BioClin (Ireland)

Abstract The mainstream magnetic iron oxide particles used as contrast media for magnetic resonance (MR) imaging are composed of a magnetic iron oxide core surrounded by a dextran or carboxydextran coat. The core size ranges from 2 nm to less than 10 nm, and the hydrodynamic diameter ranges from 20 nm to about 120 nm. The coat prevents aggregation and sedimentation of the particles in aqueous solutions, achieves high biological tolerance, and prevents toxic side effects.Two kinds of particles are considered: (i) large particles (>30 nm), called superparamagnetic iron oxide particles (SPIOs) for liver imaging; (ii) smaller particles (<30 nm hydrodynamic diameter), called ultrasmall SPIOs (USPIOs), e.g. for MR angiography.To characterize the particles, Mössbauer spectra are presented for the two particle ensembles. These spectra allow insight into the magnetic coupling, the valency of the iron ions and a rough estimate of the core size to be deduced. On the basis of the concentration dependence of the MR signal intensities, two applications are discussed together with two representative clinical examples.Future indications for MR diagnostics, e.g. the labeling and tracking of stem cells during stem‐cell therapy control, are outlined. Copyright © 2004 John Wiley & Sons, Ltd.

大豆オリゴ糖を発酵原料とした食酢のラット脂質代謝に及ぼす影響について, コレステロール・胆汁酸無添加飼料に粉末化した大豆オリゴ糖酢 (SOV) を添加して検討し, 以下の結果を得た。1) SOV 15%添加飼料中の含有オリゴ糖成分は約3.3%で, そのうち約64%がマンニノトリオースであった。2) SOV摂取により血清総コレステロールが低下傾向を示し, 血清中のVLDL-+LDL-Chol (=T-Chol-HDL-Chol) ならびにトリアシルグリセロール値は有意に低値であった。3) SOV摂取により肝臓コレステロール含量は有意な低下を示したが, 糞中総胆汁酸量には影響が認められなかった。4) SOV摂取により盲腸内容物中の総短鎖脂肪酸量は有意に高値を示した。5) 肝臓コレステロール含量と5週目の血清中のVLDL-+LDL-Chol値には有意な相関が得られたが, 盲腸内容物中の総短鎖脂肪酸量と肝臓コレステロール含量ならびに血清中のVLDL-+LDL-Chol値に対する相関性は傾向のみで有意な差は認められなかった。

Blood donors reactive by enzyme-linked immunosorbent assay for antibody to the human immunodeficiency virus (HIV) who showed atypical patterns of viral core protein reactivity on Western blot were monitored for several months. Characterization of their antibodies was performed by 1) use of recombinant HIV proteins; 2) determination of cross-reactivity to HTLV-I, HTLV-II, and HTLV-IV: 3) assessment of immune status; and 4) identification of potentially interfering autoantibodies. Nineteen of 20 donors maintained the same HIV antibody reactivity throughout the follow-up period; the other donor became fully antibody-positive. Eighteen of 20 donors' sera showed clear reactivity with HIV recombinant core proteins. Ten of 19 donor samples demonstrated cross-reactivity to HTLV-IV; 3 of these 10 also cross-reacted with HTLV-I. The immune status of all donors was normal, although the medical histories and HLA antibody screens suggested possible autoimmune reactivity in 9 of 18 donors. During follow-up interviews, three donors reported possible risk factors for HIV infection that had not been acknowledged at the time of blood donation. We conclude that exclusion of donors with these atypical serologic test results is warranted while further studies to determine significance are being conducted.

In order to study the correlation of in vivo tumor transplantation immunity and in vitro immunologic assays, cell-mediated cytotoxicity against SV40-transformed cells was studied in AL/N strain mice by using 51Cr-release assay. Killing of SV40-transformed AL/N fibroblast cells was observed by spleen cells of AL/N mice immunized with syngeneic SV40-transformed cells. Immunization with the solubilized SV40 tumor-specific transplantation antigen (TSTA) that induced transplantation immunity in vivo did not elicit cytotoxic spleen cells in vitro. However, the spleen cells from mice immunized with solubilized TSTA and then sensitized in vitro with SV40-transformed cells became cytotoxic against SV40-transformed fibroblasts. Similarly, SV40 TSTA (T antigen) purified by immunoprecipitation was able to prime the lymphocytes in AL/N mice: the primed lymphocytes could differentiate into cytotoxic lymphocytes upon in vitro stimulation by SV40-transformed cells. These data indicate that SV40 TSTA (T antigen) plays a role in the induction of cytotoxic lymphocytes.

The synthesis of 3β,14β,19-oxygenated and of 3β,19-oxygenated-14-dehydro cardenolides from the bulk steroid pregnenolone acetate 1a is reported. The 19-oxygenated cardenolides which have been prepared include coroglaucigenin esters 4e and 4f and corotoxigenin acetate 4g. Coroglaucigenin and corotoxigenin occur in nature as glycosides in a number of plant species. In the synthetic scheme developed, successive transformations of the 3β-acetoxy-10β-methyl-5-ene moiety of 1a afford 19-hydroxy- or acyloxy-14-enes via 19-hydroxy-8(14)-enes and 8,19-oxido-14-enes.