Pituitary adenoma and cerebral infarction demonstrated by Tc-99m HMPAO using a high-resolution SPECT system.
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Adenoma, Acidophil↗
Biomedical subjects
T Togawa
Publications and source records attributed to T Togawa.
Ambulatory oxygen uptake measurement system.
An apparatus for monitoring prolonged measurement of oxygen uptake without discomfort has been developed. The system is based on the open flow-through principle. The subject wears a hood through which air is drawn by an exhaust blower. Oxygen concentration is kept constant by a servo-controlled blower, so that flow rate is essentially proportional to oxygen uptake. The flow rate of the main stream is measured by a time-of-flight flowmeter located in the exhaust hose. Oxygen concentration is measured by a limiting-current oxygen sensor. The signals representing flow rate and oxygen concentration are digitized and stored in a memory. All of the equipment is assembled in a small package (wt = 3 kg) which the subject carries on his back. The memory chip is removed from the portable device after each experiment. Data are transferred from the memory to a microcomputer and then an oxygen uptake trend is estimated. Response of the system to a step input is about 30 s. Compared with a commercially available oxygen monitoring system (Magna 88, P. K. Morgan Ltd., Rainham, UK), the maximum difference was 0.15 L/min within an oxygen uptake range of 0.25-2.3 L/min. Thus, the measurements made with our portable device agree with the results obtained using the conventional method.
Adult↗
High performance liquid chromatographic determination of bound sulfide and sulfite and thiosulfate at their low levels in human serum by pre-column fluorescence derivatization with monobromobimane.
A sensitive and specific high performance liquid chromatographic method for the determination of sulfide, sulfite, and thiosulfate was established. Inorganic sulfur anions were converted into fluorescent derivatives with monobromobimane. The derivatives were separated on a coupled column chromatography with a reversed-phase octadecyl silica column connected with a weakly basic anion exchanger column by isocratic elution with acetic acid solution (pH 3)-acetonitrile (13:3, v/v) containing 25 mM NaClO4. The method was applied to the determination of bound sulfide and sulfite and thiosulfate in normal human serum. Thiosulfate could be determined directly by use of an ultrafiltered sample. For the determination of bound sulfide and sulfite, the pretreatment step with continuous flow gas dialysis was effective for the sample after releasing sulfide and sulfite by reduction with dithiothreitol. The limits of quantification by the present method were 0.05 microM for thiosulfate, 0.5 microM for bound sulfide, and 0.2 microM for bound sulfite.
Bridged Bicyclo Compounds↗
[Tl-201/Ga-67 uptake ratio in lung tumors--comparison between planar and SPECT methods].
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Adenocarcinoma↗
Comparison of laser Doppler fluxmetry and the thermal diffusion method of measuring skin blood flow with hydrogen clearance.
Laser Doppler fluxmetry (LDF) and the thermal diffusion method (TDF) were compared with the hydrogen clearance method in ten rabbit ears. The LDF signal followed the rapid change in blood flow caused by aortic occlusion and the signal obtained by TDF showed a time delay and the response was less steep compared with the LDF signal. Simultaneous recording showed both methods correlated well with the hydrogen clearance method, but the relationship varied among the studies (the slope 0.0189-0.0967 for LDF, the slope 0.052-0.682 for TDF). Both methods appear to provide a good indicator of the response pattern of blood flow in the region tested. However, variability among the subjects indicates that the quantitative application of both techniques is difficult.
Animals↗
[Assessment of skull base involvement of nasopharyngeal carcinoma by bone SPECT using three detectors system].
SPECT of the skull was performed on twelve patients with histologically proven nasopharyngeal carcinoma using newly developed three detectors SPECT system (Toshiba GCA 9300A) mounted with fan-beam collimators, for the purpose of early detection of skull base involvement of the disease. This SPECT system has extremely improved resolution with FWHM of 8 mm in the center, and it provides clear tomographic images of the skull which has anatomically complex structure. SPECT image was taken 3 hours after injection of 740 MBq (20 mCi) of 99mTc-MDP following whole body skeletal survey. In twelve patients with confirmed nasopharyngeal carcinoma, 8 patients showed positive findings on SPECT. Three of SPECT positive patients also showed destructive findings on CT. Other five positive patients did not show destructive findings on CT at their initial examinations, but in three of them CT findings turned to positive later. SPECT was superior to CT in early detection of skull base involvement. We believe that SPECT of the skull is a diagnostic tool for early detection of skull base involvement of nasopharyngeal carcinoma.
Adult↗
Physiological monitoring techniques for home health care.
Practical techniques of nonconstrained physiological monitoring which are acceptable in daily life have been attempted, and obtained preliminary results: Successive records of temperature profile on a bed provide information such as body movement, and sleep hours. ECG can be recorded automatically in a bathtub with electrodes on the inside wall of the tub. Heart rate can be measured by ECG taken at a toilet seat. Proposed techniques do not require any effort of measurement procedure to the subject, and thus it is expected that physiological data can be accumulated automatically even though subjects never aware the monitoring procedure.
