Artifact reduction in low and ultra-low dose chest computed tomography for patients with pacemaker: A phantom study

INTRODUCTION

Implanted pacemakers (PM) would decrease the detection of lung nodules in chest computed tomography (CT) due to the metal artifact. This study aimed to explore the computer-aided diagnosis (CAD) detectability of pulmonary nodules for the patients implanted with PMs in low- and ultra-low-dose chest CT screening.

METHODS

Four different sizes of artificial nodules were placed in an anthropomorphic chest phantom with two alternative diameters utilized. A commercially available PM was placed on the surface of the left chest wall of the phantom. The image acquisitions were performed with 120 kV and 150 kV with a dedicated selective photon shield made of tin filter (Sn150 kV) at low- and ultra-low- radiation doses (1.0 and 0.5 mGy of volume CT dose index), and reconstructed with and without Iterative Metal Artifact Reduction (iMAR, Siemens Healthineers, Erlangen, Germany). The relative artifact index (AIr) was calculated as an index of metal artifacts, and the nodule detectability was evaluated with a CAD system.

RESULTS

Sn150 kV reduced AIr in all acquisitions when comparing 120 kV and Sn150 kV. Although PM reduced the detectability of nodules, Sn150 kV showed higher detectability compared to 120 kV. The use of iMAR showed inconsistent results in nodule detectability.

CONCLUSION

Sn150 kV reduced PM-induced metal artifacts and improved nodule detectability with CAD compared to 120 kV acquisition in many conditions including low and ultra-low doses and large phantoms, but iMAR did not improve the detectability.

IMPLICATIONS FOR PRACTICE

Based on the results of the current phantom study, low and ultra-low dose with Sn150 kV acquisition reduced PM-induced metal artifacts and improved nodule detectability.

Microhardness Measurements on Tooth and Alveolar Bone in Rodent Oral Disease Models

The mechanical property, microhardness, is evaluated in dental enamel, dentin, and bone in oral disease models, including dental fluorosis and periodontitis. Micro-CT (µCT) provides 3D imaging information (volume and mineral density) and scanning electron microscopy (SEM) produces microstructure images (enamel prism and bone lacuna-canalicular). Complementarily to structural analysis by µCT and SEM, microhardness is one of the informative parameters to evaluate how structural changes alter mechanical properties. Despite being a useful parameter, studies on microhardness of alveolar bone in oral diseases are limited. To date, divergent microhardness measurement methods have been reported. Since microhardness values vary depending on the sample preparation (polishing and flat surface) and indentation sites, diverse protocols can cause discrepancies among studies. Standardization of the microhardness protocol is essential for consistent and accurate evaluation in oral disease models. In the present study, we demonstrate a standardized protocol for microhardness analysis in tooth and alveolar bone. Specimens used are as follows: for the dental fluorosis model, incisors were collected from mice treated with/without fluoride-containing water for 6 weeks; for ligature-induced periodontal bone resorption (L-PBR) model, alveolar bones with periodontal bone resorption were collected from mice ligated on the maxillary 2nd molar. At 2 weeks after the ligation, the maxilla was collected. Vickers hardness was analyzed in these specimens according to the standardized protocol. The protocol provides detailed materials and methods for resin embedding, serial polishing, and indentation sites for incisors and alveolar. To the best of our knowledge, this is the first standardized microhardness protocol to evaluate the mechanical properties of tooth and alveolar bone in rodent oral disease models.

Inhibition of SARS-CoV-2 infection by Porphyromonas gingivalis and the oral microbiome

The COVID-19 pandemic persists despite the availability of vaccines, and it is therefore crucial to develop new therapeutic and preventive approaches. In this study, we investigated the potential role of the oral microbiome in SARS-CoV-2 infection. Using an in vitro SARS-CoV-2 pseudovirus infection assay, we found a potent inhibitory effect exerted by Porphyromonas gingivalis on SARS-CoV-2 infection mediated by known P. gingivalis compounds such as phosphoglycerol dihydroceramide (PGDHC) and gingipains as well as by unknown bacterial factors. We found that the gingipain-mediated inhibition of infection is likely due to cytotoxicity, while PGDHC inhibited virus infection by an unknown mechanism. Unidentified factors present in P. gingivalis supernatant inhibited SARS-CoV-2 likely via the fusion step of the virus life cycle. We addressed the role of other oral bacteria and found certain periodontal pathogens capable of inhibiting SARS-CoV-2 pseudovirus infection by inducing cytotoxicity on target cells. In the human oral cavity, we observed the modulatory activity of oral microbial communities varied among individuals in that some saliva-based cultures were capable of inhibiting while others were enhancing infection. These findings contribute to our understanding of the complex relationship between the oral microbiome and viral infections, offering potential avenues for innovative therapeutic strategies in combating COVID-19.

In Situ Raman Study of Neurodegenerated Human Neuroblastoma Cells Exposed to Outer-Membrane Vesicles Isolated from Porphyromonas gingivalis

The aim of this study was to elucidate the chemistry of cellular degeneration in human neuroblastoma cells upon exposure to outer-membrane vesicles (OMVs) produced by Porphyromonas gingivalis (Pg) oral bacteria by monitoring their metabolomic evolution using in situ Raman spectroscopy. Pg-OMVs are a key factor in Alzheimer's disease (AD) pathogenesis, as they act as efficient vectors for the delivery of toxins promoting neuronal damage. However, the chemical mechanisms underlying the direct impact of Pg-OMVs on cell metabolites at the molecular scale still remain conspicuously unclear. A widely used in vitro model employing neuroblastoma SH-SY5Y cells (a sub-line of the SK-N-SH cell line) was spectroscopically analyzed in situ before and 6 h after Pg-OMV contamination. Concurrently, Raman characterizations were also performed on isolated Pg-OMVs, which included phosphorylated dihydroceramide (PDHC) lipids and lipopolysaccharide (LPS), the latter in turn being contaminated with a highly pathogenic class of cysteine proteases, a key factor in neuronal cell degradation. Raman characterizations located lipopolysaccharide fingerprints in the vesicle structure and unveiled so far unproved aspects of the chemistry behind protein degradation induced by Pg-OMV contamination of SH-SY5Y cells. The observed alterations of cells' Raman profiles were then discussed in view of key factors including the formation of amyloid β (Aβ) plaques and hyperphosphorylated Tau neurofibrillary tangles, and the formation of cholesterol agglomerates that exacerbate AD pathologies.

CpG ODN/Mangiferin Dual Delivery through Calcium Alginate Hydrogels Inhibits Immune-Mediated Osteoclastogenesis and Promotes Alveolar Bone Regeneration in Mice

The immune system plays an important role in the skeletal system during bone repair and regeneration. The controlled release of biological factors from the immune system could facilitate and optimize the bone remodeling process through the regulation of the activities of bone cells. This study aimed to determine the effect of the controlled delivery of immunomodulatory biologicals on bone regeneration. Immunostimulatory cytosine-phosphate-guanosine oligodeoxynucleotides (CpG ODN) and glucosylxanthone Mangiferin (MAG)-embedded microbeads were incubated with P. gingivalis-challenged splenocytes, or co-cultured with RAW264.7 cells. The effect of CpG ODN/MAG-containing microbeads on bone regeneration was then tested in vivo in a mouse alveolar bone defect model. The results demonstrated that MAG significantly antagonized P. gingivalis proliferation and reduced the live/dead cell ratio. After the addition of CpG ODN + MAG microbeads, anti-inflammatory cytokines IL-10 and IL-4 were upregulated on day 2 but not day 4, whereas pro-inflammatory cytokine IL-1β responses showed no difference at both timepoints. RANKL production by splenocytes and TRAP+ cell formation of RAW264.7 cells were inhibited by the addition of CpG ODN + MAG microbeads. Alveolar bony defects, filled with CpG ODN + MAG microbeads, showed significantly increased new bone after 4 weeks. In summary, this study evaluated a new hydrogel-based regimen for the local delivery and controlled release of biologicals to repair and regenerate alveolar bony defects. The combined CpG ODN + MAG treatment may promote alveolar bone regeneration through the anti-microbial/anti-inflammatory effects and the inhibition of RANKL-mediated osteoclastogenesis.

Soluble Sema4D cleaved from osteoclast precursors by TACE suppresses osteoblastogenesis

Bone remodelling is mediated by orchestrated communication between osteoclasts and osteoblasts which, in part, is regulated by coupling and anti-coupling factors. Amongst formally known anti-coupling factors, Semaphorin 4D (Sema4D), produced by osteoclasts, plays a key role in downmodulating osteoblastogenesis. Sema4D is produced in both membrane-bound and soluble forms; however, the mechanism responsible for producing sSema4D from osteoclasts is unknown. Sema4D, TACE and MT1-MMP are all expressed on the surface of RANKL-primed osteoclast precursors. However, only Sema4D and TACE were colocalized, not Sema4D and MT1-MMP. When TACE and MT1-MMP were either chemically inhibited or suppressed by siRNA, TACE was found to be more engaged in shedding Sema4D. Anti-TACE-mAb inhibited sSema4D release from osteoclast precursors by ~90%. Supernatant collected from osteoclast precursors (OC-sup) suppressed osteoblastogenesis from MC3T3-E1 cells, as measured by alkaline phosphatase activity, but OC-sup harvested from the osteoclast precursors treated with anti-TACE-mAb restored osteoblastogenesis activity in a manner that compensates for diminished sSema4D. Finally, systemic administration of anti-TACE-mAb downregulated the generation of sSema4D in the mouse model of critical-sized bone defect, whereas local injection of recombinant sSema4D to anti-TACE-mAb-treated defect upregulated local osteoblastogenesis. Therefore, a novel pathway is proposed whereby TACE-mediated shedding of Sema4D expressed on the osteoclast precursors generates functionally active sSema4D to suppress osteoblastogenesis.

