Differential Diagnosis of OKC and SBC on Panoramic Radiographs: Leveraging Deep Learning Algorithms.

This study aims to determine whether it can distinguish odontogenic keratocyst (OKC) and simple bone cyst (SBC) based solely on preoperative panoramic radiographs through a deep learning algorithm. (1) Methods: We conducted a retrospective analysis of patient data from January 2018 to December 2022 at Pusan National University Dental Hospital. This study included 63 cases of OKC confirmed by histological examination after surgical excision and 125 cases of SBC that underwent surgical curettage. All panoramic radiographs were obtained utilizing the Proline XC system (Planmeca Co., Helsinki, Finland), which already had diagnostic data on them. The panoramic images were cut into 299 × 299 cropped sizes and divided into 80% training and 20% validation data sets for 5-fold cross-validation. Inception-ResNet-V2 system was adopted to train for OKC and SBC discrimination. (2) Results: The classification network for diagnostic performance evaluation achieved 0.829 accuracy, 0.800 precision, 0.615 recall, and a 0.695 F1 score. (4) Conclusions: The deep learning algorithm demonstrated notable accuracy in distinguishing OKC from SBC, facilitated by CAM visualization. This progress is expected to become an essential resource for clinicians, improving diagnostic and treatment outcomes.

Characteristics of impacted mandibular third molar-related lesions.

Objectives: This study identifies factors for differential diagnosis among lesions by retrospectively comparing panoramic and cone-beam computed tomography images and analyzing the characteristics of lesions associated with impacted mandibular third molars (IMTs). Materials and Methods: A retrospective cohort study was conducted in patients who simultaneously underwent IMT extraction surgery and related benign tumor resection or cyst enucleation at our institution from 2017 to 2021. To compare the characteristics of each group, two comparative analyses were conducted. The first comparison considered the most frequently observed lesions associated with IMTs: dentigerous cysts, odontogenic keratocysts (OKCs), and ameloblastoma. The second comparison involved placing dentigerous cysts, which have a relatively low recurrence rate, into group A and placing OKC, ameloblastoma, and odontogenic myxoma, which have high recurrence rates, into group B. Results: Significant differences in the size of the lesion were found in the order of ameloblastoma, OKC, and dentigerous cyst (P <0.05). The buccolingual width of ameloblastoma differed significantly from that of the other groups, with no significant difference observed between the OKCs and dentigerous cysts (P=0.083). Conclusion: Patient age and lesion size differed significantly among lesion types associated with IMTs, with younger age and larger lesions for OKCs and odontogenic tumors. OKCs are likely to have a larger mesiodistal width than dentigerous cysts. The buccolingual width of ameloblastomas was larger than those of dentigerous cysts and OKCs.

Retrospective analysis on prognosis of oral cancer patients according to surgical approaches for effective cancer ablation: swing approach versus visor approach.

BACKGROUND: For the surgical treatment of oral cancer, it is sometimes necessary to expand intraoral access within the oral cavity. The "swing approach" that involves lip splitting of the mandible and temporary mandibular osteotomy and the "visor approach" that does not split the lower lip and mandible are mainly used. This study analyzed postoperative outcomes such as complications, recurrence rate, and survival rate by these two approaches. The goal of this study is to evaluate the surgical outcomes of patients using these two approaches, to propose effective perioperative management for oral cancer surgery, and to compare the prognosis of oral cancer patients. MATERIALS AND METHODS: From 2005 to 2020, 29 patients who underwent surgery at the Department of Oral and Maxillofacial Surgery of Pusan National University Dental Hospital for oral cancer lesions occurred in the mandible, floor of mouth, and tongue were selected for the study. Based on the surgical approach used, a chart review was conducted on various prognostic clinical factors such as the patients' sex and age, primary site, TNM stage, histopathologic grade, recurrence and metastasis, postoperative survival rate, adjuvant chemo-radiation therapy, satisfaction with aesthetics/function/swallowing, length of hospital stay, tracheostomy and its duration, and neck dissection and its type. Statistical analysis was conducted using SPSS 25.0 (SPSS Inc., Chicago, IL) through Fisher's exact t-test. RESULT: There was no statistically significant difference between two groups in terms of clinical and pathological findings, such as survival rate, the need for adjuvant therapies, and the local recurrence rate. Although better outcomes were observed in terms of function, aesthetics, and postoperative complications in the group with visor approach, there was still no statistically significant difference between two groups. However, the duration of hospital stay was shorter in the visor approach group. CONCLUSION: There was no statistically significant difference in clinical prognostic factors between the swing approach and the visor approach. Therefore, when choosing between the two approaches for the ablation of oral cancer, it is considered to select the surgical priority approach that can be easy access based on the size and location of the lesion. The visor approach had advantages of aesthetics and healing period.

