Micro-computed tomography-based anatomical study of the branch canals in mandibular anterior teeth in a Chinese population.

OBJECTIVES: To analyze the incidence and distribution of branch canals in mandibular anterior teeth. MATERIALS AND METHODS: Three hundred mandibular anterior teeth, comprising 100 central incisors, 100 lateral incisors, and 100 canines, were scanned using a micro-computed tomography (micro-CT) system. Three-dimensional (3-D) visualization reconstruction of the root canal system and its branch canals was performed on each specimen. Data regarding the number of branch canals, the distance from the anatomical apex to the branch canal, and the orientation of each branch orifice were collected and analyzed. RESULTS: One hundred and fifty-three primary branch canals and 35 secondary branch canals were detected in the specimens overall. The incidence of branch canals in mandibular anterior teeth was 34%, with the highest incidence (50%) exhibited in mandibular canines, followed by lateral incisors (29%). Of the 153 primary branch canals found in the mandibular anterior tooth samples investigated, 82.35% appeared within 3 mm of the apical region, while 71.90% were labial and lingual canals. CONCLUSIONS: There was regularity in the distribution and orientation of branch canals in mandibular anterior teeth. CLINICAL RELEVANCE: This knowledge may be employed as a guide in clinical endodontic therapy.

Planar chiral [2.2]paracyclophanyl-based boron fluoride complexes: synthesis, crystal structure and photophysical properties.

Planar chiral [2.2]paracyclophanyl-based boron fluoride complexes (3a-3d) were designed and facilely synthesized. The X-ray structure study, theoretical calculations and CD spectra reveal the intense emission and planar chiral structures of these complexes. In particular, 3a-3d show moderate quantum yields and large Stokes shifts both in solution and solid state. Furthermore, the blue-shifted mechanochromic properties of 3a and 3b were both investigated in the solid state. This work is the first study on planar chiral boron monofluoride complexes within the boron fluoride complex field.

Axially chiral 1,4-dihydropyridine derivatives: aggregation-induced emission in exciplexes and application as viscosity probes.

By combining the fluorophores of axially chiral 1,1'-binaphthol (BINOL) and 1,4-dihydropyridine derivatives, axially chiral 1,4-dihydropyridine derivatives ((R)-/(S)-2) with aggregation-induced emission (AIE) in exciplexes were designed and synthesized. (R)-/(S)-2 emitted low fluorescence in THF solutions of their locally excited states; however, they emitted red-shifted fluorescence in the aggregate state upon exciplex formation. Moreover, (R)-/(S)-2 showed linear and multi-exponential relationships between their local excited and exciplex fluorescence intensities and the viscosity of the medium, which allowed us to determine the viscosities of different mixed solvents. In addition, as an axially chiral viscosity probe, (R)-/(S)-2 show excellent CD signals and have potential applications in the fields of chiral recognition and fluorescence imaging, which will broaden the new family of AIE fluorophores. To the best of our knowledge, there are few reports of axially chiral intramolecular exciplex-mediated AIE molecules.

Blockade of Cyclophilin D Attenuates Oxidative Stress-Induced Cell Death in Human Dental Pulp Cells.

Pathological stimuli, such as bacterial activity, dental bleaching, and nonpolymerized resin monomers, can cause death of dental pulp cells (DPCs) through oxidative stress- (OS-) induced mitochondrial dysfunction. However, the crucial molecular mechanisms that mediate such a phenomenon remain largely unknown. OS is characterized by the overproduction of reactive oxygen species (ROS), e.g., H2O2, O2 -, and ·OH. Mitochondria are a major source of ROS and the principal attack target of ROS. Cyclophilin D (CypD), as the only crucial protein for mitochondrial permeability transition pore (mPTP) induction, facilitates the opening of mPTP and causes mitochondrial dysfunction, leading to cell death. In the present study, we hypothesized that CypD-mediated mitochondrial molecular pathways were closely involved in the process of OS-induced death of human DPCs (HDPCs). We tested the phenotypic and molecular changes of HDPCs in a well-established OS model-H2O2 treatment. We showed that H2O2 dramatically reduced the viability and increased the death of HDPCs in a time- and dose-dependent manner by performing MTT, flow cytometry, and TUNEL assays and quantifying the expression changes of Bax and Bcl-2 proteins. H2O2 also induced mitochondrial dysfunction, as reflected by the increased mitochondrial ROS, reduced ATP production, and activation of mPTP (decreased mitochondrial membrane potential and enhanced intracellular Ca2+ level). An antioxidant (N-acetyl-L-cysteine) effectively preserved mitochondrial function and significantly attenuated H2O2-induced cytotoxicity and death. Moreover, H2O2 treatment markedly upregulated the CypD protein level in HDPCs. Notably, genetic or pharmacological blockade of CypD significantly attenuated H2O2-induced mitochondrial dysfunction and cell death. These findings provided novel insights into the role of a CypD-dependent mitochondrial pathway in the H2O2-induced death in HDPCs, indicating that CypD may be a potential therapeutic target to prevent OS-mediated injury in dental pulp.

Peroxidase-positive Auer bodies in plasma cells in multiple myeloma: a case report.

Reports of clinical cases with Auer bodies in the plasma cells in multiple myeloma (MM) are rare; however, most of those reported contain peroxidase (POX)-negative Auer bodies rather than the POX-positive Auer bodies observed in myeloid progenitors, indicating differences in their chemical properties. Furthermore, the cases with POX-positive Auer bodies similar to those observed in myeloid cells are extremely rare in non-myeloid cells. Here, we report the clinical features, laboratory investigations, diagnosis and treatment of a case of MM with POX-positive Auer bodies in plasma cells and review related the literature to advance the prognostic evaluation, diagnosis and treatment of similar cases.