Porphyromonas gingivalis outer membrane vesicles exacerbate retinal microvascular endothelial cell dysfunction in diabetic retinopathy

Diabetic retinopathy (DR) is one of the leading causes of blindness. Periodontitis is one of the highest oral incidences and has been closely related to various systemic conditions through Porphyromonas gingivalis (P. gingivalis). P. gingivalis OMVs, derived from P. gingivalis, can cause endothelial dysfunction and potentially affect microvascular diseases. Current epidemiological studies provide limited evidence suggesting that periodontitis is associated with DR. However, there is a lack of basic research elucidating how periodontitis affects the severity of DR. This study aimed to explore the potential of P. gingivalis OMVs to contribute to the pathogenesis of DR and explore how it affect the retinal microvascular endothelium. The results demonstrated that P. gingivalis OMVs accelerated the blood-retinal barrier damage in DR mice. In vitro studies showed that the expression of inflammatory factors in human retinal microvascular endothelial cells (HRMECs) was increased after P. gingivalis OMVs stimulation, and the increased reactive oxygen species production, mitochondrial dysfunction, apoptosis, and altered endothelial permeability were observed in HRMECs under P. gingivalis OMVs stimulation. In addition, we found that protease-activated receptor-2 (PAR-2) regulated OMVs-induced TNF-α, MMP-9 mRNA expression, cell death, and endothelial permeability. Overall, we suggested that P. gingivalis OMVs induced mitochondria-related cell death of HRMECs and accelerated endothelial dysfunction, thus aggravating DR, in which PAR-2 plays a potential role. This study is the first research report to delineate the potential molecular mechanism of P. gingivalis OMVs on DR pathogenesis, which uniquely focused on elucidating the possible impact of periodontal pathogen derivatives on DR progression.

Extracellular Release of Citrullinated Vimentin Directly Acts on Osteoclasts to Promote Bone Resorption in a Mouse Model of Periodontitis

Elevated osteoclast (OC)-mediated bone resorption, a common pathological feature between periodontitis and rheumatoid arthritis (RA), implicates a possible mutually shared pathogenesis. The autoantibody to citrullinated vimentin (CV), a representative biomarker of RA, is reported to promote osteoclastogenesis (OC-genesis). However, its effect on OC-genesis in the context of periodontitis remains to be elucidated. In an in vitro experiment, the addition of exogenous CV upregulated the development of Tartrate-resistant acid phosphatase (TRAP)-positive multinuclear OCs from mouse bone marrow cells and increased the formation of resorption pits. However, Cl-amidine, an irreversible pan-peptidyl arginine deiminase (PAD) inhibitor, suppressed the production and secretion of CV from RANKL-stimulated OC precursors, suggesting that the citrullination of vimentin occurs in OC precursors. On the other hand, the anti-vimentin neutralizing antibody suppressed in vitro Receptor activator of nuclear factor kappa-Β ligand (RANKL)-induced OC-genesis. The CV-induced upregulation of OC-genesis was abrogated by the Protein kinase C (PKC)-δ inhibitor Rottlerin, accompanied by the downmodulation of OC-genesis-related genes, including Osteoclast stimulatory transmembrane protein (OC-STAMP), TRAP and Matrix Metallopeptidase 9 (MMP9) as well as extracellular signal-regulated kinase (ERK) mitogen-activated protein (MAP)-kinase phosphorylation. Elevated levels of soluble CV and vimentin-bearing mononuclear cells were found in the bone resorption lesions of periodontitis induced in mice in the absence of an anti-CV antibody. Finally, local injection of anti-vimentin neutralizing antibody suppressed the periodontal bone loss induced in mice. Collectively, these results indicated that the extracellular release of CV promoted OC-genesis and bone resorption in periodontitis.

TLR9 Signaling Is Required for the Porphyromonas gingivalis-Induced Activation of IL-10-Expressing B Cells

Immune cell pattern-recognition receptors such as Toll-like receptors (TLRs) play important roles in the regulation of host responses to periodontal pathogens. Our previous studies have demonstrated that immune regulatory B cells were activated by TLRs and alleviated periodontitis inflammation and bone loss. The purpose of this study is to determine the role of TLR9 signaling in the activation and IL-10 production of the primed-immune B cells in vitro. Wild-type (WT) and TLR9 knockout (TLR9KO) mice (C57BL/6 background, n = 5) were pre-immunized intraperitoneally with 1 × 108 formalin-fixed P. gingivalis and boosted once with 1 × 107 formalin-fixed P. gingivalis. Isolated splenocytes and purified B cells from each mouse were cultured with 1 × 108 formalin-fixed P. gingivalis for 48 h. Immunocytochemistry was performed to detect CD45+ IL-10+ cells. Levels of IL-10 expression and secretion in splenocytes and B cells were detected using qRT-PCR and ELISA, respectively. After stimulation with fixed P. gingivalis, the percentage of CD45+ IL-10+ B cells and the level of IL-10 expression were significantly increased (p < 0.01) in splenocytes and purified B cells isolated from WT mice. However, these changes were not observed in splenocytes and purified B cells from TLR9KO mice when the cells were treated with fixed P. gingivalis. The percentage of CD45+ IL-10+ B cells was significantly reduced in splenocytes and purified B cells from TLR9KO mice compared to those from WT mice when challenged with P. gingivalis. IL-10 expression in B cells from TLR9KO mice was significantly decreased compared to those from WT mice at both the mRNA and protein levels. Additionally, P. gingivalis-induced up-regulation of TNF-α mRNA expressions were consistently observed in B cells from both WT and TLR9KO mice. P. gingivalis-induced B10 activation and IL-10 production during adaptive responses by primed B cells requires TLR9 signaling and can be achieved independent of T-cell help.

In Situ Raman Analysis of Biofilm Exopolysaccharides Formed in Streptococcus mutans and Streptococcus sanguinis Commensal Cultures

This study probed in vitro the mechanisms of competition/coexistence between Streptococcus sanguinis (known for being correlated with health in the oral cavity) and Streptococcus mutans (responsible for aciduric oral environment and formation of caries) by means of quantitative Raman spectroscopy and imaging. In situ Raman assessments of live bacterial culture/coculture focusing on biofilm exopolysaccharides supported the hypothesis that both species engaged in antagonistic interactions. Experiments of simultaneous colonization always resulted in coexistence, but they also revealed fundamental alterations of the biofilm with respect to their water-insoluble glucan structure. Raman spectra (collected at fixed time but different bacterial ratios) showed clear changes in chemical bonds in glucans, which pointed to an action by Streptococcus sanguinis to discontinue the impermeability of the biofilm constructed by Streptococcus mutans. The concurrent effects of glycosidic bond cleavage in water-insoluble α - 1,3-glucan and oxidation at various sites in glucans' molecular chains supported the hypothesis that secretion of oxygen radicals was the main "chemical weapon" used by Streptococcus sanguinis in coculture.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

Hypomorphic RAG deficiency: impact of disease burden on survival and thymic recovery argues for early diagnosis and HSCT

Patients with hypomorphic mutations in the RAG1 or RAG2 gene present with either Omenn syndrome or atypical combined immunodeficiency with a wide phenotypic range. Hematopoietic stem cell transplantation (HSCT) is potentially curative, but data are scarce. We report on a worldwide cohort of 60 patients with hypomorphic RAG variants who underwent HSCT, 78% of whom experienced infections (29% active at HSCT), 72% had autoimmunity, and 18% had granulomas pretransplant. These complications are frequently associated with organ damage. Eight individuals (13%) were diagnosed by newborn screening or family history. HSCT was performed at a median of 3.4 years (range 0.3-42.9 years) from matched unrelated donors, matched sibling or matched family donors, or mismatched donors in 48%, 22%, and 30% of the patients, respectively. Grafts were T-cell depleted in 15 cases (25%). Overall survival at 1 and 4 years was 77.5% and 67.5% (median follow-up of 39 months). Infection was the main cause of death. In univariable analysis, active infection, organ damage pre-HSCT, T-cell depletion of the graft, and transplant from a mismatched family donor were predictive of worse outcome, whereas organ damage and T-cell depletion remained significant in multivariable analysis (hazard ratio [HR] = 6.01, HR = 8.46, respectively). All patients diagnosed by newborn screening or family history survived. Cumulative incidences of acute and chronic graft-versus-host disease were 35% and 22%, respectively. Cumulative incidences of new-onset autoimmunity was 15%. Immune reconstitution, particularly recovery of naïve CD4+ T cells, was faster and more robust in patients transplanted before 3.5 years of age, and without organ damage. These findings support the indication for early transplantation.

Assessment of SARS-CoV-2 entry in gingival epithelial cells expressing CD147

SARS-CoV-2, the causative agent of the debilitating COVID-19, is mainly transmitted by first infecting nose and lung epithelial cells. The mouth is also believed to be a viral portal site since certain types of oral epithelial cells were shown to express ACE2 receptor. However, it is unclear whether oral epithelial cells are directly infected by SARS-CoV-2. In this study, we addressed whether epithelial cells of the oral gingiva were susceptible to infection. Interestingly, we found that KRT5+ and KRT18+ gingival epithelial cells do not express ACE2 but highly express TMPRSS2 and Furin as well as CD147, which was proposed to be an alternative receptor for SARS-CoV-2. However, using SARS-CoV-2 pseudoviruses containing the spike protein, we observed that gingival epithelial cells were not susceptible to infection due to the lack of ACE2 expression and the inability of CD147 to mediate viral entry. These results strongly suggest that epithelial cells from the gingiva are not susceptible to SARS-CoV-2 and CD147 is not a receptor for the SARS-CoV-2 virus. The susceptibility of oral cells from other oral structures under healthy and pathological conditions still needs to be confirmed to better understand the role of the oral cavity in COVID-19 infection and transmission.

