Kimio Sakamaki

Augmentation effects of lymphocyte activation by antigen-presenting macrophages 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.

High-speed soft x-ray techniques

The construction and the characteristics of recent high- speed soft x-ray generators designed by the authors are described. The flash x-ray generators having cold-cathode radiation tubes are three types as follows: (1) soft generator utilizing an ignitron, (2) plasma generator for producing high-intensity characteristic x rays, and (3) water-window generator having a high-durability fermite capillary. In general, when we employed the flash x-ray generators with diodes, the pulse widths had values of less than 200 ns. Next, the x-ray duration was almost equivalent to the durations of the tube voltage and current during their damped oscillations when the water-window generator was employed. The maximum tube voltage was increased up to 100 kV, and the tube currents achieved with high-intensity generators were more than 10 kA. In order to obtain kilohertz-range repetition rates, we have developed two types of stroboscopic x-ray generators having hot-cathode tubes as follows: (4) low-photon-energy generator utilizing and triode and (5) high-photon-energy generator with a diode. As the duration was controlled in a microsecond range by using the low-photon-energy generator, sufficient x-ray intensifier for the normal radiography were obtained. The maximum photon energy could be increased up to about 200 keV by the high-photon-energy generator having a double transformer. Using these generation, we performed high-speed soft radiography.

Tentative study on x-ray enhancement by fluorescent emission of radiation by plasma x-ray source

Tentative study on characteristic x-ray enhancement by fluorescent emission of radiation by plasma x-ray source is described. The enhancement was performed by the plasma flash x-ray generator having a cold-cathode triode. And the generator employs a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of 200 nF, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current was less than 30 kA. The characteristic x-ray intensity substantially increased according to the growth in the plasma x-ray source. When the linear plasma x-ray source formed, the bremsstrahlung x-rays were absorbed without using a monochromatic filter, and high- intensity characteristic x-rays were produced.

Primary malignant melanomas of the oral mucosa

7 patients with primary malignant melanoma of the oral mucosa treated during the past 15 years by extensive resection, and simultaneous neck dissection in 3 of them, are reported. 4 patients died. However, most of the patients stayed alive relatively long postoperatively.

Tentative study on high-photon-energy quasi-x-ray laser generator by forming plasma x-ray source

Tentative study on high-photon-energy quasi-x-ray-laser generator by forming plasma x-ray source is described. The generator employs a high-voltage power supply, a low-impedance coaxial transmission line, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulse generator as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the copper target by the electric field in the tube, the plasma x- ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was much higher than the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the plasma x-ray source formed, and the characteristic x-ray intensities of K-series lines increased. When the plate target was employed, we observed high-intensity characteristic x-rays from the axial direction of the linear plasma x-ray source. In the case where the rod target was employed, we detected higher-intensity characteristic x-rays.

Characteristics of the plasma flash x-ray generator and applications

Various characteristics of a plasma flash x-ray generator having a cold-cathode radiation tube and its application to high-speed soft radiography are described. The x-ray generator employs a high-voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of about 200 nF, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is of a demountable triode which is connected to the turbo molecular pump with a pressure of approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source which consists of metal ions and electrons is produced by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current was less than 30 kA. In this experiment, we employed four types of plasma targets as follows: (1) single target, (2) coaxial double target, (3) alloy target, and (4) plate target. When the single target in conjunction with the monochromatic filter was employed, high-intensity quasi- monochromatic x-rays were obtained. Next, the characteristic x-ray intensities from the outer target increased in the case where the double target was used. By using the alloy (copper tungsten) target, the x-ray intensities of the copper K-series lines increased. Finally, when the linear plasma x-ray source was formed by using the plate target, the bremsstrahlung x- rays were absorbed and were converted into florescent rays, and high-intensity characteristic x-rays were produced.

