171 research outputs found
Present and Future of EGFR Inhibitors for Head and Neck Squamous Cell Cancer
Although EGFR is expressed at high levels in head and neck squamous cell carcinomas (HNSCCs) and mutations are extremely rare, monotherapy with EGFR inhibitors has shown limited success. The PI3kinase/Akt pathway is responsible for cellular survival, and inhibition of phosphatidylinositol (PI) synthesis has antiproliferative, anti-invasive, and antiangiogenesis effects on HNSCC. Molecular crosstalk has been observed between EGFR and IGF1R signaling through the PI3kinase/Akt pathway in HNSCC, as has molecular crosstalk between the NFκB and STAT3 signaling pathways. Therefore, the combination of an EGFR antagonist with an agent that inhibits the activation of both Akt and NFκB may overcome resistance to EGFR antagonists in HNSCC
Management of deep neck infection by a transnasal approach: a case report
<p>Abstract</p> <p>Introduction</p> <p>Deep neck infection is a life-threatening condition, and intravenous antibiotic therapy is preferable in the early stages of the disease. However, in the advanced stages, surgical drainage should be performed. Although several surgical treatment strategies are available, it is necessary to standardize treatment according to the patient's general condition and history.</p> <p>Case presentation</p> <p>We report the case of a 68-year-old man with a deep neck abscess and with severe diabetes mellitus and inflammation. Computed tomography identified a deep neck infection extending from the level of the epipharynx to that of the hyoid bone. We performed surgical drainage by transnasal endoscopy. The patient exhibited no evidence of either recurrent disease or post-surgical complications within 30 months of follow-up.</p> <p>Conclusions</p> <p>This case report provides evidence that transnasal endoscopic drainage should be recommended as a standard approach in patients with a deep neck abscess and with a severe general condition, diabetes mellitus, and inflammation.</p
Mineral trioxide aggregate induces osteoblastogenesis via Atf6
AbstractMineral trioxide aggregate (MTA) has been recommended for various uses in endodontics. To understand the effects of MTA on alveolar bone, we examined whether MTA induces osteoblastic differentiation using MC3T3-E1 cells. MTA enhanced mineralization concomitant with alkaline phosphatase activity in a dose- and time-dependent manner. MTA increased production of collagens (Type I and Type III) and matrix metalloproteinases (MMP-9 and MMP-13), suggesting that MTA affects bone matrix remodeling. MTA also induced Bglap (osteocalcin) but not Bmp2 (bone morphogenetic protein-2) mRNA expression. We observed induction of Atf6 (activating transcription factor 6, an endoplasmic reticulum (ER) stress response transcription factor) mRNA expression and activation of Atf6 by MTA treatment. Forced expression of p50Atf6 (active form of Atf6) markedly enhanced Bglap mRNA expression. Chromatin immunoprecipitation assay was performed to investigate the increase in p50Atf6 binding to the Bglap promoter region by MTA treatment. Furthermore, knockdown of Atf6 gene expression by introduction of Tet-on Atf6 shRNA expression vector abrogated MTA-induced mineralization. These results suggest that MTA induces in vitro osteoblastogenesis through the Atf6–osteocalcin axis as ER stress signaling. Therefore, MTA in endodontic treatment may affect alveolar bone healing in the resorbed region caused by pulpal infection
MRI and CT features of a malignant myoepithelioma of the scrotum : A case report and literature review
Malignant myoepithelioma of the scrotum is extremely rare. We report the case of a 51-year-old man with malignant myoepithelioma of the scrotum, wherein computed tomography and magnetic resonance imaging revealed a lobulated soft tissue mass with calcification, cystic component, and solid component with gradual contrast enhancement on dynamic contrast-enhanced scans. The patient presented with scrotal induration, and there was no elevation of tumor markers and no evidence of a metastatic lesion on computed tomography and magnetic resonance imaging. Histopathological examination of the resected scrotal specimen confirmed a well-circumscribed solid tumor with septa, a small area of hemorrhage, and necrosis. The subsequent diagnosis was malignant myoepithelioma of the scrotum. This case shows that scrotal malignant myoepithelioma might appear as a well-defined lobulated mass with cystic regions. We conjecture that the enhancement pattern and apparent diffusion coefficient values can be potential markers for scrotal myoepithelial tumors
Resting-state functional connectivity-based biomarkers and functional MRI-based neurofeedback for psychiatric disorders: a challenge for developing theranostic biomarkers
Psychiatric research has been hampered by an explanatory gap between
psychiatric symptoms and their neural underpinnings, which has resulted in poor
treatment outcomes. This situation has prompted us to shift from symptom-based
diagnosis to data-driven diagnosis, aiming to redefine psychiatric disorders as
disorders of neural circuitry. Promising candidates for data-driven diagnosis
include resting-state functional connectivity MRI (rs-fcMRI)-based biomarkers.