Prediction of Total-Body and Partial-Body Exposures to Radiation Using Plasma Proteomic Expression Profiles

There is a need to identify new biomarkers of radiation exposure for not only systemic total-body irradiation (TBI) but also to characterize partial-body irradiation and organ specific radiation injury. In the current study, we sought to develop novel biodosimetry models of radiation exposure using TBI and organ specific partial-body irradiation to only the brain, lung or gut using a multivariate proteomics approach. Subset panels of significantly altered proteins were selected to build predictive models of radiation exposure in a variety of sample cohort configurations relevant to practical field application of biodosimetry diagnostics during future radiological or nuclear event scenarios. Female C57BL/6 mice, 8-15 weeks old, received a single total-body or partial-body dose of 2 or 8 Gy TBI or 2 or 8 Gy to only the lung or gut, or 2, 8 or 16 Gy to only the brain using a Pantak X-ray source. Plasma was collected by cardiac puncture at days 1, 3 and 7 postirradiation for total-body exposures and only the lung and brain exposures, and at days 3, 7 and 14 postirradiation for gut exposures. Plasma was then screened using the aptamer-based SOMAscan proteomic assay technology, for changes in expression of 1,310 protein analytes. A subset panel of protein biomarkers which demonstrated significant changes (P < 0.01) in expression after irradiation were used to build predictive models of radiation exposure using different sample cohorts. Model 1 compared controls vs. all pooled irradiated samples, which included TBI and all organ specific partial irradiation. Model 2 compared controls vs. TBI vs. partial irradiation (with all organ specific partial exposure pooled within the partial-irradiated group), and model 3 compared controls vs. each individual organ specific partial-body exposure separately (brain, gut and lung). Detectable values were obtained for all 1,310 proteins included in the SOMAscan assay for all samples. Each model algorithm built using a unique sample cohort was validated with a training set of samples and tested with a separate new sample series. Overall predictive accuracies of 89%, 78% and 55% resulted for models 1-3, respectively, representing novel predictive panels of radiation responsive proteomic biomarkers. Though relatively high overall predictive accuracies were achieved for models 1 and 2, all three models showed limited accuracy at differentiating between the controls and partial-irradiated body samples. In our study we were able to identify novel panels of radiation responsive proteins useful for predicting radiation exposure and to create predictive models of partial-body exposure including organ specific radiation exposures. This proof-of-concept study also illustrates the inherent physiological limitations of distinguishing between small-body exposures and the unirradiated using proteomic biomarkers of radiation exposure. As use of biodosimetry diagnostics in future mass casualty settings will be complicated by the heterogeneity of partial-body exposure received in the field, further work remains in adapting these diagnostic tools for practical use.

Locally Secreted Semaphorin 4D Is Engaged in Both Pathogenic Bone Resorption and Retarded Bone Regeneration in a Ligature-Induced Mouse Model of Periodontitis

It is well known that Semaphorin 4D (Sema4D) inhibits IGF-1-mediated osteogenesis by binding with PlexinB1 expressed on osteoblasts. However, its elevated level in the gingival crevice fluid of periodontitis patients and the broader scope of its activities in the context of potential upregulation of osteoclast-mediated periodontal bone-resorption suggest the need for further investigation of this multifaceted molecule. In short, the pathophysiological role of Sema4D in periodontitis requires further study. Accordingly, attachment of the ligature to the maxillary molar of mice for 7 days induced alveolar bone-resorption accompanied by locally elevated, soluble Sema4D (sSema4D), TNF-α and RANKL. Removal of the ligature induced spontaneous bone regeneration during the following 14 days, which was significantly promoted by anti-Sema4D-mAb administration. Anti-Sema4D-mAb was also suppressed in vitro osteoclastogenesis and pit formation by RANKL-stimulated BMMCs. While anti-Sema4D-mAb downmodulated the bone-resorption induced in mouse periodontitis, it neither affected local production of TNF-α and RANKL nor systemic skeletal bone remodeling. RANKL-induced osteoclastogenesis and resorptive activity were also suppressed by blocking of CD72, but not Plexin B2, suggesting that sSema4D released by osteoclasts promotes osteoclastogenesis via ligation to CD72 receptor. Overall, our data indicated that ssSema4D released by osteoclasts may play a dual function by decreasing bone formation, while upregulating bone-resorption.

The role of Piezo1 mechanosensor in osteoclastogenesis from monocytes

Objectives

Interrelations between bone and the immune system are involved in both homeostatic and pathogenic bone remodeling processes. Although emerging evidence supports that mechanosensitive Ca2+-channel Piezo1 plays a pivotal role in osteoblast-mediated bone regeneration, possible engagement of Piezo1 in the differentiation of osteoclasts from monocytes and resulting bone resorption is largely unknown. In the present study, we sought to establish the role of Piezo1 in RANKL-stimulated monocytes for their differentiation to osteoclasts in vitro.

Methods

Mouse RAW 264.7 monocyte cell line or bone marrow derived mononuclear cells (BMMCs) were stimulated with M-CSF and/or RANKL, in the presence or absence of Yoda1 (Piezo1 activator) or with or without hydrostatic pressure (HP). Ca2+ influx assay was employed to confirm Piezo1 channel activity. To evaluate the level of osteoclastogenesis and bone-resorptive function by mature osteoclasts, TRAP staining and pit formation assays were performed. To monitor the expressions of mRNAs for Piezo1 as well as OC-STAMP, TRAP (ACP5) and MMP9, qPCR were employed.

Results

Yoda1-mediated Ca2+ influx was significantly elevated in RANKL BMMCs and RAW264.7 cells, while significantly suppressing the expressions of osteoclastogenesis-related genes, OC-STAMP, MMP9 and ACP5. Moreover, the number and size of multi-nucleated TRAP-positive cells as well as formation of resorption pits were significantly down-regulated by the treatment with Yoda1 as well as HP.

Conclusions

The present study suggests that mechanosensitive Piezo1 channel expressed on monocytes may play a gatekeeper role in down-modulating over-activation of osteoclastogenesis and function to resorb bone.

Supported by NIH NIDCR grants, DE-027851, DE-028715 and DE-331851

Association between anti-P. gingivalis antibodies and anti-citrullinated vimentin antibodies in the patients with rheumatoid arthritis

Objectives

Anti-citrullinated-protein auto-antibodies (ACPA), especially that react to citrullinated vimentin (CV), are implicated in the pathogenesis of Rheumatoid arthritis (RA). P. gingivalis (Pg), a key pathogen of periodontitis, can citrullinate the host proteins by production of Pg-derived peptidylarginine deiminase (PPAD). This study evaluated the relationship among antibodies (Abs) that react cyclic citrullinated protein (CCP), CV and periodontal pathogens in the serum of RA patients or control subjects.

Methods

Blood serum of healthy subjects (n=10) and RA patients (n=26) were obtained from Precision for Medicine. Six distinctive peptide sequences of Vimentin (#1–#6) and corresponding CV (#1’–#6’) peptides were synthesized. ELISA was employed to detect IgG Ab titers for CCP, intact vimentin and CV peptides. Fixed periodontal pathogens, Pg 33277, F. nucleatum, P. intermedia, A. actinomycetemcomitans (Aa) Y4, S. mitis, S. gordonii, A. odontolyticus, and C. gingivalis were also used as IgG ELISA antigens.

Results

The levels of anti-CCP Ab were higher in RA patients with anti-Pg Ab than those without anti-Pg Ab. Since elevated anti-Pg Ab is hallmark of periodontitis, it is conceivable that RA patients with anti-Pg Ab would have periodontitis. However, there was no association between anti-CCP Ab and the Abs reactive to the other bacteria. Very interestingly, RA patients with anti-Pg Ab, but not those without anti-Pg Ab, showed significantly elevated Ab response to #6’ CV peptide compared to intact #6 vimentin peptide, among six peptide sequences tested.

Conclusions

Our findings indicated that periodontitis may be associated with the induction of ACPA via PPAD-mediated citrullination of host proteins.

Supported by NIH NIDCR grants, DE-027851, DE-028715 and DE-331851

Prognostic value of the combination of pulmonary-systemic pressure ratio and a new systemic inflammation-nutrition index in patients admitted for acute decompensated heart failure

Background

Concomitant presence of pulmonary hypertension in heart failure (HF) is associated with increased adverse events and may be related to interventricular uncoupling and impaired cardiac efficiency. It has recently been shown that an increased mean pulmonary artery pressure to mean systemic arterial pressure ratio (MPS ratio), a marker of interventricular coupling and efficiency, is associated with worse clinical outcomes in patients with advanced HF. On the other hand, systemic inflammation plays a critical role in the outcomes of heart failure, and malnutrition is also associated with poor outcome in heart failure patients It has been recently reported that advanced lung cancer inflammation index (ALI), which is calculated as body mass index × serum albumin / neutrophil to lymphocyte ratio (NLR), is an independent prognostic marker in several types of cancer. However, there is no information available on the prognostic value of the combination of MPS ratio and ALI in patients with acute decompensated HF (ADHF).

Methods and results

We studied 219 patients admitted for ADHF, who underwent right heart catheterization at the admission and were discharged with survival. During a follow up period of 5.1±4.2 yrs, 57 had cardiovascular death (CVD). MPS ratio was significantly greater (0.401±0.107 vs 0.346±0.105, p=0.0009) and ALI was significantly smaller (34.2±18.7 vs 52.0±27.1, p&lt;0.0001) in patients with than without CVD At multivariate Cox analysis, MPS ratio and ALIwere significantly associated with CVD, independently of eGFR and prior heart failure hospitalization, after the adjustment with left ventricular end-diastolic dimension and serum sodium level. The patients with both greater MPS ratio&gt;0.350 (AUC 0.652 [0.569–0.735]) and smaller ALI &lt;35.767 (AUC 0.714 [0.636–0.792]) had a significantly increased risk of CVD than those with either greater MPS or smaller ALI and none of them (67% vs 22% vs 11%, p&lt;0.0001, respectively).

Conclusion

The combination of MPS ratio and ALI might be useful for stratifying ADHF patients at higher risk for CVD.

Funding Acknowledgement

Type of funding sources: None.

Prognostic value of sarcopenia and malnutrition in patients admitted for acute decompensated heart failure with reduced or preserved left ventricular ejection fraction

Background

Sarcopenia and malnutrition are associated with poor clinical outcome in patients with chronic heart failure. However, there is little information available on the prognostic significance of the combination of sarcopenia and malnutrition in patients with acute decompensated heart failure (ADHF), relating to reduced or preserved left ventricular ejection fraction (HFrEF or HFpEF).

Methods

We prospectively studied 543 consecutive ADHF patients who survived to discharge (HFrEF [LVEF &lt;45%] n=245 and HFpEF [LVEF≥45%] n=298). At the discharge, sarcopenia and malnutrition was evaluated by free-fat mass index (FFMI) and geriatric nutrition risk index (GNRI), respectively. FFMI was calculated as follows: FFMI = (7.38 + 0.02908 × urinary creatinine [mg/day])/ (height in meter)2. Sarcopenia was defined as FFMI &lt;17 kg/m2 in men and &lt;15 kg/m2 in women. GNRI was calculated as follows: 14.89 × serum albumin (g/dl) + 41.7 × BMI/22, and malnutrition was defined as GNRI&lt;92. The endpoint was all-cause death.

