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1.
ACS Appl Mater Interfaces ; 16(20): 26478-26490, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38697094

ABSTRACT

TOLEDs (transparent organic light-emitting diodes) have emerged as one of the most promising ways to implement next-generation display form factors. Transparent OLEDs can provide new added value to HMDs (head mounted displays), automobiles, smart windows, mobile devices, TVs, etc. through their transparency, which allows objects to be seen from the other side. However, previous approaches using metal thin films have faced limitations in attempting to achieve high transmittance. In this study, TOLEDs were designed using a new cathode structure consisting of an interlayer and an emission pattern layer, and these layers connect the light-emitting part and the nonemitting part by themselves without requiring the use of another interconnection layer. This structure, which was intended to improve transmittance, was implemented by applying an in situ evaporation process that adds only one shadow mask without the need to use any difficult methods. Through this process, the optimal condition was found when the light-emitting part was deposited in a mesh pattern with a length of 120 µm and a width of 80 µm, in which case the transmittance of the TOLED improved by up to 83% while maintaining electro-optical performance. It was also confirmed that this new structure can be applied to flexible devices.

2.
Int J Oral Maxillofac Implants ; 39(1): 153-163, 2024 Feb 27.
Article in English | MEDLINE | ID: mdl-38416009

ABSTRACT

PURPOSE: To evaluate the usefulness of ridge augmentation using a customized titanium mesh (CTM) that was preformed by trimming and bending the commercial titanium mesh on a virtually reconstructed 3D acrylic resin model using clinical, radiologic, histologic, and histomorphometric analyses. MATERIALS AND METHODS: This study was designed prospectively for patients who required vertical ridge augmentation using a staged approach before implant surgery. After installation of the CTM, grafting was performed using deproteinized porcine bone mineral covered with an absorbable membrane. Computed tomography was performed preoperatively and 6 months after simultaneous/staged guided bone regeneration to measure planned, reconstructed, and lacking bone volume, and the reconstruction rate was calculated based on these values. Clinical complications were also recorded, particularly the mesh exposure rate. At re-entry, the bone core was obtained using a trephine bur, and histologic and histomorphometric analyses were performed. RESULTS: A total of 10 sites in eight patients were used for the study analysis. The mean planned bone volume was 1.15 cm3 (range: 0.78 to 1.56 cm3), mean lacking bone volume was 0.13 cm3 (range: 0 to 0.59 cm3), and mean reconstructed bone volume was 1.02 cm3 (range: 0.56 to 1.43 cm3). The exposure rate was 30% (3 out of 10 sites). The reconstruction rate was over 80%, except for one case that showed suppuration. From histomorphometric analysis, 27.52% ± 16.87% of new bone, 7.62% ± 5.19% of residual graft, and 64.86% ± 23.76% of connective tissue were observed. The core biopsy samples demonstrated different pseudoperiosteum layer appearances based on the healing stage of the augmented sites. In the premature bone, the inner osteogenic layer consisted of multiple layers of osteoblast cells with adjacent large blood vessels. However, in the mature augmented site, there was no specific inner osteogenic layer, and the outer fibrous layer was dominant. CONCLUSIONS: The fabrication of CTM based on the application of the 3D-printing technique makes vertical ridge augmentation easier and can reduce complications and achieve target bone acquisition. In addition, it is expected that quantitative analysis of the pseudoperiosteum layer will be facilitated using the CTM.


Subject(s)
Dental Implants , Titanium , Swine , Animals , Humans , Prospective Studies , Surgical Mesh , Printing, Three-Dimensional
3.
Micromachines (Basel) ; 15(1)2024 Jan 18.
Article in English | MEDLINE | ID: mdl-38258265

