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Biomedical subjects

J Gaillard

Publications and source records attributed to J Gaillard.

At least 91 records · Page 5Linked to original sources
PubMed1984

Unusual features in EPR and Mössbauer spectra of the 2[4Fe-4Se]+ ferredoxin from Clostridium pasteurianum.

The electronic and magnetic properties of the selenium-substituted 2[4Fe-4Se]2+/+ ferredoxin (Fd) from Clostridium pasteurianum have been investigated by EPR and Mössbauer spectroscopy. The [4Fe-4Se]2+ clusters of oxidized Fd are diamagnetic and the Mössbauer spectra are nearly identical to those of oxidized 2[4Fe-4S]2+ Fd. The addition of 2e- per molecule of Se-substituted Fd causes the simultaneous appearance of three EPR signals: one (g1,2,3 = 2.103, 1.940, 1.888) is reminiscent of [4Fe-4S]+ EPR spectra and accounts for 0.7 to 0.8 spin/molecule. The two others consist of a broad signal with g = 4.5, 3.5, and approximately 2 (0.7 to 0.8 spin/molecule) and of a narrow peak at g = 5.172 which is observed up to 60 K. Peculiar features are also present in the Mössbauer spectra of 2[4Fe-4Se]+ Fd below 20 K: a subcomponent with lines near to +/- 4 mm/s and accounting for 20% of the total iron corresponds to two antiferromagnetically coupled sites in approximately a 3:1 ratio and displays fully developed paramagnetic hyperfine interactions at 4.2 K without any applied field. At 77 K, however, the reduced Se-substituted Fd yields a Mössbauer spectrum similar to that of 2[4Fe-4S]+ Fd. The new EPR and Mössbauer spectroscopic features of the 2[4Fe-4Se]+ Fd are attributed to S = 3/2 and S = 7/2 spin states which accompany the classical S = 1/2 state of [4Fe-4X]+ (X = S, Se) structures.

Clostridium↗
PubMed1984

[Castleman's tumor with thoracic localization. Apropos of a case].

Castleman tumor usually presents as a mediastinal tumor which is never accurately diagnosed before surgery. Pathological findings and postoperative course establish the benign nature of this tumor. However, plasmocytic forms with prominent hematologic manifestations may be difficult to distinguish from a malignant lymphoma or thymoma. Differential diagnosis is all the more important that no complementary postoperative treatment is indicated in benign lymphoid tumors.

Adult↗
PubMed1984

Characterization and spectral properties of Proteus mirabilis PR catalase.

Purified catalase from a peroxide-resistant mutant (PR) of Proteus mirabilis displayed great similarities with the bovine liver catalase on the basis of its amino acid composition, content in prosthetic groups, and spectroscopic data. The bacterial enzyme was found to have 2.6 +/- 0.2 mol of protoheme IX per tetramer, with an equivalent amount of titrable iron atoms. The optical absorption of P. mirabilis PR catalase in the presence of various anionic species (cyanide, azide, formate) was examined. The dissociation constant of the formate-enzyme complex was determined as 60 +/- 2 mM at pH 7.5. Inhibition and spectral shifts induced by some thiol compounds were very similar to those reported with mammalian catalase. The electron paramagnetic resonance (EPR) spectra (at 9 GHz and 6 K) of bacterial catalase and its various complexes were reported. Two major different rhombic high-spin ferric signals could be seen in the g = 6 region, using either the pure enzyme or the cell crude extract. The balance between the two rhombic forms was reversibly altered by pH. Various changes in rhombicity were also observed after binding with anionic ligands. The EPR spectrum (at 40 K) of nitrosyl ferrous catalase was very similar to reported data with horse liver catalase.

Amino Acids↗
PubMed1984

[Cimetidine treatment of primary hyperparathyroidism].

Since Sherwood's report in 1979, contradictory findings have been published with regards to the treatment of primary hyperparathyroidism with cimetidine. We studied 16 patients with primary hyperparathyroidism treated with 1,200 mg of Cimetidine and followed-up clinically and biochemically. A decrease in serum calcium and urinary CAMP was observed after the fourth week of cimetidine therapy with no significant change in parathormone levels. In none of the cases did Cimetidine seem to provide a treatment of hyperparathyroidism, a condition which remains curable with surgery.

Calcium↗