A histological study of the adult ligamentum arteriosum: Novel findings with application to a patent ductus arteriosus.

The ligamentum arteriosum (LA) is the vestigial fibrous remnant of the ductus arteriosus (DA), a fetal vessel arising from the left dorsal segment of the sixth aortic arch that connects the left pulmonary artery to the aortic arch. Incomplete obliteration of the DA results in a patent ductus arteriosus (PDA), causing the shunting of oxygen-rich blood to recirculate to the lungs, which can lead to pulmonary hypertension. The current study aims to further elucidate the structural characteristics of the LA via histological analysis with data gathered from adult cadaveric specimens. The LA was harvested and histologically observed with Hematoxylin and Eosin, van Gieson, and Masson's trichrome staining. Fibrous and muscle tissues were observed in all 25 specimens. The LA was categorized into three types based on the morphological features of the LA. Type I (vessel-like structure), type II (fibrotic tissue with duct-like structure), and type III (no duct-like structure) were found in 4.0%, 80.0%, and 16.0%, respectively. Finally, the remnant of a valve in the LA was also observed at the junction between the AA and LA. We suggest that this valve be called the "pulmonary-aortic valve." In the majority of the adult LAs, a duct-like structure was still present. These data could better elucidate our understanding of the pathology and etiology of a PDA.

Reproduction of the Antitumor Effect of Cisplatin and Cetuximab Using a Three-dimensional Spheroid Model in Oral Cancer.

Background/Aim: Cancer research has been conducted using cultured cells as part of drug discovery testing, but conventional two-dimensional culture methods are unable to reflect the complex tumor microenvironment. On the other hand, three-dimensional cultures have recently been attracting attention as in vitro models that more closely resemble the in vivo physiological environment. The purpose of this study was to establish a 3D culture method for oral cancer and to verify its practicality. Materials and Methods: Three-dimensional cultures were performed using several oral cancer cell lines. Western blotting was used for protein expression analysis of the collected cell masses (spheroids), and H-E staining was used for structural observation. The cultures were exposed to cisplatin and cetuximab and the morphological changes of spheroids over time and the expression changes of target proteins were compared. Results: Each cell line formed spheroidal cell aggregates and showed enhancement of cell adhesion molecules over time. H-E staining showed tumor tissue-like structures specific to each cell line. Cisplatin showed concentration-dependent antitumor effects due to loss of cell adhesion and spheroid disruption in each cell line, while cetuximab exhibited antitumor effects that correlated with EGFR expression in each cell line. Conclusion: Spheroids made from oral cancer cell lines appeared to have tumor-like characteristics that may reflect their clinical significance. In the future, it may become possible to produce tumor spheroids from tissue samples of oral cancer patients, and then apply them to drug screening and to develop individualized diagnostic and treatment methods.

Potential role of myeloid-derived suppressor cells in transition from reaction to repair phase of bone healing process.

Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells with immunosuppressive functions; these cells play a key role in infection, immunization, chronic inflammation, and cancer. Recent studies have reported that immunosuppression plays an important role in the healing process of tissues and that Treg play an important role in fracture healing. MDSCs suppress active T cell proliferation and reduce the severity of arthritis in mice and humans. Together, these findings suggest that MDSCs play a role in bone biotransformation. In the present study, we examined the role of MDSCs in the bone healing process by creating a bone injury at the tibial epiphysis in mice. MDSCs were identified by CD11b and GR1 immunohistochemistry and their role in new bone formation was observed by detection of Runx2 and osteocalcin expression. Significant numbers of MDSCs were observed in transitional areas from the reactionary to repair stages. Interestingly, MDSCs exhibited Runx2 and osteocalcin expression in the transitional area but not in the reactionary area. And at the same area, cllagene-1 and ALP expression level increased in osteoblast progenitor cells. These data is suggesting that MDSCs emerge to suppress inflammation and support new bone formation. Here, we report, for the first time (to our knowledge), the role of MDSCs in the initiation of bone formation. MDSC appeared at the transition from inflammation to bone making and regulates bone healing by suppressing inflammation.

Effect of Patient Clinical Variables in Osteoporosis Classification Using Hip X-rays in Deep Learning Analysis.

