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Objective Among different PET tracers, 18F-fludeoxyglucose (FDG) and 11C-choline are known to have a high tumor uptake correlated with a high mitotic index of tumor cells. Thus, the uptake of 18F-FDG and 11C-choline may be dependent on the cell cycle. In the present study, we examined the uptake of 18F-FDG and 11C-choline in cancer cell lines by cell cycle synchronization to clarify the biological properties of cancer cells with respect to each tracer. Methods HeLa S3 Cells were synchronized by the double thymidine (TdR) block methods. 18F-FDG and 11C-choline were administered to synchronized cells, and the radioactivity per cell was measured to compare the cellular uptake of the tracers during S, G2/M, and G1 phases. Flow cytometry (FCM) was performed to measure the proportion of cells in G1, S, and G2/M phases. Furthermore, the levels of glucose transporter 1 (GLUT1) and choline transporter-like protein 1 (CTL1) in the cell were evaluated by FCM. Results The uptake of 18F-FDG was the highest in S to G2/M phases, and markedly decreased in G1 phase. The uptake of 11C-choline reached its peak in G2/M, and decreased in G1 phase. The level of GLUT1 expression was similar to that of 18F-FDG uptake during the cell cycle, and the level of CTL1 expression was similar to that of 11C-choline uptake throughout the cell cycle. Conclusions In this in vitro study, we demonstrated that 18F-FDG and 11C-choline had the highest uptake in S to G2/M phases and in G2/M phase, respectively, with a rapid decrease in G1 phase. These findings suggest that 18F-FDG and 11C-choline have a high accumulation in tumor cells with a high mitotic index. Furthermore, our study suggests that the expression of GLUT1 and CTL1 has cell cycle dependence, and the changes of 18F-FDG and 11C-choline accumulation seem to be caused by the above properties of these transporters.

3D Accuitomo F17は頭頸部領域を対象としたコーンビームCT装置である.5種類の撮影領域(field of view:FOV)(40×40mm,60×60mm,80×80mm,100×100mm,170×100mm)が搭載され,5つのボクセルサイズ(80μm,125μm,160μm,200μm,250μm)で画像の解像度を変えることができる「ズーム再構成」の機能を持つ.本研究の目的は,本装置の顎関節構造の描出能を検討することである.最初に1体のヒト乾燥頭蓋骨を,全てのFOVで撮影,そのうち最も大きいFOV(170×120mm)で得られた画像データをもとに全てのボクセルサイズでズーム再構成を行った.次に変形性顎関節症を疑った3名の患者に対し同様の検討を行った.その結果,FOVが小さいほど画質は良好であり,大きなFOVで撮影しても小さなピクセルサイズで再構成することで明瞭な画像が得られた.以上より本装置においては,大きなFOVで両側の顎関節を撮影することで,両側下顎頭の滑走運動の協調性を評価でき,さらに小さなボクセルサイズで再構成することで高解像度の画像が得られることが明らかになった.今回の検討により3D Accuitomo F17は顎関節構造の描出において有用であることが示唆された., 3D Accuitomo F17 is cone beam computed tomography (CT) unit for examination of maxillofacial area. It adopts five kinds of field of view (FOV) (40×40mm, 60×60mm, 80×80mm, 100×100mm, 170×120mm) and developed "zoom reconstruction" function that provides five kinds of voxel size (80μm, 125μm, 160μm, 200μm, 250μm) to change the image resolution. The purpose of this study is to evaluate the usefulness of this unit for visualization of temporomandibular joint (TMJ) structures. Firstly, we scanned one dry human skull by all of FOV, and underwent zoom reconstruction by all of voxel size using image data were obtained in largest FOV (170×120mm). Secondary, we performed similar examination to three patients were suspected osteoarthrosis of TMJ. As the results, the image quality of TMJ structures were good so that FOV was small, and clear images were obtained when we reconstructed them at small pixel size even if we we scanned it in large FOV. Therefore, it seems that we can evaluate of coordination of in the condylar movement by scanning bilateral movement in large FOV, and we can obtain clear images at small voxel size. This results of this study suggest that 3D Accuitomo F17 is very useful cone beam unit for the visualization of TMJ region.

