三叉神経一次感覚ニューロンにおける内向き整流作用のグルタミン酸受容体依存性神経修飾機構

In the present study, we showed that activation of metabotropic glutamate receptors in rat mesencephalic trigminal (Mes V) neurons (which are important in the genesis and control of oral-motor activities) can modulate hyperpolarization-activated inward current (Ih). Whole-cell recordings were obtained from rat Mes V neurons, and I_h was induced by a hyperpolarizing current or voltage pulses. Application of ACPD, which is a group I and II mGluRs agonist, suppressed the voltage-and time-dependent voltage sag under current-clamp recording, and suppressed the steady-state inward current under voltage-clamp recording, suggesting that it inhibited I_h. Further investigation revealed that group II mGluRs activation and the release of intracellular Ca^ mediated ACPD-in-duced inhibition of I_h. Additionally, low-frequency (<10Hz) resonant properties exhibited at membrane potentials ranging from resting potential to hyperpolarization were substantially reduced by ACPD, indicating that modulation of I_h by mGluRs activation induces substantial changes in the frequency preference with which neurons respond to synaptic inputs

ミニープレートの破折

Mini-plate fracture was found in a case of the bone grafting after the segmental mandibular excision, and a case of osteomyelitis in the radiographic follow-up examinations. It was emphasized that usefulness of mini-plate would be evaluated by modification in shape and number of mini-plate used for fixation or reconstruction

Acute inflammation at a mandibular solitary horizontal incompletely impacted molar

Acute inflammation is frequently seen in the elderly around incompletely impacted molars located apart from molars or premolars. To identify the factors causing acute inflammation in the solitary molars without second molars or without second and first molars, ages of patients and rates of acute inflammation in 75 horizontal incompletely impacted mandibular molars in contact or not in contact with molars in subjects 41 years old or older were studied using orthopantomographs. Acute inflammation was seen in nine third molars out of 48 third molars in contact with second molars (18.8%), whereas acute inflammation was seen in 11 molars out of 19 solitary molars without second molars or without first and second molars (57.9%) (p < 0.01). The mean age of 48 subjects with third molars in contact with the second molar was 50.42 ± 7.62 years, and the mean age of 19 subjects with isolated molars was 65.16 ± 10.41 years (p < 0.0001). These indicate that a solitary horizontal incompletely impacted molar leads more frequently to acute inflammation along with aging due to possible bone resorption resulting from teeth loss

Ultrastructural Study of Varied Calcified Materials in the Pleomorphic Adenoma Occurring in the Soft Palate

A case of pleomorphic adenoma derived from the palatine gland was studied with light microscope, transmission electron microscope and X-ray microprobe analysor. Some irregular basophlic masses were found under the light microscope in the stromal tissue close to tumor cells, which were ultrastructurally composed of needle-shaped crystals and bordered by a lamina limitans-like structure. Furthermore, transmission electron microscopic findings showed that numerous membranous vesicles with appatite deposited in various degrees were scattered between collagen fibers. These vesicles seemed to be matrix vesicles which may be related to a stromal change of pleomorphic adenoma

ステロイド使用による下顎頭骨坏死の1例

Avascular necrosis or osteonecrosis has been discussed as a possible cause of condylar degeneration and pain. Avascular necrosis is a degenerative disease originates from diminished blood flow in the bone marrow. Avascular necrosis is seen in relationship with idiopathic, corticosteroids, alcoholism, sickle cell disease, pregnancy, and Caisson\u27s disease. Corticosteroid has been suggested to be an etiologic factor affecting bone organization, fat metabolism, and blood vessel. Indeed, corticosteroid can affect the bilateral joints of the shoulder, hip, and knee. However, the occurrence of the avascular necrosis of in the temporomandibular joint alone has not been reported. The clinical, laboratory, radiographic, and imagings features of a case of the condylar process of the mandible are presented

顎舌骨筋運動ニューロンと一次求心線維のシナプス接合について

Horseradish peroxidase conjugated with wheat germ agglutinin (HRP-WGA) was injected into the muscle branch of the mylohyoid nerve in rats. HRP-labeled neuronal cell bodies were observed ipsilaterally in the caudal portion of the trigeminal mesencephalic nucleus and the ventromedial division of the trigeminal motor nucleus (Vmo.vm). Electron microscope observations were carried out on sections through Vmo.vm containing HRP-labeled cell bodies. Synaptic contacts were found between HRP-labeled axon terminals and HRP-labeled nerve cells. The results suggested that mylohyoid muscle spindle afferents are synaptic contacts on the mylohyoid motoneurons

Parathyroid hormone 1 (1-34) acts on the scales and involves calcium metabolism in goldfish

金沢大学環日本海域環境研究センターThe effect of fugu parathyroid hormone 1 (fugu PTH1) on osteoblasts and osteoclasts in teleosts was examined with an assay system using teleost scale and the following markers: alkaline phosphatase (ALP) for osteoblasts and tartrate-resistant acid phosphatase (TRAP) for osteoclasts. Synthetic fugu PTH1 (1-34) (100 pg/ml-10 ng/ml) significantly increased ALP activity at 6 h of incubation. High-dose (10 ng/ml) fugu PTH1 significantly increased ALP activity even after 18 h of incubation. In the case of TRAP activity, fugu PTH1 did not change at 6 h of incubation, but fugu PTH1 (100 pg/ml-10 ng/ml) significantly increased TRAP activity at 18 h. Similar results were obtained for human PTH (1-34), but there was an even greater response with fugu PTH1 than with human PTH. In vitro, we demonstrated that both the receptor activator of the NF-κB ligand in osteoblasts and the receptor activator NF-κB mRNA expression in osteoclasts increased significantly by fugu PTH1 treatment. In an in vivo experiment, fugu PTH1 induced hypercalcemia resulted from the increase of both osteoblastic and osteoclastic activities in the scale as well as the decrease of scale calcium contents after fugu PTH1 injection. In addition, an in vitro experiment with intramuscular autotransplanted scale indicated that the ratio of multinucleated osteoclasts/mononucleated osteoclasts in PTH-treated scales was significantly higher than that in the control scales. Thus, we concluded that PTH acts on osteoblasts and osteoclasts in the scales and regulates calcium metabolism in goldfish. © 2011 Elsevier Inc. All rights reserved