Molecular basis of host plant recognition by silkworm larvae

Herbivorous insects can identify their host plants by sensing plant secondary metabolites as chemical cues. We previously reported the two-factor host acceptance system of the silkworm Bombyx mori larvae. The chemosensory neurons in the maxillary palp (MP) of the larvae detect mulberry secondary metabolites, chlorogenic acid (CGA), and isoquercetin (ISQ), with ultrahigh sensitivity, for host plant recognition and feeding initiation. Nevertheless, the molecular basis for the ultrasensitive sensing of these compounds remains unknown. In this study, we demonstrated that two gustatory receptors (Grs), BmGr6 and BmGr9, are responsible for sensing the mulberry compounds with attomolar sensitivity for host plant recognition by silkworm larvae. Calcium imaging assay using cultured cells expressing the silkworm putative sugar receptors (BmGr4-10) revealed that BmGr6 and BmGr9 serve as receptors for CGA and ISQ with attomolar sensitivity in human embryonic kidney 293T cells. CRISPR/Cas9-mediated knockout (KO) of BmGr6 and BmGr9 resulted in a low probability of making a test bite of the mulberry leaves, suggesting that they lost the ability to recognize host leaves. Electrophysiological recordings showed that the loss of host recognition ability in the Gr-KO strains was due to a drastic decrease in MP sensitivity toward ISQ in BmGr6-KO larvae and toward CGA and ISQ in BmGr9-KO larvae. Our findings have revealed that the two Grs, previously considered to be sugar receptors, are molecules responsible for detecting plant phenolics in host plant recognition.

Dietary compounds activate an insect gustatory receptor on enteroendocrine cells to elicit myosuppressin secretion

Sensing of midgut internal contents is important for ensuring appropriate hormonal response and digestion following the ingestion of dietary components. Studies in mammals have demonstrated that taste receptors (TRs), a subgroup of G protein-coupled receptors (GPCRs), are expressed in gut enteroendocrine cells (EECs) to sense dietary compounds and regulate the production and/or secretion of peptide hormones. Although progress has been made in identifying expression patterns of gustatory receptors (GRs) in gut EECs, it is currently unknown whether these receptors, which act as ligand-gated ion channels, serve similar functions as mammalian GPCR TRs to elicit hormone production and/or secretion. A Bombyx mori Gr, BmGr6, has been demonstrated to express in cells by oral sensory organs, midgut and nervous system; and to sense isoquercitrin and chlorogenic acid, which are non-nutritional secondary metabolites of host mulberry. Here, we show that BmGr6 co-expresses with Bommo-myosuppressin (BMS) in midgut EECs, responds to dietary compounds and is involved in regulation of BMS secretion. The presence of dietary compounds in midgut lumen after food intake resulted in an increase of BMS secretions in hemolymph of both wild-type and BmGr9 knockout larvae, but BMS secretions in BmGr6 knockout larvae decreased relative to wild-type. In addition, loss of BmGr6 led to a significant decrease in weight gain, excrement, hemolymph carbohydrates levels and hemolymph lipid levels. Interestingly, although BMS is produced in both midgut EECs and brain neurosecretory cells (NSCs), BMS levels in tissue extracts suggested that the increase in hemolymph BMS during feeding conditions is primarily due to secretion from midgut EECs. Our studies indicate that BmGr6 expressed in midgut EECs responds to the presence of dietary compounds in the lumen by eliciting BMS secretion in B. mori larvae.

Efficacy and safety of pemafibrate versus bezafibrate in coronary artery disease patients receiving statin treatment: a randomized, open-label, cross-over study

Background

Fibrates activate peroxisome proliferator-activated receptor (PPAR)-α which is associated with lipid metabolism. Bezafibrate is a non-selective PPAR-α agonist, whereas pemafibrate has been developed as a higher selective PPAR-α agonist.

Objective

The efficacy and safety of pemafibrate for 24-week in patients with dyslipidemia was examined in comparison with bezafibrate.

Methods

Sixty patients with hypertriglyceridemia (fasting triglyceride (TG) level of ≥150 mg/dL) were treated with pemafibrate of 0.2 mg/day or bezafibrate of 400 mg/day for 24-week in a randomized cross-over study. Percent change from baseline in TG levels was the primary endpoint, and that in HDL-C and apolipoprotein A-I (Apo A-I) levels was the secondary endpoints.

Results

A significantly greater reduction in TG percent change was observed in pemafibrate than in bezafibrate (−46.1% vs. −34.7%, p<0.001). There was no significant difference in HDL-C percent change between pemafibrate and bezafibrate (18.4% vs. 14.0%, p=0.067), whereas Apo A-I percent change was significantly greater in pemafibrate than in bezafibrate (9.2% vs. 5.7%, p=0.018). Pemafibrate and bezafibrate significantly decreased alanine aminotransferase (ALT) and gamma-glutamyltransferase (γ-GT) levels, and pemafibrate showed a greater reduction than bezafibrate (ALT: −21.9% vs. −10.6%, p=0.048; γ-GT: −43.5% vs. −33.1%, p=0.025). Creatinine levels significantly increased in both treatments (both p<0.001), however, creatinine percent change was significantly smaller in pemafibrate than in bezafibrate (5.72% vs. 15.5%, p<0.001). There was no difference in frequency of adverse event (AE) or serious AE between two treatments, but frequency of creatinine elevation (≥0.5 mg/d and/or 25%) was significantly higher in bezafibrate than in pemafibrate (16/60 vs. 3/60, p=0.004).

Conclusion

As compared with bezafibrate, pemafibrate is more effective to reduce TG levels and to elevate Apo A-I levels, and it is safer in terms of liver and renal function.

Funding Acknowledgement

Type of funding sources: None.

Molecular and Kinetic Models for Pore Formation of Bacillus thuringiensis Cry Toxin

Cry proteins from Bacillus thuringiensis (Bt) and other bacteria are pesticidal pore-forming toxins. Since 2010, when the ABC transporter C2 (ABCC2) was identified as a Cry1Ac protein resistant gene, our understanding of the mode of action of Cry protein has progressed substantially. ABCC2 mediates high Cry1A toxicity because of its high activity for helping pore formation. With the discovery of ABCC2, the classical killing model based on pore formation and osmotic lysis became nearly conclusive. Nevertheless, we are still far from a complete understanding of how Cry proteins form pores in the cell membrane through interactions with their host gut membrane proteins, known as receptors. Why does ABCC2 mediate pore formation with high efficiency unlike other Cry1A-binding proteins? Is the “prepore” formation indispensable for pore formation? What is the mechanism underlying the synergism between ABCC2 and the 12-cadherin domain protein? We examine potential mechanisms of pore formation via receptor interactions in this paper by merging findings from prior studies on the Cry mode of action before and after the discovery of ABC transporters as Cry protein receptors. We also attempt to explain Cry toxicity using Cry–receptor binding affinities, which successfully predicts actual Cry toxicity toward cultured cells coexpressing ABC transporters and cadherin.

OP0112 THE EVER-LARGEST ASIAN GWAS FOR SYSTEMIC SCLEROSIS AND TRANS-POPULATION META-ANALYSIS IDENTIFIED SEVEN NOVEL LOCI AND A CANDIDATE CAUSAL SNP IN A CIS-REGULATORY ELEMENT OF THE FCGR REGION

Background

Genome-wide association studies (GWASs) have identified 29 disease-associated single nucleotide polymorphisms (SNPs) for systemic sclerosis (SSc) in non-human leukocyte antigen (HLA) regions (1-7). While these GWASs have clarified genetic architectures of SSc, study subjects were mainly Caucasians limiting application of the findings to Asians.

