjuvant C3d to cleavage-independent native-like HIV-1 Env trimers improves the elicited antibody response

An effective HIV vaccine likely requires the elicitation of neutralizing antibodies (NAbs) against multiple HIV-1 clades. The recently developed cleavage-independent native flexibly linked (NFL) envelope (Env) trimers exhibit well-ordered conformation and elicit autologous tier 2 NAbs in multiple animal models. Here, we investigated whether the fusion of molecular adjuvant C3d to the Env trimers can improve B- cell germinal center (GC) formation and antibody responses. To generate Env-C3d trimers, we performed a glycine-serine- based (G4S) flexible peptide linker screening and identified a linker range that allowed native folding. A 30-60- amino- acid- long linker facilitates Env-to-C3d association and achieves the secretion of well-ordered trimers and the structural integrity and functional integrity of Env and C3d. The fusion of C3d did not dramatically affect the antigenicity of the Env trimers and enhanced the ability of the Env trimers to engage and activate B cells in vitro. In mice, the fusion of C3d enhanced germinal center formation, the magnitude of Env-specific binding antibodies, and the avidity of the antibodies in the presence of an adjuvant. The Sigma Adjuvant System (SAS) did not affect the trimer integrity in vitro but contributed to altered immunogenicity in vivo, resulting in increased tier 1 neutralization, likely by increased exposure of variable region 3 (V3). Taken together, the results indicate that the fusion of the molecular adjuvant, C3d, to the Env trimers improves antibody responses and could be useful for Env-based vaccines against HIV.

The memory of pathogenic IgE is contained within CD23 + IgG1 + memory B cells poised to switch to IgE in food allergy

Food allergy is caused by allergen-specific IgE antibodies but little is known about the B cell memory of persistent IgE responses. Here we describe in human pediatric peanut allergy CD23 + IgG1 + memory B cells arising in type 2 responses that contain peanut specific clones and generate IgE cells on activation. These 'type2-marked' IgG1 + memory B cells differentially express IL-4/IL-13 regulated genes FCER2 / CD23, IL4R , and germline IGHE and carry highly mutated B cell receptors (BCRs). Further, high affinity memory B cells specific for the main peanut allergen Ara h 2 mapped to the population of 'type2-marked' IgG1 + memory B cells and included convergent BCRs across different individuals. Our findings indicate that CD23 + IgG1 + memory B cells transcribing germline IGHE are a unique memory population containing precursors of pathogenic IgE.

One-Sentence Summary

We describe a unique population of IgG + memory B cells poised to switch to IgE that contains high affinity allergen-specific clones in peanut allergy.

The influence of vulnerability on depression among Japanese university athletes

Objective

This study examined the estimated causal relationship between vulnerability and depressive symptoms in Japanese university athletes and how the degree of vulnerability affects depressive symptoms.

Materials and methods

In Study 1, 248 Japanese university athletes completed a continual survey from Time 1 to Time 3. In Study 2, 562 Japanese university athletes responded to another survey during the same period. Structural equation modeling was performed to estimate the causal relationship using the cross-lagged effects model for the three waves. Next, a binomial logistic regression analysis was performed to examine the influence of vulnerability on depression.

Results

Results of the cross-lagged effects model showed that all paths from vulnerability to depressive symptoms were significant, and all paths from depressive symptoms to vulnerability were not significant. Thus, vulnerability was the causative variable and depressive symptoms were the outcome variables within the causal relationship. The logistic regression results showed that those with high vulnerability were 1.7 times more likely to have moderate or higher depressive symptoms than those with low vulnerability. Vulnerable individuals are at a higher risk for developing depressive symptoms. By verifying the causal relationship between vulnerability and depressive symptoms, we can contribute to the enhancement of mental health care in accordance with the weakest link model. Appropriate psychological support for athletes can decrease depression and improve their mental health.

Concomitant left atrial appendage closure with left ventricular assist device surgery can reduce ischemic cerebrovascular accidents

Background

It remains unknown if concomitant left atrial appendage closure (LAAC) at the time of left ventricular assist device (LVAD) surgery can reduce ischemic cerebrovascular accidents.

Purpose

The purpose of this study is to assess the impact of LAAC at LVAD surgery on the incidence of ischemic cerebrovascular accidents.

