Suppression of subgingival bacteria by antimicrobial photodynamic therapy using transgingival irradiation: A randomized clinical trial.

BACKGROUND: Antimicrobial photodynamic therapy (aPDT) is an effective method for eradicating bacteria in periodontal therapy. Standard aPDT requires the insertion of a laser tip into a periodontal pocket, in which the direction of irradiation is limited. Therefore, we devised an aPDT method that uses a transgingival near-infrared wavelength and indocyanine green-encapsulated and chitosan-coated nanoparticles as a photosensitizer. METHODS: Forty patients undergoing supportive periodontal therapy, who had a single root tooth with a pocket of 5 mm or deeper, were used as subjects. In the test group, aPDT was performed by laser irradiation from outside the gingiva using photosensitizer nanoparticles. In the control group, pseudo aPDT without photosensitizer was performed by transgingival irradiation. Subgingival plaque was sampled from inside the pocket before, immediately after, and 1 week after treatment, and evaluated by colony counting and real-time polymerase chain reaction. RESULTS: There were no significant differences in age, sex, periodontal pocket depth, and bleeding on probing between the test and control groups. Compared with the colony count before treatment, the count in the test group was significantly reduced immediately after treatment. The number of patients with colony reduction to ≤50% and ≤10% was significantly higher in the test group than in the control group. None of the participants reported pain, although one participant reported discomfort. CONCLUSION: As a bacterial control method for residual pockets in patients undergoing supportive periodontal therapy, transgingival aPDT is a promising treatment strategy that is not generally accompanied by pain or discomfort.

Two differential cavities in syringomyelia of pediatric Chiari I malformation presenting with unilateral foot drop.

INTRODUCTION: Patients with Chiari I malformation (CM1) may have chronic symptoms of syringomyelia, including numbness and weakness of the upper limbs, typically during young adulthood. Acute or subacute presentation of unilateral foot drop has been rarely reported as a first symptom of CM1-associated syringomyelia exclusively in childhood or adolescence. Why these patients do not show any symptoms of the upper limbs although holocord syringomyelia is always observed on magnetic resonance imaging (MRI) is unclear. CASE PRESENTATION: A four-year-old girl presented rapidly with isolated left foot drop. Conventional MRI revealed holocord syringomyelia associated with CM1. Three-dimensional constructive interference in steady state (3D-CISS) imaging further demonstrated that the syringomyelia was comprised of two differential cavities that communicated with each other via a small pore: a centrally positioned upper cavity and a left-deviated lower one. Surgical decompression of the foramen magnum resolved the symptom with radiological improvement of the two cavities. CONCLUSION: In contrast to a centrally enlarged syrinx that is often asymptomatic, a paracentrally extended syrinx usually produces segmental signs related to its levels. Thus, the left foot drop in this case would have been due to the ipsilaterally deviated lower cavity that was distinguished from the central upper cavity by 3D-CISS imaging. Further reports using this imaging technique are needed to verify the hypothetic pathology.

Incidence and risk factors of acute encephalopathy with biphasic seizures in febrile status epilepticus.

OBJECTIVE: To clarify the incidence and risk factors of acute encephalopathy with biphasic seizures and late reduced diffusion (AESD) in pediatric patients with febrile status epilepticus (FSE). METHODS: We retrospectively surveyed patients with FSE (≥20 min and ≥40 min) who were younger than 6 years by mailing a questionnaire to 1123 hospitals in Japan. The survey period was 2 years. We then collected clinical data on patients with prolonged febrile seizures (PFS) ≥40 min and those with AESD, and compared clinical data between the PFS and AESD groups. RESULTS: The response rate for the primary survey was 42.3%, and 28.0% of hospitals which had applicable cases responded in the secondary survey. The incidence of AESD was 4.3% in patients with FSE ≥20 min and 7.1% in those with FSE ≥40 min. In the second survey, a total of 548 patients had FSE ≥40 min (AESD group, n = 93; PFS group, n = 455). Univariate analysis revealed significant between-group differences in pH, aspartate aminotransferase, alanine aminotransferase, lactate dehydrogenase, creatine kinase, NH3, procalcitonin (PCT), uric acid, blood urea nitrogen, creatinine (Cr), and lactate. Multivariate analysis using stratified values showed that high PCT was an only risk factor for AESD. A prediction score of ≥3 was indicative of AESD, as determined using the following indexes: HCO3- < 20 mmol/L (1 point), Cl <100 mEq/L (1 point), Cr ≥0.35 mg/dL (1 point), glucose ≥200 mg/dL (1 point), and PCT ≥1.7 pg/mL (2 points). The scoring system had sensitivity of 84.2% and specificity of 81.0%. CONCLUSION: Incidence data and prediction scores for AESD will be useful for future intervention trials for AESD.