Objectives

The study was conducted to identify novel causal variants for SSc specific to Japanese subjects as well as those shared with European population. We also aimed to clarify mechanistic effects of the variants on pathogenesis of SSc.

Methods

A total of 114,108 subjects comprising 1,499 cases and 112,609 controls were enrolled in the two-staged study leading to the ever-largest Asian GWAS for SSc. After applying a strict quality control both for genotype and samples, imputation was conducted using the reference panel of the phase 3v5 1,000 genome project data combined with a high-depth whole-genome sequence data of 3,256 Japanese subjects. We conducted logistic regression analyses and also combined the Japanese GWAS results with those of Europeans (6) by an inverse-variance fixed-effect model. Polygenicity and enrichment of functional annotations were evaluated by linkage disequilibrium score regression (LDSC), Haploreg and IMPACT programs. We also constructed polygenic risk score (PRS) to predict SSc development.

Results

We identified three (FCRLA-FCGR, TNFAIP3, PLD4) and four (EOMES, ESR1, SLC12A5, TPI1P2) novel loci in Japanese GWAS and a trans-population meta-analysis, respectively. One of Japanese novel risk SNPs, rs6697139, located within FCGR gene clusters had a strong effect size (OR 2.05, P=4.9×10-11). We also found the complete LD variant, rs10917688, was positioned in cis-regulatory element and binding motif for an immunomodulatory transcription factor IRF8 in B cells, another genome-wide significant locus in our trans-ethnic meta-analysis and the previous European GWAS. Notably, the association of risk allele of rs10917688 was significant only in the presence of the risk allele of the IRF8. Intriguingly, rs10917688 was annotated as one enhancer-related histone marks, H3K4me1, in B cells, implying that FCGR gene(s) in B cells may play an important role in the pathogenesis of SSc. Furhtermore, significant heritability enrichment of active histone marks and a transcription factor C-Myc were found in B cells both in European and Japanese populations by LDSC and IMPACT, highlighting a possibility of a shared disease mechanism where abnormal B-cell activation may be one of the key drivers for the disease development. Finally, PRS using effects sizes of European GWAS moderately fit in the development of Japanese SSc (AUC 0.593), paving a path to personalized medicine for SSc.

Conclusion

Our study identified seven novel susceptibility loci in SSc. Downstream analyses highlighted a novel disease mechanism of SSc where an interactive role of FCGR gene(s) and IRF8 may accelerate the disease development and B cells may play a key role on the pathogenesis of SSc.

References

[1]F. C. Arnett et al. Ann Rheum Dis, 2010.

[2]T. R. Radstake et al. Nat Genet, 2010.

[3]Y. Allanore et al. PLoS Genet, 2011.

[4]O. Gorlova et al. PLoS Genet, 2011.

[5]C. Terao et al. Ann Rheum Dis, 2017.

[6]E. López-Isac et al. Nat Commun, 2019.

[7]W. Pu et al. J Invest Dermatol, 2021.

Disclosure of Interests

None declared

The orthostatic hypotension in patients with Stanford type A aortic dissection after surgery

Funding Acknowledgements

Type of funding sources: None.

Background

Orthostatic hypotension (OH) is sometimes observed during cardiac rehabilitation in patients with surgery for aortic dissection. However, little is known about the primary determinant of OH and influence of surgical range on incidence of OH.

Purpose

The aim of this study was to elucidate the incidence of OH in patients with surgery for aortic dissection, and compare it between the patients with ascending aortic replacement surgery (ascending group) and those with ascending aorta and hemiarch or total arch replacement surgery (arch group).

Methods

We analyzed 59 patients who underwent emergent surgery due to Stanford type A aortic dissection from January 2014 to March 2018, and compared the incidence of OH between ascending group (n = 28, age 69.8 ± 11.3 years) and arch group (n = 31, age 64.1 ± 13.0 years).

Results

The incidence of OH in total patients was 30.5%. There were no significant differences in patient characteristics including body tall, body weight, antihypertensive use and progress of rehabilitation between 2 groups. The arch group showed a significant higher incidence of OH as compared with ascending group (arch group: 46.4% vs. ascending group: 16.1%, p = 0.03). Moreover, the patients who occurred OH were significantly taller than those who did not occur OH.

Conclusions

OH was observed in about one third of patients with surgery for aortic dissection and it showed a close relationship with patient’s height and the range repaired by surgical operation. More careful cardiac rehabilitation is needed for tall patients with large area replacement of aorta.

Association of Pharmacist-led Deprescribing Intervention with the Functional Recovery in Convalescent Setting

So far, no studies investigated the association between pharmacist intervention and rehabilitation outcomes. The aim of study was to establish whether the pharmacist-led deprescribing intervention affects rehabilitation outcomes. This retrospective, observational, single-center, cohort study included consecutive geriatric patients (n = 448) with pharmacist-led intervention between 2017 and 2019. Participants were divided based on pharmacist-led deprescribing and non deprescribing interventions during hospitalization. Demographic data, laboratory data, the Functional Independence Measure were (FIM) analyzed between the groups. Multiple linear regression analysis was performed to analyze the relationship between pharmacist-led deprescribing and FIM total gain. The primary outcome was FIM total gain. The rate of pharmacist intervention during the study period was 92.4%. A multiple linear regression analysis of FMI-T gain, adjusting for confounding factors, revealed that the pharmacist-led deprescribing intervention was independently correlated with FMI-T gain. Particularly, the use of dyslipidemia drugs, antipsychotic drugs, hypnotics, and nonsteroidal anti-inflammatory drugs significantly decreased during hospitalization. The pharmacist-led deprescribing intervention was independently and significantly associated with FIM-T gain. The pharmacist-led deprescribing intervention improved functional recovery in a rehabilitation setting.

Ivermectin represses Wnt/β-catenin signaling by binding to TELO2, a regulator of phosphatidylinositol 3-kinase-related kinases

Ivermectin (IVM), an avermectin-derivative anthelmintic, specifically binds to glutamate-gated chloride ion channels (GluCls), causing paralysis in invertebrates. IVM also exhibits other biological activities such as Wnt/β-catenin pathway inhibition in vertebrates that do not possess GluCls. This study showed that affinity purification using immobilized IVM B1a isolated TELO2, a cofactor of phosphatidylinositol 3-kinase-related kinases (PIKKs), as a specific IVM B1a-binding protein. TELO2 knockdown reduced cytoplasmic β-catenin and the transcriptional activation of β-catenin/TCF. IVM B1a bound to TELO2 through the C-terminal α-helix, in which mutations conferred IVM resistance. IVM reduced the TELO2 and PIKK protein levels and the AKT and S6 kinase phosphorylation levels. The inhibition of mTOR kinase reduced the cytoplasmic β-catenin level. Therefore, IVM binds to TELO2, inhibiting PIKKs and reducing the cytoplasmic β-catenin level. In conclusion, our data indicate TELO2 as a druggable target for human diseases involving abnormalities of the Wnt/β-catenin pathway and PIKKs, including mTOR.

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Ivermectin is a chemical suppressor of the eyeless phenotype in zebrafish embryos

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Ivermectin physically interacts with TELO2

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TELO2 mediates Wnt/β-catenin signaling inhibition by ivermectin

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Ivermectin reduces the PIKK protein levels and downstream signaling

Comparison of clinical effect of living alone between urban area and rural area in patient with acute coronary syndrome

Background and objective

Living alone is reported as an independent risk factor for worse clinical outcomes after percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS). Manifestations of psychological stress such as depression and anxiety in patients living alone is thought to be associated with subsequent cardiovascular events. The impact of living alone on the psychological factors of patients may be differ depending on their living environment. However, comparison of the effects of living alone in different living environment on the prognosis of patients with ACS has not been reported.

