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U Y Ryo

Publications and source records attributed to U Y Ryo.

At least 37 records · Page 2Linked to original sources
PubMed1991

Tc-99m HMPAO diffuse pulmonary uptake demonstrated in cigarette smokers.

Tc-99m HMPAO, a lipophilic radiotracer used as a brain SPECT imaging agent in the diagnosis of strokes and dementias, is normally localized in the brain and the heart and is excreted through the kidneys (50%) and the hepatobiliary system (14% to 30%). There is no pulmonary localization except in the lungs of smokers. To evaluate pulmonary localization of Tc-99m HMPAO in relation to smoking, 23 patients (aged 27 to 76 years) who were referred for brain imaging studies for strokes or dementias also underwent lung imaging studies immediately following the brain imaging. Anterior and/or posterior lung images were obtained 30 to 45 minutes after IV injection of 15 mCi Tc-99m HMPAO. Diffuse pulmonary uptake was graded semiquantitatively: 3+, pulmonary uptake is equal to or higher than hepatic uptake; 2+, pulmonary uptake is less than hepatic uptake but higher than cardiac uptake; 1+, pulmonary uptake is equal to cardiac uptake; 0, pulmonary uptake is less than cardiac uptake. Each patient's smoking history, including duration and daily consumption, was recorded. Four patients' lung images showed 3+ lung uptake; 6 patients, 2+; 1 patient, 1+; and 12 patients, 0 uptake. Eleven patients with lung uptakes of 3+ to 1+ had a history of cigarette smoking. Twelve patients with lung uptake less than cardiac uptake had no smoking history. Pulmonary distribution of Tc-99m HMPAO is usually negligible in the normal lung. Our results indicate that lung uptake correlates significantly (chi-square = 23, d.f. = 1, P = 0.0001) with smoking history.

Adult↗
PubMed1991

Prediction of radionuclide bone imaging findings by Gleason histologic grading of prostate carcinoma.

To evaluate a relationship between Gleason scores and Tc-99m HMDP bone imaging findings, data from 48 men (aged 45 to 77; mean, 67) with prostate carcinoma who had a bone imaging study at the time of presentation were reviewed. Cumulative Gleason scores were divided into two groups: high scores (6-10), 32 men; low scores (2-5), 16 men. Of the 32 men with high Gleason scores, 15 tested positive for multiple metastases and 17 tested negative. Tumors of the 16 men with low Gleason scores were negative for metastasis. A chi-square association between Gleason scores and the presence of metastases, either of a superscan pattern or multiple metastases, was 10.9 (1 df, P less than 0.001). The results indicate that a superscan pattern or multiple metastases were found exclusively in the bone images of patients with high histologic grades; bone images negative for metastases were associated with low-grade tumors. We conclude that positive bone imaging for metastases at the initial scan occurs only in patients who have high Gleason scores, that patients with high Gleason scores might or might not have skeletal metastasis, and that skeletal metastasis is not predictable in patients with low Gleason scores.

Adenocarcinoma↗
PubMed1991

Altered gastric emptying in the head-injured patient: relationship to feeding intolerance.

Most patients with moderate to severe head injury initially do not tolerate enteral feedings postinjury. This intolerance is more prolonged than that found in patients suffering other types of trauma. The authors prospectively evaluated 12 patients with moderate to severe head injury (Glasgow Coma Scale score between 4 and 10) throughout their hospitalization for liquid gastric emptying as a possible mechanism for intolerance to enteral feeding. During Week 1, the majority of patients displayed a delay in gastric emptying. Patients also displayed an abnormal biphasic response (gastric emptying faster than normal during the early stage but prolonged later). By Week 2, many patients still had delayed and abnormal biphasic responses to gastric emptying. By Week 3, an improvement was observed with the majority of patients exhibiting rapid gastric emptying, but delays and abnormal biphasic responses were still seen. Patients who initially had rapid or normal gastric emptying tolerated full-strength full-rate feedings significantly earlier compared with those who experienced delayed gastric emptying (8.5 +/- 0.5 days vs. 13.7 +/- 3.2 days, p less than 0.001). All patients tolerated full-strength full-rate feedings by Day 16 postinjury (range 7 to 16 days) except the two patients who displayed delayed gastric emptying for prolonged periods of time (mean 25 days). This is the first study to longitudinally evaluate gastric emptying following head injury. The authors suggest that patients with moderate to severe head injury often experience alterations in gastric emptying which may affect their ability to tolerate enteral feedings.

Adolescent↗
PubMed1991

Thallium redistribution does not predict perioperative cardiac complications following vascular surgery.