Malignant lymphoma is considered to be neoplasm of lymph node or lymphoid tissue. The head and neck resion is favorite site of this tumor, but intraoral presentation of lymphomas is an uncommon occurrence, and sublingual gland is extremely rare site. We report here a case of malignant lymphoma in the sublingual space. Malignant lymphoma is deficient in a clinical finding, and it is difficult diagnosis. At first, we performed ultrasonography for this case, and suspected it was a tumor not a cyst because significant blood flow was detected as a power Doppler signal in this lesion. It is said to be malignant 80% of a tumor to occur in sublingual gland. For reasons mentioned above, we doubted this lesion with a malignant tumor. The histological diagnosis was diffuse large B-cell lymphoma in the sublingual gland. We confirmed usefulness of power Doppler to differentiate the mass revealed occurred in this region.

The diagnosis of jaw bones using X-ray computed tomography (CT) is important to determine placement of dental implants. A Clinico-statistical study were made on 490 cases which applied preoperative dental mutiplannar reconstructing CT (dental MPR) imaging for dental implant treatment in Iwate Medical University Hospital, during a five-year period from 2002 to 2006. The following results were obtained: 1) The 490 cases consisted of 179 males and 311 females. They ranged in age from 16 to 80 years, the average age was 53.6 years old. 2) The largest number of cases were in their 50's and, in most generations, there were more female cases than male. 3) similar cases have been increasing every year. 4) Most patients were referred from other clinics to our hospital. 5) Of the cases that underwent CT scanning more were mandible than maxilla. 6) Implantation prearranged region revealed a predominance of mandible in anterior teeth, and maxilla in molar teeth. 7) The cases that were using diagnostic surgical stents increased in the first three years, but were constant afterwards.

Background: Magnetocardiography (MCG) has the potential for collecting three-dimensional (3D) intracardiac electric information, because the magnetic field is unaffected by the shape of the lungs and torso. In the present study, we report on the generation of a 3D heart outline and conduction pathway by means of a current density map using a 64-channel SQUID system, and an evaluation of its significance in patients with atrial flutter (AFL) and atrial fibrillation (AFIB) Methods: The subjects consisted of 20 healthy volunteers, and 3 patients with AFL and 4 patients with AFIB. A 64-channel MCG was recorded after digitization at 500 Hz, and a 3D current density was reconstructed from the magnetic fields using a space filter in conjunction with the minimum normalization method of Tikhonov. A 3D heart outline was generated from the integrated current density by the space filter. The conduction pathway was superimposed on a heart outline generated by a magnetic field. The heart outline was verified by the silhouette on the magnetic resonance (MR) images. An MCG was recorded pre- and post interventional therapy, and therapeutic efficacy was evaluated. Results: The 3D heart outline of the atrium and ventricle corresponded to the silhouette of the right atrium and left ventricle, respectively, on an MR image. The serial conduction pathway of the QRS segment superimposed on the 3D heart outline map demonstrated the conduction pattern generated within the heart. The MCG revealed a counter-clockwise rotation in patients with AFL, and random micro-reentry in the case of AFIB. After interventional therapy, restoration of the sinus rhythm was verified in patients with both AFL and AFIB. Conclusions: A 64-channel MCG was used to evaluate the 3D heart outline and conduction pathway in patients with AFL and AFIB without the need for MR images. Condensed Abstract A 64-channel MCG was used to evaluate the 3D heart out line and conduction pathway in patients with AFL and AFIB.

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 (^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.

Objectives It is known that, in fluorine-18 fluorodeoxyglucose Positron Emission Tomography (FDG PET) for the diagnosis of oral cancer, FDG uptake may vary even among different cases of the same squamous cell carcinoma. However, the details of this phenomenon have not yet been elucidated. In this study, we analyzed the relationship between histopathological findings in oral squamous cell cancer and PET findings on FDG uptake.