Purpose

The aim of the present study was to compare the clinical effect of living alone on clinical outcomes in patients with ACS between urban area and rural area.

Methods

Data from a multi-center, observational study of consecutive patients who underwent emergency PCI for ACS between January 2012 and December 2016 were analyzed. The primary endpoint was major adverse cardiac and cerebrovascular events (MACCE). MACCE was defined as composite of cardiovascular death, ACS, and stroke.

Results

In this study, 1349 patients were enrolled and divided into two population according to their living environment: urban area population (n=417), and rural area population (n=932). In urban area population, 87 patients (20.9%) were living alone, and 330 (79.1%) were living together. In rural area population, 169 (18.1%) were living alone, and 763 (81.9%) were living together. There are no significant differences in baseline characteristics between the living alone group and the living together group in both urban area population and rural area population. During a median follow-up period of 2.1 years, Kaplan-Meier curves showed the living alone group had higher risk of MACCE than the living together group in urban area population (log-rank, p=0.01). On the other hands, there are no significant differences in the incidences of MACCE between two groups in rural area population (p=0.86). After adjustment for other covariates, the living alone was significantly associated with MACCE (hazard ratio [HR], 2.83; 95% confidential interval [CI], 1.16–6.91; p=0.02) compared with the living together group in urban area population. However, in rural area population, the living alone group was not significantly associated with MACCE (HR, 1.02; 95% CI, 0.66–1.57; p=0.92) compared with the living together group.

Conclusion

Living alone was significantly associated with worse clinical outcomes after emergency PCI of ACS in urban area but not in rural area.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Comparison of clinical outcomes between percutaneous coronary intervention for the de novo lesion versus in-stent restenosis lesion

Background and objective

Percutaneous coronary intervention (PCI) with metallic coronary stent (bare-metal stents [BMS] and drug-eluting stents [DES]) implantation is most frequently performed therapeutic procedures for coronary artery disease. In-stent restenosis (ISR) is a critical drawback of metallic coronary stents. Incidence of ISR has been reported in up to 30% after BMS implantation. The use of DES has greatly reduced the proportion of restenosis compared with the BMS. However, ISR still remains the primary concern after PCI even in the contemporary DES era, and thought to be associated with worse clinical outcomes. However, comparative data on ISR and de novo lesions are rare.

Purpose

The aim of the present study was to compare the clinical outcomes after PCI for the de novo lesion and the ISR lesion.

Methods

We performed a retrospective analysis of patients who underwent PCI between 2013 and 2020. The incidences of major adverse cardiac and cerebrovascular events (MACCE) and all-cause death were evaluated. MACCE was defined as composite of cardiovascular death, non-fatal myocardial infarction, and stroke.

Results

In this study, 1538 patients were enrolled and divided into two groups: PCI for de novo lesion group (n=1258, 81.8%), and PCI for ISR lesion group (n=280, 18.2%). Patients in the ISR lesion group were significantly older and had higher prevalence of hypertension, diabetes mellitus, dyslipidemia and chronic kidney disease than patients in the de novo lesion group. During a median follow-up period of 1.9 years, Kaplan-Meier curves showed no significant differences in the incidences of MACCE (log-rank, p=0.86) and all-cause death (p=0.84) between two groups. After adjustment for other covariates, PCI for ISR lesion were not significantly associated with MACCE (hazard ratio [HR], 1.10; 95% confidential interval [CI], 0.61–1.97; p=0.76) and all-cause death (HR, 0.93; 95% CI, 0.56–1.56; p=0.79)

Conclusion

PCI for the ISR lesion was not associated with worse clinical outcomes compared with PCI for the de novo lesion.

Funding Acknowledgement

Type of funding sources: None.

The relationship among extent of lipid-rich plaque, factors associated with a reduction of lipid-rich plaque and late lumen loss: a near-infrared spectroscopy and intravascular ultrasound study

Background

Near-infrared spectroscopy (NIRS) and intravascular ultrasound (IVUS) are useful imaging modalities to identify lipid-rich plaque (LRP) which is associated with an increased risk of future cardiovascular events in individuals undergoing PCI. Pathological studies have raised concerns that treating LRP with stents may impair vascular healing. However, the impact of stent implantation to LRP lesions was less known. Moreover, little information is available about changes in the extent of LRP at before and after PCI.

Purpose

The aim of this study was to investigate changes in LRP by NIRS between pre- and post-stent implantation, and to evaluate an association among impact of LRP by NIRS at pre- and post-stenting and late lumen loss (LLL) by angiography.

Methods

We studied 175 lesions in 149 patients who underwent PCI under NIRS-IVUS guidance and follow-up angiography at 8-month later from 2017 to 2020. Plaque characteristics on IVUS, the extent of LRP [defined as a long segment with a 4-mm maximum lipid core burden index (maxLCBI4mm)] on NIRS, and quantitative coronary angiography measurements were analyzed. We evaluated a change of the extent of LRP between pre- and post-stenting at index PCI procedure, and association between the extent of LRP and a 8-month LLL at follow-up coronary angiography. A large LRP was defined as maxLCBI4mm>400 at pre-stenting.

Results

Mean age was 64.5 years old, and 123 (82%) patients were male. The prevalence of large LRP was 51% and median plaque burden at minimum lumen area was 81%. The extent of LRP at culprit lesion significantly decreased from pre- to post-stenting (median maxLCBI4mm [interquartile range (IQR)]: 407 [199, 580] to 133 [13, 319], p<0.001) (Figure 1). In multivariable liner regression analysis, independent predictors for the reduction of LRP were a pre-stenting LRP (β coefficient = −57.0, 95% confidence interval (CI) [−65.1 to −48.8], p<0.001) and plaque burden (β coefficient = −30.0, 95% CI [−56.6 to −3.4], p<0.001), respectively. On the other hands, patient comorbidities, lipid profile and inflammatory markers were not associated with the reduction of LRP (all p>0.05). Median LLL at follow-up angiogram was 0.17 [0.07–0.35] mm. Both the extent of pre- and post-stenting LRP were not associated with LLL (r=0.018, p=0.80 and r=0.022, p=0.76, respectively) (Figure 2). In addition, there was no significant difference in LLL between the post-stenting large and non-large LRP (median [IQR] 0.18 [0.08–0.35] vs. 0.17 [0.07–0.35]; P=0.95).

Conclusions

This study showed coronary stent implantation significantly reduced the NIRS-derived LRP in patients undergoing PCI. Although the extent of pre-stenting LRP and IVUS plaque burden predicted the reduction of LRP, the extent of pre- and post-stenting LRP were not associated with LLL. These findings suggest that stent implantation for LRP, even in a large LRP, is safe and does not affect LLL.

Funding Acknowledgement

Type of funding sources: None. Figure 1. Scatter plotsFigure 2. CENTRAL Figure

Coronary lipid-rich plaque characteristics with acute coronary syndrome and chronic coronary syndrome: a near infrared spectroscopy and intravascular ultrasound study

Background

Asians have a much lower incidence of adverse coronary events than Caucasians, and the characteristics of vulnerable plaque might be different among the ethnics.

Purpose

The aim of this study was to investigate the clinical characteristics of lipid-rich plaque (LRP) in the Asian population and we also aimed to distinguish the characteristics of an acute coronary syndrome (ACS) culprit lesion and a chronic coronary syndrome (CCS) culprit lesion. Furthermore, we evaluated the association between lipid core burden index (LCBI) and cardiovascular risk factors, lipid profiles, and inflammatory biomarkers, as determined in vivo by near infrared spectroscopy intravascular ultrasound (NIRS-IVUS) imaging in patients undergoing percutaneous coronary intervention (PCI).