Utility of preoperative stress thallium scintigraphy (STS) was determined in 59 patients, thought to be at increased risk, prior to major vascular surgery from July 1987 to February 1990. Forty-seven had oral dipyridamole and 12 underwent exercise STS. Thallium redistribution (TR) was present in 61% (n = 36); fixed defects were present in 59% (n = 35); and some combination of defects was present in 76% (n = 45). Perioperative cardiac complications (CC = congestive heart failure [n = 3], ventricular arrhythmia [n = 2], and MI [n = 1]) were present in 8.5% (6 CC in 5 patients). Incidence of CC was 8.3% (3/36) in those with TR, and 8.7% (2/23) without TR (relative risk = 0.95). Perioperative MI was present in 2.8% (1/36) with TR vs. 0% (0/23) without. Though mortality was 3.4%, no perioperative deaths were from cardiac disease. Utility of STS is not clearly established for prediction of perioperative cardiac risk after major vascular surgery.

Adult↗
PubMed1991

Neutron-activated holmium-166-poly (L-lactic acid) microspheres: a potential agent for the internal radiation therapy of hepatic tumors.

Biodegradable Poly(L-lactic acid) microspheres containing neutron-activable 165Ho were designed for internal radiation therapy of hepatic tumors. Spheres composed of Poly(L-lactic acid) (PLA) were prepared with excellent reproducibility containing up to 36% of a holmium complex. The prepared spheres were irradiated in a high neutron flux converting 165Ho to 166Ho (Emax = 1.84 MeV, half-life = 26.9 hr). Thus, these microspheres can be prepared under conditions that do not require the handling of a hazardous radionuclide, and then irradiated just prior to administration. In vitro studies in plasma (n = 6) revealed 97.3% (+/- 1.9) retention of 166Ho in the microspheres after 240 hr. PLA spheres administered via the portal vein in rabbits (n = 6) show 94.5% (+/- 3.4) retention of the original 166Ho activity in the liver after 6 days.

Animals↗
PubMed1990

Relation of urinary tract infection and vesicoureteral reflux to scars: follow-up of thirty-eight patients.

A prospective study compared the outcome of vesicoureteral reflux and recurrent urinary tract infections in children (3 boys, 62 girls) who received medical prophylaxis or underwent surgical correction of reflux. Thirty-eight children returned for reevaluation 6 to 13 years (average 9.5 years) after entry. There was a marked decrease in prevalence and severity of reflux. At entry, 13 had significant scarring that had progressed at follow-up. New scars were documented by dimercaptosuccinic acid scan at follow-up in eight children on the medical regimen and two who were initially treated with surgical correction of reflux. Four patients with high-grade sterile reflux were followed for 6 to 10 years without the development of cortical scars. Our data support the role of urinary tract infection and vesicoureteral reflux, but not sterile reflux, in the pathogenesis of chronic pyelonephritis and reflux nephropathy.

Adolescent↗
PubMed1990

Tc-99m HMPAO SPECT of the brain in the neonate.

A brain scan with Tc-99m hexamethylpropyleneamineoxime (HMPAO) performed on a neonate demonstrated normal localization only in the sensorimotor cortex, basal ganglia, and cerebellum. This pattern of localization is remarkably similar to previously published PET images of the neonate. Because Tc-99m HMPAO is readily available and has biochemical and physical characteristics that are suitable for perfusion imaging of the brain, it likely will become a major imaging agent in nuclear medicine. Normal scan findings in the neonatal age group with Tc-99m HMPAO have not been previously reported because of limited clinical use to date.

Brain↗
PubMed1990

I-123 hydroxyiodobenzyl propanediamine (HIPDM) cerebral blood flow imaging demonstrating transtentorial diaschisis.

To assess the clinical significance of transtentorial diaschisis (TTD) as demonstrated by I-123 HIPDM brain imaging, SPECT and/or planar images of 35 patients with stroke, 26 patients with Alzheimer's disease (AD), 2 patients with Creutzfeldt-Jakob disease (CJD), and 1 patient with a schizoaffective disorder were analyzed. TTD was observed in 21 of the 35 patients with strokes. In 13 stroke patients, TTD was associated with large infarcts in the middle cerebral artery (MCA) territory; in the remaining 8 stroke patients, TTD was associated with internal capsule and/or basal ganglia infarcts. TTD was not associated with small occipital or parietal infarcts. Despite cortical perfusion decrements, TTD was not seen in the AD patients, the CJD patients, or the patient with schizoaffective disorder. It is concluded that 1) TTD frequently occurs following cerebral infarct of the MCA territory (60% of the patients in this sample); 2) absence of TTD in the presence of a large cerebral perfusion abnormality may represent neuronal dysfunction of the cerebral cortex; and 3) the presence of TTD without a significant cortical perfusion abnormality may indicate basal ganglia and/or internal capsule infarct.