Although biomarkers have been developed with the aim of diagnosing patients and
predicting the efficacy of therapy, the focus has shifted to the identification
of biomarkers that represent therapeutic targets, which would allow for more
personalized treatment approaches. This type of biomarker (i.e., theranostic
biomarker) is expected to elucidate the disease mechanism of psychiatric
conditions and to offer an individualized neural circuit-based therapeutic
target based on the neural cause of a condition. To this end, researchers have
developed rs-fcMRI-based biomarkers and investigated a causal relationship
between potential biomarkers and disease-specific behavior using functional MRI
(fMRI)-based neurofeedback on functional connectivity. In this review, we
introduce recent approach for creating a theranostic biomarker, which consists
mainly of two parts: (i) developing an rs-fcMRI-based biomarker that can
predict diagnosis and/or symptoms with high accuracy, and (ii) the introduction
of a proof-of-concept study investigating the relationship between normalizing
the biomarker and symptom changes using fMRI-based neurofeedback. In parallel
with the introduction of recent studies, we review rs-fcMRI-based biomarker and
fMRI-based neurofeedback, focusing on the technological improvements and
limitations associated with clinical use.Comment: 46 pages, 5 figure
Hyperplasia of lymphoid structures in the hypopharynx: a case report
<p>Abstract</p> <p>Introduction</p> <p>Ectopic tonsillar tissue simulating a benign tumor of the hypopharynx is described in this report.</p> <p>Case presentation</p> <p>We report the case of a 79-year-old Japanese woman with globus sensation. Because clinical observation revealed benign features, tumor tissue was laryngoscopically resected. From the pathological features, for example, existence of germinal center, lymphoid tissue, and crypt involving lymphoepithelial symbiosis, we diagnosed that the lesion was a hyperplasia of ectopic tonsillar tissue.</p> <p>Conclusions</p> <p>Although ectopic tonsillar tissue of the hypopharynx is relatively rare, it should be kept in mind during differential diagnosis.</p
Crystal structure of CmABCB1 multi-drug exporter in lipidic mesophase revealed by LCP-SFX
がんの多剤排出の原因となっているABCトランスポーターの立体構造をSACLAのX線自由電子レーザーを用いて決定. 京都大学プレスリリース. 2021-12-23.CmABCB1 is a Cyanidioschyzon merolae homolog of human ABCB1, a well known ATP-binding cassette (ABC) transporter responsible for multi-drug resistance in various cancers. Three-dimensional structures of ABCB1 homologs have revealed the snapshots of inward- and outward-facing states of the transporters in action. However, sufficient information to establish the sequential movements of the open–close cycles of the alternating-access model is still lacking. Serial femtosecond crystallography (SFX) using X-ray free-electron lasers has proven its worth in determining novel structures and recording sequential conformational changes of proteins at room temperature, especially for medically important membrane proteins, but it has never been applied to ABC transporters. In this study, 7.7 monoacylglycerol with cholesterol as the host lipid was used and obtained well diffracting microcrystals of the 130 kDa CmABCB1 dimer. Successful SFX experiments were performed by adjusting the viscosity of the crystal suspension of the sponge phase with hydroxypropyl methylcellulose and using the high-viscosity sample injector for data collection at the SACLA beamline. An outward-facing structure of CmABCB1 at a maximum resolution of 2.22 Å is reported, determined by SFX experiments with crystals formed in the lipidic cubic phase (LCP-SFX), which has never been applied to ABC transporters. In the type I crystal, CmABCB1 dimers interact with adjacent molecules via not only the nucleotide-binding domains but also the transmembrane domains (TMDs); such an interaction was not observed in the previous type II crystal. Although most parts of the structure are similar to those in the previous type II structure, the substrate-exit region of the TMD adopts a different configuration in the type I structure. This difference between the two types of structures reflects the flexibility of the substrate-exit region of CmABCB1, which might be essential for the smooth release of various substrates from the transporter
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