ABSTRACT

Free-form factor optoelectronics is becoming more important for various applications. Specifically, flexible and transparent optoelectronics offers the potential to be adopted in wearable devices in displays, solar cells, or biomedical applications. However, current transparent electrodes are limited in conductivity and flexibility. This study aims to address these challenges and explore potential solutions. For the next-generation transparent conductive electrode, Al-doped zinc oxide (AZO) and silver (AZO/Ag/AZO) deposited by in-line magnetron sputtering without thermal treatment was investigated, and this transparent electrode was used as a transparent organic light-emitting diode (OLED) anode to maximize the transparency characteristics. The experiment and simulation involved adjusting the thickness of Ag and AZO and OLED structure to enhance the transmittance and device performance. The AZO/Ag/AZO with Ag of 12 nm and AZO of 32 nm thickness achieved the results of the highest figure of merit (FOM) (Φ550 = 4.65 mΩ-1) and lowest roughness. The full structure of transparent OLED (TrOLED) with AZO/Ag/AZO anode and Mg:Ag cathode reached 64.84% transmittance at 550 nm, and 300 cd/m2 at about 4 V. The results demonstrate the feasibility of adopting flexible substrates, such as PET, without the need for thermal treatment. This research provides valuable insights into the development of transparent and flexible electronic devices.

4.
Nanomaterials (Basel) ; 13(21)2023 Oct 24.
Article in English | MEDLINE | ID: mdl-37947665

ABSTRACT

The vacuum process using small molecule-based organic materials to make organic photodiodes (OPDIs) will provide many promising features, such as well-defined molecular structure, large scalability, process repeatability, and good compatibility for CMOS integration, compared to the widely used Solution process. We present the performance of planar heterojunction OPDIs based on pentacene as the electron donor and C60 as the electron acceptor. In these devices, MoO3 and BCP interfacial layers were interlaced between the electrodes and the active layer as the electron- and hole-blocking layer, respectively. Typically, BCP played a good role in suppressing the dark current by two orders higher than that without that layer. These devices showed a significant dependence of the performance on the thickness of the pentacene. In particular, with the pentacene thickness of 25 nm, an external quantum efficiency at the 360 nm wavelength according to the peak absorption of C60 was enhanced by 1.5 times due to a cavity effect, compared to that of the non-cavity device. This work shows the importance of a vacuum processing approach based on small molecules for OPDIs, and the possibility of improving the performance via the optimization of the device architecture.

5.
Biomed Res Int ; 2022: 7194640, 2022.
Article in English | MEDLINE | ID: mdl-36317115

ABSTRACT

Objective: Tooth extraction causes a wound with hard and soft tissue defects in the alveolar ridge. Few studies have reported the function of microRNAs (miRNAs) in the healing of extraction sockets. This study used bioinformatics analysis to reveal the possible relevance and role of miRNAs during the early stages following tooth extraction. Materials and Methods: Socket tissues from beagle dogs (Canis familiaris; two males and two females) were collected 1 and 12 hours after extraction of premolars on both sides of the mandible. miRNA expression was profiled through miRNA sequencing, and hub miRNAs showing characteristic expression patterns were selected and subjected to target enrichment analysis. Alkaline phosphatase (ALP) activity analysis and reverse transcription-quantitative polymerase chain reaction (RT-qPCR) were performed to verify the effect of hub miRNA on osteoblast differentiation and bone regeneration in vivo. Results: Five miRNAs were identified to have consistently high expression levels, with cfa-miR-451 showing the highest expression. Additionally, 20 hub miRNAs were selected as candidates expected to play an important role in the healing process. Pathways, such as the MAPK, axon guidance, TGF-ß, and Wnt signaling, were significantly enriched. Among hub miRNAs, miR-190a-5p increased ALP activity and mRNA expression of osteogenic markers and increased new bone formation in vivo. Conclusions: Our findings suggest that miRNAs may be involved in the earliest stages of socket healing after tooth extraction and can play an important role in moderating the entire socket healing mechanism in the extraction socket.