Results

During a follow-up period of 2.8±1.4 years, 161 patients had all-cause death. Multivariate Cox analysis showed that both FFMI and GNRI were independently associated with all-cause death in both HFrEF (p=0.0064 and p&lt;0.0001, respectively) and HFpEF patients (p=0.0140 and p=0.0007, respectively) after adjustment for relevant baseline clinical and study characteristics. In HFrEF, patients with both sarcopenia and malnutrition had a significantly higher risk of the total mortality than those with either or none of them. On the other hand, in HFpEF, patients with both and either sarcopenia or malnutrition had a significantly higher risk of the total mortality than those with none of them, while there was no significant difference in the risk between both and either sarcopenia or malnutrition.

Conclusions

Sarcopenia or malnutrition at discharge was associated with all-cause death even in ADHF patients, irrespective of reduced or preserved LVEF. The combination of sarcopenia and malnutrition could provide prognostic information in ADHF patients with reduced LVEF.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Prognostic value of simple risk index and plasma volume status in patients with acute decompensated heart failure

Background

Increased heart rate (HR) and low systolic blood pressure (SBP) are associated with adverse clinical outcomes in patients admitted for acute decompensated heart failure (ADHF), and simple risk index (SRI) based on easily assessed clinical characteristics (age, HR, and SBP) provides prognostic information. On the other hand, plasma volume (PV) expansion plays an essential role in heart failure, and PV status is has been reported to be associated with adverse outcomes in ADHF patients. However, there is no information available on the value of the combination of SRI and PV status in patients admitted for ADHF.

Methods and results

We studied 301 patients admitted for ADHF. At the admission, SRI was calculated as (HR x [age/10]2)/SBP. PV status was calculated as the following: Actual PV = (1 − hematocrit) x [a + (b x body weight)] (a=1530 in males and a=864 in females, b=41 in males and b=47.9 in females), Ideal PV = c x body weight (c=39 in males and c=40 in females), and PV status = [(actual PV − ideal PV)/ideal PV] x 100(%). During a follow-up period of 4.3±3.2 yrs, 95 patients had all-cause death (ACD) and 68 patients had cardiovascular death (CVD). At multivariate Cox analysis, SRI and PV status were significantly associated with ACD and CVD, independently of the prior history of heart failure hospitalization and serum creatinine and sodium levels, after the adjustment with serum albumin level and anemia. Patients with both greater SRI (≥35.1 by ROC analysis; AUC 0.599 [0.524–0.674]) and greater PV status (≥8.1% by ROC analysis; AUC 0.625 [0.550–0.700]) had a significantly higher risk of ACD and CVD than those with either or none of them (ACD: 49% vs 27% vs 24%, p&lt;0.0001, CVD: 39% vs 18% vs 15%, p&lt;0.0001,respectively).

Conclusion

The combination of SRI and PV status might be useful for stratifying patients at risk for the total mortality and cardiovascular death in patients with ADHF.

Funding Acknowledgement

Type of funding sources: None.

The impact of substrate and trigger ablation for reduction of functional mitral regurgitation in patients with persistent atrial fibrillation

Background

Functional mitral regurgitation (FMR) is not uncommon in atrial fibrillation (AF) patients. Left atrial (LA) substrate remodeling and corresponding mitral valve annulus dilation has been reported as the most possible cause of FMR. Percutaneous catheter ablation (CA) is an effective treatment for AF. Although significant FMR could be improved by sinus restoration, patients with mitral regurgitation were more likely to experience recurrent AF post ablation, especially those with significant mitral regurgitation. There is no information available on the efficacy of CA for persistent AF in patients with FMR.

Purpose

The purpose of this study is to investigate the predictors of FMR improvement by CA and to determine the efficacy of substrate and trigger CA for persistent AF in patients with FMR.

Methods

We prospectively studied 512 consecutive patients admitted for persistent AF ablation from the EARNEST-PVI (Prospective Multicenter Randomized Study of Effect of Extensive Ablation on Recurrence in Patients with Persistent Atrial Fibrillation Treated with Pulmonary Vein Isolation) trial.

On admission, enrolled patients were randomly assigned in a 1:1 ratio to pulmonary vein isolation (PVI) or PVI-plus additional ablation (linear ablation or/and CFAE ablation). Of the 512 patients, we studied 94 patients with preoperative echocardiography showing moderate or greater baseline FMR. FMR grades were classified into 5 grades (0/1/2/3/4). The FMR improvement group (FMRI(+)) was defined as a case in which the FMR was improved by two or more grades compared the preoperative echocardiography and the one year follow-up examination.

Results

Of the 94 patients, 42 were in the PVI group and 52 were in the PVI-plus additional ablation group. There were 30 cases in the FMRI(+) group and 64 cases in the FMRI(−) group. There were no significant baseline differences in age, sinus rhythm maintenance, plasma B-type natriuretic peptide (BNP) level, left ventricular diastolic dimension, or left atrium dimension between the FMRI(+) and FMRI(−) groups. AF duration was significantly shorter in the FMRI(+) group than FMRI(−) groups (5.8±9.4 months vs 12.4±15.4 months, p&lt;0.0001). In addition, significantly more additional ablation cases were observed in the FMRI(+) group than in the FMRI(−) group (73.3% vs 46.8%, p=0.016). In multivariate analyses, only additional ablation was an independent predictor of FMRI (odds ratio 0.226 95% CI 0.081–0.626; p=0.004).

Conclusions

Catheter ablation is a valid option for the treatment of AF in patients with functional MR and additional substrate and trigger ablation were the only independent predictor of FMR improvement.

Funding Acknowledgement

Type of funding sources: None.

Prognostic value of a new systemic inflammation-nutrition index in patients admitted with acute decompensated heart failure; a comparison with malnutrition

Background

Systemic inflammation plays a critical role in the outcomes of heart failure. Malnutrition is also associated with poor outcome in heart failure patients. It has been recently reported that advanced lung cancer inflammation index (ALI), which is calculated as body mass index × serum albumin / neutrophil to lymphocyte ratio (NLR), is an independent prognostic marker in several types of cancer. However, there is no information available on the prognostic impact of ALI in patients admitted with acute decompensated heart failure (ADHF), especially in comparison with malnutrition.

Methods and results

We studied 263 ADHF patients discharged with survival. At the discharge, we measured ALI. Malnutrition was assessed by prognostic nutritional index (PNI) and controlling nutritional status score (CONUT). During a follow up period of 5.1±4.3 yrs, 67 patients had cardiovascular death (CVD). ALI was significantly smaller in patients with than without CVD (32.5±18.2 vs 52.2±30.2, p&lt;0.0001). At multivariate Cox regression analysis, ALI was significantly associated with CVD, independently of prior heart failure hospitalization, systolic blood pressure and eGFR, although PNI and CONUT showed the association with CVD at unvariate analysis. By receiver-operator curve analysis, AUC of ALI was 0.733 (0.664–0.803), which was significantly greater than that of PNI (0.664 [0.590–0.739]) and CONUT (0.591 [0.509–0.672]). Patients with lowest tertile of ALI (&lt;32.0) had a increased risk of mortality than middle tertile (NLR=32.0–53.6; HR 2.06 [1.15–3.71]) and highest tertile (ALI&gt;53.6: HR 5.80 [2.60–12.94]) (48% vs 21% vs 9%, p&lt;0.0001, respectively).

Conclusion

ALI, a systemic inflammation-nutrition index, is more useful prognostic marker than malnutrition in patients admitted with ADHF.

Funding Acknowledgement

Type of funding sources: None.

Long-term prognostic value of the combination of malnutrition and fib-4 index in patients admitted with acute decompensated heart failure

Background

Malnutrition is associated with increased mortality risk in patients with acute decompensated heart failure (ADHF). Cardiohepatic interactions have been a focus of attention among heart failure. It was reported that liver stiffness assessed by non-invasive fibrosis marker such as Fibrosis-4 (FIB4) index provide prognostic information in ADHF patients. However, there is no information available on the long-term prognostic value of the combination of malnutrition and FIB4 index in patients admitted for ADHF.

Methods and results

We studied 294 patients admitted for ADHF, who were discharged with survival. Nutritional status was evaluated by Geriatric Nutritional Risk Index (GNRI) calculated as follows: 14.89 × serum albumin (g/dl) + 41.7 × BMI/22, and malnutrition was defined as GNRI &lt;92. FIB4 index was calculated by the formula: age (yrs) × AST[U/L] / (platelets [103/μL] × (ALT[U/L])1/2), and abnormal FIB4 index was defined as &gt;2.67. During a mean follow-up period of 4.3±3.3 yrs, 94 patients had all-cause death. At multivariate Cox regression analysis, GNRI and FIB4 index were significantly associated with the total mortality, independently of prior heart failure hospitalization, systolic blood pressure, and serum creatinine level. Patients with malnutrition and abnormal FIB4 index had a significantly higher risk of the total mortality than those with either and none of them (49% vs 32% vs 20%, p&lt;0.0001, respectively).

Conclusions

The combination of malnutrition and FIB4 index might be useful for stratifying ADHF patients at higher risk for the total mortality.

Funding Acknowledgement

Type of funding sources: None.

B-Cell RANKL Contributes to Pathogen-Induced Alveolar Bone Loss in an Experimental Periodontitis Mouse Model

Periodontitis is a bacterially-induced inflammatory disease that leads to tooth loss. It results from the damaging effects of a dysregulated immune response, mediated largely by neutrophils, macrophages, T cells and B cells, on the tooth-supporting tissues including the alveolar bone. Specifically, infiltrating B cells at inflamed gingival sites with an ability to secrete RANKL and inflammatory cytokines are thought to play roles in alveolar bone resorption. However, the direct contribution of B cells in alveolar bone resorption has not been fully appreciated. In this study we sought to define the contribution of RANKL expressing B cells in periodontitis by employing a mouse model of pathogen-induced periodontitis that used conditional knockout mice with B cell-targeted RANKL deletion. Briefly, alveolar bone loss was assessed in the wild-type, B-cell deficient (Jh), or B-cell-RANKL deleted (RANKLΔB) mice orally infected with the periodontal pathogen Tannerella forsythia. The RANKLΔB mice were obtained by crossing Cd19-Cre knock-in mice with mice homozygous for conditional RANKL-flox allele (RANKLflox/flox). The alveolar bone resorption was determined by morphometric analysis and osteoclastic activity of the jaw bone. In addition, the bone resorptive potential of the activated effector B cells was assessed ex vivo. The data showed that the RANKL producing B cells increased significantly in the T. forsythia-infected wild-type mice compared to the sham-infected mice. Moreover, T. forsythia-infection induced higher alveolar bone loss in the wild-type and RANKLflox/flox mice compared to infection either in the B cell deficient (Jh) or the B-cell specific RANKL deletion (RANKLΔB) mice. These data established that the oral-pathogen activated B cells contribute significantly to alveolar bone resorption via RANKL production.