Background and Objectives: A few deep learning studies have reported that combining image features with patient variables enhanced identification accuracy compared with image-only models. However, previous studies have not statistically reported the additional effect of patient variables on the image-only models. This study aimed to statistically evaluate the osteoporosis identification ability of deep learning by combining hip radiographs with patient variables. Materials andMethods: We collected a dataset containing 1699 images from patients who underwent skeletal-bone-mineral density measurements and hip radiography at a general hospital from 2014 to 2021. Osteoporosis was assessed from hip radiographs using convolutional neural network (CNN) models (ResNet18, 34, 50, 101, and 152). We also investigated ensemble models with patient clinical variables added to each CNN. Accuracy, precision, recall, specificity, F1 score, and area under the curve (AUC) were calculated as performance metrics. Furthermore, we statistically compared the accuracy of the image-only model with that of an ensemble model that included images plus patient factors, including effect size for each performance metric. Results: All metrics were improved in the ResNet34 ensemble model compared with the image-only model. The AUC score in the ensemble model was significantly improved compared with the image-only model (difference 0.004; 95% CI 0.002-0.0007; p = 0.0004, effect size: 0.871). Conclusions: This study revealed the additional effect of patient variables in identification of osteoporosis using deep CNNs with hip radiographs. Our results provided evidence that the patient variables had additive synergistic effects on the image in osteoporosis identification.

High-mobility group box 1 induces bone destruction associated with advanced oral squamous cancer via RAGE and TLR4.

Bone destruction of maxillary and mandibular bone by invasive oral squamous cell cancer (OSCC) raises various problems in the management of patients, resulting in poor outcomes and survival. However, the mechanism behind bone destruction by OSCC remains unclear. High-mobility group box 1 (HMGB1), a highly conserved ubiquitous nuclear non-histone DNA-binding protein, has been demonstrated to be secreted by aggressive cancers and regulate osteoclastogenesis, a central player during bone destruction. We therefore reasoned that HMGB1 secreted by OSCCs contributes to bone destruction. Our results showed that HMGB1 is produced by human cell lines of OSCC and promotes osteoclastogenesis via up-regulation of the expression of receptor activator of nuclear factor kappa-Β ligand in osteoblasts and osteocytes, and consequently osteoclastic bone destruction in mice. Further, we found that these actions of HMGB1 are mediated via the receptor for advanced glycation end products and toll-like receptors. These findings suggest that HMGB1 of OSCC and its down-stream signal pathways are potential targets for the treatment of bone destruction associated with advanced OSCC.

Maxillofacial Trauma Surgery Patients With Titanium Osteosynthesis Miniplates: Remove or Not?

The authors examined the timing and causes of titanium miniplate removal after maxillofacial trauma surgery. The authors performed a retrospective study of maxillofacial fracture patients in whom maxillofacial osteosynthesis miniplates were inserted or removed at the Kagawa Prefectural Central Hospital, between 2008 and 2017. Predictive variables were age, sex, fracture site distribution, and time to miniplate removal with or without complications in relation to primary outcome variables. Among 185 patients, 440 miniplates were inserted and 272 miniplates were removed. In total, 116 patients (73.4%) had 282 miniplates (64.1%) removed, of which 4.8% fracture sites and 5.7% miniplates were removed because of complications. The mean time to miniplate removal was 630.9 and 258.0 days in patients with and without complications, respectively. There was a statistically significant difference in miniplate removal and miniplate retention relative to age and sex. This difference was not related to the presence or absence of sex- or age-related complications. The miniplates as osteosynthesis material were safe and useful for a long period of time with relatively few complications. Because complications requiring miniplate removal occurred within 1 or after 5 years postoperatively, osteosynthesis miniplate treatments should be decided while considering the patient's age and sex. Long-term follow-up is recommended for miniplates that remain implanted for >1 year.

Morphological characteristics of radicular cysts using computed tomography.

The purpose of this study was to evaluate computed tomography (CT) findings of radicular cysts with a focus on location, size, and condition of the surrounding bone. Subjects comprised 60 men and 86 women (mean age 47.2 years) with histopathologically confirmed radicular cysts who underwent CT examination between 2012 and 2014. Mesiodistal and buccolingual diameters were measured at the location where the lesion appeared to be largest on CT axial images. Of the 146 cases, 103 lesions were in the maxilla and 43 were in the mandible. Mesiodistal diameter of the maxillary lesions was significantly larger than that of the mandibular lesions. However, the ratio of mesiodistal diameter to buccolingual diameter in the mandible was significantly larger than that in the maxilla. Bone expansion was more significant in the maxilla than in the mandible. Mesiodistal and buccolingual diameters in only the maxilla and perilesional sclerotic radiolucency in images of both jaws were significantly associated with the severity of clinical symptoms. The findings suggest that radicular cysts in the maxilla are accompanied by bone expansion in the mesiodistal and buccolingual directions and those in the mandible progress in the mesiodistal direction without bone expansion. Clinical acute symptoms (pain and swelling) are correlated with lesion size in the maxilla; such a correlation is not clear for mandibular lesions, and discovery of mandibular lesions may, therefore, be delayed.

Impact of the Stroma on the Biological Characteristics of the Parenchyma in Oral Squamous Cell Carcinoma.