Porphyromonas gingivalis Components/Secretions Synergistically Enhance Pneumonia Caused by Streptococcus pneumoniae in Mice.

Streptococcus pneumoniae is an important causative organism of respiratory tract infections. Although periodontal bacteria have been shown to influence respiratory infections such as aspiration pneumonia, the synergistic effect of S. pneumoniae and Porphyromonas gingivalis, a periodontopathic bacterium, on pneumococcal infections is unclear. To investigate whether P. gingivalis accelerates pneumococcal infections, we tested the effects of inoculating P. gingivalis culture supernatant (PgSup) into S. pneumoniae-infected mice. Mice were intratracheally injected with S. pneumoniae and PgSup to induce pneumonia, and lung histopathological sections and the absolute number and frequency of neutrophils and macrophages in the lung were analyzed. Proinflammatory cytokine/chemokine expression was examined by qPCR and ELISA. Inflammatory cell infiltration was observed in S. pneumoniae-infected mice and S. pnemoniae and PgSup mixed-infected mice, and mixed-infected mice showed more pronounced inflammation in lung. The ratios of monocytes/macrophages and neutrophils were not significantly different between the lungs of S. pneumoniae-infected mice and those of mixed-infected mice. PgSup synergistically increased TNF-α expression/production and IL-17 production compared with S. pneumoniae infection alone. We demonstrated that PgSup enhanced inflammation in pneumonia caused by S. pneumoniae, suggesting that virulence factors produced by P. gingivalis are involved in the exacerbation of respiratory tract infections such as aspiration pneumonia.

Photodynamic Inactivation of an Endodontic Bacteria Using Diode Laser and Indocyanine Green-Loaded Nanosphere.

Apical periodontitis, an inflammatory lesion causing bone resorption around the apex of teeth, is treated by eradicating infectious bacteria from the root canal. However, it has a high recurrence rate and often requires retreatment. We investigated the bactericidal effect of antimicrobial photodynamic therapy (aPDT)/photodynamic antimicrobial chemotherapy (PACT) using indocyanine green (ICG)-loaded nanospheres coated with chitosan and a diode laser on a biofilm of Enterococcus faecalis, a pathogen of refractory apical periodontitis. Biofilm of E. faecalis was cultured in a porcine infected root canal model. ICG solution was injected into the root canal, which was then irradiated with a laser (810 nm wavelength) from outside the root canal. The bactericidal effect was evaluated by colony counts and scanning electron microscopy. The result of the colony counts showed a maximum 1.89 log reduction after irradiation at 2.1 W for 5 min. The temperature rise during aPDT/PACT was confirmed to be within a safe range. Furthermore, the light energy transmittance through the root was at a peak approximately 1 min after the start of irradiation, indicating that most of the ICG in the root canal was consumed. This study shows that aPDT/PACT can suppress E. faecalis in infected root canals with high efficiency.

Changes in prefrontal cerebral hemodynamics during intermittent pain stimulation to gingiva: Preliminary study using functional near infrared spectroscopy.