Methods

We evaluated 207 patients (ACS, n=75; CCS, n=132) who underwent PCI under NIRS-IVUS. Plaque characteristics and the extent of LRP [defined as a long segment with a 4-mm maximum LCBI (maxLCBI4mm)] on NIRS in de-novo culprit and non-culprit segments were analyzed.

Results

The mean age was 65 years old and 82% of patients were male. The ACS culprit lesions had a significantly higher maxLCBI4mm (median [interquartile range (IQR)]: 533 [385–745] vs. 361 [174–527], p<0.001) than the CCS culprit lesions. Whereas, no significant difference was seen in maxLCBI4mm between ACS and CCS non-culprit lesion segments (246 [53, 342] vs. 185 [37, 350], p=0.47) (Figure 1). Receiver-operating characteristic analysis showed that the NIRS maxLCBI4mm could distinguish the ACS culprit segment from the CCS culprit segment, with a sensitivity of 73% and a specificity of 69% (c-statistic = 0.69; p<0.001, cut-off value of max LCBI4mm = 408) (Figure 2). On multivariate logistic analysis, a large LRP (defined as maxLCBI4mm ≥400) was the strongest independent predictor of the ACS culprit segment (odds ratio, 3.87; 95% confidence interval, 1.95–8.02). In non-culprit segments, 19.8% of patients had at least one large LRP without a small lumen. No significant correlation was found between the extent of LRP and circulating lipid profiles and inflammatory makers biomarkers (hs-CRP, IL-6, TNF-α) in both the culprit and non-culprit lesion segments, whereas the extent of LRP was positively correlated with IVUS plaque burden (r=0.24, p<0.001).

Conclusions

We confirmed that NIRS-IVUS plaque assessment could be useful to differentiate ACS from CCS culprit lesions, and that a threshold maxLCBI4mm ≥400 was clinically suitable in Japanese patients. No systemic surrogate markers were found to be associated with the extent of LRP by NIRS in culprit and non-culprit segments. Consequently, we believe that direct intravascular evaluation of coronary plaque characteristics remains important for identification of high-risk LRP.

Funding Acknowledgement

Type of funding sources: None. Figure 1. The difference of maxLCBI4mmFigure 2. ROC curve

Outcomes of robot-assisted versus conventional laparoscopic low anterior resection in patients with rectal cancer: propensity-matched analysis of the National Clinical Database in Japan

BACKGROUND

Robot-assisted laparoscopic surgery has several advantages over conventional laparoscopy. However, population-based comparative studies for low anterior resection are limited. This article aimed to compare peri-operative results of robot-assisted low anterior resection (RALAR) and laparoscopy.

METHODS

This retrospective cohort study used data from patients treated with RALAR or conventional laparoscopic low anterior resection (CLLAR) between October 2018 and December 2019, as recorded in the Japanese National Clinical Database, a data set registering clinical information, perioperative outcomes, and mortality. Of note, the registry does not include information on the tumour location (centimetres from the anal verge) and diverting stoma creation. Perioperative outcomes, including rate of conversion to open surgery, were compared between RALAR and CLLAR groups. Confounding factors were adjusted for using propensity score matching.

RESULTS

Of 21 415 patients treated during the study interval, 20 220 were reviewed. Two homogeneous groups of 2843 patients were created by propensity score matching. The conversion rate to open surgery was significantly lower in the RALAR group than in the CLLAR group (0.7 versus 2.0 per cent; P < 0.001). The RALAR group had a longer operating time (median: 352 versus 283 min; P < 0.001), less intraoperative blood loss (15 versus 20 ml; P < 0.001), a lower in-hospital mortality rate (0.1 versus 0.5 per cent; P = 0.007), and a shorter postoperative hospital stay (median: 13 versus 14 days; P < 0.001) compared with the CLLAR group. The CLLAR group had a lower rate of readmission within 30 days (2.4 versus 3.3 per cent; P = 0.045).

CONCLUSION

These data highlight the reduced conversion rate, in-hospital mortality rate, intraoperative blood loss, and length of postoperative hospital stay for rectal cancer surgery in patients treated using robot-assisted laparoscopic surgery compared with laparoscopic low anterior resection.

Ultrasensitive detection by maxillary palp neurons allows non-host recognition without consumption of harmful allelochemicals

Most lepidopteran insect larvae exhibit stepwise feeding behaviors, such as palpation using the maxillary palps (MPs) followed by test biting and persistent biting. However, the purpose of palpation has been unclear. In particular, nothing is known about the neurons in the MP and their mode of recognition of undesired plants, although such neurons have been suggested to exist. In this study, we used larvae of the stenophagous insect Bombyx mori and compared the roles of palpation and test biting in the selection of feeding behavior. When the larvae were given non-host plant leaves, they did not initiate test biting, indicating that non-host plant leaves were recognized via palpation without biting, and that this behavior resulted in a lack of persistent biting, as the leaves were judged non-suitable for consumption. Surface extracts of inedible leaves significantly suppressed test biting of mulberry leaves, a host plant of B. mori, suggesting that secondary metabolites on the leaf surface of inedible leaves function as test biting suppressors, even when another conditions are suitable for test biting. The allelochemical coumarin, which is found in the inedible leaves of cherry, Cerasus speciosa, significantly suppressed test biting of mulberry leaves, suggesting that coumarin is a possible deterrent to the eating of cherry leaves. Using the electrophysiological method of tip recording and a leaf-surface extract as the test material, leaf-surface compound-responsive neurons were identified in the MP. In addition, several neurons that respond to coumarin in the attomolar range were identified, suggesting that the larvae use ultrasensitive neurons in the MP to recognize inedible leaves. In the HEK293T cell heterologous expression system, the B. mori gustatory receptors BmGr53 and BmGr19, which were previously found to be expressed in the MP and to respond to coumarin in the attomolar range, responded to a leaf-surface extract of C. speciosa, suggesting that these receptors may be present on the inedible-leaf-recognizing neurons of the MP. These findings suggest that ultrasensitive plant secondary metabolite-recognizing neurons in the MP allow for the recognition of non-host plants via palpation without risking damage caused by ingesting harmful allelochemicals.

Effects of evolocumab on plasma levels of proprotein convertase subtilisin/kexin type 9 and lipoprotein(a) in acute myocardial infarction

Background

There are two types of circulating proprotein convertase subtilisin/kexin type 9 (PCSK9), mature and furin-cleaved. Most types of lipoprotein(a) [Lp(a)], an independent risk factor of cardiovascular events, bound to mature PCSK9.

Purpose

This study examined the effects of monoclonal anti-PCSK9 antibody on plasma PCSK9 and Lp(a) levels in acute myocardial infarction (MI).

Methods

Acute MI patients (n=36) were randomly divided into evolocumab (140 mg; n=17) and non-evolocumab (n=19) groups. Changes in plasma PCSK9 and Lp(a) levels were monitored before and 1, 3, 5, 10, and 20 days after evolocumab administration.

Results

In the non-evolocumab group, plasma levels of mature PCSK9, furin-cleaved PCSK9, and Lp(a) (236.4±57.3 ng/mL, 22.4±5.8 ng/mL, and 19.2. ± 16.5 mg/dL, respectively) significantly increased by day 3 (408.8±77.1 ng/mL, P&lt;0.001; 47.2±15.7 ng/mL, P&lt;0.001; and 39.7±21.3 mg/dL, P&lt;0.005, respectively) and returned to the baseline by day 10 or 20. In the evolocumab group, mature PCSK9 significantly increased by &gt;1000 ng/mL with a simultaneous decline of furin-cleaved PCSK9 below the measurement sensitivity level after day 3. The incremental area under the curve for plasma Lp(a) levels was significantly smaller in the evolocumab group compared with the non-evolocumab group (P=0.038).