Activities of Daily Living↗
Determination of trace amounts of sulphide in human red blood cells by high-performance liquid chromatography with fluorimetric detection after derivatization with p-phenylenediamine and iron(III).
A high-performance liquid chromatographic method based on pre-column fluorescence derivatization has been developed for the determination of trace amounts of sulphide. After the sulphide had been converted into a fluorescent derivative, thionine, by the reaction with p-phenylenediamine and Fe3+, it was separated on a reversed-phase column and detected fluorimetrically (excitation, 600 nm; emission, 623 nm). Sulphide ion can be determined in the range from 0.01 to 3.0 mumol dm-3 with a relative standard deviation (n = 5) of 2.54% at 0.02 mumol dm-3 and 1.74% at 1.0 mumol dm-3. The proposed method was applied to the determination of sulphide in human red blood cells from ten healthy subjects, by generating sulphide in a microdiffusion apparatus; the concentrations found ranged from 0.123 to 0.189 mumol dm-3.
Chromatography, High Pressure Liquid↗
[Diagnosis of pancreatic cancer using 201Tl-chloride and a three-head rotating gamma camera SPECT system].
201Tl SPECT was performed on 17 patients with pancreatic cancer or chronic pancreatitis using a three-head rotating gamma camera SPECT system. In 7 of 10 patients with pancreatic cancer, the lesions were clearly delineated by 201Tl SPECT. Whereas the lesion of 30 mm in diameter was visualized, a large tumor of 80 mm in diameter could not be visualized. Namely, it was thought that 201Tl uptake by pancreatic cancer might be well correlated with tumor blood flow and/or its histological subtype rather than with tumor size. In 5 of 7 patients with chronic pancreatitis, no uptake by the pancreas was shown. The sensitivity, specificity, and accuracy in diagnosing pancreatic cancer by 201Tl SPECT were 70%, 71%, and 71%, respectively. The present results obtained by 201Tl SPECT were thought satisfactory enough to evaluate pancreatic cancer under the present conditions where there was no useful imaging agent for visualizing pancreatic cancer by SPECT. 201Tl SPECT is expected to be a new diagnostic tool for investigation of pancreatic tumorous lesion.
Adenocarcinoma↗
[Blood flow measurement of brain tumor by 123I-IMP using 3-heads rotating gamma camera SPECT].
Using 3-heads rotating gamma camera SPECT system, regional blood flow was measured from the super-early image obtained 4 to 6 minutes after the intravenous injection of 123I-IMP on 11 patients with various brain tumors. Two cases of olfactory groove meningioma and malignant astrocytoma showed significantly high 123I-IMP uptake by the lesion visualized by MRI compared to the uptake by normal brain cortex on super-early image but 123I-IMP uptake by the tumor decreased on early image. In both cases, blood flow of the tumor measured from super-early image showed values much higher than those of normal brain cortex. It was thought that usual correction method based on early image did not correctly represent the blood flow of the lesion but that the present method based on super-early image could show the increase of blood flow of the tumor.
Adult↗
Metabolic pathways of sodium bisulfite injected intravenously in rabbits.
The metabolites of sodium bisulfite in rabbits through intravenous injection were examined according to the high performance liquid chromatography method for determination of sulfur-containing substances. Most of the administered sulfite was oxidized to sulfate, and a small part was converted to thiosulfate, S-sulfoalbumin, S-sulfoglutathione and S-sulfocysteine. Furthermore, it was found that S-sulfocysteine administered intravenously to a rabbit was partially changed to inorganic sulfate and thiosulfate. These metabolites produced from sulfite in rabbits indicated the presence of the many and complicated metabolic pathways of sulfite in vivo.
Animals↗
In vivo T1 measurements of canine brain for deep tissue temperature measurements with MRI.
The possibility of deep tissue temperature imaging with a magnetic resonance (MR) imager was studied in 30 mongrel dogs. The coronary view of the brain of a dog anesthetized with muscle relaxant and pentobarbital and ventilated automatically with air was taken with a special head coil by a 0.1 Tesla MR imager, Asahi Mark-J, driven by a spin warp pulse sequence. T1s in the imaging of the right and left white matter, grey matter, thalamus and caudate nucleus were measured with rectal temperature in group I (10 dogs) for a control study every 30 min until 120 min without intervention, in group II (10 dogs) for hyperthermia with extracorporeal bypass method, before heating, at 41 and 42 degrees C, in group III (10 dogs) for hypothermia, before cooling, at 35 and 30 degrees C and after rewarming, respectively. In groups I, II and III, the T1s at all sites except the white matter at 42 degrees C did not change significantly at any rectal temperature. T1 prolongation in the white matter at 42 degrees C may be due to edema, probably because of biological reaction to hyperthermia. The present study suggests that deep tissue temperature imaging in vivo by T1s measured with the MR imager may be impossible in spite of obvious evidence of T1 dependance on temperature in theoretical, in vitro and ex vivo studies already achieved.