Subject(s)
MicroRNAs , Tooth Socket , Dogs , Male , Animals , MicroRNAs/genetics , MicroRNAs/pharmacology , Periodontal Ligament , Alveolar Process/surgery , Tooth Extraction
6.
J Periodontal Implant Sci ; 52(5): 411-421, 2022 Oct.
Article in English | MEDLINE | ID: mdl-36302647

ABSTRACT

PURPOSE: In this study, we aimed to evaluate the degree of heat generation when a novel drill design with an irrigation slot was used with metal sleeve-free (MF) and metal sleeve-incorporated (MI) surgical guides in an environment similar to that of the actual oral cavity. METHODS: A typodont with a missing mandibular right first molar and 21 bovine rib blocks were used. Three-dimensional-printed MF and MI surgical guides, designed for the placement of internal tapered implant fixtures, were used with slot and non-slot drills. The following groups were compared: group 1, MI surgical guide with slot drill; group 2, MI surgical guide with a non-slot drill; and group 3, MF surgical guide with a slot drill. A constant-temperature water bath at 36°C was used. The drilling was performed in 6 stages, and the initial, highest, and lowest temperatures of the cortical bone were measured at each stage using a non-contact infrared thermometer. RESULTS: There were no temperature increases above the initial temperature in any drilling procedure. The only significant difference between the non-slot and slot groups was observed with the use of the first drill in the MI group, with a higher temperature in the non-slot group (P=0.012). When the heat generation during the first and the second drilling was compared in the non-slot group, the heat generation during the first drilling was significantly higher (P<0.001), and there was no significant difference in heat generation between the drills in the slot group. CONCLUSIONS: Within the limitations of this study, implant-site preparation with the surgical guide showed no critical increase in the temperature of the cortical bone, regardless of whether there was a slot in the drill. In particular, the slotted drill had a cooling effect during the initial drilling.

7.
Sci Rep ; 12(1): 8867, 2022 05 25.
Article in English | MEDLINE | ID: mdl-35614070

ABSTRACT

We aimed to compare the short- and long-term outcomes of simultaneous laparoscopic, hybrid, and open resection for colorectal cancer and synchronous liver metastases. We retrospectively analyzed the data of 647 patients with simultaneous resection of colorectal cancer and liver metastases between January 2006 and December 2018 at three tertiary referral hospitals. Patient's baseline characteristics, perioperative outcomes, pathological examination results, liver-specific recurrence rate and survivals were compared between the propensity score-matched groups. Forty-two and 81 patients were selected for the laparoscopic vs. hybrid groups, and 48 and 136 patients for laparoscopic vs. open groups, respectively. The laparoscopic group had fewer wound complications (2.1 vs. 13.2%; p = 0.028) than the open group, and a shorter postoperative hospital stay than the hybrid and open groups (8 vs. 11 days, p < 0.001 for both). The 5-year liver-specific recurrence rates were 38.7% and 46.0% in the laparoscopic and hybrid groups, respectively (p = 0.270), and 34.0% and 37.0% in the laparoscopic and open groups, respectively (p = 0.391). Simultaneous laparoscopic resection for colorectal cancer and liver metastases can be performed safely with significantly enhanced postoperative recovery and comparable long-term outcomes compared to hybrid and open resection.


Subject(s)
Colorectal Neoplasms , Laparoscopy , Liver Neoplasms , Colorectal Neoplasms/pathology , Colorectal Neoplasms/surgery , Hepatectomy/methods , Humans , Laparoscopy/methods , Length of Stay , Liver Neoplasms/secondary , Liver Neoplasms/surgery , Postoperative Complications/surgery , Propensity Score , Retrospective Studies , Treatment Outcome
8.
Plant Pathol J ; 38(2): 53-77, 2022 Apr.
Article in English | MEDLINE | ID: mdl-35385913

ABSTRACT

The global nematicides market is expected to continue growing. With an increasing demand for synthetic chemical-free organic foods, botanical nematicides are taking the lead as replacements. Consequently, in the recent years, there have been vigorous efforts towards identification of the active secondary metabolites from various plants. These include mostly glucosinolates and their hydrolysis products such as isothiocyanates; flavonoids, alkaloids, limonoids, quassinoids, saponins, and the more recently probed essential oils, among others. And despite their overwhelming potential, variabilities in quality, efficacy, potency and composition continue to persist, and commercialization of new botanical nematicides is still lagging. Herein, we have reviewed the history of botanical nematicides and regional progresses, the potency of the identified phytochemicals from the key important plant families, and deciphered some of the impediments involved in standardization of the active compounds in addition to the concerns over the safety of the purified compounds to non-target microbial communities.