Fibular free flap with proximal perforator skin paddle due to aberrant anatomy - a case report.

BACKGROUND: The fibular free flap is considered one of the most valuable options for mandible reconstruction. A perforator flap has gained widespread acceptance in oral and maxillofacial reconstruction. Typically, the fibula flap is obtained primarily with the distal perforator due to its reliable blood supply, with less attention given to the proximal perforators during the harvesting process. Normally, the distal perforator of the fibula exhibits stability and shows limited anatomical variations. However, there have been reported cases in which the distal perforator is absent. At times, these vascular abnormalities remain undetectable through Doppler examination or preoperative angiography evaluation. Therefore, this case details the experience of encountering the rare event of vascular abnormality in oral cancer surgery. CASE PRESENTATION: This article reports the case of a patient who presented with a congenital absence of the distal perforator in the peroneal artery, attributed to a vascular abnormality. Additionally, we provide a review of the concept of utilizing the proximal perforator as an alternative approach in the flap harvesting process. CONCLUSIONS: While the distal perforator of the peroneal artery is typically utilized for fibula free flap procedures, surgeons must remain cognizant of the potential for its absence due to aberrant anatomy. Recognizing an alternative approach in such cases can be pivotal for precise surgical planning and favorable outcomes in oral and maxillofacial reconstruction.

Cystic lesion between a deciduous tooth and the succeeding permanent tooth: a retrospective analysis of 87 cases.

Objectives: The purpose of this study is to investigate the characteristics of dentigerous and radicular cysts that occur between deciduous and succeeding permanent teeth and to propose considerations for differential diagnosis of cysts at the treatment planning stage in the outpatient clinic. Materials and Methods: A total of 87 patients with a cystic lesion located between a deciduous tooth and the succeeding permanent tooth participated in the study. Twelve variables were analyzed to diagnose such a cyst. For data analysis, Fisher's exact test was used to determine the statistical significance of the variables. Results: Of the total 87 patients who participated in this study, 69 were diagnosed with dentigerous cysts and 18 were diagnosed with radicular cysts. Seven of the 12 differential factors analyzed in this study were statistically significant: age, location, symptoms, dental caries, endodontic treatment, delayed eruption, and size. Conclusion: Several criteria can be considered for diagnosis of dentigerous cysts or radicular cysts. Age, location, presence of symptoms and dental caries, previous endodontic treatment, cystic size, and delayed eruption of impacted permanent teeth are reliable factors that should be considered when diagnosing dentigerous and radicular cysts.

Pim-2 regulates bone resorptive activity of osteoclasts via V-ATPase a3 isoform expression in periodontal disease.

Cytoplasmic serine/threonine Pim kinases have emerged as important modulators of immune regulation and oncology. However, their regulatory roles in bone remodeling remain obscure. Here, we aimed to determine the roles of Pim kinases in periodontal disease (PD), focusing on the regulation of osteoclastogenesis and bone resorptive activity. We investigated Pim kinases expression in PD by analyzing data from the online Gene Expression Omnibus database and using ligature-induced periodontitis mouse model. The expression of Pim kinases during receptor activator of nuclear factor kB ligand (RANKL)-induced osteoclastogenesis was assessed in mouse bone marrow-derived macrophages (BMMs) using reverse transcription polymerase chain reaction. Osteoclast differentiation and bone resorption activity were respectively verified by tartrate-resistant acid phosphatase staining and dentin disc-based bone resorption assays. We silenced and overexpressed Pim-2 using small interfering RNA (siRNA) and retroviral vector, respectively, to investigate the molecular mechanisms underlying Pim-2 regulation in RANKL-induced osteoclastogenesis and bone resorption activity. Upregulated expression of Pim-2 was observed in both patients with PD and periodontitis-affected mouse gingival tissues. siRNA-mediated silencing of Pim-2 in BMMs diminished RANKL-induced resorptive activity without affecting osteoclastogenesis. Moreover, RANKL-triggered stimulation of a3 isoform, which is a subunit of vacuolar-type ATPase, was selectively attenuated in BMMs on silencing Pim-2. The overexpression of Pim-2 with a retroviral vector stimulated the a3 subunit, thus inducing bone resorption activity. Taken together, these results suggest that Pim-2 acts as a major modulator of osteoclastic activity by regulating a3 isoform expression in PD.

