Biomedical subjects

D L Ferguson

Publications and source records attributed to D L Ferguson.

36 records · Page 2Linked to original sources

PubMed1981

Cationic Tc-99m complexes as potential myocardial imaging agents.

Nineteen cationic Tc-99m complexes, based upon four different ligand series, have been synthesized under "no carrier added" conditions and qualitatively evaluated as myocardial imaging agents in a dog model. Of these complexes, the four halogen derivatives of the diars series [diars = o-phenylenebis(dimethylarsine)] successfully concentrate in the myocardium. These Tc-99m diars complexes are shown by thin-layer chromatography to be identical to the Tc-99 analogs that have been fully characterized as trans octahedral complexes of Tc(III) by classical chemical techniques. Tissue distribution studies in rats show a definite difference in the biodistributions of [99mTc(diars)2Cl2]+ and [99mTc(diars)2Br2]+, despite the similar size, shape, charge, and lipophilicity of these two complexes. A tissue distribution study in resting beagle dogs shows that [99mTc(diars)2Br2]+ accumulates in the normal myocardium about half as well as TI-201 (0.022 compared with 0.038% dose/g).

Animals↗

PubMed1981

Survival of patients with localized diffuse histiocytic lymphoma.

Twenty-eight patients with previously untreated diffuse histiocytic lymphoma (DHL) were identified to be in pathologic stage (PS) I (11), IE (3), II (8), or IIE (6) by exploratory laparotomy and splenectomy. Six patients were treated with total nodal radiotherapy; 14 with an extended mantle; 5 with an inverted Y or whole abdomen; and 3 with an involved field. Twenty-six patients achieved a complete remission (93%) and 2 patients had persistent local disease. The median survival and disease-free survival and for the complete response group are 56 and 51.5 mo, respectively. Ten of the 11 stage I or IE patients had supradiaphragmatic lymph node disease. Patients with stage I or IE disease (n = 14) demonstrated a median survival of 72.5 mo and a median disease-free survival of 69.5 mo; there was 1 disease-related death. Patients with stage II or IIE disease (n = 14) demonstrated a median survival of 33 mo and median disease-free survival of 29.5 mo; there were 10 relapses or deaths. Patients in stages I, IE, II, or IIE with infradiaphragmatic disease (n = 7) had a median survival of 36 mo, while patients with supradiaphragmatic presentation (n = 21) demonstrated median survival of 68 mo (p = 0.37). The data indicate that patients with diffuse histiocytic lymphoma with stage I supradiaphragmatic lymph node disease are curable using radiotherapy alone, achieving a 93% 11-yr actuarial disease-free survival. Patients with stage II or IIE diseases are not readily curable with radiation therapy alone, achieving a 33% 11-yr actuarial disease-free survival; radiotherapy with adjuvant chemotherapy or chemotherapy alone should be considered for this group.

Actuarial Analysis↗

PubMed1980

Comparative evaluation of three diphosphonates: in vitro adsorption (C- 14 labeled) and in vivo osteogenic uptake (Tc-99m complexed).

We have investigated the in vitro adsorption of three C-14-labeled diphosphonates on calcium phosphate. The three are 1-hydroxy[1-14C]ethylidene diphosphonate (C-14 HEDP), [14C]methylenediphosphonate (C-14 MDP), and hydroxy[14C]methylenediphosphonate (C-14 HMDP). All three adsorbed significantly more, per mole of calcium, on amorphous calcium phosphate than on crystalline hydroxyapatite. Among the three diphosphonates, C-14 HMDP adsorbed--on both amorphous and crystalline calcium phosphate--to a greater degree than did the other two bone-seeking agents. Moreover, when HMDP was complexed with Sn(II) and Tc-99m, it produced a significantly higher uptake of Tc-99m, per mg of calcium, in an isolated in vivo site of osteogenesis. The mechanisms of adsorption are discussed relative to the hydroxyl group on the diphosphonate, to the solubility of the calcium salts to the diphosphonates, and to the form of the calcium phosphate. These studies form a working rationale for the clinically observed high contrast obtained with Tc-99m HMDP between normal bone and soft tissue, and between normal and abnormal bone.

Adsorption↗

PubMed1980

Preparation and biological distribution of technetium diphosphonate radiotracers synthesized without stannous ion.

Two HEDP complexes of technetium (either Tc-99 or a mixture of Tc-99 and Tc-99m) have been prepared without the use of stannous ion. The first, Tc(NaBH4)-HEDP, is synthesized by reduction of TcO4- with NaBH4 in the presence of excess HEDP; this is analogous to the preparation of Tc(Sn)-HEDP in commercial kits wherein SN(II) functions as the reductant. The second, Tc-HEDP, is prepared by substitution of HEDP onto the pre-formed, pre-reduced, technetium center TcBr62-. The HEDP-to-Tc ratio in Tc-HEDP was found to be 1.0 by double-labeling procedures (Tc-99 and [3H]HEDP), implying that in solution this material is polymeric or at least dimeric. Preparations of Tc(NaBH4)-HEDP and Tc-HEDP with Tc-99m are excellent bone-imaging agents in both rats and dogs. Tissue distribution studies in rats show that uptake of Tc(NaBH4)-HEDP and Tc-HEDP by the bone is at least equivalent to that achieved by Tc(Sn)-HEDP prepared in commercial kits with Sn(II) as the reductant. Tin is therefore not necessary for the bone-seeking properties of Tc(Sn)-HEDP, and the in vivo distribution of a given HEDP radiotracer seems to depend primarily on the presence of the HEDP ligand and not on the exact nature of the technetium complex itself. Synthesis of technetium radiotracers by a substitution route, rather than by redox, is practicable; this route has the potential of introducing hitherto unattainable flexibility and subtlety into the preparation of technetium radiotracers.

Etidronic Acid↗

PubMed1979