9.
Nutrients ; 13(8)2021 Jul 28.
Article in English | MEDLINE | ID: mdl-34444764

ABSTRACT

BACKGROUND: Mangosteen and propolis extracts (MAEC) have been potential therapeutic agents known to exhibit powerful antioxidant and anti-inflammatory properties. The aim of the current study was to evaluate the clinical and immunological efficacy of MAEC as well as safety and patient-reported outcomes (PROMs) on gingivitis and incipient periodontitis. METHODS: This study was performed on 104 patients diagnosed with gingivitis or incipient periodontitis. At baseline, the participants were randomly allocated to either the test group, with daily intake of a single capsule containing 194 mg of MAEC for eight weeks, or control group, with placebo. Clinical periodontal evaluation and immunological parameters from saliva and gingival sulcular fluid were assessed at baseline, four, and eight weeks. Individual PROMs were assessed by OHIP-14 questionnaires. RESULTS: There was a significant difference of modified gingival index at four and eight weeks between the test and control groups. In the test group, crevicular interleukin (IL)-6 was reduced, and the salivary matrix metalloproteinase (MMP)-9 was increased after eight weeks. PROMs were improved up to four weeks compared to placebo. CONCLUSION: Oral administration of MAEC would have a potential to reduce gingival inflammation clinically and immunologically in the patients with gingivitis and incipient periodontitis.


Subject(s)
Garcinia mangostana/chemistry , Gingivitis/drug therapy , Plant Extracts/therapeutic use , Propolis/therapeutic use , Adult , Aged , Biomarkers , Female , Humans , Interleukin-6 , Male , Matrix Metalloproteinase 9 , Middle Aged , Periodontal Index , Periodontitis/drug therapy , Saliva , Surveys and Questionnaires , Young Adult
10.
Materials (Basel) ; 14(14)2021 Jul 08.
Article in English | MEDLINE | ID: mdl-34300744

ABSTRACT

Vertical ridge augmentation for long-term implant stability is difficult in severely resorbed areas. We examined the clinical, radiological, and histological outcomes of guided-bone regeneration using novel titanium-reinforced microporous expanded polytetrafluoroethylene (MP-ePTFE) membranes. Eighteen patients who underwent implant placement using a staged approach were enrolled (period: 2018-2019). Vertical ridge augmentation was performed in areas with vertical bone defects ≥4 mm. Twenty-six implant fixtures were placed in 14 patients. At implant placement six fixtures had relatively low stability. On cone-beam computed tomography, the average vertical changes were 4.2 ± 1.9 (buccal), 5.9 ± 2.7 (central), and 4.4 ± 2.8 mm (lingual) at six months after vertical ridge augmentation. Histomorphometric analyses revealed that the average proportions of new bone, residual bone substitute material, and soft tissue were 34.91 ± 11.61%, 7.16 ± 2.74%, and 57.93 ± 11.09%, respectively. Stable marginal bone levels were observed at 1-year post-loading. The residual bone graft material area was significantly lower in the exposed group (p = 0.003). There was no significant difference in the vertical height change in the buccal side between immediately after the augmentation procedure and the implant placement reentry time (p = 0.371). However, all implants functioned well regardless of the exposure during the observation period. Thus, vertical ridge augmentation around implants using titanium-reinforced MP-ePTFE membranes can be successful.

11.
J Clin Med ; 10(4)2021 Feb 22.
Article in English | MEDLINE | ID: mdl-33671765

ABSTRACT

This study aimed to evaluate the feasibility of diagnosing periodontitis via the identification of 18 bacterial species in mouth-rinse samples. Patients (n = 110) who underwent dental examinations in the Department of Periodontology at the Veterans Health Service Medical Center between 2018 and 2019 were included. They were divided into healthy and periodontitis groups. The overall number of bacteria, and those of 18 specific bacteria, were determined via real-time polymerase chain reaction in 92 mouth-rinse samples. Differences between groups were evaluated through logistic regression after adjusting for sex, age, and smoking history. There was a significant difference in the prevalence (healthy vs. periodontitis group) of Aggregatibacter actinomycetemcomitans (2.9% vs. 13.5%), Treponema denticola (42.9% vs. 69.2%), and Prevotella nigrescens (80% vs. 2.7%). Levels of Treponema denticola, Prevotella nigrescens, and Streptococcus mitis were significantly associated with severe periodontitis. We demonstrated the feasibility of detecting periopathogenic bacteria in mouth-rinse samples obtained from patients with periodontitis. As we did not comprehensively assess all periopathogenic bacteria, further studies are required to assess the potential of oral-rinsing solutions to indicate oral infection risk and the need to improve oral hygiene, and to serve as a complementary method for periodontal disease diagnosis.