Cemento-osseous dysplasia: clinical presentation and symptoms.

Objectives: The purpose of this study was to evaluate risk factors and symptoms in cemento-osseous dysplasia (COD) patients. Materials and Methods: In this study, 62 patients who were diagnosed histologically with COD were investigated from 2010 to 2020 at the author's institution. We compared clinical and radiological characteristics of symptomatic and asymptomatic patients. The factors were sex, age, lesion size, site, radiologic stage of lesion, apical involvement, sign of infection, and history of tooth extraction. Statistical analysis was performed using Fisher's exact test and the chi-square test. Results: COD was more prevalent in female patients. With the exception of three cases, all were focal COD. The majority of patients presented with symptoms when the lesion was smaller than 1.5 cm in size. Symptoms were observed when the apex of the tooth was included in the lesion or there was a local infection around the lesion. The history of tooth extraction and previous endodontic treatment were evaluated, and history was not a significant predictor for the onset of symptoms. Conclusion: In this study, risk factors associated with symptomatic patients were size of lesion, apical involvement, and local infection.

Effect of Observer's Sex and Chin Prominences on the Perception of the Lower Lip-Chin Prominence Angle.

ABSTRACT: This study aimed to identify the preferred range of lower lip-chin prominence angles in the Korean population and evaluate the effect of the individual lower lip-chin prominence angle on perceptions of esthetic chin profile.Chin prominence silhouettes were used to assess the lower lip-chin prominence preference. The observers randomly categorized each image as (1) normal, (2) slightly abnormal but not requiring surgical correction, and (3) abnormal and requiring surgery. Individual lower-chin prominence angles of all observers were analyzed using standardized clinical photographs.The normal range of lower lip-chin prominence angle is 0° to 25°; socially acceptable range is 0° to -10°, 25° to 40°; range needing surgery is -10° to -30° and 40° to 45°. Women are more tolerant to chin protrusion. A protrusive chin is more acceptable in observers with retrusive chin profile.Skeletal Class II profile is more acceptable than skeletal Class III in the Korean population. The individual lower-chin prominence angle could affect perception of desired surgery. These findings indicate that patient-specific treatment planning is important in achieving satisfaction in chin surgery.

Effects of photobiomodulation on bone remodeling in an osteoblast-osteoclast co-culture system.

The general bone anabolic effect of photobiomodulation (PBM) is largely accepted. As a result, PBM therapy is expected to be beneficial in the medical fields of dentistry and bone healing. However, most of the previous in vitro studies on PBM and bone metabolism were performed with single-cell cultures of osteoclast-lineage cells or osteoblast-lineage cells. In the present study, the bone-modulating effects of PBM were evaluated in an in vitro osteoblast/osteoclast co-culture system. Mouse bone marrow-derived macrophages (BMMs) and mouse calvarial pre-osteoblasts cells were purified and used as precursor cells for osteoclasts and osteoblasts, respectively. The PBM effects on single-cell culture of osteoclasts or osteoblasts as well as co-culture were examined by 1.2 J/cm2 low-level Ga-Al-As laser (λ = 808 ± 3 nm, 80 mW, and 80 mA; spot size, 1cm2; NDLux, Seoul, Korea) irradiation for 30 s at daily intervals throughout culture period. At the end of culture, the osteoclast differentiation and osteoblast differentiation were assessed by TRAP staining and ALP staining, respectively. The expressions of osteoclastogenic cytokines were evaluated by RT-PCR and Western blot analyses. Under the single-cell culture condition, PBM enhanced osteoblast differentiation but had minor effects on osteoclast differentiation. However, in the co-culture condition, its osteoblastogenic effect was maintained, and osteoclast differentiation was substantially reduced. Subsequent RT-PCR analyses and western blot results revealed marked reduction in receptor activator of NF-κB ligand (RANKL) expression and elevation in osteoprotegerin (OPG) expression by PBM in co-cultured cells. More importantly, these alterations in RANKL/OPG levels were not observed under the single-cell culture conditions. Our results highlight the different effects of PBM on bone cells based on culture conditions. Further, our findings suggest the indirect anti-osteoclastogenic effect of PBM, which is accompanied by a decrease in RANKL expression and an increase in OPG expression.