Methods

Between January 2012 and November 2021, 310 patients underwent LVAD surgery with HeartMate II or III. Out of 310 patients, 98 patients (31.6%) underwent concomitant LAAC. The cohort was divided into two groups: patients with LAAC (Group A, n=98) and without LAAC (Group B, n=212). To minimize device bias, LVAD surgery with HeartWare HVAD device was excluded. The ischemic cerebrovascular accident was defined as ischemic stroke, hemorrhagic stroke or transient ischemic attack. We reviewed early and long-term clinical outcomes. The incidence of ischemic cerebrovascular accidents was compared between two groups using the Kaplan-Meier method. We also investigated if LAAC was associated with ischemic cerebrovascular accidents by Cox proportional hazards analysis.

Results

There were no significant differences in baseline characteristics between two groups including age (Group A: 55.0±12.3 years old, Group B: 56.9±14.1 years old, p=0.26), preoperative CHADS2 score (Group A: 2.40±1.1, Group B: 2.58±1.1, p=0.19) and history of atrial fibrillation (Group A: 42.9%, Group B: 42.5%, p=0.95). In-hospital mortality was not significantly different between the two groups (Group A: 7.1%, Group B: 12.3%, p=0.16). In terms of postoperative complications, there were no significant differences between two groups in requiring extracorporeal membrane oxygenation, re-exploration for bleeding and newly required hemodialysis. Median follow up period was 474 days. Thirty-five patients (11.2%) developed ischemic cerebrovascular accidents (5 patients in Group A and 30 patients in Group B). The rate of freedom from ischemic cerebrovascular accidents in Group A (94.1% at 500 days and 94.1% at 1500 days) was significantly higher than that in Group B (88.2% at 500 days and 77.4% at 1500 days; log rank=0.024). In a Cox proportional hazards regression analysis including LAAC, age, history of atrial fibrillation, diabetes mellitus and Heartmate 3 device implantation, LAAC was associated with reducing the incidence of ischemic cerebrovascular accidents (hazard ratio 0.37, 95% CI 0.13–0.89, p=0.02).

Conclusion

Concomitant LAAC at the time of LVAD surgery can reduce ischemic cerebrovascular accidents without increasing perioperative mortality and complications.

Funding Acknowledgement

Type of funding sources: None.

Klebsiella invasive liver abscess syndrome presenting with a central nervous system manifestation secondary to latent cholecystitis: a case report

Background

Brain abscess is a life-threatening event. Moreover, when Klebsiella pneumoniae is the cause, rapid diagnosis and appropriate treatment are required. Klebsiella invasive liver abscess syndrome, a bloodstream metastatic infection of potentially aggressive nature, has been recognized to cause infection in the central nervous system, and concern for Klebsiella liver abscess syndrome is increasing globally.

Case presentation

A 73-year-old Japanese woman was admitted to the institution complaining of aggravated dysarthria and weakness in the right upper extremities with onset 5 days earlier. Magnetic resonance imaging revealed a brain abscess in the left basal ganglia, and abdominal computed tomography revealed a liver abscess in liver segment 7. The patient’s dysarthria symptoms became increasingly worse over the next few days, so surgical drainage via frontotemporal craniotomy was performed on admission day 3, and subsequent culture from the brain abscess showed growth of Klebsiella pneumoniae. On admission day 9, percutaneous transhepatic drainage of the liver segment 7 abscess was undertaken. The pus culture also showed growth of Klebsiella pneumoniae, thus associating the liver abscess with the brain abscess. Following long-term conservative treatment with antibiotics and abscess drainage, the liver abscess disappeared. However, the patient continuously presented with right upper quadrant pain, and abdominal computed tomography showed swelling of the gallbladder. Consequently, percutaneous transhepatic gallbladder drainage was initially administered, and the bile culture was also positive for Klebsiella pneumoniae. For radical treatment, a laparoscopic cholecystectomy was performed on admission day 99. The postoperative period was complicated by an intraabdominal abscess; however, conservative therapy was successful. She was subsequently discharged, and 12-month follow-up revealed no further sequelae.

Conclusions

We describe a rare case of Klebsiella liver abscess syndrome, which first presented with a central nervous system manifestation. Our patient was successfully treated via an early surgical intervention and subsequent antibiotic therapy. Although surgical drainage remains the cornerstone treatment for brain abscess, when a brain abscess is found, and there is a high index of suspicion for the existence of a liver abscess, Klebsiella liver abscess syndrome should be considered as a possible diagnosis.

