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Biomedical subjects

S Uematsu

Publications and source records attributed to S Uematsu.

At least 109 records · Page 6Linked to original sources

Indium-111 leukocyte imaging in patients with rheumatoid arthritis.

This study evaluates the usefulness of labeled leukocyte imaging in patients with rheumatoid arthritis. In 33 patients, the incidence of pain and swelling in 66 wrist joints and 66 knee joints was compared with the accumulation of [111In]leukocytes. No accumulation of [111In]leukocytes was seen in any of the patients' wrists (0/12) or knee joints (0/14) when both pain and swelling were absent. In contrast, 93% (25/27) of wrist joints and 80% (24/30) of knee joints with both pain and swelling were positive by [111In]leukocyte scintigraphy. There was little correlation between the stage of the disease, as determined by radiography, and [111In]leukocyte accumulation. This study suggests that [111In]leukocyte imaging may be a reliable procedure for monitoring the activity of rheumatoid arthritis, especially for confirming the lack of an ongoing inflammatory response.

Adult↗

[Application of NMR-CT in the staging of cancer of the digestive organs].

To assess the potential of NMR-CT for demonstrating cancer of the digestive organs, we examined a total of 232 patients (89 with esophageal cancer, 52 with liver cancer, 40 with colorectal cancer, 9 with pancreatic cancer, 9 with gastric cancer, and 33 with other diseases). NMR-CT has many features, but we use especially those features which it is possible to select not only in the transverse plane but also in the coronal and sagittal planes, and it has excellent soft tissue contrast resolution. Our machine is a Picker International NMR-CT using a superconducting magnet of 0.256 tesla. Diagnosis of lymph node involvement of esophageal cancer. Using only the coronal plane, each patient was scanned by the spin echo technique (TE = 40, TR = 400) from the plane of the descending aorta to the plane of the trachea 1 cm in thickness, at 1 cm intervals, continuously. All the vessels were clearly differentiated as no-signal regions, especially in coronal images, from areas of carcinomatous involvement. Lymph nodes were identified as intense grey masses in fat tissue of high intensity. Twenty cases were proved by surgery or autopsy, and it was possible to assess 160 lymph-node groups. A total of 25 patients were imaged as having positive lymph nodes, but 17 of them had metastasis-positive nodes. In other 135 nodes imaged as negative lymph nodes, only two had metastasis and 133 were negative for metastasis. Overall accuracy was 93.8%. Diagnosis of liver cancer. Intrahepatic vessels were clearly imaged without using contrast enhancement in NMR-CT, so it was easy to diagnose the segment containing the tumor and to detect tumor emboli in the portal vein. The capsule was imaged in 84% (16/19) using IR techniques, although only 37% (7/19) could be imaged by X-CT. Diagnosis of colorectal cancer. Using the sagittal plane, the sacrum, urinary bladder and other organs were imaged better parallel to their axis, so that the relationship between rectal cancer and surrounding organs could be clearly visualised with NMR-CT. With regard to lymphatic metastasis, coronal imaging was useful for picturing mesenteric and pelvic vessels, so that lymph nodes were imaged as low-intensity masses along the vessels. Lymph metastasis almost 1 cm size can be detected using coronal NMR-CT.

Digestive System Neoplasms↗

Thermographic presentation of cutaneous sensory and vasomotor activity in the injured peripheral nerve.

Impaired function of cutaneous segments of monkey peripheral nerves experimentally blocked by lidocaine anesthesia was clearly visualized by means of elevated temperature measurements obtained on computerized color telethermography. Mean temperature elevations in the segments of anesthetized primate nerves were 2.40 degrees C at the ulnar segment 17 minutes after nerve block, and 1.20 degrees C at the peroneal nerve at 20 minutes. The vasomotor activity of specific nerves, recorded after local anesthesia and displayed by color telethermographic imaging, corresponded to the distribution of sensory segments identified by more cumbersome means. Telethermography is therefore shown to be a useful tool, both qualitatively and quantitatively, in mapping cutaneous distribution of peripheral nerves and for evaluation of peripheral nerve injuries.

Animals↗

Thermographic imaging of cutaneous sensory segment in patients with peripheral nerve injury. Skin-temperature stability between sides of the body.

Sensory examination based on the patient's subjective assessment of symptoms may raise difficult questions about whether the individual's expressed complaint is based on organic nerve damage, psychogenic factors, or even malingering. A prototype computerized telethermograph has allowed clinical quantification of peripheral nerve injury. The system makes possible mapping and imaging of the damaged area, as well as skin temperature measurements. In normal persons, the skin temperature difference between sides of the body was only 0.24 degree +/- 0.073 degree C. In contrast, in patients with peripheral nerve injury, the temperature of the skin innervated by the damaged nerve deviated an average of 1.55 degrees C (p less than 0.001). The new technique requires further refinement, but it appears that use of this method may be cost-effective in helping to resolve medicolegal conflicts concerning peripheral nerve injury.

Adolescent↗

Electrocorticography: information derived from intraoperative recordings during seizure surgery.

The findings of 100 consecutive electrocorticographies in 94 epileptic patients were reviewed. Most of these patients underwent temporal lobectomies. A well defined and circumscript cortical spike focus was found in only 28 tracings whereas multiple sub-foci of spike activity or dissipated areas of spiking were demonstrated in 46 recordings. Cortical spike activity was minimal in 14 and absent in 12 tracings. Additional one-lead depth electrodes (inserted mainly into amygdala and hippocampus) yielded rather little information in contrast to the wealth of information derived from chronic multiple-leads depth implants prior to surgery. The frequent occurrence of dissipated spike foci suggests that, in partial epilepsies (and especially in temporal lobe epilepsy), epileptogenic zones are more widespread than one would expect from the scalp EEG recordings. These findings lend support to the use of en-bloc removal of large portions of an affected lobe.

Adolescent↗

[Evaluation of gamma camera collimator for regional cerebral blood flow measurements using a 133Xe inhalation method].

In the measurements of regional cerebral blood flow (rCBF) using inhalation of 133Xe gas, the activity present is generally limited in lower levels than those of usual brain scintigraphy. Measurements with low count-rate are usually resulted in diminishing the accuracies of results obtained. Therefore, it is necessary to make measurements using a high sensitive collimator for getting as much count-rate as possible when a gamma camera is used. The relationships among sensitivity and structures of multi-parallel collimator were mathematically analyzed. The results of analysis suggested that sensitivity usually increased by using a collimator with holes of reduced height and diameter. A prototype multi-parallel collimator with holes of low height and small diameter was made in our laboratory for testing sensitivity and resolution. The collimator possessing 1141 holes of 6 mm phi in hole diameter, 1.5 cm is hole height and septal thickness of 1 mm lead showed 24 times more sensitive than those of a general all purpose collimator supplied by the manufacturer. However, resolution measured in FWHM was of 9 to 14 mm at the collimator face and of 29 to 38 mm at 5 cm from the face. The results indicated that this collimator was useful enough in rCBF measurements with 133Xe inhalation using a gamma camera. The mathematical analysis however, suggested that optimum collimator for rCBF measurements was approximate 4.5 mm phi in hole diameter and 1.0 cm in hole height.

Adult↗