Conclusion

Mature and furin-cleaved PCSK9 are transiently upregulated after MI onset. Evolocumab significantly increases mature PCSK9 and decreases furin-cleaved PCSK9 and might inhibit transient increase of plasma Lp(a) in acute MI.

Figure 1

Funding Acknowledgement

Type of funding source: None

Combined impact of residual inflammatory risk and chronic kidney disease on long-term clinical outcomes in patients undergoing percutaneous coronary intervention

Background

Inflammatory status pre-percutaneous coronary intervention (PCI) and post-PCI has been reported not only associated with poor prognosis, but also to impair renal function. Statins reduce cardiovascular events by lowering lipids and have anti-inflammatory impacts, but residual inflammatory risk (RIR) exists. It remains unclear that the synergistic effect of RIR and chronic kidney disease (CKD) on long-term clinical outcome in stable coronary artery disease (CAD) patients undergoing PCI in statin era.

Aim

The aim of this study was to investigate the long-term combined impact of RIR evaluating hs-CRP at follow-up and CKD among stable CAD patients undergoing PCI in statin era.

Methods

This is a single-center, observational, retrospective cohort study assessing consecutive 2,984 stable CAD patients who underwent first PCI from 2000 to 2016. We analyzed 2,087 patients for whom hs-CRP at follow-up (6–9 months later) was available. High residual inflammatory risk was defined as hs-CRP &gt;0.6 mg/L according to the median value at follow up. Patients were assigned to four groups as Group1 (high RIR and CKD), Group2 (low RIR and CKD), Group3 (high RIR and non-CKD) or Group4 (low RIR and non-CKD). We evaluated all-cause death and major adverse cardiac events (MACE), defined as a composite of cardiovascular (CV) death, non-fatal myocardial infarction (MI) and non-fatal stroke.

Results

Of patients (83% men; mean age 67 years), there were 299 (14.3%) patients in group 1, 201 (9.6%) patients in group 2, 754 (36.1%) patients in group 3, and 833 (39.9%) patients in group 4. The median follow-up period was 5.2 years (IQR, 1.9–9.9 years). In total, 189 (frequency, 16.1%) cases of all-cause death and 128 (11.2%) MACE were identified during follow-up, including 53 (4.6%) CV deaths, 27 (2.4%) MIs and 52 (4.8%) strokes. The rate of all-cause death and MACE in group 1 was significantly higher than other groups (p&lt;0.001, respectively). There was a stepwise increase in the incidence rates of all-cause death and MACE. After adjustment for important covariates, the presence of high RIR and/or CKD were independently associated with higher incidence of MACE and higher all-cause mortality. (shown on figure).

Conclusion

The presence of both high RIR and CKD conferred a synergistic adverse effect on the risk for long-term adverse cardiac events in patients undergoing PCI.

Kaplan-Meier curve

Funding Acknowledgement

Type of funding source: None

Chronotropic incompetence and exercise capacity after mitral valve surgery: the importance of blood hemoglobin level

Background

Chronotropic incompetence (CI) is sometimes observed during exercise training of cardiac rehabilitation in patients with cardiac surgery, however, little is known concerning the differences between patients with mitral valve (MV) and aortic valve (AV) surgery.

Purpose

Because the possibility exists that cardiac sympathetic nerves might be impaired by left atrium incision, we hypothesized that the incidence of CI was higher in patients with MV surgery (Mitral Valve Replacement and Mitral Valvuloplasty) as compared with patients with AV surgery (Aortic Valve Replacement). And if so, which factor determines the exercise capacity of patients after MV surgery. We thus aimed this study to elucidate the hypothesis with cardiopulmonary exercise testing (CPX).

Methods

We performed CPX by ramp loading with ergometer exercise in total 61 patients who had undergone elective cardiac valve operation (25 patients with MV surgery, age 59.2±9.9 years; 36 patients with AV surgery, age 64.6±12.3 years). We analyzed chronotropic response index (CRI), peak oxygen uptake (peak VO2/W), anaerobic threshold (AT), and peak oxygen pulse (peak VO2/HR) with CPX, and blood hemoglobin concentration (Hb).

Results

The value of CRI was significantly decreased in the patients with MV surgery compared with those with AV surgery (MV; 0.19±0.10 vs. AV; 0.41±0.17, p&lt;0.001). Peak VO2, peak VO2/HR and Hb were not significantly different between patients with MV and those with AV surgery. Patients with MV surgery showed correlations between peak VO2 and Hb (r=0.45, p&lt;0.05), AT and Hb (r=0.52, p&lt;0.01), and a strong correlation between peak VO2 and peak VO2/HR (r=0.63, p&lt;0.001), but not in those with AV surgery.

Conclusions

The present study demonstrated that higher incidence of CI was shown in patients with MV surgery as compared with those with AV surgery. The exercise capacity of patients with MV surgery was determined by peak VO2/HR and Hb. These results suggest that 1) left atrium incision impairs cardiac sympathetic nerves and causes CI, 2) peak VO2/HR which is consisted of arterio-venous oxygen difference and Hb is critical indicator for exercise capacity in patients with MV surgery with CI.

Main results

Funding Acknowledgement

Type of funding source: None

Diet choice: The two-factor host acceptance system of silkworm larvae

Many herbivorous insects are mono- or oligophagous, having evolved to select a limited range of host plants. They specifically identify host-plant leaves using their keen sense of taste. Plant secondary metabolites and sugars are thought to be key chemical cues that enable insects to identify host plants and evaluate their quality as food. However, the neuronal and behavioral mechanisms of host-plant recognition are poorly understood. Here, we report a two-factor host acceptance system in larvae of the silkworm Bombyx mori, a specialist on several mulberry species. The first step is controlled by a chemosensory organ, the maxillary palp (MP). During palpation at the leaf edge, the MP detects trace amounts of leaf-surface compounds, which enables host-plant recognition without biting. Chemosensory neurons in the MP are tuned with ultrahigh sensitivity (thresholds of attomolar to femtomolar) to chlorogenic acid (CGA), quercetin glycosides, and β-sitosterol (βsito). Only if these 3 compounds are detected does the larva make a test bite, which is evaluated in the second step. Low-sensitivity neurons in another chemosensory organ, the maxillary galea (MG), mainly detect sucrose in the leaf sap exuded by test biting, allowing larvae to accept the leaf and proceed to persistent biting (feeding). The two-factor host acceptance system reported here may commonly underlie stereotyped feeding behavior in many phytophagous insects and determine their feeding habits.

Function and Role of ATP-Binding Cassette Transporters as Receptors for 3D-Cry Toxins

When ABC transporter family C2 (ABCC2) and ABC transporter family B1 (ABCB1) were heterologously expressed in non-susceptible cultured cells, the cells swelled in response to Cry1A and Cry3 toxins, respectively. Consistent with the notion that 3D-Cry toxins form cation-permeable pores, Bombyx mori ABCC2 (BmABCC2) facilitated cation-permeable pore formation by Cry1A when expressed in Xenopus oocytes. Furthermore, BmABCC2 had a high binding affinity (KD) to Cry1Aa of 3.1 × 10-10 M. These findings suggest that ABC transporters, including ABCC2 and ABCB1, are functional receptors for 3D-Cry toxins. In addition, the Cry2 toxins most distant from Cry1A toxins on the phylogenetic tree used ABC transporter A2 as a receptor. These data suggest that 3D-Cry toxins use ABC transporters as receptors. In terms of inducing cell swelling, ABCC2 has greater activity than cadherin-like receptor. The pore opening of ABC transporters was hypothesized to be linked to their receptor function, but this was repudiated by experiments using mutants deficient in export activity. The synergistic relationship between ABCC2 and cadherin-like receptor explains their ability to cause resistance in one species of insect.