Water-soluble dietary fiber alleviates cancer-induced muscle wasting through changes in gut microenvironment in mice

Cancer cachexia and the associated skeletal muscle wasting are considered poor prognostic factors, although effective treatment has not yet been established. Recent studies have indicated that the pathogenesis of skeletal muscle loss may involve dysbiosis of the gut microbiota and the accompanying chronic inflammation or altered metabolism. In this study, we evaluated the possible effects of modifying the gut microenvironment with partially hydrolyzed guar gum (PHGG), a soluble dietary fiber, on cancer‐related muscle wasting and its mechanism using a colon‐26 murine cachexia model. Compared with a fiber‐free (FF) diet, PHGG contained fiber‐rich (FR) diet–attenuated skeletal muscle loss in cachectic mice by suppressing the elevation of the major muscle‐specific ubiquitin ligases Atrogin‐1 and MuRF1, as well as the autophagy markers LC3 and Bnip3. Although tight‐junction markers were partially reduced in both FR and FF diet–fed cachectic mice, the abundance of Bifidobacterium, Akkermansia, and unclassified S24‐7 family increased by FR diet, contributing to the retention of the colonic mucus layer. The reinforcement of the gut barrier function resulted in the controlled entry of pathogens into the host system and reduced circulating levels of lipopolysaccharide‐binding protein (LBP) and IL‐6, which in turn led to the suppression of proteolysis by downregulating the ubiquitin‐proteasome system and autophagy pathway. These results suggest that dietary fiber may have the potential to alleviate skeletal muscle loss in cancer cachexia, providing new insights for developing effective strategies in the future.

The first case of SMARCA4-deficient sarcoma of stomach

SMARCA4-deficient sarcoma was first reported in the chest and recently in the uterus, but not in the stomach. Here, we present a patient diagnosed with SMARCA4-deficient sarcoma of the stomach, using histochemistry. An emergency operation was performed due to perforation of the tumor. However, one month after the operation, two nodes recurred, and six cycles of combination chemotherapy consisting of adriamycin and ifosfamide were administered. The combination chemotherapy showed a remarkable effect, and complete remission was achieved. The patient was alive without recurrence after 48-month follow-up. SMARCA4-deficient sarcoma is an exceedingly rare tumor with an extremely poor therapeutic response to anticancer drugs. Herein, we present the first case of SMARCA4-deficient sarcoma of the stomach, where a complete response to chemotherapy was achieved.

Intracardiac device associated interference with tricuspid valve apparatus on echocardiography: What can we learn from pathology?

Funding Acknowledgements

Type of funding sources: None.

Background

 New or worsening tricuspid regurgitation (TR) is associated with right-sided heart failure and worsened outcomes. Cardiac Implantable Electronic Devices (CIEDs), which are being implanted at growing rates worldwide, are increasingly being recognized as associated with TR occurrence related to interference with the tricuspid valve (TV) apparatus. Purpose: We sought to identify echocardiographic features in the right ventricle and TV that differentiate patients who have anatomically demonstrated interference with the TV on direct pathology inspection. 

Methods

 Explanted hearts from 44 consecutive patients undergoing orthotopic heart transplant (55 ±13 yrs, 68% men) with known implanted CIEDs were dissected to assess the presence (n = 18) or absence (n = 26) of CIED interference with the TV (Figure). Echocardiographic measurements performed prior to transplantation, including left and right ventricular (LV, RV) size and performance metrics as well as TR severity, were compared between both groups using non-parametric testing. 

Results

 Echocardiographic features of patients with and without anatomically demonstrated TV interference are shown in the Table. Although overall LV dimensions and volumes were not different between the two groups and LV ejection fraction was severely reduced in both groups, patients demonstrating CIED interference trended towards larger right atrial volumes (Table) and also larger RV and tricuspid annular sizes. Importantly, however, they were more than 4 times likely to have abnormal right ventricular function. Lastly, patients with tricuspid apparatus interference tended to have more significant TR, although these differences have not reached statistical significance (Table). 