BACKGROUND/PURPOSE: Elucidating the transmission mechanism of pain signals from the orofacial area and the corresponding modification mechanism will not only aid in the understanding of pain mechanisms but also provide useful information regarding the development of pain mitigation methods. In this study, the involvement of the pain suppression system in the trigeminal area was investigated through an analysis of the activation status over time in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS). MATERIALS AND METHODS: In 28 healthy, right-handed male volunteers (average age, 30.1 ±â€¯4.2 years) as subjects, a mild, intermittent, acute pain stimulus was administered through the implementation of pocket probing of the gingiva surrounding the right maxillary central incisor. In the prefrontal cortex, the levels of hemoglobin (Hb) were measured using the fNIRS measurement system. Average values of both oxy-Hb and deoxy-Hb were calculated at four stages: rest stage, 20 s prior to the pain stimulus application, and three stages at 20-s intervals within 1 min of stimulation. One-way analysis of variance and multiple comparisons were used to compare representative values to investigate the changes due to pain. RESULTS: Oxy-Hb levels decreased the most during the 20 s stage directly after stimulus application. This change was seen mainly on the contralateral side, after which it returned to the resting baseline level before the stimulus application. CONCLUSION: Our data demonstrate that in healthy males, a mechanism exists to mitigate pain involving the pain suppression system in the 20 s after feeling mild pain to the gingiva.

Retraction notice to "Gelatin scaffold combined with bone morphogenetic protein-4 induces odontoblast-like cell differentiation involving integrin profile changes, autophagy-related gene 10, and Wnt5 sequentially in human induced pluripotent stem cells" [Differentiation 93 (2017) 1-14].

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the authors, with the approval of the Editor-in-Chief. The journal was initially contacted by the corresponding author to report the unavailability of the raw data of the results presented by the article, as well as the similarity between the Western blots from Figure 11A (MMP-3) and Figure 11C (MMP-3). Also, a significant amount of text has been reused from the articles that the authors have previously published in the Experimental Cell Research 341 (2016) 92-104 https://doi.org/10.1016/j.yexcr.2016.01.010 and the Journal of Biological Chemistry 289 (2014) 14380-14391 https://doi.org/10.1074/jbc.M113.526772. All of the authors except Nobuaki Ozeki and Taiki Hiyama have reportedly agreed to retract the article. N. Ozeki left Aichi Gakuin University in March 2018 and does not respond to co-authors inquiries, while T. Hiyama left Aichi Gakuin University and could not be reached. The authors deeply regret this error and any inconvenience it may have caused.

Application of Deep Learning in the Identification of Cerebral Hemodynamics Data Obtained from Functional Near-Infrared Spectroscopy: A Preliminary Study of Pre- and Post-Tooth Clenching Assessment.

In fields using functional near-infrared spectroscopy (fNIRS), there is a need for an easy-to-understand method that allows visual presentation and rapid analysis of data and test results. This preliminary study examined whether deep learning (DL) could be applied to the analysis of fNIRS-derived brain activity data. To create a visual presentation of the data, an imaging program was developed for the analysis of hemoglobin (Hb) data from the prefrontal cortex in healthy volunteers, obtained by fNIRS before and after tooth clenching. Three types of imaging data were prepared: oxygenated hemoglobin (oxy-Hb) data, deoxygenated hemoglobin (deoxy-Hb) data, and mixed data (using both oxy-Hb and deoxy-Hb data). To differentiate between rest and tooth clenching, a cross-validation test using the image data for DL and a convolutional neural network was performed. The network identification rate using Hb imaging data was relatively high (80‒90%). These results demonstrated that a method using DL for the assessment of fNIRS imaging data may provide a useful analysis system.

[A Suspected Case of Hemorrhagic Hereditary Telangiectasia Presented with Cerebral Hemorrhage in Infancy].

Hereditary hemorrhagic telangiectasia (HHT) is characterized by telangiectasias in multiple organs. We experienced an infant with cerebral hemorrhaging and suspected HHT based on his family history of HHT. Computed tomography angiography confirmed a cerebral arteriovenous fistula. The onset of cerebral arteriovenous fistulas associated with HHT is relatively early, and the incidence of bleeding is relatively common. When HHT is suspected based on a family history, early imaging screening is recommended to improve the neurological prognosis, even in asymptomatic cases. (Received April 7, 2020; Accepted May 7, 2020; Published August 1, 2020).