Observation of Coulomb-Assisted Nuclear Bound State of Ξ^{-}-^{14}N System

In an emulsion-counter hybrid experiment performed at J-PARC, a Ξ^{-} absorption event was observed which decayed into twin single-Λ hypernuclei. Kinematic calculations enabled a unique identification of the reaction process as Ξ^{-}+^{14}N→_{Λ}^{10}Be+_{Λ}^{5}He. For the binding energy of the Ξ^{-} hyperon in the Ξ^{-}-^{14}N system a value of 1.27±0.21  MeV was deduced. The energy level of Ξ^{-} is likely a nuclear 1p state which indicates a weak ΞN-ΛΛ coupling.

Potential Role of Phosphoglycerol Dihydroceramide Produced by Periodontal Pathogen Porphyromonas gingivalis in the Pathogenesis of Alzheimer's Disease

Background

Among different types of sphingolipids produced by human cells, the possible engagement of ceramide species in the pathogenesis of Alzheimer’s disease (AD) has attracted recent attention. While ceramides are primarily generated by de novo synthesis in mammalian cells, only a limited number of bacterial species, produce ceramides, including phosphoglycerol dihydroceramide (PGDHC) that is produced by the key periodontal pathogen Porphyromonas gingivalis. Emerging evidence indicates that virulence factors produced by P. gingivalis, such as lipopolysaccharide and gingipain, may be engaged in the initiation and/or progression of AD. However, the potential role of PGDHC in the pathogenesis of AD remains unknown. Therefore, the aim of this study was to evaluate the influence of PGDHC on hallmark findings in AD.

Material and Methods

CHO-7WD10 and SH-SY-5Y cells were exposed to PGDHC and lipopolysaccharide (LPS) isolated from P. gingivalis. Soluble Aβ42 peptide, amyloid precursor protein (APP), phosphorylated tau and senescence-associated secretory phenotype (SASP) factors were quantified using ELISA and Western blot assays.

Results

Our results indicate that P. gingivalis (Pg)-derived PGDHC, but not Pg-LPS, upregulated secretion of soluble Aβ42 peptide and expression of APP in CHO-7WD10 cells. Furthermore, hyperphosphorylation of tau protein was observed in SH-SY-5Y cells in response to PGDHC lipid. In contrast, Pg-LPS had little, or no significant effect on the tau phosphorylation induced in SH-SY-5Y cells. However, both PGDHC and Pg-LPS contributed to the senescence of SH-SY5Y cells as indicated by the production of senescence-associated secretory phenotype (SASP) markers, including beta-galactosidase, cathepsin B (CtsB), and pro-inflammatory cytokines TNF-α, and IL-6. Additionally, PGDHC diminished expression of the senescence-protection marker sirtuin-1 in SH-SY-5Y cells.

Conclusions

Altogether, our results indicate that P. gingivalis-derived PGDHC ceramide promotes amyloidogenesis and hyperphosphorylation, as well as the production of SASP factors. Thus, PGDHC may represent a novel class of bacterial-derived virulence factors for AD associated with periodontitis.

A prospective, randomized, comparison of the coronary vasomotion associated with drug-coated balloon versus drug-eluting stent

Background

It is widely known that even new-generation drug-eluting stent (DES) induce coronary vasomotion abnormality. On the other hand, recent studies reported that drug-coated balloon (DCB) for native coronary artery was non-inferior to DES in medium term outcomes. However, there is no available information about vasomotion after treatment with DCB.

Purpose

The aim of this study was to prospectively compare coronary vasomotion in patients treated with DCB versus new-generation DES.

Methods

Twenty-seven patients were randomly treated with angioplasty with DCB (n=12) versus implantation of bioabsorbable polymer everolimus-eluting stent (BP-EES, n=15) after successful predilation. At 8 months after treatment, endothelium-dependent and -independent vasomotion were evaluated by intracoronary infusion of incremental doses of acetylcholine (for right coronary artery: low-dose 5μg, high-dose 50μg and for left coronary artery: low-dose 10μg, high-dose 100μg) and nitroglycerine (200μg). Mean luminal diameter of the distal segments, beginning 5 mm and ending 15 mm distal to the edge of the treated segment was quantitatively measured by angiography.

Results

Clinical and procedural characteristics were not different between two groups. Vasoconstriction after acetylcholine infusion was less pronounced in the DCB group than the BP-EES group (low-dose: 4±13% vs −4±14%, p=0.158, high-dose: −2±14% vs −28±30%, p=0.013). The response to nitroglycerin was not different between two groups (17±13% vs 18±24%, p=0.838).

Conclusion

Vasoconstriction after acetylcholine infusion in the peri-treated region was more pronounced in the BP-EES group than in the DCB group, which suggests that endothelial function of coronary vessel treated by DCB can be more preserved than new-generation DES.

Figure 1

Funding Acknowledgement

Type of funding source: None

Predictors of silent cerebral infarction associated with catheter ablation for atrial fibrillation

Introduction

Cather ablation (CA) has been identified as an effective and safe treatment option for patients with atrial fibrillation (AF). One of the serious complications associated AF is cerebral infarction (CI). Recent studies reported that CA was associated with lower incidence of ischemic stroke in patients with AF. However, CA for AF itself has a potential risk of CI. Several previous studies showed that the incidence of silent CI (SCI) assessed by magnetic resonance imaging (MRI) of the brain occurred 5 to 18% during CA for AF. Recently, CA for AF made a remarkable progress in technology. However, there are few information available that the impact of 3-dimensional electroanatomical mapping system on the incidence of SCI. This study aimed to clarify the prevalence and predictors of SCI during CA for AF.

Methods

We enrolled 893 consecutive patients (male 534, age 71±10 years), who underwent CA for AF and MRI of brain 1 day after the procedure. We collected patients data such as physical examinations, blood sampling, echo cardiography, and CA data. A brain MRI was performed the next day following the procedure to identify any CIs. One-hundred and forty-six of patients used the Rhythmia® mapping system catheter, and the other mapping system such as CARTO or EnSite system used in the remaining 747 patients.

Results

The MRI depicted acute micro-CIs in 144 (16%) patients, but neither symptoms nor abnormal neurological findings were present in these patients. Patients with SCI had significantly higher prevalence of persistent AF (60 vs 43%, p=0.0002), CHADS2 Score (2 (1–3) vs 1 (1–2), p=0.0001), higher prevalence of previous stroke (19 vs 12%, p=0.02), larger left atrial (LA) diameter (43.2±6.4 vs 41.7±6.5mm, p=0.01), lower left ventricular ejection fraction (LVEF) (59.0±13.2 vs 64.2±11.3%, p≤0.0001), higher B-type natriuretic peptide level (221±236 vs 163±225 pg/dl, p≤0.0001), more Rhythmia® mapping system use (30 vs 8%, p&lt;0.0001), and longer procedure time (129±46 vs 108±39 min, p≤0.0001) than those without SCI, while there were no significant differences in age, LA appendage flow velocity, kind of anti-coagulant agent between the two groups. Multivariate regression analysis identified Rhythmia® use [odds ratio (OR) 4.26, (95% CI 2.32–7.84), p=0.0001], LVEF (OR 1.02, p=0.0059), CHADS2 score (OR 1.27, p=0.009), and procedure time (OR 1.005, p=0.04) as independent risk factors of acute SCI during CA for AF.

Conclusion

Acute SCI occurred about 16% after CA for AF. Rhythmia® mapping system use exhibited a higher incidence of acute SCI after catheter ablation for AF than the other mapping system use. Rhythmia® mapping system use, LVEF, CHADS2 score, and procedure time are associated with SCI relating CA for AF.

Funding Acknowledgement

Type of funding source: None

Impact of simple nutrition index on the long-term mortality of acute decompensated heart failure patients with preserved left ventricular ejection fraction: insight from PURSUIT-HFpEF registry

Background

The novel nutrition index; triglyceride (TG) × total cholesterol (TG) × body weight (BW) index (TCBI) has been reported to be an easy and useful predictor for patients with coronary artery disease. However, there is no information available on the prognostic value of TCBI in patients with heart failure with preserved LVEF (HFpEF) who admitted with acute decompensated heart failure (ADHF).

Methods and results

Data were extracted from The Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT HFpEF) study. PURSUIT-HFpEF study is a prospective multicenter observational study in which collaborating hospitals recorded clinical, echocardiographic, and outcome data of ADHF pts with HFpEF. We enrolled consecutive 757 HFpEF patients who admitted with ADHF from June 2016 to June 2019. TCBI was calculated by the formula; TG × TC × BW / 1000 at the discharge. After we excluded patients with in-hospital death or without sufficient data, we analyzed 419 patients. The primary endpoint was all-cause mortality. During a median follow up period of 1.1 (0.9–1.9) years, 59 patients died. ROC analysis revealed that TCBI at discharge was a fair discriminator for predicting all-cause mortality (AUC 0.676, sensitivity 53%, specificity 78%). Multivariate Cox proportional analysis showed that TCBI (p=0.002) was an independent predictor for all cause death after adjustment with major confounders such as age, gender, NT-proBNP, hemoglobin and serum creatinine level. We divided patients into 4 groups according to quartiles of TCBI. Kaplan-Meier analysis showed a significantly higher risk of all-cause death in relation to the decrease in TCBI.

Conclusion

TCBI, a simple and novel nutrition index, is a useful and strong long-term prognostic indicator in ADHF patients with HFpEF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnositics K.K.; Fuji Film Toyoma Chemical Co. Ltd.