Idiopathic bone cavity: clinical and radiological features of 90 retrospective cases and surgical treatment.

OBJECTIVES: The purpose of this study was to evaluate the clinical and radiographic characteristics of idiopathic bone cavity (IBC) to determine the effect of surgical intervention on the process of healing. MATERIALS AND METHODS: All cases diagnosed with IBC during the period of 2011 to 2020 at our Department of Oral and Maxillofacial Surgery were searched. Ninety cases were retrieved. The features evaluated were sex, age, contour of the lesion, number of teeth involved, site, history of trauma, and postoperative healing pattern. The significance of differences was assessed by Mann-Whitney U test and chi-square test. RESULTS: The female:male ratio showed no predilection toward either sex (0.9:0.8). The mean age of the collected sample was 22.05±14.38 years, and the age ranged from 10 to 58 years. All cases presented in the mandible and showed well-circumscribed radiolucency. Margins were either scalloped or round in shape, and the size varied from one tooth to six teeth involvement. Seventy cases involved three or fewer roots. Three cases showed bilateral lesion. Four cases had a history of trauma at the area of the lesion. Fifty-one cases were followed for six months after surgery, and all showed increased bone density at the lesion. CONCLUSION: There is no definitive radiological or clinical feature of IBC. Considering the diversity of clinical and radiological features, such a diagnosis relies primarily on surgical findings of an empty bone cavity with no epithelial lining. Our data suggest that surgical intervention be the first choice of treatment as opposed to observation.

Primary repair of untreated cleft palate in an elderly patient: a case report.

Untreated adult or elderly cleft lip and palate patients are rarely seen, but studies on delayed primary palatal closure have been performed in the less developed Asian and African countries, where access to medical care is difficult. A 64-year-old woman visited our clinic with untreated cleft palate with a 40×20-mm-wide defect in the medial palate. Two-flap palatoplasty under general anesthesia was performed to close the cleft palate. After 1 month, the result was favorable without any complications including oronasal fistula. Cleft palate primary repair in an elderly patient is rare and has some surgical problems that are associated with a wide range of defects, but good results can be obtained if surgery is performed well with appropriate considerations.

Prognosis of teeth in mandibular fracture lines.

BACKGROUND/AIMS: Teeth in a jaw fracture line, because of the presence of the periodontal ligament, may communicate with the oral cavity. There are no guidelines for the management of teeth in mandibular fracture lines. The aim of this study was to investigate the factors related to dental problems with teeth involved in mandibular fracture lines and to determine the best treatment option. MATERIAL AND METHODS: This retrospective study was based on the medical and radiographic records of patients with mandibular fractures. The relationships among the patient's age, gender, smoking history, amount of bony displacement, surgery, trauma-surgery period, apical involvement, tooth mobility, and periodontal status were investigated. Group comparisons were performed using the chi-squared test, Fisher's exact test, and Mann-Whitney U-test. RESULT: A total of 238 patients (247 fracture lines) with mandibular fractures including a tooth in the line of the fracture were examined. Post-operative dental complications occurred in 42 cases (17.0%). Extraction of related teeth occurred in 34 cases (80.9%) compared to eight cases (19.0%) related to root canal therapy. This study defined "dental problem" as "a case with a tooth extracted or endodontically treated after trauma." The variables associated with an increased risk of dental problems were the amount of bony displacement (p < .01), tooth mobility (p < .01), and pre-existing marginal alveolar bone loss (p = .027). CONCLUSION: The prognosis of teeth in mandibular fracture lines was related to tooth mobility, periodontal state, and the amount of bony displacement.

cDNA-Derived RNA Phage Assembly Reveals Critical Residues in the Maturation Protein of the Pseudomonas aeruginosa Leviphage PP7.