Quasi-monochromatic x-ray production from the cerium target

Quasi-monochromatic x-ray production from the plasma flash x-ray generator having a cerium-target radiation tube is described. The K-series characteristic x-rays from the cerium target are very useful in order to perform angiography using iodine-based contrast medium because the photon energies of the x-rays are just over the K-absorption edge of iodine. The generator employs a high-voltage power supply, a low-impedance coaxial transmission line, a high- voltage condenser with a capacity of 200 nF, a turbo- molecular pump, thyristor pulse generator as a trigger device, and a flash x-ray tube. The high-voltage main condenser is charge dup to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x- rays are then produced. The x-ray tube is of a demountable triode that is connected to the turbo molecular pump with a pressure approximately 1 mPa. As the electron flows from the cathode electrode are roughly converged to the cerium target by the electric field in the tube, the plasma x-ray source, which consists of metal ions and electrons, forms by the target evaporating. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was much higher than the initial charging voltage of the main condenser, and the peak current was about 25 kA with a charging voltage of 60kV. When the charging voltage was increased, the plasma x- ray source formed, and the characteristic x-ray intensities of K-series lines increased. In this experiment, we observed low-photon-energy bremsstrauhlung rays at the region of less than the K-absorption edge, because the tube current maximized at a low tube voltage.

Multiple myeloma with a distinct “sun-ray appearance” occurring in the jaw

SummaryThis 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.

Flash water-window x-ray generator WFX-98

The fundamental study on a flash water-window x-ray generator (WFX-98) is described. This generator is composed of a high- voltage power supply, a polarity-inversion ignitron pulser, an oil-diffusion pump, and a radiation tube with a capillary. The high-voltage condenser of about 0.2 (mu) F in the pulser is charged up to 20 kV by the power supply, and the electric charges in the condenser are discharged to the capillary in the tube after closing the ignitron. In the present work, the chamber is evacuated by the pump with a pressure of about 1 mPa, and the titanium anode and cathode electrodes are employed to produce L-series characteristic x-rays in the water-window range. The diameter and the length of the ferrite capillary are 2.0 and 29 mm, respectively. Both the cathode voltage and the discharge current displayed damped oscillations. The peak values of the voltage and current increased when the charging voltage was increased, and their maximum values were -11 kV and 3.8 kA, respectively.

Monochromatic plasma x-ray generator and its applications

The constructions of a plasma flash x-ray generator having a cold-cathode radiation tube and its application to soft radiography are described. The x-ray generator employs a high- voltage power supply, a low-impedance coaxial transmission line with a gap switch, a high-voltage condenser with a capacity of 0.2 (mu) F, a turbo-molecular pump, a thyristor pulser as a trigger device, and a flash x-ray tube. The high- voltage main condenser is charged up to 60 kV by the power supply, and the electric charges in the condenser are discharged to the tube after triggering the cathode electrode. The flash x-rays are then produced. The x-ray tube is a demountable triode which is connected to the turbo molecular pump with a pressure of approximately 1 mPa. This tube consists of a rod-shaped carbon cathode, a trigger electrode made from a copper wire, a stainless-steel vacuum chamber, insulators, a polyethylene terephthalate x-ray window, and two anode electrodes (targets) of molybdenum and silver. The space between the anode and cathode electrodes had a constant value of approximately 20 mm, and the trigger electrode is set in the center of the cathode electrode. As the electron flows from the cathode electrode are roughly converged to the target by the electric field in the tube, the plasma x-ray source which consists of metal ions and electrons is produced by the target evaporating. Because the bremsstrahlung spectra are absorbed by the monochromatic filter, K-series characteristic x-rays are obtained. Both the tube voltage and current displayed damped oscillations, and their peak values increased according to increases in the charging voltage. In the present work, the peak tube voltage was almost equivalent to the initial charging voltage of the main condenser, and the peak current had a value of about 25 kA with a charging voltage of 60 kV. When the charging voltage was increased, the intensities of the K-series characteristic x-rays increased. Next, the intensities decreased as the monochromatic filter was inserted. Using this quasi-monochromatic plasma flash x- ray generator, we performed high-speed soft radiography with x-ray durations of about 1 microsecond.