Objective: Research on FDG-uptake by blood cells has revealed that FDG is incorporated by macrophages and granulocytes, as well as activated lymphocytes. These characteristics of FDG suggest the possibility of visualizing the distribution of immunocytes in target organs. The aim of this study was to investigate if mouse spleen-derived lymphocytes, activated by macrophages presenting sheep red blood cell (sRBC) antigens, could be traced by FDG.Methods: One percent of a sRBC suspension was injected into the peritoneal cavity of mice thereby creating immunity to the sRBC antigen. The splenocytes, consisting mostly of lymphocytes, were isolated, and serum containing the anti-sRBC antibody was mixed with sRBC to prepare sRBC-antibody complexes (sRBC-AbCs). Then five percent of a thioglycolate medium was injected into the peritoneal cavity of the same mice, and macrophages of ascitic cell origin were obtained. These macrophages were added to the sRBC-AbCs to induce sRBC antigen presenting macrophages. These were incubated with splenocytes obtained from sRBC immunized mouse (sRBC immunized splenocytes) or nonimmunized splenocytes to induce a T cell immune response. [3H]deoxyglucose ([3H]DG) and FDG were incorporated in splenocytes, and the quantity of their uptake was measured.Results: [3H]DG uptake by sRBC-immunized splenocytes was about eleven times as high as that of non-immunized splenocytes. In contrast, [3H]DG uptake by sRBC-immunized splenocytes, co-cultured with macrophages phagocytizing sRBC-AbCs, was about 40 times higher compared with non-immunized splenocytes. Splenocytes in non-immunized mice picked up very little [3H]DG, despite co-culture with macrophages phagocytizing sRBC-AbCs. Similar tendencies were observed with FDG.Conclusions: These results suggest that the SUV calculated in PET reflects not only the number of lymphocytes, but also the activation state of the lymphocytes themselves. In addition, the biodistribution of antigen specific lymphocytes, that have been taken up FDGin vitro and returned to the body, can be observed through PET.

COMMCAT IS-2000^は顎顔面領域専用の断層エックス線撮影装置で,顎関節の矢状断および冠状断撮影の機能を有する。本装置の顎関節撮影における有用性をエックス線不透過性の鋼鉄製マーカーを付けた4個のヒト乾燥頭蓋骨を用いて検討した。スライス位置の正確性を調べるため下顎頭の表面中央にマーカーを固定し,マーカー直上,それより近心,遠心にそれぞれ1mm,2mm離れた計5点に対して矢状断撮影を行ったところ,スライス位置の誤差は±1mmの範囲内であった。写真の寸法精度を調べるため,下顎頭の実測値と断層写真上での寸法をデジタルキャリパーを用いて比較した。両者の差は前後径では平均0.43mm,近遠心径では平均0.52mmであった。断層軌道および断層厚さの違いが写真画質におよぼす影響を調べた。同一撮影条件下ではhypocycloidal軌道で1mmの断層厚さで撮影した場合,ぶれや周囲の構造物の写り込みが少ないため,最も写真画質が良好であることがわかった。以上の結果よりCOMMCAT IS-2000^はTMJの骨構造を画像化する上で有用な診断装置であることが示唆された。, The COMMCAT IS-2000^ (Imaging Sciences International, Hatfield, PA, USA) is a tomographic machine for scanning the dentomaxillofacial region and is capable of imaging the sagittal and coronal sections of the temporomandibular joint (TMJ). The feasibility and accuracy of tomography for the TMJ were examined by use of the COMMCAT IS-2000^ and four dried human skulls with radiopaque steel markers. To assess the setting accuracy of the slice position, a steel marker was fixed at the center of the superior surface of the condyle, and images of five sagittal sections were taken, i.e., directly above the marker and 1 mm and 2 mm distance from it in both the medial and distal planes. The deviation of the slice position was found to be within ± 1 mm for all test subjects. To evaluate the dimensional accuracy of this method, the difference between the actual value and the graphically observed value with respect to the tomographic image of the condyle was examined using a digital caliper. The difference between values for the anteroposterior distance was 0.43 mm and that for the mediolateral distance was 0.52 mm. The effect of the difference in tomographic motion and slice thickness on the image quality was then evaluated. Under identical exposure conditions, hypocycloidal tube motion and the slice thickness of 1 mm produced the best image quality because blurring of the image and the degree of superimposition of the surrounding structures were minimal. These results suggest that the COMMCAT IS-2000^ is a high-quality diagnostic tool for visualizing the bone structure of the TMJ.