PP7 is a leviphage, with a single-stranded RNA genome, that infects Pseudomonas aeruginosa PAO1. A reverse genetic system for PP7 was previously created by using reverse-transcribed cDNA (PP7O) from a virion-derived RNA genome. Here, we have found that the PP7O cDNA contained 20 nucleotide differences from the PP7 genome sequence deposited in the database. We created another reverse genetic system exploiting chemically synthesized cDNA (PP7S) based on the database sequence. Unlike PP7O, which yielded infectious PP7 virions, PP7S-derived particles were incapable of plaque formation on PAO1 cells, which was restored in the PAO1 cells expressing the maturation protein (MP) from PP7O Using this reverse genetic system, we revealed two amino acid residues involved in the known roles of MP (i.e., adsorption and genome replication), fortuitously providing a lesson that the viral RNA genome sequencing needs functional verification, possibly by a reverse genetic system.IMPORTANCE The biological significance of RNA phages has been largely ignored, ironically, because few studies have focused on RNA phages. As an initial attempt to properly represent RNA phages in the phageome, we previously created, by using reverse-transcribed cDNA, a reverse genetic system for the small RNA phage PP7, which infects the opportunistic human pathogen Pseudomonas aeruginosa We report another system by using chemically synthesized cDNA based on the database genome that has 20 nucleotide differences from the previous cDNA. Investigation of those cDNA-derived phage virions revealed that two amino acids of the maturation protein are crucial for the normal phage lifecycle at different steps. Our study provides insight into the molecular basis for the RNA phage lifecycle and a lesson that the RNA genome sequencing needs to be carefully validated by cDNA-based phage assembly systems.

Long-term follow-up of intersegmental displacement after orthognathic surgery using cone-beam computed tomographic superimposition.

OBJECTIVES: To evaluate intersegmental displacement during long-term follow-up after bilateral sagittal split osteotomy (BSSO) by mandibular body area superimposition. MATERIALS AND METHODS: Cone-beam computed tomography (CBCT) images of 23 patients ages 18-37 years with class III malocclusion before orthognathic surgery were obtained. A three-dimensional (3D) CBCT examination was performed at four stages: surgery (T0), 6 months after surgery (T1), 1 year after surgery (T2), and long-term follow-up (6.1 ± 2.1 years, T3). The CBCT datasets were superimposed on the symphyseal area and the lower part of the distal segment of the mandible between T0 and the other time points (T1, T2, and T3). The reference points (both condyle, coronoid, and sigmoid) were estimated by the CBCT analyzed program. RESULTS: The coronoid, condylion, and sigmoid showed changes within 6 months after surgery, but there was no significant change in the intersegmental displacement between 6 months and 6 years after surgery. The distances between the left and right coronoid, condylion, and sigmoid from T0 to T3 were noted. CONCLUSIONS: The change in intersegmental displacement between T0 and T3 affecting relapse after orthognathic surgery was not significantly different. This suggests that the mandible itself may have a stable morphology during the follow-up period.

Complications associated with specific characteristics of supernumerary teeth.

OBJECTIVES: The purpose of this study was to identify the characteristics of supernumerary teeth, analyze the associated complications, and to present new clinical knowledge on surgical interventions for supernumerary teeth. STUDY DESIGN: This retrospective cohort study was based on the medical records and radiographic records of patients who underwent surgical extraction of supernumerary teeth. The relationships among the patient's age, gender, anatomic features of supernumerary teeth, and presence and type of complications (i.e., spacing, rotation, delayed eruption of the adjacent tooth, cyst formation.) were investigated. The groups were compared by using the Mann-Whitney U test, the Kolmogorov-Smirnov test, and multiple logistic regression analysis (P < .05). RESULTS: The study population consisted of 705 participants who underwent extraction for 1036 supernumerary teeth. The mean age of the participants was 11.5 years, and 73.5% of the participants were males. The complication rate was 55.6%. Variables associated with an increased risk of complications were the patient's age, dentition, tuberculate shape, and horizontal direction of eruption (P < .05). CONCLUSIONS: An increase in the patient's age or abnormalities in the shape and direction of eruption of supernumerary teeth was associated with complications. These parameters should be considered while formulating the treatment plan.