Conclusion

 CIED interreference with tricuspid valve apparatus occurs frequently (41%) among patients with CIEDs, who undergo orthotopic heart transplantation. This may be associated with worsening TV function with subsequent changes in right atrial and ventricular geometry and function. In light of prior data showing poor outcomes with CIED associated TR, this study emphasizes the importance of non-invasive assessment of CIED interference with the tricuspid valve, in order to improve device placement and patient outcomes. Abstract Figure  Abstract Table

Treatment with broad-spectrum antibiotics upregulates Sglt1 and induces small intestinal villous hyperplasia in mice

Although extensive evidence indicates that the gut microbiota plays a crucial role in regulating glucose homeostasis, the exact regulatory mechanism remains unclear. This study aimed to investigate the effect of broad-spectrum antibiotics on the expression of glucose transporters, histomorphology of the small intestine, and glucose metabolism in mice. C57BL/6 mice were administered drinking water with or without a broad-spectrum antibiotic combination for 4 weeks. Thereafter, an oral glucose tolerance test was performed. Body weight, small intestine histopathology, mRNA levels of glucose transporters (SGLT1 and GLUT2) and intestinal transcription factors (CDX1 and CDX2) were evaluated. SGLT1 and CDX1 were upregulated in the small intestine upon antibiotic administration compared with that in the control group. The height and surface area of the jejunal villi were significantly higher upon antibiotic administration than in the control group. Fasting glucose levels were significantly higher upon antibiotic administration than in the control group. The present results indicate that treatment with broad-spectrum antibiotics upregulates SGLT1 and CDX1 and induces hyperplasia in the small intestine, thus increasing fasting blood glucose levels. Our results further the current understanding of the effects of broad-spectrum antibiotics on the gut microbiota and glucose homeostasis that may have future clinical implications.

Design of microfluidic channels to prevent negative filtration in implantable hemofiltration devices

In order to improve the quality of life of dialysis patients, our group have been developing an implantable hemofiltration device (IHFD) composed of multiple layers of dialysis membranes and microfluidic channels. To improve the hemodialysis performance of IHFD, preventing the negative filtration, which is caused by the oncotic pressure of blood, is mandatory. In this study, we fabricated IHFDs with five different microchannel designs and experimentally investigated the performance of each device in in vitro experiment. In addition, the successful IHFD was further evaluated by ex vivo experiments with a beagle dog. The experiments verified the effectiveness of the microchannel design, which will be used for the IHFD for in vivo experiments with pigs in the future.

The efficacy and safety of dupilumab in Chinese patients with moderate-to-severe atopic dermatitis: a randomized, double-blind, placebo-controlled study

BACKGROUND

Dupilumab is an antibody against interleukin 4 receptor α, used in treating atopic dermatitis (AD).

OBJECTIVES

To evaluate the efficacy and safety of dupilumab in adult Chinese patients with moderate-to-severe AD.

METHODS

In this randomized, double-blind, placebo-controlled, parallel-group, phase III study, conducted between December 2018 and February 2020, patients with AD received dupilumab (300mg) or placebo once every 2 weeks for 16 weeks, and were followed up for 12 weeks. The primary efficacy endpoint was the proportion of patients with both Investigator's Global Assessment (IGA) score of 0-1 and a reduction from baseline of ≥2 points at week 16.

RESULTS

Overall, 165 patients (mean age: 30.6 years; 71.5% male) were randomized: 82 to dupilumab and 83 to placebo. At week 16, 26.8% of patients in the dupilumab group and 4.8% of patients in the placebo group achieved the primary endpoint (difference, 22.0%; 95% confidence interval [CI], 11.37-32.65%; p<0.0001). Compared with placebo, higher proportions of patients in the dupilumab group achieved ≥75% reduction in the Eczema Area and Severity Index score (57.3% vs 14.5%; difference, 42.9%; 95% CI, 29.75-55.97%; p<0.0001) and had ≥3-point (52.4% vs 9.6%; difference, 42.8%; 95% CI, 30.26-55.34%; p<0.0001) and ≥4-point (39.0% vs 4.8%; difference, 34.2%; 95% CI, 22.69-45.72%; p<0.0001) reductions in weekly average daily peak daily pruritus numerical rating scale scores. The incidence of TEAEs during the treatment period was similar in the two groups. The incidence of conjunctivitis, allergic conjunctivitis, and injection site reaction was higher in the dupilumab group than in the placebo group.

CONCLUSIONS

In adult Chinese patients, dupilumab was effective in improving the signs and symptoms of AD and demonstrated a favorable safety profile.