Solid tumors consist of the tumor parenchyma and stroma. The standard concept of oncology is that the tumor parenchyma regulates the tumor stroma and promotes tumor progression, and that the tumor parenchyma represents the tumor itself and defines the biological characteristics of the tumor tissue. Thus, the tumor stroma plays a pivotal role in assisting tumor parenchymal growth and invasiveness and is regarded as a supporter of the tumor parenchyma. The tumor parenchyma and stroma interact with each other. However, the influence of the stroma on the parenchyma is not clear. Therefore, in this study, we investigated the effect of the stroma on the parenchyma in oral squamous cell carcinoma (OSCC). We isolated tumor stroma from two types of OSCCs with different invasiveness (endophytic type OSCC (ED-st) and exophytic type OSCC (EX-st)) and examined the effect of the stroma on the parenchyma in terms of proliferation, invasion, and morphology by co-culturing and co-transplanting the OSCC cell line (HSC-2) with the two types of stroma. Both types of stroma were partially positive for alpha-smooth muscle actin. The tumor stroma increased the proliferation and invasion of tumor cells and altered the morphology of tumor cells in vitro and in vivo. ED-st exerted a greater effect on the tumor parenchyma in proliferation and invasion than EX-st. Morphological analysis showed that ED-st changed the morphology of HSC-2 cells to the invasive type of OSCC, and EX-st altered the morphology of HSC-2 cells to verrucous OSCC. This study suggests that the tumor stroma influences the biological characteristics of the parenchyma and that the origin of the stroma is strongly associated with the biological characteristics of the tumor.

Immunohistochemistry of YAP and dNp63 and survival analysis of patients bearing precancerous lesion and oral squamous cell carcinoma.

Background: Yes-associated protein (YAP) is a candidate oncogene in various human cancers, and recently, it has been reported that YAP expression and its activity was enhanced by ΔNp63. However, the role of YAP and ΔNp63 expression in carcinogenesis and progression of oral squamous cell carcinoma (OSCC) has been unknown. Therefore, we investigated how YAP and ΔNp63 influence carcinogenesis and progression of OSCC. Methods: We performed immunohistochemical analyses in whole tissue samples to investigate YAP and ΔNp63 expression in normal oral mucosa, epithelial hyperplasia, oral epithelial dysplasia (OED; low/high grade), carcinoma in situ (CIS), and OSCC. Furthermore, in OSCC, we analyzed clinical significance by using Kaplan-Meier survival analysis. Results: In normal oral mucosa and epithelial hyperplasia, YAP expression was primarily confined to the basal and parabasal layers, but YAP expression was elevated in OED, CIS, and OSCC. In OED, YAP and ΔNp63 expression levels were markedly higher in high grade than in low grade. In OSCC groups, YAP and ΔNp63 expression patterns tended to differ according to histopathological differentiation of OSCC. Furthermore, the YAP high expression group, which showed YAP staining in >50% positive cells with strong cytoplasmic staining or >10% positive cells with nuclear reactivity, showed a tendency to have a poor survival rate. Conclusion: YAP and ΔNp63 expression levels correlated with grade of oral OED. Additionally, YAP expression was associated with OSCC survival rate. Our results suggested that YAP and ΔNp63 expression might serve as predictive markers to distinguish OSCC development and progression.

Feasible Advantage of Bioactive/Bioresorbable Devices Made of Forged Composites of Hydroxyapatite Particles and Poly-L-lactide in Alveolar Bone Augmentation: A Preliminary Study.

Purpose: We aimed to document the clinical usefulness of uncalcined and unsintered hydroxyapatite (u-HA) particles and poly-L-lactide (PLLA) composite materials and their advantageous properties. Methods: Between April 2016 and March 2018, five patients required anterior maxillary alveolar ridge augmentation using fixation with u-HA/PLLA screws for an onlay block bone graft harvested from the mandibular ramus at our institute. Bone biopsies were obtained from the dental implantation site following bone healing for histomorphometric and immunohistochemical (IHC) measurements. Results: Many stromal cells were positive for Osterix, RUNX2, and SOX9 but were negative for CD68. On cell counting, based on IHC staining for Osterix, RUNX2, SOX9 and CD68 from peripheral u-HA/PLLA screw or bone areas, both areas consistently showed no significant difference in terms of Osterix, RUNX2, and SOX9. Hematoxylin-eosin staining revealed direct bone connection to the biomaterials, and no inflammatory cells infiltrated the areas surrounding the bone or artificial material. Area between the bone and u-HA/PLLA screw was seamless with no boundary. Round small cells and immature fibroblasts were noted. The new bone showed the presence of bone lamellae, normal osteocytes, and osteoblasts. Conclusion: The u-HA/PLLA materials showed excellent biodegradability and bioactive osteoconductivity. In addition, this material induced no apparent inflammatory or foreign body reactions following implantation, and it directly bonded to the human bone. Therefore, this u-HA/PLLA material seems ideal and most suitable for use as a substitute for osteosynthesis.