A retrospective analysis of risk factors of oromaxillofacial infection in patients presenting to a hospital emergency ward.

BACKGROUND: The purpose of this study was to review the clinical features of oromaxillofacial infections in patients presenting to a hospital emergency ward, to identify the key factors affecting the requirement for hospitalization, and the potential risk factors predisposing to a prolonged length of hospital stay. METHODS: A retrospective medical record review of the 598 patients treated for oromaxillofacial infection from 2013 to 2017 at the oral and maxillofacial surgery department, Yangsan Pusan National University Hospital, was conducted. The following information was collected from each patient: sex, age, past medical history, site of infection, etiology, admission or outpatient care, level of C-reactive protein (mg/dL), fascial spaces involved, treatment method, and duration of hospitalization. Chi-squared tests were used to identify risk factors, which were further analyzed using multivariable logistic regression. RESULTS: A total of 606 patients were eligible for inclusion in the study, of which eight were excluded due to having incomplete charts; thus, 598 patients were included: 55% were male, mean patient age was 47.1 ± 19.9 years, and 12.9% of patients were diabetic. Furthermore, 71.2% of patients had infection originating in the mandible; the most common tooth of origin was lower posterior, and 29.8% of patients were hospitalized. Risk factors for hospital admission were elderly patients with concurrent disease, elevated C-reactive protein level, and multiple-space infection in the oromaxillofacial area. The duration of hospitalization was correlated with both diabetes and age. CONCLUSIONS: The requirement for hospital admission is determined by the severity of the infection; even severe infections, once treated with appropriate surgery, have no relation to the length of hospital stay. The important risk factors for increased duration of hospitalization are diabetes mellitus and older age. The understanding of risk factors associated with a prolonged hospital stay during the treatment of oromaxillofacial infection will aid in treatment planning as well as highlight the importance of adequate diabetes control in patients at risk of such infection.

Automatic three-dimensional analysis of bone volume and quality change after maxillary sinus augmentation.

INTRODUCTION: Maxillary sinus augmentation is a widely used surgical procedure to increase the bone volume before implant placement. In order to predict the stability of the implant, analysis of the change in bone volume and quality after a sinus graft procedure is necessary. The purpose of this study was to analyze the change in volume and quality of bone graft material after maxillary sinus augmentation using cone beam computed tomography (CBCT). METHODS AND MATERIALS: Maxillary sinus lift procedures using bovine bone materials (Bio-Oss, Geistrich, Swiss) without immediate implantation were performed at the Pusan National University Dental Hospital in 22 patients, from 2014 to 2017. CBCT images were captured before surgery (T1), a day after surgery (T2), and after 4 to 7 months at follow-up (T3). The T2 and T3 images were registered to the T1 image using histogram matching and intensity-based registration. A total of 30 sinuses were analyzed three-dimensionally (3-D), using self-made software MATLAB 2018a (MathWorks, Natick, Massachusetts). The volume and structural indices of the bone graft material were measured and analyzed. RESULTS: The average volume of graft material showed a decrease, while the average gray value showed an increase during the follow-up period, but these changes were not statistically significant. The structural indices of the graft material after histogram matching showed a significant difference in homogeneity, connectivity, thickness, and roughness at the postoperative follow-up. CONCLUSIONS: The volume and gray value showed no statistically significant changes after the maxillary sinus lift procedures. The results of this study show that structural analysis using histogram matching can be used as a promising tool to analyze the quality of graft materials.

Reverse Genetic Systems for Pseudomonas aeruginosa Leviphages.

Reverse genetic systems for RNA viruses are the platforms to introduce mutations into the RNA genomes and thus have helped understand their life cycle and harness them for human purposes to develop vaccines and delivery systems. These systems are based on the complementary DNA (cDNA) of the RNA viruses, whose transcripts derived from bacterial RNA polymerases act not only as the primary mRNA for phage protein synthesis, but also as the template for phage RNA replicases (aka. RNA-dependent RNA polymerases). Here, we present a protocol optimized for the small RNA phages of Leviviridae (i.e., leviphages) infecting Pseudomonas aeruginosa. This protocol includes three fundamental steps: (i) Creation of a promoter-fused cDNA, (ii) generation of a clone into mini-Tn7-based vector, and (iii) introduction of the clone into non-susceptible hosts. As the representative example, we describe the reverse genetic system for PP7, which infects a set of P. aeruginosa strains such as PAO1. The cDNA was fused to the T7 promoter, which was cloned in mini-Tn7-Gm. This construct was introduced into P. aeruginosa PAK and E. coli HB101. Functional assembly of PP7 phages from the culture supernatants were assessed by plaque formation on PAO1 and the phage particles were observed under transmission microscope. We found that the host cells should be cultured at 30 °C for the maximal phage production (~1012 pfu/mL). The reverse genetic systems will provide a new insight into the life cycle of the RNA phages and help develop engineered variants with new traits for phage applications regarding selective diagnosis and efficient therapy.