12.
Diagnostics (Basel) ; 11(2)2021 Feb 03.
Article in English | MEDLINE | ID: mdl-33546446

ABSTRACT

Fracture of a dental implant (DI) is a rare mechanical complication that is a critical cause of DI failure and explantation. The purpose of this study was to evaluate the reliability and validity of a three different deep convolutional neural network (DCNN) architectures (VGGNet-19, GoogLeNet Inception-v3, and automated DCNN) for the detection and classification of fractured DI using panoramic and periapical radiographic images. A total of 21,398 DIs were reviewed at two dental hospitals, and 251 intact and 194 fractured DI radiographic images were identified and included as the dataset in this study. All three DCNN architectures achieved a fractured DI detection and classification accuracy of over 0.80 AUC. In particular, automated DCNN architecture using periapical images showed the highest and most reliable detection (AUC = 0.984, 95% CI = 0.900-1.000) and classification (AUC = 0.869, 95% CI = 0.778-0.929) accuracy performance compared to fine-tuned and pre-trained VGGNet-19 and GoogLeNet Inception-v3 architectures. The three DCNN architectures showed acceptable accuracy in the detection and classification of fractured DIs, with the best accuracy performance achieved by the automated DCNN architecture using only periapical images.

13.
Sci Rep ; 11(1): 1714, 2021 01 18.
Article in English | MEDLINE | ID: mdl-33462323

ABSTRACT

Information regarding profilometric changes at a soft tissue level following implant placement with different protocols is insufficient. Therefore, this study aimed to comparatively investigate the profilometric tissue changes with respect to late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites. Sixteen patients were randomly assigned to the following groups: implant placement 4 months post-ARP (group LP/ARP) and tooth extraction and implant placement 4-8 weeks post-extraction (group EP). Dental impressions were obtained immediately after final prosthesis insertion and at 3, 6, and 12 months. At the time of implant placement, bone augmentation was performed in the majority of the patients. Profilometric changes of the tissue contour were minimal between the final prosthesis insertion and 12 months in the mid-facial area (0.04-0.35 mm in group LP/ARP, 0.04-0.19 mm in group EP). The overall tissue volume increased in both groups (1.70 mm3 in group LP/ARP, 0.96 mm3 in group EP). In conclusion, LP/ARP and EP led to similar stability of the peri-implant tissue contour between the final prosthesis insertion and at 12 months. Moreover, the change of peri-implant tissue on the soft tissue level was minimal in both modalities.


Subject(s)
Alveolar Process/surgery , Dental Implants , Aged , Alveolar Ridge Augmentation/methods , Bone Regeneration , Female , Humans , Male , Middle Aged , Surface Properties , Time Factors , Tooth Extraction , Tooth Socket/surgery , Treatment Outcome
14.
J Invertebr Pathol ; 166: 107221, 2019 09.
Article in English | MEDLINE | ID: mdl-31356819

