To examine the influence of occlusal stimuli on the vasculature in the dental pulp, using an occlusal hypofunction model.Twenty 7-week-old male Sprague-Dawley rats were divided into two groups. To produce occlusal hypofunction, the appliances were attached to the maxillary and mandibular incisors. Untreated rats served as controls. Serial horizontal paraffin sections of the mandibular first molar were processed by conventional methods. To evaluate the microvasculature in the dental pulp, sections of each specimen were stained with hematoxylin-eosin.In the experimental group, the arterioles in the tooth pulp tissue ran convergently, and their inside diameter was significantly smaller than that of the control group.This study suggests that occlusal stimuli influence the periodontal ligament throughout the microvasculature of the dental pulp.
Melanotic or melanocytic medulloblastoma is a rare variant of medulloblastoma, especially when the tumor shows advanced neuronal differentiation. We report a case of this tumor, which developed in the cerebellar vermis in an 8‐year‐old girl. Initial biopsy specimens were identified as classical medulloblastoma with a high MIB1 index. Surgical removal of the tumor was performed after chemo‐radiotherapy, and black pigments were noticed on the tumor surface. Histologically, the tumor was composed of classical medulloblastoma with the presence of pigmented epithelial cells forming tubules and clusters. Immunohistochemically, the pigmented tumor cells were positive for S100 protein, HMB45, and MART1, indicating that the pigments were derived from melanosomes, and these features were compatible with melanocytic medulloblastoma. Interestingly, some of the non‐pigmented or amelanotic tumor cells were also positive for HMB45 and S100 protein. Although the tumor showed an unusual cell combination, it was distinguished from atypical teratoid/rhabdoid tumor (AT/RT) by nuclear expression of INI1/BAF45 protein. The tumor also possessed ganglion‐like cells within the neuropil matrix, which resembled small mature ganglion cells, and was consequently designated as ganglioneurocytoma. The melanotic medulloblastoma and part of the ganglioneurocytomatous area were fused with each other. Hence, the present case provides new information indicating that melanocytic medulloblastoma differs from AT/RT, and that it can exhibit advanced neuronal differentiation. In addition, reduction of the tumor MIB1 index was observed after chemo‐radiotherapy.
The navel orangeworm, Amyelois transitella (Walker), is an agricultural insect pest that can be controlled by disrupting male-female communication with sex pheromones, a technique known as mating disruption. Insect pheromone-binding proteins (PBPs) provide fast transport of hydrophobic pheromones through the aqueous sensillar lymph and promote sensitive delivery of pheromones to receptors. Here we present the three-dimensional structure of a PBP from A. transitella (AtraPBPl) in solution at pH 4.5 determined by nuclear magnetic resonance (NMR) spectroscopy. Pulsed-field gradient NMR diffusion experiments, multiangle light scattering, and 15N NMR relaxation analysis indicate that AtraPBP1 forms a stable monomer in solution at pH 4.5 in contrast to forming mostly dimers at pH 7. The NMR structure of AtraPBP1 at pH 4.5 contains seven α-helices (α1, L8-L23; α2, D27-F36; α3, R46-V62; α4, A73-M78; α5, D84-S100; α6, R107-L125; α7, M131-E141) that adopt an overall main-chain fold similar to that of PBPs found in Antheraea polyphemus and Bombyx mori. The AtraPBP1 structure is stabilized by three disulfide bonds formed by C19/C54, C50/C108, and C97/C117 and salt bridges formed by H69/E60, H70/E57, H80/E132, H95/E141, and H123/D40. All five His residues are cationic at pH 4.5, whereas H80 and H95 become neutral at pH 7.0. The C-terminal helix (α7) contains hydrophobic residues (M 131, V133, V134, V135, V138, L139, and Al 40) that contact conserved residues (W37, L59, A73, F76, A77,I94, V111, and V115) suggested to interact with bound pheromone. Our NMR studies reveal that acid-induced formation of the C-terminal helix at pH 4.5 is triggered by a histidine protonation switch that promotes rapid release of bound pheromone under acidic conditions.
Orthodontic space closure following tooth extraction is often hindered by alveolar bone deficiency. This study investigates the therapeutic use of nuclear factor-kappa B (NF-κB) decoy oligodeoxynucleotides loaded with polylactic-co-glycolic acid nanospheres (PLGA-NfDs) to mitigate alveolar bone loss during orthodontic tooth movement (OTM) following the bilateral extraction of maxillary first molars in a controlled experiment involving forty rats of OTM model with ethics approved. The decreased tendency of the OTM distance and inclination angle with increased bone volume and improved trabecular bone structure indicated minimized alveolar bone destruction. Reverse transcription-quantitative polymerase chain reaction and histomorphometric analysis demonstrated the suppression of inflammation and bone resorption by downregulating the expression of tartrate-resistant acid phosphatase, tumor necrosis factor-α, interleukin-1β, cathepsin K, NF-κB p65, and receptor activator of NF-κB ligand while provoking periodontal regeneration by upregulating the expression of alkaline phosphatase, transforming growth factor-β1, osteopontin, and fibroblast growth factor-2. Importantly, relative gene expression over the maxillary second molar compression side in proximity to the alveolus highlighted the pharmacological effect of intra-socket PLGA-NfD administration, as evidenced by elevated osteocalcin expression, indicative of enhanced osteocytogenesis. These findings emphasize that locally administered PLGA-NfD serves as an effective inflammatory suppressor and yields periodontal regenerative responses following tooth extraction.
: Many reports on orthodontic miniscrew insertion focus on insertion conditions, such as technique, but not on the insertion environment, such as the operator's dominant hand. This study aimed to ascertain whether the operator's dominant hand affects laterality in the success rate of manual and motorized miniscrew insertion methods.