Inhibition of JAK2/STAT3 and activation of caspase­9/3 are involved in KYS05090S­induced apoptosis in ovarian cancer cells.

To overcome the poor prognosis of patients with ovarian cancer, attempting to target ovarian cancer with effective antitumor compounds has been conducted for numerous years. Although the 3,4­dihydroquinazoline derivative KYS05090S was known to exert antitumor effects in A549 and ovarian cancer cells by inhibition of T­type Ca2+ channels, the complete underlying antitumor mechanism of this compound remains unclear. Thus, in the present study, the potential apoptotic mechanism of KYS05090S was elucidated in SKOV3 and OVCAR3 ovarian cancer cells. KYS05090S exerted significant cytotoxicity in SKOV3 and OVCAR3 ovarian cancer cells, and also increased the number of apoptotic bodies, and the number of terminal deoxynucleotidyl transferase dUTP nick end labeling positive cells and the sub­G1 population as a feature of apoptosis. Consistently, KYS05090S induced cleavage of poly(ADP­ribose) polymerase and caspase­9/3 in ovarian cancer cells. Notably, KYS05090S attenuated the expression of anti­apoptotic proteins, including cyclin D1 and B­cell lymphoma­2 (Bcl­2), and reduced the phosphorylation of Janus kinase 2 (JAK2) and signal transducer and activator of transcription 3 (STAT3) in ovarian cancer cells. Additionally, KYS05090S blocked the nuclear translocation of STAT3 and suppressed the signaling of JAK2/STAT3 in interleukin­6­treated SKOV3 cells, as a STAT3 activator. Overall, these observations indicated that inhibition of JAK2/STAT3 signaling and activation of caspase­9/3 are critically involved in the effects of KYS05090S on apoptosis in ovarian cancer types, and the compound may be beneficial as a potent antitumor agent.

Zoledronate Enhances Osteocyte-Mediated Osteoclast Differentiation by IL-6/RANKL Axis.

Bisphosphonates are one of the most widely used synthetic pyrophosphate analogues for the treatment of bone resorbing diseases such as osteoporosis, multiple myeloma, and bone metastases. Although the therapeutic usefulness of bisphosphonates mainly depends on their anti-osteoclastogenic effect, a severe side-effect of bisphosphonates called bisphosphonate-related osteonecrosis of the jaw (BRONJ) could not be explained by the anti-osteoclastogenic effect of bisphosphonates. In the present study, we have evaluated the changes in osteoclastogenesis- or osteoblastogenesis-supporting activities of osteocytes induced by bisphosphonates. Zoledronate, a nitrogen-containing bisphosphonate, markedly increased both the receptor activator of nuclear factor kB ligand (RANKL) as well as sclerostin in osteocyte-like MLO-Y4 cells, which were functionally revalidated by osteoclast/osteoblast generating activities of the conditioned medium obtained from zoledronate-treated MLO-Y4 cells. Of note, the zoledronate treatment-induced upregulation of the RANKL expression was mediated by autocrine interleukin-6 (IL-6) and subsequent activation of the signal transducer and activator of transcription 3 (STAT3) pathway. These results were evidenced by the blunted RANKL expression in the presence of a Janus activated kinase (JAK2)/STAT3 inhibitor, AG490. Also, the osteoclastogenesis-supporting activity was significantly decreased in zoledronate-treated MLO-Y4 cells in the presence of IL-6 neutralizing IgG compared to that of the control IgG. Thus, our results show previously unanticipated effects of anti-bone resorptive bisphosphonate and suggest a potential clinical importance of osteocytes in BRONJ development.