Positron emission tomography using fluorine-18 fluoro-deoxyglucose (FDG PET) is useful for the detection of malignant tumor recurrences and for the evaluation of a therapeutic response to these;including ones found in the lung, colon, head and neck regions. The experimental study demonstrated FDG uptake was higher in faster-growing rather than in slower-growing tumors. These findings show FDG accumulation exhibits cell cycle dependency. However, the precise mechanism remains to be elucidated. In this study, the relationship between FDG uptake and the cell cycle phase in HeLa S3 cells, as well as how they compare to the conventional tracer ^67Ga citrate (Ga) with single photon emission tomography (SPECT) was assessed. Synchronization of HeLa S3 cells was accomplished via a double thymidine block. The uptake of FDG and Ga was determined after cell cycle synchronization. The glucose transporter was independently evaluated for the level of its Glut 1 glucose transporter membrane protein. FDG uptake in HeLa S3 cells was significantly higher in the early S phase and G_2/M phase compared to the G_1 phase. In addition, Ga uptake was higher in the G_2/M phase. Immunochemical assays for the Glut 1 transporter showed an increase in membrane expression within S phase cells. It has been concluded that cell cycle dependency is reflected in the uptake of FDG and Ga, seen during PET or SPECT imaging of tumor tissue. These results reveal tumor proliferative activity, and can assist in evaluating a therapeutic response. Furthermore, the increased FDG uptake, in part due to increased membrane expression of the Glut 1 glucose transporter, contributes to this phenomenon.

A preliminary experiment for producing narrow-photon-energy cone-beam x-rays using a silicon single crystal is described. In order to produce low-photon-energy x-rays, a 100-µm-focus x-ray generator in conjunction with a (111) plane silicon crystal is employed. The x-ray beams from the source are confined by an x-y diaphragm, and monochromatic cone beams are formed by the crystal and three lead plates. The x-ray generator consists of a main controller and a unit with a high-voltage circuit and a 100-µm-focus x-ray tube. In this experiment, the maximum tube voltage and current were 35 kV and 0.50 mA, respectively, and the x-ray intensity of the microfocus generator was 343 μGy/s at 1.0 m from the source with a tube voltage of 30 kV and a current of 0.50 mA. The effective photon energy is determined by Bragg's angle, and the photon-energy width is regulated by the angle delta. Using this generator in conjunction with a computed radiography system, quasi-monochromatic radiography was performed using a cone beam with an effective energy of approximately 15.5 keV.

A fluorescent x-ray tomography system is useful in performing fluorescent x-ray analysis for target atoms in biomedical objects utilizing a drug deliverly system. This tomography system is employed in order to measure iodine distribution in objects, and the system consists of a cerium x-ray generator, a 58-μm-thick stannum filter, a tungsten collimator, and a computed radiography system. Because K-series characteristic x-rays from the cerium target are absorbed effectively by iodine-based contrast media, iodine fluorescent x-rays from iodine atoms in the objects are produced. In the tomography system, when the objects are exposed by fan beams, the stannum filter easily transmits iodine Kα rays from a slice plane, and tomograms are obtained using the CR system and the collimator.

Madin-Darby canine kidney (MDCK) cells were originally anchorage-dependent epithelial cells. Here, we have isolated a novel MDCK-derived cell population, termed 6 M-4, by means of culturing MDCK cells in suspension for nearly 6 months in the presence of Streptomyces griseus metalloendopeptidase (MEP). The isolated cells showed unique proliferation characteristics, which differed from parental MDCK cells. They proliferated adherently on a polystyrene matrix, but proliferated non-adherently both in the presence of MEP and on a non-adhesive matrix coated with poly 2-methacryloyloxyethyl phosphorylcholine (MPC). The 6 M-4 cells consisted of at least two cell types. One type, termed 6 M-4-TR7, would not grow in soft agar and showed a novel phenotype in that the cells were susceptible to both TNF-alpha and verotoxin 1 (VT1). In addition, the isolated adhesion-independent cells sustained epithelial traits of parental MDCK cells. We further show that these MDCK-derivative cells are suitable for influenza virus cultivation. Hemagglutination (HA) titers of influenzaviruses A and B were increased in the suspension culture of 6 M-4-TR7 cells supplemented with the MEP in comparison to adherently growing cells in the presence of trypsin.

QT dispersion reveals heterogeneities in the repolarization time in the three-dimensional (3D) structure of the ventricular myocardium. In this study, we report on a 3D function map of recovery time (RT) dispersions as measured by 64-channel magnetocardiography (MCG). MCG were simultaneously recorded in 29 controls and 21 patients with previous myocardial infarction (MI). The 3D current density was calculated from 64-channel MCG data in the B z component using a space filter. The heart outline, reconstructed from the integrated the current density, revealed both the atrium and ventricle. The RT for the intervals between QRS onset and the time of the maximum dT/dt of T wave, and the peak to the end of the T wave (Tpeak-negative dT/dt) were automatically measured by means of a computer from 3D MCG data. The corrected RT (RTc) and corrected Tpeak-negative dT/dt were then calculated using Bazett’s formula. The 3D RTc and the corrected Tpeak-negative dT/dt dispersion map were superimposed on the heart outline generated by MCG. The RTc was significantly longer for the MI group than in the control group (67±25 ms1/2 vs. 16±6 ms1/2) (p