Energy dispersive spectroscopy-scanning transmission electron microscope observations of free radical production in human polymorphonuclear leukocytes phagocytosing non-opsonized Tannerella forsythia.

We investigated the association between human polymorphonuclear leukocytes (PMNs) and non-opsonized Tannerella forsythia ATCC 43037 displaying a serum-resistant surface layer (S-layer). When PMNs were mixed with T. forsythia in suspension, the cells phagocytosed T. forsythia cells. Nitro blue tetrazolium (NBT) reduction, indicative of O2- production, was observed by light microscopy; cerium (Ce) perhydroxide deposition, indicative of H2 O2 production, was observed by electron microscopy. We examined the relationship between high-molecular-weight proteins of the S-layer and Ce reaction (for T. forsythia phagocytosis) using electron microscopic immunolabeling. Immunogold particles were localized within the PMNs and on cell surfaces, labelling at the same Ce-reacted sites where the S-layer was present. We then used energy dispersive spectroscopy (EDS)-scanning transmission electron microscope (STEM) to perform Ce and nitrogen (N) (for S-layer immunocytochemistry) elemental analysis on the phagocytosed cells. That is, the elemental mapping and analysis of N by EDS appeared to reflect the presence of the same moieties detected by the 3,3'-diaminobenzidine-tetrahydrochloride (DAB) reaction with horseradish peroxidase (HRP)-conjugated secondary antibodies, instead of immunogold labeling. We focused on the use of EDS-STEM to visualize the presence of N resulting from the DAB reaction. In a parallel set of experiments, we used EDS-STEM to perform Ce and gold (Au; from immunogold labeling of the S-layer) elemental analysis on the same phagocytosing cells.

Gelatin scaffold combined with bone morphogenetic protein-4 induces odontoblast-like cell differentiation involving integrin profile changes, autophagy-related gene 10, and Wnt5 sequentially in human induced pluripotent stem cells.

While human induced pluripotent stem (hiPS) cells have potential use in regenerative medicine, there are no reports on odontoblastic differentiation of hiPS cells. In the current study, to examine integrin profiles and explore the early signaling cascade of odontoblastic differentiation in hiPS cells, we investigated the regulation of autophagy-related gene (Atg) and wingless/int1 (Wnt) signaling in gelatin scaffold (GS) combined with bone morphogenetic protein (BMP)-4 (GS/BMP-4)-mediated odontoblastic differentiation. Following GS/BMP-4 treatment, there was a dramatic loss of α3 and α6 integrins, and reciprocal strong induction of α1 integrin expression in the differentiated cells. GS/BMP-4 increased the mRNA and protein levels of Atg10, Lrp5/Fzd9 (an Atg10 receptor), and Wnt5 together with the amount of autophagosomes and autophagic fluxes. Treatment with siRNAs against Atg10 and Wnt5a individually suppressed the GS/BMP-4-induced increase in odontoblastic differentiation. The odontoblastic phenotype was inhibited by chloroquine, but increased after treatment with rapamycin (an autophagy enhancer). Taken together with our previous findings, we have replicated our results from the rodent system in a novel human system. We have revealed a unique sequential cascade involving Atg10, Wnt5a, α1 integrin, and matrix metalloproteinase-3 in GS/BMP-4-induced differentiation of hiPS cells into odontoblast-like cells at a relatively early stage.

Measurement of cerebral blood volume dynamics during volitional swallowing using functional near-infrared spectroscopy: an exploratory study.