ABSTRACT

Xenorhabdus nematophila, an entomopathogenic bacterium, is mutualistic with the nematode Steinernema carpocapsae. The bacterium produces secondary metabolites to inhibit target insect phospholipase A2 (PLA2) and induce immunosuppression, which is required for the pathogenicity of this bacterium-nematode complex. However, it was unclear if immunosuppressive intensity of the bacteria was correlated with their insecticidal potency. We compared six different X. nematophila strains inhibiting the immune responses of the beet armyworm (Spodoptera exigua) to explain their virulence variations. In addition to four known strains obtained from the Korean Agricultural Culture Collection, we identified two new strains (SK1 and SK2) of X. nematophila from two different isolates of S. carpocapsae. Although all six strains were virulent, they showed significant variation in median lethal bacterial dosage (LD50). The LD50 of most strains was 15-30 CFU/larva, however, the LD50 of the SK1 strain was more than two-fold higher against S. exigua larvae. Immunosuppressive activities of the six strains were measured by comparing hemocyte-spreading behavior and nodule formation; the SK1 strain was significantly less potent than other bacterial strains. These suppressed hemocyte behaviors were recovered by adding arachidonic acid (a catalytic product of PLA2) into all six strains. Bacterial culture broth was fractionated with different organic solvents and the ability to inhibit immune response and PLA2 activity were assessed. All organic extracts had immunosuppressive activities and PLA2-inhibitory activities. GC-MS analysis showed that these organic extracts possessed a total of 87 different compounds. There were variations in chemical components among the six bacterial strains. Organic extracts of SK1 strain, which exhibited the lowest virulence, contained the least number of secondary metabolites.


Subject(s)
Gram-Negative Bacterial Infections/immunology , Virulence/physiology , Xenorhabdus/immunology , Xenorhabdus/metabolism , Xenorhabdus/pathogenicity , Animals , Gram-Negative Bacterial Infections/metabolism , Host Microbial Interactions/physiology , Spodoptera/microbiology
15.
Int J Oral Maxillofac Implants ; 34(5): 1247­1253, 2019.
Article in English | MEDLINE | ID: mdl-31184635

ABSTRACT

The aim of this case report is to report clinical, radiologic, and histologic healing outcomes following functional endoscopic sinus surgery (FESS) to manage maxillary sinusitis after lateral sinus augmentation. Three patients who underwent lateral sinus augmentation developed maxillary sinusitis after 3 to 4 weeks. Pharmacologic interventions were performed, but the patients' symptoms did not resolve. The patients were referred to an otorhinolaryngologist and underwent FESS without the removal of bone substitute material or implants. The patients' symptoms disappeared completely after FESS. The implants were osseointegrated successfully and have functioned well to date (between 4 months and 7 years after definitive prosthesis delivery). No pathologic change was noted clinically or radiologically after FESS. However, biopsy specimens demonstrated some new bone formation with varying degrees of fibrotic change and tissue density, which is not compatible with the clinical and radiologic observations. FESS without intraoral debridement may be sufficient to resolve maxillary sinusitis after lateral sinus augmentation; this may not lead to favorable histologic healing in the augmented sinus.


Subject(s)
Bone Substitutes , Maxillary Sinusitis , Humans , Maxillary Sinus , Wound Healing
16.
Clin Oral Implants Res ; 30(3): 206-217, 2019 Mar.
Article in English | MEDLINE | ID: mdl-30672029

ABSTRACT

OBJECTIVES: This study investigated fracture rates and risk indicators for fractures in internal connection dental implants. MATERIAL AND METHODS: We performed a retrospective analysis of 19,006 internal connection implants used in fixed restoration in 5,124 patients (4,570 males, 554 females) at the Dental Hospital of Veterans Health Service Medical Center between 2006 and 2015. Patients were followed through June 2018 (0.03-12.39 years post-installation). Clinical factors (age, sex, implant diameter, implant length, placement site, bone graft, fixture material, cervical feature, abutment connection, microthread, and platform switching) were recorded. Kaplan-Meier survival analysis identified risk indicators associated with an implant fracture. Cox regression models elucidated potential fracture risks. RESULTS: One hundred and seventy-four implants fractured in 135 patients, for an incidence rate of 0.92% after an average of 4.95 ± 2.14 years of use. Kaplan-Meier estimates showed that the 3-, 5-, and 10-year survival rates of implants were 99.8%, 99.2%, and 97.7%, respectively. In the multivariable Cox regression model, the diameter, location, history of bone graft, and microthread presence were significantly correlated with implant fractures. Wide-diameter implants had a reduced fracture risk within 90 months, after which the diameter did not correlate with fractures. Implants placed in the anterior mandible had a lower fracture risk within 90 months; mandibular premolar implants corresponded with a lower risk after 90 months. Implants without a history of bone graft or microthreads were more likely to fracture throughout the follow-up time. CONCLUSIONS: These results elucidate risk indicators for implant fractures and facilitate their reduction in clinical practice.