Effect of empagliflozin as add-on therapy on transtubular potassium concentration gradient in patients with type 2 diabetes hospitalized for acute decompensated heart failure

Background

The transtubular potassium concentration gradient (TTKG) has been reported to be a marker of renal aldosterone bioactivity, and has been shown to be a surrogate of arterial underfilling in patients with acute decompensated heart failure (ADHF). Moreover, high TTKG at discharge has been shown to be associated with poor prognosis in ADHF patients. Empagliflozin, one of the sodium glucose cotransporter 2 inhibitors, has been shown to reduce the risk of cardiovascular mortality in patients with type 2 diabetes mellitus (T2D) and cardiovascular disease. However, little is known about the effect of empagliflozin as add-on therapy on TTKG in T2D patients with ADHF.

Purpose

We sought to elucidate the effect of empagliflozin as add-on therapy on TTKG in T2D patients with ADHF.

Methods

We enrolled 58 consecutive T2D patients admitted for ADHF. On admission, enrolled patients were randomly assigned in a 1:1 ratio to either empagliflozin add-on therapy (EMPA(+)) or conventional glucose-lowering therapy (EMPA(−)). All patients in EMPA(+) group received empagliflozin (10 mg/day) throughout the study period. Left ventricular ejection fraction (LVEF) was measured at baseline using echocardiography. Body weight and vital signs, such as blood pressure and heart rate, were measured, and blood and urine samples were collected at baseline and 1, 2, 3 and 7 days after randomization. The TTKG was measured using the first morning urine samples collected on each day. TTKG was calculated according to the following equation: TTKG = (Ku/Ks)×(plasma osmolality/urine osmolality), where Ku is urine potassium concentration and Ks is serum potassium concentration, as previously reported.

Results

Thirty patients were assigned to the EMPA(+) group, and 28 patients were assigned to the EMPA(−) group. There were no significant baseline differences in LVEF, plasma B-type natriuretic peptide (BNP) level, body mass index, or serum creatinine level between the EMPA(+) and EMPA(−) groups. TTKG did not significantly differ between the two groups at baseline. However, seven days after randomization, plasma BNP level was significantly lower in the EMPA(+) group than in the EMPA(−) group (median 227 [IQR 114–381] pg/mL vs 362 [227–554] pg/mL, p=0.0294). Furthermore, TTKG of the EMPA(+) group was significantly lower at 2, 3 and 7 days after randomization (Figure).

Conclusions

This study demonstrated that empagliflozin as add-on therapy can lower TTKG in T2D patients with ADHF.

Figure 1

Funding Acknowledgement

Type of funding source: None

Role of diuretics on long-term mortality may differ in volume status in patients with acute myocardial infarction

Background

Diuretics has been reported to have a potential for an activation of the renin-angiotensin-aldosterone system and the sympathetic nervous system, leading to a possibility of poor clinical outcome in patients with cardiovascular disease. However, few data are available on clinical impact of diuretics on long-term outcome in patients with acute myocardial infarction (AMI) based on plasma volume status.

Methods

To address the issue, a total of 3,416 survived patients with AMI who were registered to a large database of the Osaka Acute Coronary Insufficiency Study (OACIS) were studied. Plasma volume status was assessed with the estimated plasma volume status (ePVS) that was calculated at discharge as follows: actual PV = (1 − hematocrit) × [a + (b × body weight)] (a=1530 in males and a=864 in females, b=41.0 in males and b=47.9 in females); ideal PV = c × body weight (c=39 in males and c=40 in females), and ePVS = [(actual PV − ideal PV)/ideal PV] × 100 (%). Multivariable Cox regression analysis and propensity score matching were performed to account for imbalances in covariates. The endpoint was all-cause of death (ACD) within 5 years.

Results

During a median follow-up period of 855±656 days, 193 patients had ACD. In whole population, there was no significant difference in long-term mortality risk between patients with and without diuretics in both multivariate cox regression model and propensity score matching population. When patients were divided into 2 groups according to ePVS with a median value of 4.2%, 46 and 147 patients had ACD in groups with low ePVS and high ePVS, respectively. Multivariate Cox analysis showed that use of diuretics was independently associated with an increased risk of ACD in low ePVS group, (HR: 2.63, 95% confidence interval [CI]: 1.22–5.63, p=0.01), but not in high ePVS group (HR: 0.70, 95% CI: 0.44–1.10, p=0.12). These observations were consistent in the propensity-score matched cohorts; the 5-year mortality rate was significantly higher in patients with diuretics than those without among low ePVS group (4.7% vs 1.7%, p=0.041), but not among high ePVS group (8.0% vs 10.3%, p=0.247).

Conclusion

Prescription of diuretics at discharge was associated with increased risk of 5-year mortality in patients with AMI without PV expansion, but not with PV expansion. The role of diuretics on long-term mortality may differ in plasma volume status. Therefore, prescription of diuretics after AMI may be considered based on plasma volume status.

Funding Acknowledgement

Type of funding source: None

Comparative prognostic impact of ACCI and AHEAD risk score in heart failure with reduced, mid-range and preserved left ventricular ejection fraction admitted for acute decompensated heart failure

Background

Comorbidities are strongly associated with poor clinical outcome in heart failure patients (pts). The Age-adjusted Charlson comorbidity index (ACCI), which is well-known widely used comorbidity index, recently has been used as a robust prognostic model in heart failure pts. On the other hand, AHEAD risk score has been recently reported as a useful long-term risk stratification score in acute decompensated heart failure (ADHF) pts. Recently, a new group of heart failure pts with mid-range ejection fraction (HFmrEF) has been defined, separated from reduced ejection fraction (HFrEF) and preserved ejection fraction (HFpEF). We sought to compare the prognostic value of ACCI and AHEAD score in ADHF pts, relating to HFrEF, HFmrEF and HFpEF.

Methods

We prospectively studied 410 consecutive ADHF pts (HFrEF [n=143], HFmrEF [n=99] and HFpEF [n=168]) with survival discharge. ACCI contains 19 issues which was weighted according to their potential influence on mortality. AHEAD risk score is a simple index, which is range 0–5; atrial fibrillation, hemoglobin &lt;13 mg/dL for men and 12 mg/dL for women, age &gt;70 years, creatinine &gt;130 μmol/L, and diabetes mellitus. The endpoint of this study was all cause death (ACD).

Results

During a follow-up period of 2.4±1.4 years, 119 pts had ACD (42, 29 and 48 pts in HFrEF, HFmrEF and HFpEF, respectively). At univariate Cox analysis, ACCI and AHEAD risk score were significantly associated with ACD in each subgroup. At multivariate Cox analysis, in HFrEF pts, ACCI, but not AHEAD risk score, showed the significant and independent association with ACD. In HFmrEF, both ACCI and AHEAD risk score was significantly and independently associated with ACD and ROC analysis showed AUC of ACCI was greater than that of AHEAD risk score (0.778 [0.683–0.855] vs 0.637 [0.572–0.764], p=0.07). On the other hand, in HFpEF pts, AHEAD risk score, but not ACCI, showed the significant and independent association ACD.

Conclusion

ACCI provides more prognostic value in HFrEF pts, and AHEAD risk score has more prognostic value in HFpEF pts. In HFmrEF pts, both ACCI and AHEAD score might have prognostic values, although ACCI tends to be more associated with ACD than AHEAD score.

Funding Acknowledgement

Type of funding source: None

Tuning cytokines enriches dendritic cells and regulatory T cells in the periodontium

BACKGROUND

Periodontal disease results from the pathogenic interactions between the tissue, immune system, and microbiota; however, standard therapy fails to address the cellular mechanism underlying the chronic inflammation. Dendritic cells (DC) are key regulators of T cell fate, and biomaterials that recruit and program DC locally can direct T cell effector responses. We hypothesized that a biomaterial that recruited and programmed DC toward a tolerogenic phenotype could enrich regulatory T cells within periodontal tissue, with the eventual goal of attenuating T cell mediated pathology.

METHODS

The interaction of previously identified factors that could induce tolerance, granulocyte-macrophage colony stimulating factor (GM-CSF) and thymic stromal lymphopoietin (TSLP), with the periodontitis network was confirmed in silico. The effect of the cytokines on DC migration was explored in vitro using time-lapse imaging. Finally, regulatory T cell enrichment in the dermis and periodontal tissue in response to alginate hydrogels delivering TSLP and GM-CSF was examinedin vivo in mice using immunohistochemistry and live-animal imaging.

RESULTS

The GM-CSF and TSLP interactome connects to the periodontitis network. GM-CSF enhances DC migration in vitro. An intradermal injection of an alginate hydrogel releasing GM-CSF enhanced DC numbers and the addition of TSLP enriched FOXP3+ regulatory T cells locally. Injection of a hydrogel with GM-CSF and TSLP into the periodontal tissue in mice increased DC and FOXP3+ cell numbers in the tissue, FOXP3+ cells in the lymph node, and IL-10 in the tissue.

CONCLUSION

Local biomaterial-mediated delivery of GM-CSF and TSLP can enrich DC and FOXP3+ cells and holds promise for treating the pathologic inflammation of periodontal disease.

Prognostic significance of cardiac 123I-MIBG SPECT imaging in patients with acute decompensated heart failure with preserved left ventricular ejection fraction

Background

Cardiac sympathetic nerve dysfunction, which is assessed by I-123 metaiodobenzylguanidine (MIBG) imaging, is associated with the poor outcomes in patients with heart failure (HF). Most of the literature on the use of 123I-MIBG imaging is based on planar images in patients with chronic HF and reduced left ventricular ejection fraction (HFrEF), because It is technically challenging to conduct precise 123I-MIBG SPECT analysis in globally denervated heart, which is frequently observed in HFrEF patients. There was no information available on cardiac sympathetic nerve dysfunction evaluated by cardiac MIBG SPECT imaging in acute decompensated HF (ADHF) patients with preserved left ventricular ejection fraction (HFpEF).

Purpose

We aimed to clarify the prognostic significance of 123I-MIBG SPECT myocardial imaging in ADHF patients with HFpEF.

Methods

We enrolled 183 patients who were admitted for ADHF with HFpEF, discharged with survival. All patients underwent cardiac MIBG imaging at the timing of discharge. The cardiac MIBG heart to mediastinum ratio (H/M) was calculated on the early image and the delayed image (late H/M). We studied 156 patients after excluding 27 patients whose MIBG SPECT reconstruction was difficult due to too low MIBG uptake or extracardiac accumulation interference. SPECT analysis on the delayed image was conducted by using CardioBull, a fully automated software for the quantification of I-123 MIBG SPECT. All of 17 regional tracer uptake were compared with normal control database. A scoring algorithm for the evaluation of low uptake employs a 5-point scoring system as 0–4 for normal, mildly abnormal, moderately abnormal, severe abnormal, and perfusion defect, respectively. The summed severity (SSS) scores were obtained by summing the score for all segments. SSS could range from 0 to 68. The endpoint of this study is cardiac events defined as the composite of unplanned heart failure hospitalization and cardiac death.