The aim of this study was to examine cerebral blood volume dynamics during volitional swallowing using multi-channel functional near-infrared spectroscopy (fNIRS) to understand the basic cortical activation patterns. Fifteen volunteers (age, 26.5±1.3 years, mean±SD) performed volitional swallowing of a 5-ml bolus of water as a task. A 52-channel fNIRS system was used for measuring oxy-Hb levels. We determined the oxy-Hb concentration changes in each channel by calculating the differences between rest and task oxy-Hb levels. Differences in rest and task data were assessed using a paired-t test (p<0.05). A significant increase in oxy-Hb was found in 21 channels. The cortical regions that exhibited increased oxy-Hb concentration included the bilateral precentral gyrus, postcentral gyrus, inferior frontal gyrus, superior temporal gyrus, middle temporal gyrus, and supramarginal gyrus. These data provide a description of cortical activation patterns during volitional swallowing using fNIRS, which will be useful for the evaluation of dysphasia and the effects of the rehabilitation [Corrected].

Increased expression of interleukin (IL)-35 and IL-17, but not IL-27, in gingival tissues with chronic periodontitis.

BACKGROUND: Interleukin (IL)-35 plays an important role in immune regulation through the suppression of effector T-cell populations, including T-helper 17 (Th17) cells. Although Th17 cells and IL-17 are involved in the pathogenesis of periodontitis, the level of IL-35 in inflamed periodontal tissues is unclear. Here, IL-35, IL-17, and IL-27 production/expression in gingival crevicular fluid (GCF) and human gingival tissue were investigated. METHODS: GCF samples were collected from buccal (mesial, center, and distal) sites of teeth from patients with chronic periodontitis (CP) and healthy controls and were analyzed by enzyme-linked immunosorbent assay for IL-35 (periodontitis, n = 36; healthy, n = 30) and IL-17 (periodontitis, n = 16; healthy, n = 13). Gingival tissue, including sulcus/pocket epithelium and underlying connective tissue, was collected from an additional 10 healthy participants and 10 patients with CP and were analyzed by quantitative polymerase chain reaction (qPCR) for Epstein Barr virus-induced gene 3 (EBI3), IL12A, and IL17A. IL27p28 was also tested by qPCR. RESULTS: IL-35 and IL-17 were significantly higher in GCF from patients with periodontitis than healthy participants (P <0.01, P <0.05, respectively). In both healthy participants and those with periodontitis, positive correlations were found among IL-35 and probing depth and clinical attachment level (CAL) as well as between IL-17 and CAL. EBI3, IL12A (components of IL-35), and IL17A messenger RNA expression levels were significantly higher in inflamed gingival tissue than in healthy control tissues (P <0.05). IL27p28 was not detected in any sample, suggesting that IL-27 is not produced in large quantities in periodontal tissue. CONCLUSION: IL-35 and IL-17, but not IL-27, may play important roles in the pathogenesis of periodontitis.

Experimental pain in the gingiva and its impact on prefrontal cortical hemodynamics: a functional near-infrared spectroscopy study.

Evaluating alterations in brain activity in response to pain stimulus can help understand the mechanisms underlying pain perception. We measured oxygenated hemoglobin (oxy-Hb) levels using functional near-infrared spectroscopy (fNIRS) in order to assess prefrontal cortex activation after inducing a pain stimulus to the gingiva. Twenty-three right-handed, healthy male subjects (mean age: 29.3±3.6 years) were subjected to a mild pain stimulus to the tissue around the right maxillary central incisor. The periodontal pain stimulus (PPS) was elicited from a pocket probe, and a multi-channel fNIRS system with its accompanying 22-channel probes was used for measuring oxy-Hb levels. Mean oxy-Hb levels for each channel were calculated on the basis of values obtained at rest and during the PPS load, for 1min each. The change in oxy-Hb level was calculated by subtracting oxy-Hb at rest from oxy-Hb levels during PPS load. Oxy-Hb levels in each channel during both conditions were then compared using the paired t-test and Bonferroni correction. Pain stimulation caused oxy-Hb levels to decrease in virtually all areas of the prefrontal cortex, particularly, in the superior frontal gyrus, the middle frontal gyrus, and the orbital part of the superior, middle, and inferior frontal gyrus, on the brain side contralateral to the pain load. This measurement could prove beneficial as an index for objective pain evaluation.

