A rapidly emerging clinical application of positron emission tomography (PET) is the detection of cancer with radionuchde tracer, because it provides information unavailable by ultrasound, computed tomography or magnetic resonance imaging The most commonly used radiotracer for PET oncologic imaging is fluorme-18-labeled fluorodeoxyglucose (18;F-FDG) Early studies show PET has potential value in viewing the region of the tumor, detecting, staging, grading, monitoring response to anticancer therapy, and differentiating recurrent or residual disease from post treatment changes. However, limitations of FDG-PET in the head and neck region, namely, physiological FDG uptake in the salivary glands and palatine tonsils, have been reported, increasing the false-positive rates in image interpretation
This review was designed to address these distinctions of oral cancer PET imaging (1) Specialization of PET equipment, (2) Cancer cell metabolism, proliferation and tracers, (3) Clinical diagnosis of oral cancer with PET, (4) Pitfalls in oncologic diagnosis with FDG-PET imaging.
We have shown that conditioning stimulation of the amygdaloid nucleus has an inhibitory effect on the nociceptive neurons in the tngermnal caudal nucleus and the medial reticular subnuclei of the rat The purpose of this study is to investigate whether the opioid receptor is involved in the inhibitory effect of amygdaloid stimulation of the nociceptive neurons
The animals were anesthetized with N2O-O2 (2・1) and 0.5%-halothane, and immobilized with pancuromum bromide. The peripheral test stimulus (a single rectangular pulse of 2.0 msec in duration) was applied to the facial skin in the receptive field of nociceptive neurons, and the ipsilateral amygdaloid conditioning stimuli to the recording site were trains of 33 pulses (0.5 msec in duration, 100-300 μA) delivered at 330Hz. Fifty-six wide dynamic range (WDR) neurons and 15 nociceptive specifc (NS) neurons were recorded WDR neurons were distributed in the superficial layer of the caudal nucleus and diffusely throughout the reticular subnucleus, whereas most of the NS neurons were distributed in the dorsal part of the reticular subnucleus The conditioning stimulation in the central nucleus, basomedial and basolateral nuclei markedly inhibited the activities in 8 of 8 nociceptive neurons (3 WDR and 5 NS neurons) The inhibitory effect was 73 6±12 8% (mean±S.D) at maximum Naloxone (2mg/kg, 1v.), opioid receptor antagonist, did not exert an influence on the amygdaloid inhibitory effect (n=4) The present results suggest that the amygdaloid nucleus inhibits the ascending nociceptive information at the 2nd order neurons through a receptor other than the opioid receptor. It has been known that the amygdaloid nucleus is a key structure for mediating stress responses Therefore, the amygdaloid antmociceptive effect may provide one of the neurophysiological bases for stress-induced analgesia (SIA), especially non-opioid type SIA.
The present study clearly demonstrated the effects of complete cerebral ischemia and selective ischemia on brain choline metabolism in ddY mice The complete cerebral ischemia mouse was produced by cervical dislocation, and the selective ischemia mouse was produced by bilateral occlusion of the common carotid arteries.
The following results were obtained
1 Complete cerebral ischemia increased brain choline contents rapidly and remarkably for 10 minutes After 10 minutes, the rate of increase of brain choline contents suddenly fell.
2 The increased level of choline contents by complete cerebral ischemia differed among the brain regions (cerebral cortex, hippocampus, medulla oblongata, cerebellum) tested
3 Selective ischemia increased choline contents in the cerebral cortex and hippocampus but not in the medulla oblongata or cerebella.
4. As with complete ischemia, hypoxia induced by N2 gas inhalation increased choline contents in all brain regions.
5. Hypoglycemia induced by insulin administration did not increase brain choline contents However, the ischemia under a hypoglycemia state produced a greater choline increase than ischemia alone
6 Complete cerebral ischemia decreased the contents of both phosphatidylcholme (PtdCh) and glycerophosphocholine (GlyCh) in the mouse brain.
The present results suggest that a main cause for the ischemic increase of brain choline contents is hypoxia by cessation of blood flow, and a low energy state caused by hypoglycemia partly contributes to this increase Furthermore, it is suggested that the ischemic increase of brain choline depends on the choline accumulation that results from decomposition of both PtdCh and GlyCh
Clinical findings of 351 out patients having temporomandibular disorders (TMD) treated in the Department of Fixed Prosthodontics, Iwate Medical University Dental Hospital, from 1999 to 2003 were surveyed as to. number of patients every year, gender ratio, age distribution, past treatment history, chief complaints, initial symptoms, initiating factors and accessory signs. The number of TMD patients varied from 52 to 95 each year Peak age distribution was in the 20's followed by the 30's. The male-female ratio was 1 . 2.8, which showed significant difference compared to the clinic as a whole, which has a ratio of 1:1 5 (p<0.05; chi-square test) Referred patients comprised 76.6% of the total number of TMD patients in the surveyed period Although a temporomandibular joint (TMJ) sound was the main initial symptom, TMJ pain was the most common symptom in the chief complaint category. This result implies that the single symptom of TMJ sound does not lead a patient to seek treatment at a dental clinic, however, pain in the TMJ and/or masticatory muscle is the key to initiate treatment.