Animals↗
[Factor analysis in thallium-201 chloride thyroid studies].
Factor analysis was applied to thyroid thallium-201 imaging to get separated image of tumor from normal thyroid tissue. Thirty-eight patients with various thyroid tumors which were histologically confirmed were included in this study. Following intravenous injection of 111 MBq (3 mCi) of 201Tl chloride, thyroid images in 64 frames were taken for 30 to 60 minutes using Toshiba gamma camera system and data were analyzed by 2 or 3 factor analysis. In 28 of 38 patients separated images of the lesions from normal thyroid were obtained and time-activity curves of various shapes corresponding to the lesions were also obtained. When the curves were classified into 3 groups according to their shapes: increasing, flat and decreasing, follicular carcinoma did not show increasing shape whilst neither of papillary carcinoma, squamous cell carcinoma and anaplastic carcinoma showed decreasing shape. The shapes of the curves were thought to be reflected in clearance of the agent from the lesions. Factor analysis in 201Tl chloride thyroid scan provided separated image of tumor from normal thyroid gland automatically and the obtained curves corresponding to the lesions provided information for estimating the characteristics of thyroid tumors.
Adult↗
[Pacemaker technology--present and future trends].
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Electric Power Supplies↗
Perioral force measurement by a radiotelemetry device.
A telemetric method was developed to monitor the active and passive perioral forces exerted on the maxillary dental arch. The system consists of intraoral and extraoral units. An electromagnetic coupling between intraoral and extraoral coils supplies the power of the intraoral unit and transmits the signals induced by variations in perioral forces. The force sensor has a diameter of 6 mm, a thickness of 1 mm, and is constructed of an 0.08 mm thick cantilever beam to which semiconductor strain gauges are cemented. Clinical application of the system was tested in four adult subjects. The forces on the labial surface of an upper central incisor were 1.5 gm/cm2 during rest, 10.9 gm/cm2 during swallowing, and 5.0 gm/cm2 during speech; the corresponding lingual forces were 4.0 gm/cm2, 19.1 gm/cm2, and 13.9 gm/cm2, respectively. Lingual forces were always higher than labial forces. The telemetry system can be used to monitor up to 6 hours of continual variations in perioral forces.
Adult↗
Non-contact skin emissivity: measurement from reflectance using step change in ambient radiation temperature.
A method of estimating skin emissivity based on reflectance measurement upon transient stepwise change in the ambient radiation temperature was proposed. To effect this change, two shades at different temperatures were switched mechanically, and the change in radiation from the skin surface was recorded through an aperture for each shade by a high-resolution, fast-response radiometer having a sensitivity within the 8-14 microns range. Measurements were made on the forehead, forearm, palm and back of the hand in 10 male and 10 female subjects. No significant differences in emissivity were observed among sites and between sexes. The overall average of the skin emissivity obtained was 0.971 +/- 0.005 (SD). This result is inconsistent with most reported skin emissivity values. However, as the former studies had many inherent inadequacies, both theoretical and experimental, it is considered that most of these reported skin emissivities are unacceptable. The method proposed in this study has the following advantages: (1) relative calibration between instruments is unnecessary, (2) non-contact measurement can be achieved, and (3) each measurement can be made within one minute.
Female↗
Observation of electrocardiograms through tap water.
Preventive diagnosis is important. Daily medical check-ups in the home which require little effort or practice on the patient's part could be one way to achieve this goal. We investigated the acquisition of electrocardiograms from a human subject in a regular bathtub. In order to prevent power line interference and base line drift due to body movements, an active notch filter and specially designed Ag/AgCl electrodes were utilised. The amplitude of the QRS complex obtained from the water (40 degrees C) was approximately 1/10 that of the direct body surface measurement. Increasing the electrical conductivity of the tap water by adding NaCl (0.2% in weight) resulted in a decrease in amplitude to 1/100 of the direct measurement. Otherwise, the waveform distortion was minimal. It was confirmed that acquisition of electrocardiograms of monitoring quality was feasible in a regular bathtub filled with ordinary tap water.
Electrocardiography↗
Two cases of adenocarcinoma of the lung in which thallium-201 gave a better delineation of metastatic lesions than gallium-67.
The authors report two cases of adenocarcinoma of the lung in which Tl-201 gave a better delineation of metastatic lesions than did Ga-67. In the case of multiple bone metastases, the metastatic lesion of the skull was clearly demonstrated by Tl-201 but not by Ga-67. In another case of multiple brain metastases, the lesions were also visualized by Tl-201 but not by Ga-67. Tl-201 is occasionally superior to Ga-67 for visualizing metastatic adenocarcinoma of the lung.
Adenocarcinoma↗