Results

During a mean follow up period of 2.4±1.6 years, 60 patients reached cardiac events. SSS was significantly high in patients with than without cardiac events (20 [10–27] vs 7 [4–16], p&lt;0.0001). SSS (p&lt;0.0001) was significantly associated with cardiac events after multivariable Cox adjustment of age, sex, creatinine and log-transformed BNP level, although late H/M showed the significant association with the endpoint at the univariate Cox analysis. Kaplan-Meier analysis showed that patients with high SSS (&gt;10, defined by median) had significantly greater risk of cardiac event (56% vs 21%, Hazard ratio: 3.56 (2.00–6.33, p&lt;0.0001). ROC curve analysis showed that area under the curve (AUC) of SSS was 0.746 [95% CI:0.670, 0.812], which was significantly higher than that of late H/M (0.618 [95% CI:0.537, 0.695]) (p=0.0159).

Conclusion

Cardiac MIBG SPECT imaging was useful for risk stratification in ADHF patients with HFpEF.

Funding Acknowledgement

Type of funding source: None

Impact of comorbidity on the predictive value of cystatin-C in patients admitted for acute decompensated heart failure: insights from a prospective study

Background

Comorbidities are strongly associated with poor clinical outcome in heart failure patients. The Age-adjusted Charlson comorbidity index (ACCI), which is well-known widely used comorbidity index, recently has been used as a robust prognostic model in heart failure patients. On the other hand, Cystatin C, as a novel and important biomarker of renal function, has been recently reported as a useful long-term risk stratification score in heart failure patients. However, there is no information available on the impact of comorbidities on the prognostic value of cystatin-C in patients admitted for acute decompensated heart failure (ADHF).

Methods

We prospectively studied 458 consecutive ADHF patients with survival discharge. Patients with hemodialysis were excluded. Echocardiography and venous blood sampling were performed just before discharge and serum cystatin-C level was measured. Comorbidity was measured with the Age-adjusted Charlson comorbidity index (ACCI). ACCI was commonly used for the evaluation of the comorbid condition which is weighted and scored, with additional points added for age. The endpoint was all-cause death (ACD).

Results

During a follow-up period of 2.8±1.5 years, 132 patients had ACD. At multivariate Cox analysis, ACCI (p=0.0015) and cystatin-C level (p=0.0145) were significantly and independently associated with ACD. Patients with high ACCI (≥6: determined by ROC analysis) had a significantly greater risk of ACD (37.2% vs 17.8%, p&lt;0.0001, HR 2.45 [1.61–3.70]). In the subgroup of higher ACCI, patients with higher cystatin-C level (≥1.56: determined by ROC analysis) had a significantly higher risk of ACD (50.3% vs 23.4%). Furthermore, in the subgroup of lower ACCI, patients with higher cystatin-C level had also significantly higher risk of ACD (34.2% vs 12.1%).

Conclusions

The prognostic value of cystatin-C is not affected by comorbidities and cystatin-C provide prognostic information even in patients admitted for ADHF, irrespective of comorbid burden.

All-cause death-free rate in ADHF pts

Funding Acknowledgement

Type of funding source: None

Prognostic value of nutritional status in patients with heart failure with preserved ejection fraction, with and without atrial fibrillation: insights From PURSUIT-HFpEF Registry

Background

Malnutrition is one of the most important comorbidities among heart failure (HF) patients, and serum cholinesterase (CHE) has been reported to be a prognostic factor in HF patients. On the other hand, atrial fibrillation (AF) is frequently observed in patients with HF with preserved ejection fraction (HFpEF). However, there is little information available on the prognostic value of nutritional status in HFpEF patients, with and without AF. We sought to clarify the prognostic value of CHE in HFpEF with and without AF and compare it with that of other nutrition indices such as gastric nutritional risk index (GNRI), controlling nutritional status (CONUT), and the prognostic nutritional index (PNI).

Methods and results

Patients data were extracted from The Prospective mUlticenteR obServational stUdy of patIenTs with Heart Failure with Preserved Ejection Fraction (PURSUIT HFpEF) study, which is a prospective multicenter observational registry for acute decompensated heart failure patients with left ventricular ejection fraction ≥50% in Osaka. We analyzed 380 patients (median age: 80 [75–87] years, male: 46%) after exclusion of patients with in-hospital death, missing follow-up data, or missing data to calculate nutritional indices. On admission, 155 patients had AF. Laboratory data were obtained at discharge. During a mean follow up period of 1.1±0.6 years, 131 patients had a composite endpoint (CE) of all-cause death and hospitalization for worsening heart failure or cerebrovascular disorder. In multivariate Cox analysis, in patients with AF, CHE was significantly associated with CE independently of age, gender and body mass index after the adjustment with serum albumin, total cholesterol levels and total lymphocyte count, while it was not significantly associated with CE in patients without AF. C-index of CHE (0.708) was higher than that of GNRI (0.555, p=0.0028), CONUT (0.651, p=0.208) and PNI (0.635, p=0.208) in AF patients, while there were no significant differences in those nutritional indices in patients without AF. Kaplan-Meier curve analysis revealed that AF patients with lower CHE (&lt;208 U/L = median value) had higher risk of CE than those with higher CHE (44% vs 18%, adjusted HR 3.26 95% CI [1.66–6.67], p=0.0005), while there was no significant difference in the occurrence rate of CE between patients with and without higher CHE in non-AF group (42% vs 31%, adjusted HR 1.28 95% CI [0.78–2.13], p=0.33).

Conclusions

Prognostic value of CHE would be stronger than other nutritional indices in HFpEF patients with AF, while it would be weak in HFpEF patients without AF.

Funding Acknowledgement

Type of funding source: Private company. Main funding source(s): Roche Diagnostics K.K.; Fuji Film Toyama Chemical Co. Ltd.

Long-term serial changes of cardiac sympathetic nerve dysfunction in acute decompensated heart failure patients with reduced, mid-range and preserved left ventricular ejection fraction

Background

Cardiac sympathetic nerve dysfunction, which is assessed by I-123 metaiodobenzylguanidine (MIBG) imaging, is associated with the poor outcomes in patients with chronic heart failure (CHF). Serial evaluation of cardiac MIBG imaging was shown to be useful for predicting adverse outcome in CHF. However, there was no information available on long-term serial changes of cardiac sympathetic nerve dysfunction after discharge of acute decompensated heart failure (ADHF) hospitalization.

Purpose

We aimed to clarify the serial change of cardiac MIBG imaging parameter in long-term after discharge of heart failure hospitalization, especially relating to HFrEF (LVEF&lt;40%), HFmrEF (40%≤LVEF&lt;50%) and HFpEF (LVEF≥50%).

Methods

We studied 112 patients (HFrEF; n=44, HFmrEF; n=23 and HFpEF; n=45) who were admitted for ADHF, discharged with survival and without heart failure hospitalization during follow-up period. All patients underwent cardiac MIBG imaging at the timing of discharge, in 6–12 months and in 18–24 months after discharge. The cardiac MIBG heart to mediastinum ratio (H/M) was calculated on the early image and the delayed image (late H/M). The cardiac MIBG washout rate (WR) was calculated from the early and delayed planar images after taking radioactive decay of I-123 into consideration.

Results

In HFrEF patients, late H/M was significantly improved from discharge to 6–12 months data (1.60±0.24 vs 1.75±0.31, p&lt;0.0001). Late H/M of HFmrEF patients was also significantly improved from discharge to 18–24 months data (1.71±0.27 vs 1.84±0.29 p=0.043). On the other hand, late H/M of HFpEF patients was not significantly changed. As for WR, WR in HFrEF and HFmrEF patients was significantly improved from discharge to 18–24 months data, although WR of HFpEF was not significantly changed.

Conclusion

The improvement in cardiac sympathetic nerve dysfunction was observed in patients with HFrEF and HFmrEF, not in HFpEF, after the discharge of acute heart failure hospitalization.

Funding Acknowledgement

Type of funding source: None

Long-term prognostic value of the combination of malnutrition and pulmonary-systemic pressure ratio in patients admitted with acute decompensated heart failure

Background

Malnutrition is associated with increased mortality risk in patients (pts) with acute decompensated heart failure (ADHF). On the other hand, concomitant presence of pulmonary hypertension in heart failure is associated with increased adverse events and may be related to interventricular uncoupling and impaired cardiac efficiency. It has recently been shown that an increased mean pulmonary artery pressure to mean systemic arterial pressure ratio (MPS ratio), a marker of interventricular coupling and efficiency, is associated with worse clinical outcomes in patients with advanced heart failure. However, there is no information available on the long-term prognostic value of the combination of malnutrition and MPS ratio in pts admitted for ADHF.

Methods and results

We studied 248 pts admitted for ADHF, who underwent right heart catheterization at the admission and were discharged with survival. Malnutrition was assessed by geriatric nutritional risk index (GNRI), prognostic nutritional index (PNI) and controlling nutritional status score (CONUT). During a mean follow-up period of 5.2±4.4 yrs, 62 pts had cardiovascular death (CVD). MPS ratio was significantly greater in pts with than without CVD (0.408±0.114 vs 0.347±0.102, p=0.0001). GNRI and PNI were significantly lower, CONUT was significantly greater in pts with than without CVD. At multivariate Cox regression analysis, GNRI and MPS ratio were significantly associated with CVD, independently of prior heart failure hospitalization, eGFR, and serum sodium level and anemia, although PNI and CONUT showed the association with CVD at unvariate analysis. Pts with malnutrition (GNRI≤median value=96.5) and greater MPS ratio (≥median value=0.346) had a significantly higher CVD risk than those with either and none of them (51% vs 20% vs 12%, p&lt;0.0001, respectively).

Conclusions

The combination of malnutrition and MPS ratio might be useful for stratifying pts at risk for CVD in patients with ADHF.