Effects of L-Menthol and Carbon Dioxide on the Adenoma Detection Rate during Colonoscopy: L-Menthol and Carbon Dioxide on Colonoscopy

BACKGROUND AND AIMS

We examined the efficacy of the combined use of L-menthol spraying (L-mentholS) as an antispasmodic agent and carbon dioxide insufflation (CO2I) on the adenoma detection rate (ADR) in a prospective, single-center trial with a 2 × 2 factorial design.

METHODS

We randomly assigned 611 patients scheduled to undergo colonoscopy to 4 groups: (1) the L-mentholS + CO2I (n = 153), (2) L-mentholS + air insufflation (AI; n = 156), (3) CO2I (n = 153), and (4) AI (n = 149) groups. We used 20 mL of 0.8%-L-menthol solution for the L-mentholS. The primary outcome was the difference in the ADR, and the secondary outcomes were the differences in colonic peristalsis and abdominal pain. -Results: The ADRs were not different among the groups: 1/2/3/4; 39.9%/43.6%/41.2%/51.0%. CO2I was associated with a significant decrease in the ADR (OR 0.57; 95% CI 0.35- 0.93) with a multiple logistic regression. The interaction between L-mentholS and CO2I was associated with a suppression of the decrease in the ADR. Both L-mentholS and CO2I were associated with a significant decrease in abdominal pain, and L-mentholS was associated with a significant improvement of peristalsis.

CONCLUSIONS

The fact that CO2I was associated with significant decreases in the ADR was a problem. The combined use of L-mentholS and CO2I could help to suppress the decrease in the ADR.

Sequentially addressable dielectrophoretic array for high-throughput sorting of large-volume biological compartments

Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.

Metformin inhibits TGF‑β1‑induced epithelial‑mesenchymal transition and liver metastasis of pancreatic cancer cells

Epithelial‑mesenchymal transition (EMT) is considered a crucial event in the development of cancer metastasis. Metformin is a drug used in the treatment of type 2 diabetes. Recently, increasing evidence has indicated that metformin possesses anti‑tumor activities. However, the effects of metformin on EMT and metastases in pancreatic cancer remain unknown. Thus, the present study investigated whether metformin inhibits EMT of human pancreatic cancer cell lines. Pancreatic cancer cells were stimulated with transforming growth factor β1 (TGF‑β1), an activator of EMT signaling, with or without metformin. After 48 h, the levels of epithelial and mesenchymal markers were evaluated by western blot analysis, immunocytochemistry and RT‑qPCR. Cancer cell migration was evaluated by an in vitro wound healing assay. The cells stimulated with TGF‑β1 acquired an elongated and fusiform morphology, which was inhibited by metformin. The wound healing assay revealed that metformin significantly suppressed the TGF‑β1‑stimulated migration of pancreatic cancer cells. Following treatment with metformin, E‑cadherin expression (epithelial marker) was upregulated, and the levels of mesenchymal markers were downregulated, which had been increased by TGF‑β1 in these cells. Exposure of the cells to TGF‑β1 activated the Smad2/3 and Akt/mammalian target of rapamycin (mTOR) pathways, and this effect was inhibited by metformin, suggesting that metformin inhibits TGF‑β1‑induced‑EMT through the down‑regulation of the Smad pathway in PANC‑1 cells and the downregulation of the Akt/mTOR pathway in BxPC‑3 cells. In an animal model of surgical orthotopic implantation, metformin inhibited liver metastasis without a significant reduction in the size of the primary pancreatic tumor. On the whole, the findings of the present study suggest that metformin inhibits EMT and cancer metastasis through the Smad or Akt/mTOR pathway.

P224 Valvuloplasty treatment and three-dimensional analysis for isolated cleft of the anterior mitral valve leaflet: a case report

Introduction: Isolated cleft of the anterior mitral valve leaflet is a very rare congenital disease and a cause of mitral regurgitation

not associated with atrioventricular septal defect. In this case, we report our experience in valvuloplasty treatment for mitral regurgitation with this rare aetiology.

Case description

23-year-old Russian women. Although cardiac murmur was pointed out in her childhood and she was diagnosed as mitral regurgitation, she refused treatment. After getting married with a Japanese man and moving to Japan, her symptoms had worsened and she visited our hospital for treatment. Preoperative transthoracic echocardiography (TTE) had indicated the regurgitation from the central part of the mitral valve. Preoperative transoesophageal echocardiography (TOE) had pointed out the isolated cleft of the anterior mitral valve.