Role of Bacillus thuringiensis Cry1A toxins domains in the binding to the ABCC2 receptor from Spodoptera exigua

Cry proteins from Bacillus thuringiensis (Bt) have been used to control insect pests either as formulated sprays or as in Bt-crops. However, field-evolved resistance to Bt proteins is threatening the long-term use of Bt products. The SeABCC2 locus has been genetically linked to resistance to a Bt bioinsecticide (Xentari™) in Spodoptera exigua (a mutation producing a truncated form of the transporter lacking an ATP binding domain was found in the resistant insects). Here, we investigated the role of SeABCC2 in the mode of action of Cry1Aa, Cry1Ab, Cry1Ac, Cry1Ca, and two Cry1A-1Ca hybrids by expressing the receptor in Sf21 and HEK293T cell lines. Cell toxicity assays showed that Sf21 cells expressing SeABCC2 become susceptible to Cry1A proteins. HEK293T cells expressing the transporter were found susceptible to Cry1A proteins but not to Cry1Ca. The results with the Cry1A-1Ca hybrids suggest that domain II from Cry1Ab/c is crucial for the toxicity to Sf21 cells, whereas domain III from Cry1Aa/b is crucial for the toxicity to HEK293T cells. Binding assays showed that the Cry1Ac binding is of high affinity and specific to cells expressing the SeABCC2 transporter. Heterologous competition experiments support a model in which domain II of Cry1Ab/c has a common binding site in the SeABCC2 protein, whereas domain III of Cry1Aa/b binds to a different binding site in the SeABCC2 protein.

Glucose, some amino acids and a plant secondary metabolite, chlorogenic acid induce the secretion of a regulatory hormone, tachykinin-related peptide, from the silkworm midgut

Enteroendocrine cells in the insect midgut are thought to secrete peptide hormones in response to the nutritional state. However, the role of dietary compounds in inducing peptide hormone secretion from enteroendocrine cells in insects remains unknown. In the present study, we demonstrated that several dietary compounds from mulberry leaves, including glucose, amino acids, and the secondary metabolite chlorogenic acid, induced significant secretion of tachykinin-related peptides from isolated silkworm midguts at the luminal concentrations measured in fed larvae. This study provides evidence that the insect midgut senses a non-nutritious secondary metabolite in addition to nutrient metabolites to monitor luminal food status and secretes a feeding regulatory hormone, suggesting that a unique dietary sensory system modulates insect feeding via enteroendocrine control.

Extracellular loop structures in silkworm ABCC transporters determine their specificities for Bacillus thuringiensis Cry toxins

Bacillus thuringiensis Cry toxins are insecticidal proteins used widely for pest control. They are lethal to a restricted range of insects via specific interactions with insect receptors such as the ABC transporter subfamily members C2 (ABCC2) and C3 (ABCC3). However, it is still unclear how these different receptors contribute to insect susceptibility to Cry1A toxins. Here, we investigated the differences between the silkworm (Bombyx mori) ABCC2 (BmABCC2_S) and ABCC3 (BmABCC3) receptors in mediating Cry toxicity. Compared with BmABCC2_S, BmABCC3 exhibited 80- and 267-fold lower binding affinities to Cry1Aa and Cry1Ab, respectively, and these decreased affinities correlated well with the lower receptor activities of BmABCC3 for these Cry1A toxins. To identify the amino acid residues responsible for these differences, we constructed BmABCC3 variants containing a partial amino acid replacement with extracellular loops (ECLs) from BmABCC2_S. Replacing three amino acids from ECL 1 or 3 increased BmABCC3 activity toward Cry1Aa and enabled its activity toward Cry1Ab. Meanwhile, BmABCC2_S and BmABCC3 exhibited no receptor activities for Cry1Ca, Cry1Da, and Cry3Bb, correlating with markedly lower binding affinities for these Cry toxins. ABCC2 from a Cry1Ab-resistant B. mori strain (BmABCC2_R), which has a tyrosine insertion in ECL 2, displayed 93-fold lower binding affinity to Cry1Ab compared with BmABCC2_S but maintained high binding affinity to Cry1Aa. These results indicate that the Cry toxin-binding affinities of ABCC transporters are largely linked to the level of Cry susceptibility of ABCC-expressing cells and that the ABCC ECL structures determine the specificities to Cry toxins.

Long-term clinical impact of serum albumin in coronary artery disease patients with preserved renal function

BACKGROUND AND AIMS

Low serum albumin level is reportedly associated with worse clinical outcomes in patients with chronic kidney disease (CKD). However, associations between decreased serum albumin level and outcomes in non-CKD patients with coronary artery disease (CAD) remain unclear. Therefore, we aimed to evaluate the prognostic value of serum albumin concentrations in stable CAD patients with preserved renal function.

METHODS AND RESULTS

We studied 1316 patients with CAD and preserved renal function (estimated glomerular filtration rate ≥60 mL/min/1.73 m²) who underwent their first PCI between 2000 and 2011 and had data available for pre-procedural serum albumin. Patients were assigned to quartiles based on pre-procedural albumin concentrations. The incidence of major adverse cardiac events (MACE), including all-cause death and non-fatal myocardial infarction, was evaluated. Mean albumin concentration was 4.1 ± 0.4 g/dL. During the median follow-up of 7.5 years, 181 events occurred (13.8%). Kaplan-Meier curves revealed that patients with decreased serum albumin concentrations showed a higher event rate for MACE (log-rank, p < 0.0001). Using the highest tertiles (>4.3 g/dL) as reference, adjusted hazard ratios were 1.97 (95% CI, 1.12-3.55), 1.77 (95% CI, 0.99-3.25), and 1.19 (95% CI, 0.68-2.15) for serum albumin concentrations of <3.9, 3.9-4.0, and 4.1-4.3 g/dL, respectively. Decreased serum albumin concentration was associated with MACE even after adjusting for other independent variables (HR, 2.21 per 1-g/dL decrease; 95% CI, 1.37-3.56, p = 0.001).

CONCLUSION

Decreased serum albumin concentration independently predicted worse long-term prognosis in non-CKD patients after PCI. Pre-procedural serum albumin concentration could offer a useful predictor for patients with CAD and preserved renal function.

The intracellular region of silkworm cadherin-like protein is not necessary to mediate the toxicity of Bacillus thuringiensis Cry1Aa and Cry1Ab toxins

The cadherin-like protein in lepidopteran insects, known as a receptor for Bacillus thuringiensis Cry1A toxins, is a single-pass membrane protein that can be divided into extracellular and intracellular regions. The extracellular region is important for toxin binding and oligomerization, whereas the role of the intracellular region during Cry1A intoxication is unclear. In the present study, we generated a deletion mutant of Bombyx mori cadherin-like protein (BtR175) that lacked the intracellular region to investigate its role in mediating Cry1A toxicity. Like wild-type BtR175, the mutant protein conferred susceptibility to Cry1Aa and Cry1Ab toxins in Sf9 cells, suggesting that the intracellular region is not required to mediate intoxication. The deletion mutant maintained another role of cadherin-like proteins; that it, synergistic activity with B. mori ABC transporter C2 (ABCC2) when mediating Cry1Aa and Cry1Ab toxicity. In addition, we evaluated the effects of reagents that have been reported to inhibit Cry1A toxicity (e.g., protein kinase A inhibitors, EDTA, and sucrose) on Cry1A toxicity in BtR175-expressing cells. Our results suggest that Cry1Aa-induced cell death in BtR175-expressing cells was not caused by signal transduction but by osmotic lysis. Overall, our data indicate that BtR175 mediates the toxicity of Cry1Aa and Cry1Ab toxins entirely via its extracellular region. They also indicate that the synergism between cadherin-like protein and ABCC2 occurs outside of cells or in the cell membrane.