Funding Acknowledgement

Type of funding source: None

Effect of Porphyromonas gingivalis infection on gut dysbiosis and resultant arthritis exacerbation in mouse model

BACKGROUND

Porphyromonas gingivalis (Pg) infection causes periodontal disease and exacerbates rheumatoid arthritis (RA). It is reported that inoculation of periodontopathogenic bacteria (i.e., Pg) can alter gut microbiota composition in the animal models. Gut microbiota dysbiosis in human has shown strong associations with systemic diseases, including RA, diabetes mellitus, and inflammatory bowel disease. Therefore, this study investigated dysbiosis-mediated arthritis by Pg oral inoculation in an experimental arthritis model mouse.

METHODS

Pg inoculation in the oral cavity twice a week for 6 weeks was performed to induce periodontitis in SKG mice. Concomitantly, a single intraperitoneal (i.p.) injection of laminarin (LA) was administered to induce experimental arthritis (Pg-LA mouse). Citrullinated protein (CP) and IL-6 levels in serum as well as periodontal, intestinal, and joint tissues were measured by ELISA. Gut microbiota composition was determined by pyrosequencing the 16 s ribosomal RNA genes after DNA purification of mouse feces. Fecal microbiota transplantation (FMT) was performed by transferring Pg-LA-derived feces to normal SKG mice. The effects of Pg peptidylarginine deiminase (PgPAD) on the level of citrullinated proteins and arthritis progression were determined using a PgPAD knockout mutant.

RESULTS

Periodontal alveolar bone loss and IL-6 in gingival tissue were induced by Pg oral infection, as well as severe joint destruction, increased arthritis scores (AS), and both IL-6 and CP productions in serum, joint, and intestinal tissues. Distribution of Deferribacteres and S24-7 was decreased, while CP was significantly increased in gingiva, joint, and intestinal tissues of Pg-inoculated experimental arthritis mice compared to experimental arthritis mice without Pg inoculation. Further, FMT from Pg-inoculated experimental arthritis mice reproduced donor gut microbiota and resulted in severe joint destruction with increased IL-6 and CP production in joint and intestinal tissues. The average AS of FMT from Pg-inoculated experimental arthritis was much higher than that of donor mouse. However, inoculation of the PgPAD knockout mutant inhibited the elevation of arthritis scores and ACPA level in serum and reduced CP amount in gingival, joint, and intestinal tissues compared to Pg wild-type inoculation.

CONCLUSION

Pg oral infection affected gut microbiota dysbiosis and joint destruction via increased CP generation.

Selenium intracanal dressing: effects on the periapical immune response

OBJECTIVES

To evaluate the selenium (Se) behavior when used as an endodontic dressing in teeth with pulp necrosis. Additionally, its effects was also compared with the calcium hydroxide (C.H.), which is used globally as a root canal dressing, and the combination of the C.H. with Se (C.H. + Se).

MATERIALS AND METHODS

The sample consisted of 60 patients requiring endodontic treatment who were divided into groups, i.e., without intracanal medication (empty) and with medications as follows: selenium (Se), calcium hydroxide (C.H.), and calcium hydroxide + selenium (C.H. + Se) (n = 15). After the coronary opening, three absorbent paper points were placed in the RCS and maintained for 2 min for microbial evaluation. Following the cleaning and shaping procedures, new paper points were introduced into the root canal system, passing passively through the root apex (2 mm) into the periapical tissues for 2 min, for immune evaluation. The collections were performed again 15 days later. Real-time PCR quantified the expression of the prokaryotic 16S ribosomal RNA. The 16S mRNA was evaluated before the cleaning and shaping procedures and 15 days later in the groups treated with or without medication.

RESULTS

A significant reduction in the microbial load was observed only in the groups that received endodontic dressing (p < 0.05). The cytokines IFN-γ, TNF-α, IL-1α, IL-17A, IL-10, IL-6 and MCP-1, were also quantified by real-time PCR. There was an increase in the gene expression level of the cytokines (T15) TNF-α and IL-10 in the C.H. group compared to the other groups (p < 0.05). The IFN-γ mRNA expression was reduced in the groups treated with the medications (Se, C.H., and C.H. + Se).

CONCLUSIONS

The findings of the present study indicate that in the case of treatment over multiple sessions, the use of root canal dressing is essential to avoid the root canal system (RCS) microbial recolonization. Selenium potentiated the effects of calcium hydroxide inducing an anti-inflammatory response in periapical tissues.

CLINICAL RELEVANCE

Se is a mineral essential for the formation of the amino acid selenocysteine, which is directly involved in the maintenance of the immune response. Selenium has been widely used in the medical field in the treatment of cancer, as an activator of bone metabolism, and as a stimulator of the immune system. In this study, it was shown that the incorporation of Se, whether as intracanal medication alone or in conjunction with other medications, may potentiate periapical tissue repair after RCS cleaning and shaping procedures.

Predifferentiated Gingival Stem Cell-Induced Bone Regeneration in Rat Alveolar Bone Defect Model

Cleft alveolus, a common birth defect of the maxillary bone, affects one in 700 live births every year. This defect is traditionally restored by autogenous bone grafts or allografts, which may possibly cause complications. Cell-based therapies using the mesenchymal stem cells (MSCs) derived from human gingiva (gingiva-derived mesenchymal stem cells [GMSCs]) is attracting the research interest due to their highly proliferative and multilineage differentiation capacity. Undifferentiated GMSCs expressed high level of MSC-distinctive surface antigens, including CD73, CD105, CD90, and CD166. Importantly, GMSCs induced with osteogenic medium for a week increased the surface markers of osteogenic phenotypes, such as CD10, CD92, and CD140b, indicating their osteogenic potential. The objective of this study was to assess the bone regenerative efficacy of predifferentiated GMSCs (dGMSCs) toward an osteogenic lineage in combination with a self-assembling hydrogel scaffold PuraMatrix™ (PM) and/or bone morphogenetic protein 2 (BMP2), on a rodent model of maxillary alveolar bone defect. A critical size maxillary alveolar defect of 7 mm × 1 mm × 1 mm was surgically created in athymic nude rats. The defect was filled with either PM/BMP2 or PM/dGMSCs or the combination of three (PM/dGMSCs/BMP2) and the bone regeneration was evaluated at 4 and 8 weeks postsurgery. New bone formation was evaluated by microcomputed tomography and histology using Hematoxylin and Eosin staining. The results demonstrated the absence of spontaneous bone healing, either at 4 or 8 weeks postsurgery in the defect group. However, the PM/dGMSCs/BMP2 group showed significant enhancement in bone regeneration at 4 and 8 weeks postsurgery, compared with the transplantation of individual material/cells alone. Apart from developing the smallest critical size defect, results showed that PM/dGMSCs/BMP2 could serve as a promising option for the regeneration of bone in the cranio/maxillofacial region in humans.

Mineral trioxide aggregate (MTA) inhibits osteoclastogenesis and osteoclast activation through calcium and aluminum activities

OBJECTIVE

To evaluate the effect(s) of mineral trioxide aggregate (MTA) on in vitro RANKL-mediated osteoclast-dependent bone resorption events and the influence of Ca²⁺ and Al³⁺ on the osteoclastogenesis inhibition by MTA.

MATERIALS AND METHODS

Two types of osteoclast precursors, RAW 264.7 (RAW) cell line or bone marrow cells (obtained from BALB/c mice and stimulated with recombinant (r) macrophage colony stimulation factor (M-CSF), were stimulated with or without recombinant (r) activator of nuclear kappa B ligand (RANKL), in the presence or absence of MTA for 6 to 8 days. White Angelus MTA and Bios MTA (Angelus, Londrina, Paraná, Brazil) were prepared and inserted into capillary tubes (direct contact surface = 0.50 mm² and 0.01 mm²). Influence of MTA on these types of osteoclast precursors was measured by the number of differentiated tartrate-resistant acid phosphatase (TRAP)-positive multinuclear cells (RAW and bone marrow cells), TRAP enzyme activity (RAW cells), cathepsin K gene expression (RAW cells), and resorptive pit formation (RAW cells) by mature osteoclasts. Besides, RAW cells were also stimulated with Ca²⁺ and Al³⁺ to evaluate the influence of these ions on MTA anti-osteoclastogenic potential.

RESULTS

In bone marrow and RAW cells, the number of TRAP-positive mature osteoclast cells induced by rRANKL was significantly inhibited by the presence of MTA compared with control rRANKL stimulation without MTA (p < 0.05), along with the reduction of TRAP enzyme activity (p < 0.05) and the low expression of cathepsin K gene (p < 0.05). In contrast, to control mature osteoclasts, the resorption area on dentin was significantly decreased for mature osteoclasts incubated with MTA (p < 0.05). rRANKL-stimulated RAW cells treated with Ca²⁺ and Al³⁺ decreased the number of osteoclasts cells. Besides, the aluminum oxide was the dominant suppressor of the osteoclastogenesis process.

CONCLUSIONS

MTA significantly suppressed RANKL-mediated osteoclastogenesis and osteoclast activity and, therefore, appears able to suppress bone resorption events in periapical lesions. This process might be related to Ca²⁺ and Al³⁺ activities.

CLINICAL RELEVANCE

MTA is an important worldwidely acknowleged biomaterial. The knowledge about its molecular activities on osteoclasts might contribute to improving the understanding of its clinical efficacy.

Analysis of effects and indications of cryosurgery for oral mucoceles

Cryosurgery is a recognized method for the treatment of mucoceles in the oral cavity. In this study, cryosurgery was used for mucoceles at the lip or buccal mucosa, and the effect and the indication were evaluated clinically. The subjects were patients with a clinical diagnosis of mucocele on the lip or buccal mucosa and who chose cryosurgery after procedures for both surgical excision and cryosurgery for the lesion were explained. Cryosurgery was performed with a freezing device using liquid nitrogen without local anesthesia. Twenty-four patients chose cryosurgery, including seven preschool children. There were no serious adverse events during and after cryosurgery. Healing progress after cryosurgery was not affected by patient age, lesion size, or how long the patients had the lesion. Two cases later underwent surgical excision because cryosurgery was not successful. Twenty-three patients chose surgical excision, one case had a recurrence. The number of younger patients who chose cryosurgery was significantly higher than that who chose surgical excision. This study suggests that cryosurgery is effective for mucoceles of the lip or buccal mucosa and is a simple and safe treatment method, especially for preschool children.