Stability and electronic spectra of C76N2 isomers.

Study of geometries of 16 possible isomers for C76N2 based on C78(C2v) by intermediate neglect of differential overlap (INDO) series of methods indicated that the most stable geometry 25,78-C76N2 where two nitrogen atoms substitute two apexes C25 and C78 near the shortest X axis and Y axis formed by two hexagons and a pentagon. Electronic structures and spectra of C76N2 were investigated. The reason for the red-shift for absorptions of C76N2 compared with that of C78(C2v) is discussed.

The susceptibility of non-fermentative Gram-negative bacilli to cefperazone and sulbactam compared with other antibacterial agents.

This study was designed to determine the bacterial susceptibility of non-fermentative Gram-negative organisms to various antibacterial agents. Bacterial susceptibility testing used the Kirby-Bauer method and data were assessed according to NCCLS 2000. Cefoperazone/sulbactam (CPER/SU) had good antibacterial activity against Pseudomonas aeruginosa.

[Analysis on the characteristics of histological location of bursin in immune organ of chicken and duck].

The distribution of Bursin in major immune organs such as bursa of Fabricius (BF), thymus (Th), Harderian gland(HG) and spleen(Sp) was investigated and compared in both chicken and duck by immuno-histochemical staining method with anti-Bursin monoclonal antibody (McAb)2F9-4. Its distributions in bone marrow(BM) and embryonic organs including BF, Th, BM, HG in chicken were also determined in addition to locating it in germinal center(GC) of Sp and lymphatic nodules of lymphonode in duck. The results showed clearly that Bursin was generally located in immune organs in both chicken and duck.

Localization of transfected B7-1 (CD80) DNA in human melanoma cells after particle-mediated gene transfer.

The purpose of this study was to evaluate stable DNA transfection of M-21 human melanoma cells with particle-mediated gene transfer (PMGT) with B7-1 cDNA and to identify sites of gene integration. Stable B7-1 transfectants (M-21-B7) were obtained with PMGT using a plasmid vector containing cDNA for both B7-1 and neomycin phosphotransferase, with subsequent selection with G418. The transfected cells were flow sorted by B7-1 expression into two populations, bright and dim.

Preponderant mitotic activity of nonleukemic cells plays an important role in failures to detect abnormal clone in childhood acute lymphoblastic leukemia.

At diagnosis, clonal chromosomal abnormalities are found in the bone marrow blasts in more than two thirds of children with acute lymphoblastic leukemia (ALL). Practically, however, failure to detect these abnormalities is frequent and usually attributed to poor marrow sampling, inadequate metaphases, and/or a preponderant mitotic activity among nonleukemic cells. The authors applied fluorescence in situ hybridization (FISH) techniques to re-examine 30 cases of karyotypically "normal" childhood ALL to explore the role of preponderant mitotic activities of nonleukemic cells in failures to detect clonal abnormalities.

Macrocalyxin I.

The title compound, 2-[1,2,3,4,4a,4b,5,6,7,8,8a,9-dodecahydro-7-hydroxy-4b,8,8-trimethylphenanthren-2-yl]propenoic acid, C20H30O3, is a naturally occurring diterpenoid which was isolated from Rabdosia macrocalyx. The hydroxy and carboxy groups, which are located at the two ends of the molecule, both serve as simultaneous hydrogen-bond donors and acceptors. Two intermolecular O-H.