A 60-year-old woman presented with multicentric skin tumors of the head. The histologically proven hemangioendothelioma was bleeding as a result of disseminated coagulopathy. In addition to immunotherapy, 6 MeV electron beam radiotherapy was used for the purpose of hemostasis with a single portal, 20 x 20 cm in size, covering the whole scalp from the top of the head. The radiotherapy was discontinued after 39 Gy/13 fractions/20 days because of the progress in size of a peripheral tumor and the stability of coagulopathy. After another electron boost delivery by two portals focused to exophytic parietal and temporal tumors of 20 Gy/10 fractions, high dose rate brachytherapy with a surface mold technique was performed, 3 Gy/fraction, four fractions/week, for a total of 36 Gy. It induced partial regression of the tumor and complete recovery of platelet counts from 2.5 x 10(4) to 18.2 x 10(4). The tumor disappeared in 3 months. No late side effects occurred, except for permanent alopecia. The patient developed a cervical lymph node metastasis 1 year after and marginal recurrence 2 years after the initial treatment. Both recurrent tumors were successfully treated by 4 MV external photons of 60 Gy/20 fractions/46 days and electron beam irradiation of 60 Gy/20 fractions/29 days, respectively. She has remained disease free for 3 years after the initial presentation.

To assess whether differentiation is possible between residual disease and complete response, 18F-fluoro-2-deoxy-D-glucose (FDG) positron emission tomography was performed in 17 cases of primary squamous cell carcinoma of the thoracic esophagus before (five control cases) or immediately after full-dose irradiation (12 treated cases). The FDG counts in the esophageal tumors were corrected by the dose of injected isotope and the weight of the patient, to produce a standardized uptake value (SUV). Endoscopy for post-treatment evaluation showed almost complete clearance of the tumor in seven treated cases (good-responders) and apparent residual tumor in the other five cases (poor-responders). There was a significant difference in the average median SUV between the controls and the treated (8.1 +/- 1.6 vs. 3.3 +/- 1.1), and between the poor-responders and good-responders (4.1 +/- 0.8 vs. 2.7 +/- 0.9). Three of the good-responders showed locoregional recurrence after four, six, and 18 months. Among the good-responders, the SUV of the cases of local recurrence was not inevitably higher than that of the others. The rate of FDG uptake in irradiated esophageal cancer approximately represents tumor response to radiotherapy, but it seemed impossible to differentiate residual disease from complete response.

Skinned nerve fiber was prepared by treating a giant axon of squid with saponin. Filamentous networks and membranous organelles such as vacuoles, smooth membranes and mitochondria were present after the extraction. Ruthenium red staining of the extracted tissue showed dense fibrillar networks in the cytoplasm that correspond to the "microtrabeculae" or "cytoskeleton" reported by other investigators. Our method of preparation, thus, gives further evidence that these structures are not the result of artifactual condensation or precipitation. The present results also indicated that the networks are composed of acid mucopolysaccharides and/or mucoproteins. The density of microtubules was not changed by the extraction per se, but the number of microtubules remaining after extraction decreased by alteration of environmental conditions such as low temperature (4 degrees C), or the presence of Ca++ (1 mM), Mg++ free medium or colchicine (1 mM). These conditions are known to inhibit axonal transport. The usefulness of our extracted cytoplasm as a model of microtubule-related physiological functions is discussed.

The abdominal ganglion of Aplysia includes neurons with a characteristic dopamine (DA) receptor, the activation of which induces a marked hyperpolarization with a specific increase in the permeability of the membrane to K+. The DA receptor of this type is called the "HK-type." A 2-min exposure to 1 microM serotonin (5-HT) had little effect on the resting membranes with the receptor of HK-type, but significantly depressed the responses to 10 microM DA. The depressing effect of 5-HT on this type of response was completely reversible after a 15-min washing with normal artificial Aplysia blood. Lineweaver-Burke type plotting of the DA-induced responses showed a systematic shift of the straight lines when the concentration of 5-HT was increased; the slope of the line became steeper but the intercept on the ordinate remained unchanged. The dose-inhibition curves, in which relative responses to a given [DA] were plotted against log [5-HT], showed a parallel shift toward the right when the concentration of DA increased. These findings suggest that 5-HT competes with DA for common binding sites at the DA receptor of HK-type, and that the blockade is not due to the interaction of 5-HT with K+-channels in the receptor membrane. The effect of other indole derivatives suggests that the DA receptor of HK-type includes anionic and cationic sites to which the NH2 group and 5-HO group of 5-HT could specifically bind, thus exhibiting competitive blockade.

