Biomedical subjects
Publications and source records attributed to C Röhr.
The oxoantimonate K(3)[SbO(4)] crystallizes in the monoclinic space group P2/c with the Na(3)[BiO(4)] structure type. The structure contains chains of [SbO(6)] octahedra connected via common edges. All K and Sb atoms lie on twofold axes, i.e. 0,y,1/4 or 1/2,y,1/4.
The two title trialkaline trioxoantimonates(III), tripotassium trioxoantimonate(III), K(3)[SbO(3)], (I), and tricaesium trioxoantimonate(III), Cs(3)[SbO(3)], (II), crystallize in the cubic Na(3)[AsS(3)] structure type in space group P2(1)3. The structures show discrete Psi-tetrahedral [SbO(3)](3-) anions with C(3v) point-group symmetry. The Sb-O distances are 1.923 (4) A in (I) and 1.928 (2) A in (II), and the O-Sb-O bond angles are 99.5 (2) degrees in (I) and 100.4 (1) degrees in (II).
beta-RbSb crystallizes with the LiAs structure type. As in the alpha phase (NaP type), Sb(-) forms approximate 4(1) helical chains (2(1) crystallographic symmetry), with Sb-Sb distances of 2.838 (1) and 2.862 (1) A. In contrast to the alpha phase, the helices have different chirality.
The antimonide oxide Ba(3)Sb(2)O consists of discrete [Sb(2)](4-) and O(2-) anions, and crystallizes with a new structure type. The Sb-Sb distances are comparable to those known from electron-precise zintl phases and the tetrahedral coordination of the O(2-) anion is also observed in some other Ba-rich metallide oxides.
Stereoselective synthesis of all four stereoisomers of methylated analogues 8 of the kappa-receptor agonist GR-89.696 is presented. Starting with orthogonally protected piperazine derivatives (R,R)-4 and (S,S)-4, the reaction sequence involves oxidation, reductive amination and modification of the piperazine nitrogen protective groups. The configuration of the stereocentre in alpha-position to the pyrrolidine moiety is determined by X-ray structure analysis of (R,S)-8. In receptor-binding studies with the radioligand U-69.593, the stereoisomer with (S)-configuration at both stereogenic centres (S,S)-8 displayed the highest kappa-receptor affinity with a K(i)-value of 0.67 nM.
The crystal structure of Ba(3)(AlO(4))H is isotypic with Ba(3)SiS(5) and contains AlO(4)(5-) and H(-) anions. The hydride and oxide anions are coordinated by six Ba and five Ba/one Al atoms in an octahedral geometry. The hydrogen content was examined by MAS-NMR experiments of the deuterated compound.
BACKGROUND: Food allergens are often accused of causing numerous ailments. This is particularly true for the pediatric population, where the incidence of food allergy is four times as high as in adults. As food challenges may provoke life-threatening reactions, intensive safety measures need to be taken during provocation, and prompt medical intervention may become necessary. METHODS: We retrospectively evaluated 349 oral challenges in 204 children with atopic dermatitis, looking for criteria to help the physician decide which patients need medical intervention. RESULTS: A total of 178 (51%) oral food challenges with the four allergens (cow's milk [CM], hen's egg [HE], wheat, and soy) showed a positive clinical reaction. Of these, 120 (67%) needed medical intervention. In 42 (35%) cases, intervention was parenteral, and oral medication was given in 78 (65%) cases. There was a strong positive correlation (90%) between the level of specific IgE and the need for medical intervention (> or = 17.50 kU/l for CM, wheat, and soy; > or = 3.50 kU/l for HE). Patient history of food allergy was an indicator of the need for medical intervention (P = 0.01). A positive patient history and a high level of specific IgE were significantly (P=0.003) associated with parenteral medication in HE. CONCLUSIONS: Patient history of food allergy is a reliable indicator of the need for medical intervention in the cases of CM, wheat, and soy regardless of the level of specific IgE. With HE, a positive patient history plus a high level of specific IgE significantly indicates the need for parenteral medication. On the basis of our results, we recommend establishing intravenous access in children with a level of specific IgE of > or = 17.50 kU/l (CAP class 4) to CM and wheat, or with specific IgE of > or =3.50 kU/l (CAP class 3) to HE.