Subject(s)
Dental Implants , Dental Restoration Failure , Dental Prosthesis Design , Dental Prosthesis, Implant-Supported , Female , Humans , Male , Retrospective Studies
17.
Insects ; 11(1)2019 Dec 31.
Article in English | MEDLINE | ID: mdl-31906089

ABSTRACT

Steinernema feltiae K1 (Filipjev) (Nematode: Steinernematidae), an entomopathogenic nematode, was isolated and identified based on its morphological and molecular diagnostic characteristics. Its infective juveniles (IJs) were highly pathogenic to three lepidopteran (LC50 = 23.7-25.0 IJs/larva) and one coleopteran (LC50 = 39.3 IJs/larva) insect species. Infected larvae of the diamondback moth, Plutella xylostella (L.) (Insecta: Lepidoptera), exhibited significant reduction in phospholipase A2 (PLA2) activity in their plasma. The decrease of PLA2 activity was followed by significant septicemia of the larvae infected with S. feltiae. Insecticidal activity induced by S. feltiae was explained by significant immunosuppression in cellular immune responses measured by hemocyte nodule formation and total hemocyte count (THC). Although S. feltiae infection suppressed nodule formation and THC in the larvae, an addition of arachidonic acid (AA, a catalytic product of PLA2) rescued these larvae from fatal immunosuppression. In contrast, an addition of dexamethasone (a specific PLA2 inhibitor) enhanced the nematode's pathogenicity in a dose-dependent manner. To discriminate the immunosuppressive activity of a symbiotic bacterium (Xenorhabdus bovienii (Proteobacteria: Enterobacterales)) from the nematode, kanamycin was applied to after nematode infection. It significantly inhibited the bacterial growth in the hemolymph. Compared to nematode treatment alone, the addition of antibiotics to nematode infection partially rescued the immunosuppression measured by phenol oxidase activity. Consequently, treatment with antibiotics significantly rescued the larvae from the insecticidal activity of S. feltiae. These results suggest that immunosuppression induced by infection of S. feltiae depends on its symbiotic bacteria by inhibiting eicosanoid biosynthesis, resulting in significant insect mortality. However, the addition of antibiotics or AA could not completely rescue the virulence of the nematode, suggesting that the nematode itself also plays a role in its insecticidal activity.

18.
Clin Implant Dent Relat Res ; 21(1): 175-182, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30394672

ABSTRACT

BACKGROUND: Various approaches are used for alveolar ridge preservation (ARP); however, there is no standard method or material. PURPOSE: To investigate the effect of ARP with a dense polytetrafluoroethylene (d-PTFE) membrane and freeze-dried irradiated allogenic bone for sockets with bone deficiency. MATERIALS AND METHODS: Thirty-four patients (with sockets exhibiting ≥3 mm hard tissue loss in ≥1 walls) were randomized to undergo natural socket healing (control) or ARP with a d-PTFE membrane and freeze-dried irradiated allogenic bone (test group). After 4 months, horizontal and vertical ridge changes were measured using cone beam computed tomography. RESULTS: Ridge width at l mm below the ridge crest demonstrated significantly less change in the test group (median =2.3; Q1 = 0.6; Q3 = 4.3 mm) than in the control group (median =3.9; Q1 =2.6; Q3 = 7.8 mm; P = .021). There was no significant difference between the two groups in horizontal ridge changes at 3 and 5 mm below the crest or vertical changes (P > .05). Requirement for bone augmentation at implant placement was significantly reduced in the test group compared to the control group (P < .001). CONCLUSION: ARP with a d-PTFE membrane and freeze-dried irradiated allogenic bone substitute reduced horizontal bone resorption in sockets with bone deficiency.