Evaluation of swallowing ability using swallowing sounds in maxillectomy patients

Maxillectomy for oral tumours often results in debilitating oral hypofunction, which markedly decreases quality of life. Dysphagia, in particular, is one of the most serious problems following maxillectomy. This study used swallowing sounds as a simple evaluation method to evaluate swallowing ability in maxillectomy patients with and without their obturator prosthesis placed. Twenty-seven maxillectomy patients (15 men, 12 women; mean age 66.0 ± 12.1 years) and 30 healthy controls (14 men, 16 women; mean age 44.9 ± 21.3 years) were recruited for this study. Participants were asked to swallow 4 mL of water, and swallowing sounds were recorded using a throat microphone. Duration of the acoustic signal and duration of peak intensity (DPI) were measured. Duration of peak intensity was significantly longer in maxillectomy patients without their obturator than with it (P < .05) and was significantly longer in maxillectomy patients without their obturator than in healthy controls (P < .025 after Bonferroni correction). With the obturator placed, DPI was significantly longer in maxillectomy patients who had undergone soft palate resection than in those who had not (P < .05). These results suggest swallowing ability in maxillectomy patients could be improved by wearing an obturator prosthesis, particularly during the oral stage. However, it is difficult to improve the oral stage of swallowing in patients who have undergone soft palate resection even with obturator placement.

Bombyx mori ABC transporter C2 structures responsible for the receptor function of Bacillus thuringiensis Cry1Aa toxin

Because Bombyx mori ABC transporter C2 (BmABCC2) has 1000-fold higher potential than B. mori cadherin-like protein as a receptor for Bacillus thuringiensis Cry1Aa toxin (Tanaka et al., 2013), the gate-opening ability of the latent pore under six extracellular loops (ECLs) of BmABCC2 was expected to be the reason for its higher potential (Heckel, 2012). In this study, cell swelling assays in Sf9 cells showed that BmABCC2 mutants lacking substrate-excreting activity retained receptor activity, indicating that the gate-opening activity of BmABCC2 is not responsible for Cry1Aa toxicity. The analysis of 29 BmABCC2 mutants demonstrated that ⁷⁷⁰DYWL⁷⁷³ of ECL 4 comprise a putative binding site to Cry1Aa. This suggests that specific toxicity of Cry1Aa toxin to a restricted range of lepidopteran insects is dependent on conservation and variation in the amino acid residues around ⁷⁷⁰DYWL⁷⁷³ of ECL 4 in the ABCC2.

Cry toxin specificities of insect ABCC transporters closely related to lepidopteran ABCC2 transporters

In this study, we examined insect and human ABCC transporters closely related to the lepidopteran ABC transporter C2 (ABCC2), a powerful receptor for the Bacillus thuringiensis Cry toxin, for their responses to various Cry toxins. ABCC2 and the lepidopteran ABC transporter C3 (ABCC3) conferred cultured cells with susceptibility to a lepidopteran-specific Cry1Aa toxin but not to lepidopteran-specific Cry1Ca and Cry1Da. One coleopteran ABCC transporter specifically responded to a coleopteran-specific Cry8Ca toxin. ABCC transporters from a dipteran insect and humans did not respond to any of the tested Cry toxins that are active to lepidopteran and coleopteran insects. These results yield important information for our understanding of insect specificity of Cry toxins and provide the first demonstration of a coleopteran ABCC transporter that serves as a Cry toxin receptor.

Polymerization Behavior and Mechanical Properties of High-Viscosity Bulk Fill and Low Shrinkage Resin Composites

The present study determined the mechanical properties and volumetric polymerization shrinkage of different categories of resin composite. Three high viscosity bulk fill resin composites were tested: Tetric EvoCeram Bulk Fill (TB, Ivoclar Vivadent), Filtek Bulk Fill posterior restorative (FB, 3M ESPE), and Sonic Fill (SF, Kerr Corp). Two low-shrinkage resin composites, Kalore (KL, GC Corp) and Filtek LS Posterior (LS, 3M ESPE), were used. Three conventional resin composites, Herculite Ultra (HU, Kerr Corp), Estelite ∑ Quick (EQ, Tokuyama Dental), and Filtek Supreme Ultra (SU, 3M ESPE), were used as comparison materials. Following ISO Specification 4049, six specimens for each resin composite were used to determine flexural strength, elastic modulus, and resilience. Volumetric polymerization shrinkage was determined using a water-filled dilatometer. Data were evaluated using analysis of variance followed by Tukey's honestly significant difference test (α=0.05). The flexural strength of the resin composites ranged from 115.4 to 148.1 MPa, the elastic modulus ranged from 5.6 to 13.4 GPa, and the resilience ranged from 0.70 to 1.0 MJ/m3. There were significant differences in flexural properties between the materials but no clear outliers. Volumetric changes as a function of time over a duration of 180 seconds depended on the type of resin composite. However, for all the resin composites, apart from LS, volumetric shrinkage began soon after the start of light irradiation, and a rapid decrease in volume during light irradiation followed by a slower decrease was observed. The low shrinkage resin composites KL and LS showed significantly lower volumetric shrinkage than the other tested materials at the measuring point of 180 seconds. In contrast, the three bulk fill resin composites showed higher volumetric change than the other resin composites. The findings from this study provide clinicians with valuable information regarding the mechanical properties and polymerization kinetics of these categories of current resin composite.

Effect of interlamellar interactions on shear induced multilamellar vesicle formation

Shear-induced multilamellar vesicle (MLV) formation has been studied by coupling the small-angle neutron scattering (SANS) technique with neutron spin echo (NSE) spectroscopy. A 10% mass fraction of the nonionic surfactant pentaethylene glycol dodecyl ether (C₁₂E₅) in water was selected as a model system for studying weak inter-lamellar interactions. These interactions are controlled either by adding an anionic surfactant, sodium dodecyl sulfate, or an antagonistic salt, rubidium tetraphenylborate. Increasing the charge density in the bilayer induces an enhanced ordering of the lamellar structure. The charge density dependence of the membrane bending modulus was determined by NSE and showed an increasing trend with charge. This behavior is well explained by a classical theoretical model. By considering the Caillé parameters calculated from the SANS data, the layer compressibility modulus B¯ is estimated and the nature of the dominant inter-lamellar interaction is determined. Shear flow induces MLV formation around a shear rate of 10 s^-1, when a small amount of charge is included in the membrane. The flow-induced layer undulations are in-phase between neighboring layers when the inter-lamellar interaction is sufficiently strong. Under these conditions, MLV formation can occur without significantly changing the inter-lamellar spacing. On the other hand, in the case of weak inter-lamellar interactions, the flow-induced undulations are not in-phase, and greater steric repulsion leads to an increase in the inter-lamellar spacing with shear rate. In this case, MLV formation occurs as the amplitude of the undulations gets larger and the steric interaction leads to in-phase undulations between neighboring membranes.

Geographical variation in the skeletal morphology of red jungle fowl

1. The skulls and postcranial skeletons of the red jungle fowl (Gallus gallus) were compared osteometrically between the populations from North and South Vietnam, North and Central Laos and Southeast Bangladesh. The populations include the three subspecies of G. g. spadiceus, G. g. gallus and G. g. murghi and were sampled to reveal the geographical morphological variations among populations in G. gallus. 2. The morphometric characteristics of subspecies murghi could be clearly distinguished from those of the other subspecies using a canonical discriminant analysis. However, the size and shape of the skull of the gallus population from South Vietnam were not statistically different from that of the subspecies spadiceus from North Laos. The canonical discriminant scores also clearly indicated that there were morphological similarities in the skulls of the populations from North Laos and South Vietnam. 3. From the results, therefore, it is concluded that red jungle fowls do not exhibit high levels of osteometric variation between geographical localities at least within the Indochinese Peninsula. 4. This contrasts with previous studies which have described these subspecies as having various external morphological differences and have argued that zoogeographical barriers exist between the north and south areas of the Indochinese Peninsula.

