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Biomedical subjects

K Y Gulenchyn

Publications and source records attributed to K Y Gulenchyn.

24 records · Page 2Linked to original sources

Technetium-99m diethyldithiocarbamate (DDC): comparison with thallium-201 DDC as an agent for brain imaging.

Technetium-99m diethyldithiocarbamate (99mTc-DDC) was prepared by reduction of [99mTc]pertechnetate with formamidine sulfinic acid in the presence of DDC at alkaline pH, both from extemporaneous solutions and in a kit formulation. The properties of 99mTc-DDC were compared in vitro and in vivo with those of 201Tl-DDC, an agent used for cerebral perfusion imaging (CPI). 99mTc-DDC is a lipophilic complex but its oil/water partition coefficient is lower than that of 201Tl-DDC. 99mTc-DDC also shows greater binding to plasma proteins. Studies in rabbits show that 99mTc-DDC enters the brain but is not retained to the same extent as 201Tl-DDC. This lack of retention may be because 99mTc-DDC does not decompose rapidly in lipid media as 201Tl-DDC does. These results suggest that 99mTc-DDC in its present formulation is not suitable for CPI with SPECT.

Animals↗

Technetium-99m MDP scintigraphy. An insensitive tool for the detection of bone marrow metastases.

Seventy-nine cases with known carcinoma of the lung or breast who underwent both bone marrow aspiration and Tc-99m MDP bone scintigraphy were reviewed. The bone images were assessed for the presence of the pattern of bone marrow expansion which is visualized by diffuse increased metaphyseal activity, particularly evident at the knees, ankles, and elbows. This pattern was found to be an insensitive marker for the presence of marrow metastases (sensitivity 15%). The specificity of the finding was 86%. When diffuse increased metaphyseal activity is present on a Tc-99m MDP bone scan in a patient with malignant disease, the possibility of bone marrow metastases should be pursued by marrow aspiration and biopsy.

Biopsy, Needle↗

Splenic hemangioma presenting as a "hot spot" on radiocolloid scintigraphy.

The appearance of a splenic hemangioma on radiocolloid scintigraphy has been reported to be that of a focal photon deficient lesion. We report a case of a patient who presented with the opposite appearance--that of a splenic "hot spot." We postulate that this appearance results from increased local blood flow presenting a greater proportion of colloid to the reticuloendothelial cells surrounding the hemangioma.

Adult↗

Radionuclide angiography and endomyocardial biopsy in the assessment of doxorubicin cardiotoxicity.

Thirty-eight patients with a mean age of 53.2 years (19 to 75 years of age), who were receiving doxorubicin (D) for malignant disease, were studied in order to determine the relationship between functional and morphologic myocardial changes at different dose levels. Serial patient evaluations included physical examination, chest x-ray, electrocardiogram (ECG), endomyocardial biopsy (EMB), and rest-exercise gated nuclear angiography (GNA), at doses of D ranging from 144 to 954 mg/m2 (mean, 426 mg/m2). Physical examination, chest x-ray, and ECG proved to be insensitive predictors of D cardiotoxicity. Correlation of GNA and EMB in 31 patient evaluations, exclusive of known heart disease, did not reveal any false-positive angiograms, and all abnormal GNAs were associated with abnormal biopsies. Use of stress GNA uncovered six abnormal ventricles which could have been missed with a rest GNA alone. It has been suggested that: (1) GNA is a reliable monitor of D therapy; (2) an exercise study should be performed when the rest ejection fraction is normal, but is unnecessary when the rest EF is abnormal; (3) all patients with a resting ejection fraction of less than 45%, exclusive of other cardiac disease, should have D discontinued; and (4) endomyocardial biopsy is useful in assessing D cardiotoxicity in patients with other possible causes of an abnormal GNA.

Adult↗