Surgical mitral valvuloplasty was scheduled, and the TOE after anaesthetic induction showed the isolated cleft of the anterior mitral valve the same as in the preoperative period and pointed out the posterior leaflet billowing. The operative finding was also similar to TOE: the largely bisected central anterior mitral valve and billowing, P2 billowing, shortening of P1 and P3, P2-3 cleft. There were no chords at the anterior cleft. The valvuloplasty was performed including five-time pump runs in total: 1) Continuous suture for the anterior cleft and ring annuloplasty were performed, and the regurgitation was seemed to be almost controlled at the water-leak test and the ink test; 2) Artificial chordae and leaflet plications were added to residual regurgitation from the posterior region; 3)The residual regurgitation was controlled to Mild but it became a lateral jet toward the ring; 4)Mild remnant flow was pointed out: the regurgitation seemed to be from the posterior cleft, where immediately below the ring suture; 5) Pericardium patch was added and the remnant flow was almost eliminated. The pump was weaned and the operation was finished without any problems.

Discussion

The cause of difficulty in this valvuloplasty was thought to be caused by the difficulty in evaluating the mitral valve morphology. It was evident that the anterior leaflet of the mitral valve was largely bisected. However, it was difficult to evaluate the coaptation line and area due to the absence of chordal cords in the anterior cleft and the billowing or shortening of the posterior leaflet. Although preoperative three-dimensional analysis helped evaluating the isolated cleft and the regurgitation was almost controlled in the evaluation in the operation field, nevertheless, a residual regurgitation occurred and indicated in the TOE after re-beating.

Conclusion

It is important and necessary to use fine evaluation of coaptation is needed in valvuloplasty for isolated cleft of the anterior mitral valve leaflet; not only apply three-dimensional analysis but also apply two-dimensional echocardiogram.

Abstract P224 Figure.

P662 Synchrony between the right and left heart systems is recovered after TAVI in patients with severe aortic stenosis

Funding Acknowledgements

Young Investigator Grant of Japanese Society of Cardiovascular Anesthesia

Background / Introduction

Evidences have shown that cardiac function decline and systolic phase change are caused by massive afterload of the stenosed aortic valve in patients with severe aortic valve stenosis. As a result of the reduction of the left ventricular afterload by valve replacement, the cardiac function recovers. However, it has not been clarified yet how the changes in cardiac function affect the relationship between the right and left heart systems, as well as the systole phase.

TAPSE and MAPSE are known as indices of simple cardiac function evaluation by measuring the movement distance of the atrioventricular annulus. We obtained these indices (i.e. TAPSE, MAPSE) within the same heartbeat using speckle tracking analysis of the atrioventricular annulus and evaluated the changes in cardiac function and phase between the right and left heart systems.

Purpose

To reveal the relationship of cardiac function and time phase between the right and left heart systems by evaluating the maximum movement distance and time of the atrioventricular annulus within the same heartbeat and the same view in patients with severe aortic valve stenosis before and after TAVI.

Methods

A prospective cohort study was conducted. We recruited and analyzed 44 patients with severe aortic valve stenosis who received TAVI treatment, able to record baseline before treatment and follow-up 6 months and 12 months after treatment at our hospital from March 2017 to May 2019. Patients were excluded if more than 2 degree of atrioventricular valve regurgitation or incomplete data. The apical four-chamber view was used for speckle tracking analysis with the origin of the apical extension and region of interest (ROI) of the mitral annulus and tricuspid annulus. For each patient before treatment, at 6 months and 12 months after treatment, the maximum contraction distance (DM), maximum contraction time (TM) of the mitral valve annulus, maximum contraction distance (DT) and maximum contraction time (TT) of the tricuspid annulus were measured. Maximum contraction distance ratio (DM/ DT) and maximum contraction time ratio (TM/ TT) were calculated. For statistical analysis, t-test and ANOVA were used, and a significance threshold of p &lt;0.05 was applied.

Results

TM/ TT decreased at 12 months after TAVI, and DM/ DT increased significantly at 6 months and 12 months after TAVI when compared to baseline before treatment.

Conclusions

In patients with severe aortic valve stenosis, the correction of cardiac function difference between the right and left heart systems occurs from 6 months after TAVI. Moreover, the correction of contraction phase difference between the right and left heart systems at 12 months after TAVI. Thus, the synchrony between the right and left heart system is recovered 12 months after TAVI.

Abstract P662 Figure.