C-type lectin-like receptor 2 promotes hematogenous tumor metastasis and prothrombotic state in tumor-bearing mice

Essentials The role of C-type lectin-like receptor-2 (CLEC-2) in cancer progression is unclear. CLEC-2-depleted mouse model is generated by using a rat anti-mouse CLEC-2 monoclonal antibody. CLEC-2 depletion inhibits hematogenous tumor metastasis of podoplanin-expressing B16F10 cells. CLEC-2 depletion prolongs cancer survival by suppressing thrombosis and inflammation.

SUMMARY

Background C-type lectin-like receptor 2 (CLEC-2) is a platelet activation receptor of sialoglycoprotein podoplanin, which is expressed on the surface of certain types of tumor cells. CLEC-2-podoplanin interactions facilitate hematogenous tumor metastasis. However, direct evidence of the role of CLEC-2 in hematogenous metastasis and cancer progression is lacking. Objective and methods We generated immunological CLEC-2-depleted mice by using anti-mouse CLEC-2 monoclonal antibody 2A2B10 and investigated whether CLEC-2 promoted hematogenous tumor metastasis and tumor growth and exacerbated the prognosis of mice bearing podoplanin-expressing B16F10 melanoma cells. Results Our results showed that hematogenous metastasis was significantly inhibited in CLEC-2-depleted mice. B16F10 cells co-cultured with wild-type platelets, but not with CLEC-2-deficient platelets, showed increased proliferation. However, B16F10 cell proliferation was not inhibited in CLEC-2-depleted mice. Histological analysis showed that thrombus formation in tumor vessels was significantly inhibited and functional vessel density was significantly increased in CLEC-2-depleted mice. These data suggest that CLEC-2 deficiency may inhibit thrombus formation in tumor vessels and increase the density of functional vessels, thus improving oxygen and nutrient supply to tumors, indirectly promoting tumor proliferation. Furthermore, the overall survival of CLEC-2-depleted mice was significantly prolonged, which may be due to the suppression of thrombus formation in the lungs and subsequent inhibition of systemic inflammation and cachexia. Conclusions These data provide a rationale for the targeted inhibition of CLEC-2 as a new strategy for preventing hematogenous tumor metastasis and for inhibiting cancer-related thromboembolism.

Water influx via aquaporin directly determines necrotic cell death induced by the Bacillus thuringiensis Cry toxin

The Bacillus thuringiensis Cry toxin causes swelling and necrosis in insect cells, but the route(s) and significance of the water influx involved in its cytotoxicity are unclear. Here, we assessed the role of aquaporins (AQPs), known as water channels, in Cry toxin intoxication. An AQP inhibitor did not interfere with any known process to form the toxin pore, but it diminished the cell swelling and loss of membrane integrity induced by the Cry toxin. Overexpression of AQPs facilitated water influx and cytotoxicity. Our results demonstrate that water influx via aquaporin directly determines necrotic cell death induced by the Cry toxin.

Expression of the fructose receptor BmGr9 and its involvement in the promotion of feeding, suggested by its co-expression with neuropeptide F1 in Bombyx mori

Insect gustatory receptors (Grs) are members of a large family of proteins with seven transmembrane domains that provide insects with the ability to detect chemical signals critical for feeding, mating, and oviposition. To date, 69 Bombyx mori Grs (BmGrs) genes have been identified via genome studies. BmGr9 has been shown to respond specifically to fructose and to function as a ligand-gated ion channel selectively activated by fructose. However, the sites where this Gr are expressed remain unclear. We demonstrated using reverse transcription (RT)-PCR that BmGr9 is widely expressed in the central nervous system (CNS), as well as oral sensory organs. Additionally, immunohistochemistry was performed using anti-BmGr9 antiserum to show that BmGr9 is expressed in cells of the oral sensory organs, including the maxillary galea, maxillary palps, labrum, and labium, as well as in putative neurosecretory cells of the CNS. Furthermore, double immunohistochemical analysis showed that most BmGr9-expressing cells co-localized with putative neuropeptide F1-expressing cells in the brain, suggesting that BmGr9 is involved in the promotion of feeding behaviors. In addition, a portion of BmGr9-expressing cells in the brain co-localized with cells expressing BmGr6, a molecule of the sugar receptor clade, suggesting that sugars other than fructose are involved in the regulation of feeding behaviors in B. mori larvae.

Quantitative Assessment of Circumferential Enhancement along the Wall of Cerebral Aneurysms Using MR Imaging

BACKGROUND AND PURPOSE

The incidence of wall enhancement of cerebral aneurysms on vessel wall MR imaging has been described as higher in ruptured intracranial aneurysms than in unruptured intracranial aneurysms, but the difference in the degree of enhancement between ruptured and unruptured aneurysms is unknown. We compared the degree of enhancement between ruptured and unruptured intracranial aneurysms by using quantitative MR imaging measures.

MATERIALS AND METHODS

We performed quantitative analyses of circumferential enhancement along the wall of cerebral aneurysms in 28 ruptured and 76 unruptured consecutive cases by using vessel wall MR imaging. A 3D-T1-weighted fast spin-echo sequence was obtained before and after contrast media injection, and the wall enhancement index was calculated. We then compared characteristics between ruptured and unruptured aneurysms.

RESULTS

The wall enhancement index was significantly higher in ruptured than in unruptured aneurysms (1.70 ± 1.06 versus 0.89 ± 0.88, respectively; P = .0001). The receiver operating characteristic curve analysis found that the most reliable cutoff value of the wall enhancement index to differentiate ruptured from unruptured aneurysms was 0.53 (sensitivity, 0.96; specificity, 0.47). The wall enhancement index remained significant in the multivariate logistic regression analysis (P < .0001).

CONCLUSIONS

Greater circumferential enhancement along the wall of cerebral aneurysms correlates with the ruptured state. A quantitative evaluation of circumferential enhancement by using vessel wall MR imaging could be useful in differentiating ruptured from unruptured intracranial aneurysms.

Characterization of a ligand-gated cation channel based on an inositol receptor in the silkworm, Bombyx mori

Insect herbivores recognize non-volatile compounds in plants to direct their feeding behavior. Gustatory receptors (Gr) appear to be required for nutrient recognition by gustatory organs in the mouthparts of insects. Gr10 is expressed in Bombyx mori (BmGr10) mouthparts such as maxillary galea, maxillary palp, and labrum. BmGr10 is predicted to function in sugar recognition; however, the precise biochemical function remains obscure. Larvae of B. mori are monophagous feeders able to find and feed on mulberry leaves. Soluble mulberry leaf extract contains sucrose, glucose, fructose, and myo-inositol. In this study, we identified BmGr10 as an inositol receptor using electrophysiological analysis with the Xenopus oocyte expression system and Ca(2+) imaging techniques using mammalian cells. These results demonstrated that Xenopus oocytes or HEK293T cells expressing BmGr10 specifically respond to myo-inositol and epi-inositol but do not respond to any mono-, di-, or tri-saccharides or to some sugar alcohols. These inositols caused Ca(2+) and Na(+) influxes into the cytoplasm independently of a G protein-mediated signaling cascade, indicating that BmGr10 is a ligand-gated cation channel. Overall, BmGr10 plays an important role in the myo-inositol recognition required for B. mori larval feeding behavior.