Immunocytochemical approach for surface layer proteins of freeze-substituted Tannerella forsythensis by energy-filtering transmission electron microscopy.

Tannerella forsythensis (Bacteroides forsythus), an anaerobic gram-negative potential periodontal pathogens in the progression of periodontitis. IT forsythensis has unique bacterial protein profiles containing major proteins with apparent molecular weight of more than 200-kDa shown by sodium dodecylsulfate-polyacrylamide gel electrophoresis. It is also known to have a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane revealed by electron microscopy. On the other hand, electron microscopy showed that the best preservation of structure was obtained when cells were postfixed with OsO4, but this resulted in very low levels of gold particles labeling. Therefore, cells were applied to pieces of filter paper and freeze-substituted by plung-freezing in Liquid propane, substituted in methanol containing 0.5% uranyl acetate, and infiltrated with LR-White resin. We also examined the relation between high molecular weight proteins and S-layer in energy-filtering transmission electron microscopy (EF-TEM) to visualize 3,3'-diaminobenzidene, tetrahydrochloride (DAB) reaction. The three-window method in electron spectroscopic images (ESI) of nitrogen (N) element, reflecting the presence of DAB moieties by the DAB reaction solution, horseradish peroxidase (HRP)-conjugated secondary antibodies instead of immunogold particles obtained by the EF-TEM. The mapping patterns of net N element were restricted to the outermost cell surface.

Loss of adherence ability to human gingival epithelial cells in S-layer protein-deficient mutants of Tannerella forsythensis.

Tannerella forsythensis, one of the important pathogens in periodontal disease, has a typical surface layer (S-layer) consisting of regularly arrayed subunits outside the outer membrane. The S-layer in T. forsythensis is suggested to be associated with haemagglutinating activity, adhesion and invasion of host cells; however, its precise functions have been unknown. ORFs encoding the major S-layer proteins (230 and 270 kDa) of T. forsythensis ATCC 43037, tfsA and tfsB, respectively, following the names in a recent report [Lee, S.-W., Sabet, M., Um, H. S., Yang, L., Kim, H. C. & Zhu, W. (2006). Gene 371, 102-111] were determined. To verify the function of the S-layer proteins, three mutants with tfsA, tfsB, or both deleted were successfully constructed by a PCR-based overlapping method. S-layer proteins were completely lost in the double mutant. The single-deletion mutants appeared to lose one of the 230 and 270 kDa proteins. Thin-section microscopy clearly revealed that the 230 and 270 kDa proteins composed the S-layer. Although the S-layer proteins may be weakly related to haemagglutinating activity, these proteins were highly responsible for adherence to human gingival epithelial cells (Ca9-22) and KB cells. These results suggest that the S-layer proteins in T. forsythensis play an important role in the initiation stage of oral infection including periodontal disease.

Increased number of anaerobic bacteria in the infected root canal in type 2 diabetic rats.

OBJECTIVE: The purpose of this study was to investigate the relationship between type 2 diabetes mellitus and anaerobic bacteria detected in infected root canals. STUDY DESIGN: Normal Wistar rats (control) received a standard laboratory diet with water (group A), and GK rats (type 2 diabetes mellitus rats) a normal laboratory diet with water (group B) or a 30% sucrose solution (group C). Chemotaxis assay was conducted on polymorphonuclear leukocytes from the 3 groups, and the numbers of anaerobic bacteria in infected root canals were determined. RESULTS: In the chemotaxis assay on the polymorphonuclear leukocytes, the chemotactic response of cells in group C was lower than that for groups A and B (P < .01). As to bacteria detected in the root canal, obligate anaerobic bacteria which stained gram negative, were significantly more numerous in group C (P < .01) than in groups A and B. CONCLUSION: The metabolic condition produced by type 2 diabetes mellitus in rats might lower the general host resistance against bacterial infection.