Alzheimer Disease↗
PubMed1990

Serum osteocalcin measurements in prostate carcinoma patients with skeletal deposits shown by bone scintigram: comparison with serum PSA/PAP measurements.

The correlation of technetium-99m-HMDP bone scintigraphic findings, serum osteocalcin as a measure of bone turnover and prostate-specific antigen (PSA) and/or prostate acid phosphatase (PAP) was determined in 19 men with bone metastasis due to prostatic carcinoma. Six of the 19 patients with metastases on bone scan showed elevation of osteocalcin. These patients had extensive metastatic disease. All 19 men with positive bone scans had high serum PSA and/or PAP levels. Serum osteocalcin measurement is less sensitive to detection of bone deposits than PSA/PAP measurements (p less than 0.0008).

Acid Phosphatase↗
PubMed1990

Prediction of postoperative loss of lung function in patients with malignant lung mass. Quantitative regional ventilation-perfusion scanning.

The quantitative measurement of regional ventilation and perfusion distribution is simply and reliably accomplished by using routinely available radioactive gas and perfusion lung scanning agents, and a large field-of-view gamma camera with an on-line computer. The preoperative prediction of postsurgical loss in lung function can be made accurately by using the quantitative ventilation-perfusion lung scan technique. Either a regional ventilation study or perfusion study may be used for the prediction, but analysis of regional ventilation distribution appears to be a better parameter than that of perfusion distribution for the prediction of postoperative loss of FEV1. In the rare case of a patient with a marked ventilation-perfusion deficit, quantitative distribution of both ventilation and perfusion may be needed for an accurate assessment of postsurgical lung function.

Forced Expiratory Volume↗
PubMed1990

Iodine-123-HIPDM lung imaging in pulmonary vein-banded pulmonary hypertension.

To evaluate the use of N,N,N'-trimethyl-N,-[2-hydroxy-3-methyl-5 iodobenzyl-1, 3 propanediamine iodine-123 (HIPDM) in lung imagings for the diagnosis of individual pulmonary vein stenosis, 14 single-pulmonary vein-banded rats underwent lung imaging. After i.v. injection of 250-300 microCi [123I]HIPDM lung images were recorded at 2 min by a gamma camera interfaced with a PDP computer. Banded lung demonstrated higher [123I]HIPDM radioactivity than that of nonbanded lungs. The activity ratio of banded-to-nonbanded lungs ranged from 4.0 to 1.22 (average 1.62). Technetium-99m-macroaggregated albumin (MAA) lung images showed decreased perfusion in banded lung, and normal perfusion in the nonbanded lung. Postmortem microscopic changes in pulmonary arteries and veins were compatible with the elevated pulmonary artery and venous pressure in vein-banded lung. Whether the high uptake of [123I]HIPDM in banded lungs relates to endothelial receptors for HIPDM is unknown. Nevertheless, the finding of high lung uptake in banded lung in [123I]HIPDM lung imaging may be potentially used to diagnose individual pulmonary vein stenosis.

Animals↗
PubMed1989

Correlation of prostate-specific antigen and technetium-99m HMDP bone imaging.

For an evaluation of the clinical utility of prostate-specific antigen (PSA), 32 prostatic carcinoma patients (ages 54-76) and 13 nonprostatic carcinoma patients (ages 60-70) underwent PSA measurements and bone imaging. At the time of bone imaging, each patient's PSA value was measured by a monoclonal immunoradiometric assay. All 13 nonprostatic carcinoma patients (11 bronchogenic, 1 colon, and 1 urinary bladder) gave normal PSA values, although 6 had metastatic bone disease. The 32 prostatic cancer patients were divided into 2 groups of 16 each; PSA levels in Group 1 were abnormal (greater than or equal to ng/ml): PSA levels in Group 2 were normal (less than 4 ng/ml). In Group 1, bone images of 14 patients showed bone metastases; 6 of the 14 showed progression of metastases in a 6- to 12-month period. Two patients in Group 1 were negative for skeletal metastases. Twelve patients in Group 2 were negative for skeletal metastases; bone imaging in 1 showed regression of skeletal metastases; and 3 patients had unchanged bone lesion(s). The data indicate that PSA measurements may enhance bone imaging interpretation and provide valuable clinical monitoring of prostatic carcinoma. In the case of a patient with positive bone imaging and an unknown primary, PSA measurements may definitively determine if metastases originated from prostatic carcinoma.

Aged↗