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Biomedical subjects

W J Shih

Publications and source records attributed to W J Shih.

At least 145 records · Page 8Linked to original sources
PubMed1992

Prostate adenocarcinoma using Gleason scores correlates with prostate-specific antigen and prostate acid phosphatase measurements.

To evaluate a relationship between Gleason scores of histopathology of prostate carcinoma and concurrent serum prostate-specific antigen (PSA) and prostate acid phosphatase (PAP) values, 65 men with prostate carcinoma were studied. These patients' cumulative Gleason scores were obtained by totaling the primary and secondary patterns, resulting in two groups: 42 patients received high (6-10) and 23 received low (2-5) Gleason scores. Serum PSA and PAP values were measured by radioimmunometric assay 1 to 7 days before surgical procedures or biopsy for prostate carcinoma. Mean serum PSA for patients in the high Gleason score group was 134.39 ng/mL (normal range: 0 to 4), and the mean serum PSA for patients in the low Gleason score group was 23.62 ng/mL. Mean serum PAP for patients with high scores was 28.08 ng/mL (normal range: 0 to 5), and the mean serum PAP for patients with low scores was 18.19 ng/mL. Patients with high Gleason scores showed significantly greater elevation of serum PSA than those with low Gleason scores (P = .047), using two samples to test for groups having unequal variants. Prostate acid phosphatase levels of patients with high scores were not significantly higher than the levels in patients with low scores (P = .60). These results indicate that PSA levels but not PAP levels correlate with Gleason scores.

Acid Phosphatase↗
PubMed1992

Urinary extravasation from the kidney of recurrent renal cell carcinoma.

A man presented with recurrent renal cell carcinoma, complicated with acute pyelonephritis, 3 months status post partial nephrectomy. He underwent cystourethroscopy and a bilateral retrograde pyelogram, then was referred for a Tc-99m DTPA renal study; the images showed an initial photon-deficient area of the right kidney being gradually filled-in by radiotracer with further extension laterally, indicating urinary extravasation. 16 days later this area was aspirated, yielding 5 ml of yellowish fluid with clots consistent with necrotic tumor and pus.

Aged↗
PubMed1992

Cholescintigraphic demonstration of transient and functional common bile duct obstruction in a patient with acute pancreatitis.

Cholescintigraphy has proven useful in diagnosis of acute and chronic cholecystitis and evaluation of common bile duct obstruction. Common bile duct obstruction may be due to mechanical obstruction such as impact stone in the common duct or functional obstruction due to sepsis with intra-hepatic cholestasis or acute viral hepatitis. We present a cholescintigram of a patient with acute pancreatitis showing complete common bile duct obstruction.

Acute Disease↗
PubMed1992

Reversible thallium-201 perfusion defects of the septal and inferoapical segments in a patient with incomplete right bundle branch block and normal coronary angiogram.

Possible causes of reversible perfusion defect in exercise-rest 201Tl myocardial images in a patient with a normal coronary artery angiogram include left bundle branch block, coronary spasm, myocardial bridges, hypertrophic cardiomyopathy, mitral valve prolapse, aortic valve disease and anomalous origin of the left coronary artery arising from the pulmonary artery. This case is a report of a 34-yr-old man with incomplete right bundle branch block and angiographically normal coronary arteries who was found to have reversible defects involving septal and inferoapical walls on stress-rest 201Tl-chloride myocardial imaging.

Adult↗
PubMed1991

A note on the analysis of titration studies.

We propose a method to incorporate all types of dropouts in the evaluation of an intervention based on binary data from a titration study. The proposed procedure does not require that the dropouts occur randomly, but instead examines each outcome individually. Our procedure has a built-in penalty factor in the estimation process that determines the amount of penalty on efficacy parameters due to efficacy-related dropouts. We also propose a method to estimate the variances associated with the estimates. The results have use in exploration of a potential dose-response relationship or to answer questions pertinent for phase III studies. We use data from a phase III antihypertension study to illustrate the procedure.

Algorithms↗
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

Intraventricular photon deficiency in gated cardiac blood pool imaging due to left ventricular metastases from renal cell carcinoma.