Using the abdominal ganglion cells of Aplysia, we analyzed the effects of various enzymes and chemical modification reagents on the acetylcholine (ACh)-induced responses of the excitatory (Na+ -dependent) and inhibitory (Cl- -dependent) types. (1) Phospholipase A (2 mg/ml) caused no appreciable effects on either type of response. (2) Phospholipase C (2 mg/ml) markedly depressed both types of response. These suggested that the phosphoryl group of the phospholipid is an important site related to the binding of ACh, common to both types of ACh-receptors. (3) Carboxypeptidase A (10 mg/ml) caused no observable effects on either type of response. (4) Carboxypeptidase B (10 mg/ml) depressed the inhibitory type of response without affecting the excitatory one. (5) Pyridoxal-5'-phosphate (1 mM) also depressed the inhibitory response without affecting the excitatory one. These findings (4, 5) suggested that the Cl- -channel in the inhibitory ACh-receptor complex includes a C-terminal lysine which may play an active role in the movement of Cl- across the receptor membrane. (6) L-Leucine aminopeptidase (1 mg/ml) depressed the excitatory response without altering the inhibitory one. (7) p-Nitrothiophenol (1 mM)-also depressed the excitatory response without affecting the inhibitory one. These findings (6, 7) suggested the presence of a certain N-terminal amino acid near a glutamate or aspartate residue within a molecular moiety of Na+ -channel included in the excitatory ACh-receptor complex.

There are many cells in the abdominal ganglion which show a fast, Cl(-)-dependent hyperpolarizing response to gamma-aminobutyric acid (GABA). This response is characterized by an initial rapid increase in membrane conductance followed by an exponential decay to the original value despite a sustained application of GABA. The decay of the response was found to be largely due to the desensitization of the GABA receptor (binding site-ionophore complex) since the equilibrium potential for chloride remained unchanged when the conductance response was depressed. The apparent or measurable rate constant of desensitization (KD) increased when the concentration of GABA increased, showing a saturation in KD-[GABA] relationship at higher concentration of GABA. The rate of desensitization did not change significantly when the resting membrane was hyperpolarized from -40 to -80 mV, though the conductance response was markedly depressed due to a characteristic voltage-dependence in the receptor activation (Matsumoto, 1982). These observations are discussed in terms of an hypothesis in which the desensitization of GABA receptor is the result of an additional binding of a GABA molecule to the activated receptor.

This manuscript presents an unusual radiographic manifestation of multiple myeloma occurring in the mandible. A 40-year-old man, referred to our hospital, presented with a swelling of the right mandible. Microscopic examination and laboratory tests confirmed the diagnosis of multiple myeloma. Radiographic examination revealed a well-developed sun-ray appearance suspected in osteogenic sarcoma. This observation suggested the possibility of the periosteal reaction in this case of multiple myeloma.

Change in slope conductance has been widely used to evaluate the ion-channel activation by receptor agonists of various postsynaptic membranes. However, the agonist-induced change in slope conductance (delta G) depends not only on the change in membrane ionic permeabilities (delta P) but also on the changes in resting potential (E) and equilibrium potential (EA) of the ion involved (A). A constant field theory was applied to describe delta GA as a function of delta PA, E and EA, assuming that delta PA is not affected by the change in E or EA. This equation predicts that delta GNa will decrease if the membrane is depolarized or when ENa becomes more positive. Similarly, delta GK is expected to increase if the membrane is depolarized or when EK becomes more negative. Further, the equation describes that delta GCl will increase if the membrane is depolarized or when ECl becomes less negative. These changes in GNa, GK and GCl are well consistent with many data previously obtained from various types of receptor membranes. We conclude that the values of slope conductance measured at different E or EA must be carefully corrected in order to estimate the real voltage dependence of delta P or the ion-channel activation by receptor agonists.