Crystallization and preliminary analysis of an 18,000 Mr fragment of duck ovotransferrin.

Crystals of an 18,000 Mr iron-binding fragment of duck ovotransferrin, corresponding to domain II of the N-terminal lobe, have been obtained. The crystals belong to the trigonal system, P31 (or enantiomer) with a = b = 41.3(1) A, c = 81.2(2) A (1 A = 0.1 nm) and one molecule per asymmetric unit assuming a solvent content of 40% by volume. The crystals are stable at +4 degrees C and diffract to at least 2.3 A resolution.

Multimodality imaging in parathyroid carcinoma: A tale of two nodules.

Parathyroid carcinoma is a rare cause of primary hyperparathyroidism. Clinical indicators of carcinoma include the severity of hyperparathyroidism and presence of a palpable neck mass. Definitive diagnosis requires surgical resection and specimen histology, or documentation of metastatic disease. We present a case of parathyroid carcinoma in a young female patient with severe hyperparathyroidism, who was also found to have subclinical hyperthyroidism in the setting of an intercurrent, solitary, functioning thyroid adenoma. A diagnostic approach to parathyroid disease, combining multimodality imaging and clinicopathologic features, is discussed.

1-Methoxy-3-(2-nitro-1-imidazolyl)-2-propanol (misonidazole).

C7H11N3O4, Mr = 201, monoclinic, P2(1)/c, a = 6.997 (1), b = 7.862 (1), c = 17.024 (3) A, beta = 97.06 (2) degrees, U = 929.4 (5) A3, Z = 4, D chi = 1.44 Mg m-3, lambda(Cu K alpha) = 1.5418 A, mu = 0.916 mm-1, F(000) = 424, ambient temperature, R = 0.049 for 1324 unique reflections. All bond lengths and angles have normal values and the planes of the nitro group and imidazole ring form a dihedral angle of 7.9 (1) degrees.

Studies on 1,3-diaryltriazene analogues of berenil: molecules with potential GC base-pair selectivity.

1,3-Bis(4-acetylphenyl)triazene (II): C16H15N3O2, Mr = 281.32, monoclinic, P2(1)/c, a = 14.002 (5), b = 12.359 (3), c = 8.457 (3) A, beta = 96.35 (2) degrees, V = 1454.5 A3, Z = 4, Dx = 1.287 Mg m-3, Cu K alpha, lambda = 1.54178 A, mu = 0.672 mm-1, F(000) = 592, T = 294 K, final R = 0.089 for 1890 unique observed reflections. 1,3-Bis(4-[2-dimethylamino)ethoxycarbonyl]phenyl)triazene monohydrate (III): C22H29N5O4.H2O, Mr = 445.52, triclinic, P1, a = 9.500 (2), b = 11.753 (3), c = 13.328 (2) A, alpha = 62.84 (1), beta = 66.60 (2), gamma = 77.58 (2) degrees, V = 1214.1 A3, Z = 2, Dx = 1.172 Mg m-3, Cu K alpha, lambda = 1.54178 A, mu = 0.640 mm-1, F(000) = 476, T = 294 K, final R = 0.063 for 1100 unique observed reflections. Both crystal structures have extended conformations for the 1,3-diaryltriazene groups, with a cisoid arrangement of phenyl rings. The terminal N--N bonds of each triazene are non-equivalent, and a hydrogen atom has been located in the N==N--NH moiety. Extensive molecular-orbital (MNDO) calculations on the model core 1,3-diphenyltriazene system have confirmed that this geometry is energetically favoured, and have revealed the shape of the energy surface for rotation about the N--NH bond in the triazene linkage.