Cardiac metastasis can occur with any widely disseminated malignancy, especially from carcinoma of the kidney, stomach, lung, breast, or from melanocarcinoma. Metastasis to the myocardium can protrude from the endocardium into the intraventricular cavity of the left ventricle. We present a case of renal cell carcinoma and left ventricle cavitary metastases, documented by an echocardiogram demonstrated in a cardiac blood pool study as a photon-deficient area in the left ventricle cavity.

Carcinoma, Renal Cell↗
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↗
PubMed1990

Characterization of high specific activity [16 alpha-123I]Iodo-17 beta-estradiol as an estrogen receptor-specific radioligand capable of imaging estrogen receptor-positive tumors.

16 alpha-[123I]Iodo-17 beta-estradiol (16 alpha-[123I]E2) has been characterized for use as a selective radioligand for estrogen receptor (ERc) that is capable of generating in situ images of ERc-positive tumors. High specific activity 16 alpha-[123I]E2 (7,500-10,000 Ci/mmol) was used in all determinations. Radiochemical purity was determined by thin layer chromatography, and the selectivity of radioligand for ERc was evaluated using size exclusion high performance liquid chromatography on ERc prepared from rodent uteri. Efficiencies of radioidination approaching 100% were achieved, and excellent receptor selectivity was obtained even when the efficiency of radioiodination was as low as 10%. Low radiochemical purity was always associated with poor selectivity for ERc. No new radioligand species was generated during the course of radiodecay; however, reduced binding over time, even when increased activity was used to compensate for radiodecay, indicated that the formation of a radioinert competitor does occur. 16 alpha-[123I]E2 demonstrated stable, high affinity binding to ERc and was concentrated by ERc-positive tissues. After injecting 16 alpha-[123I]E2 in vivo, images of ERc-containing tissues were obtained, including rabbit reproductive tract and dimethylbenzanthracene-induced tumors. The demonstrations of ERc selectivity and image formation both indicate that 16 alpha-[123I]E2 should have promise as a useful new radiopharmaceutical for imaging ERc-positive cancers.

Animals↗
PubMed1990

Group sequential designs using a family of type I error probability spending functions.

Performing planned or unplanned interim analyses on accumulating data in clinical trials is a frequent practice. In this paper, we propose a general one-parameter family of type I error probability spending functions to construct customized group sequential boundaries with unequal increments in information time. This proposed family generalized the spending functions of Lan and DeMets1 and Kim and DeMets.2 We give an example to illustrate the use of this family.

Data Interpretation, Statistical↗
PubMed1990

Assessing utility of single photon emission computed tomography (SPECT) scan in Alzheimer disease: correlation with cognitive severity.

Diagnosis of probable Alzheimer disease (AD) is made by a combination of characteristic clinical findings, when normal laboratory studies reveal no structural or metabolic cause of the dementia. Definite diagnosis of AD, however, can only be made with brain tissue examination. PET scanning reveals parietotemporal decreases in cerebral blood flow (CBF) and glucose metabolism that differentiate AD from normal elderly and from multi-infarct dementia. Preliminary studies suggest that similar defects in CBF are detectable in single photon emission computed tomography (SPECT) in AD. Utilizing the iodinated ligand [123I] HIPDM ([123I] hydroxyiodobenzylpropanediamine), we studied 19 patients with probable AD of varying severity, with emphasis on mild cases, to assess the utility of SPECT as a diagnostic test in AD. Parietotemporal perfusion on SPECT was decreased unilaterally or bilaterally in 16 of 19 AD patients, similar to the defects reported with PET. The degree and extent of decreased CBF on SPECT correlated with AD severity. Strong correlations were obtained between decreases in computer-generated ratios of parietal to cerebellar activity and the level of cognitive function. SPECT was read as normal (on the radiographic film) by the nuclear medicine physician in all cases with Mini-Mental State (MMS) score greater than 24, and showed bilateral parietal perfusion deficits in only 1 of 4 patients with MMS between 22 and 24. Ten of 12 patients with MMS less than or equal to 21 had bilateral parietal abnormalities; the other 2 had unilateral perfusion defects. All patients with MMS less than 15 were bilaterally abnormal. SPECT is less expensive and more widely available than PET, and may have an adjunctive role in diagnosis of AD and other dementias if utilized under the proper circumstances.

Aged↗