Subject(s)
Alveolar Bone Loss/surgery , Alveolar Ridge Augmentation/methods , Tooth Socket/surgery , Adult , Aged , Aged, 80 and over , Alveolar Bone Loss/diagnostic imaging , Bone Transplantation/methods , Cone-Beam Computed Tomography , Female , Humans , Male , Membranes, Artificial , Middle Aged , Polytetrafluoroethylene/therapeutic use
19.
J Invertebr Pathol ; 159: 6-17, 2018 11.
Article in English | MEDLINE | ID: mdl-30389324

ABSTRACT

Steinernema longicaudum GNUS101, an entomopathogenic nematode, was isolated from soils in Korea. Its internal transcribed space sequence was highly similar to the known S. longicaudum species. Infective juveniles (IJs) of S. longicaudum were highly virulent to lepidopteran and coleopteran insects. Two different bacteria were isolated from the hemolymph of lepidopteran larvae infected with S. longicaudum. They exhibited blue and red colonies on nutrient bromothymol blue agar. The red-colored bacterium was identified as Enterococcus mundtii KHY while the blue-colored bacterium was identified as Xenorhabdus ehlersii KSY based on 16S rRNA sequencing and biochemical characters. The bacterial species showed different growth rates, with X. ehlersii KSY growing more slowly than E. mundtii KHY. Both bacteria were entomopathogenic, but showed differences in suppressing host immune responses. X. ehlersii KSY, but not E. mundtii KHY, showed inhibitory activity against cellular immune responses of Spodoptera exigua larvae including hemocyte-spreading behavior and nodule formation in bacteria-cultured broth. Its immunosuppressive activity was reversed by adding arachidonic acid, an eicosanoid biosynthesis precursor. Furthermore, organic extracts of X. ehlersii KSY using hexane or ethyl acetate showed inhibitory activity against cellular immune responses of S. exigua larvae. Arachidonic acid addition to S. exigua larvae infected with X. ehlersii significantly rescued the survival rate of target insect. Of the two bacteria isolated from S. longicaudum GNUS101, only X. ehlersii induced immunosuppression of target insect by inhibiting eicosanoid biosynthesis.


Subject(s)
Nematoda/genetics , Nematoda/immunology , Nematoda/microbiology , Spodoptera/parasitology , Xenorhabdus/immunology , Animals , Spodoptera/immunology , Symbiosis
20.
Clin Implant Dent Relat Res ; 20(4): 463-469, 2018 Aug.
Article in English | MEDLINE | ID: mdl-29761926

ABSTRACT

BACKGROUND: Currently, there is incomplete understanding of the fracture patterns in the implant and their association with clinical factors. PURPOSE: The aim of this study was to investigate the incidence and pattern of implant fracture (IF) by using 9-year, long-term multicenter follow-up data. MATERIALS AND METHODS: The association of the incidence and differences in fracture patterns with clinical factors (based on patient variables and implant variables) was assessed for statistical significance using the Chi-square and Fisher exact test, as appropriate. RESULTS: Among a total of 19 087 implants in 8501 patients (7838 male and 663 female) placed over 9 years, fractures were observed in 70 implants (0.4%) in 57 patients (50 male and 7 female). Cases with less than 50% bone loss had a higher incidence of horizontal and vertical IFs limited to the crest module, which are defined as Type I fractures (n = 13, 18.6%). In contrast, cases with ≥50% severe bone loss exhibited a higher incidence of Type II vertical fractures (n = 22, 31.4%), extending beyond the crestal portion (P = .001). Type III fractures (n = 5, 7.1%), defined as a horizontal fracture beyond the crestal module, were also observed. CONCLUSION: Peri-implantitis-induced marginal and vertical bone loss and manufacturing-induced defects were considered to be major factors in IF. Therefore, using clinically verified implant systems and striving to minimize bone loss by preventing and actively treating peri-implantitis is essential to reduce IFs.


Subject(s)
Alveolar Bone Loss/etiology , Dental Implants/adverse effects , Dental Restoration Failure , Incidence , Peri-Implantitis/etiology , Adult , Aged , Aged, 80 and over , Alveolar Bone Loss/diagnostic imaging , Alveolar Bone Loss/epidemiology , Chi-Square Distribution , Dental Implantation, Endosseous/adverse effects , Dental Prosthesis Design , Dental Prosthesis, Implant-Supported , Female , Follow-Up Studies , Humans , Male , Middle Aged , Peri-Implantitis/diagnostic imaging , Peri-Implantitis/epidemiology
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