THE ELECTRONIC SPECTRUM AND MOLECULAR GEOMETRY OF THE JET-COOLED STIBINO (SbH2) FREE RADICAL

The jet-cooled stibino (SbH$_{2}$) free radical has been detected for the first time. This highly reactive species was produced in an electric discharge through a precursor mixture of stibine (SbH$_{3}$) diluted in high pressure argon. Stibine was synthesized by the low-temperature reduction of SbCl$_{3}$ with LiAlH$_{4}$ and stored and handled at -85 $^{o}$C to avoid decomposition. Low-resolution LIF scans revealed a single band of SbH$_{2}$ with complex rotational structure in the 514.9 - 511.0 nm region. We find that the fluorescence lifetimes of the rotational transitions in this band are very short, of the order of 50-75 ns, suggesting an upper state dissociative process. The spectrum is assigned to the \~{A}$^{2}$A$_{1}$ - \~{X}$^{2}$B$_{1}$ electronic transition by analogy with the known spectra of NH$_{2}$, PH$_{2}$ and AsH$_{2}$ and in accord with a recent high level \textit{ab initio} study. Emission spectra obtained after laser excitation of single rotational lines in the 0-0 band show a ground state bending frequency of approx. 820 \wn , consistent with theoretical predictions. The rotationally resolved spectrum of the 0-0 band, which spans some 150 \wn , was recorded at a resolution of 0.08 \wn and analyzed in detail. The spectrum is complicated by large spin splittings and Sb hyperfine effects. The molecular constants were used to determine the geometry of SbH$_{2}$ in both states

A Case of 48, XYY, +21

A 3 month-old boy with a karyotype of 48, XYY, + 21 is reported. The patient had the typical features of Down syndrome and normal male genitalia. Analysis of Q- and R-banded chromosome heteromorphisms of the patient and the parents showed that two of the three chromosomes 21 in the patient originated as a result of failure of the paternal second meiotic division. Therefore both additional chromosomes in the patient resulted from nondisjunction at paternal meiosis II

Recruitment of CD16+ monocytes into synovial tissues is mediated by fractalkine and CX3CR1 in rheumatoid arthritis patients

CD16+ monocytes, identified as a minor population of monocytes in human peripheral blood, have been implicated in several inflammatory diseases, including rheumatoid arthritis (RA). Fractalkine (FKN, CX3CL1), a member of the CX3 C subfamily, is induced by pro-inflammatory cytokines, while a receptor for FKN, CX3CR1, is capable of mediating both leukocyte migration and firm adhesion. Here, we investigated the role of FKN and CX3CR1 in activation of CD16+ monocytes and their recruitment into synovial tissues in RA patients. High levels of soluble FKN were detected in the synovial fluid and sera of RA patients. Circulating CD16+ monocytes showed a higher level of CX3CR1 expression than CD16- monocytes in both RA patients and healthy subjects. High level expression of CX3CR1 was also seen in CD16+ monocytes localized to the lining layer in RA synovial tissue. In the in vitro culture experiments, IL-10 induced CX3CR1 expression on the surface of monocytes, and TNFalpha induced membrane-bound FKN as well as soluble FKN expression in synovial fibroblasts. Moreover, soluble FKN was capable of inducing IL-1beta and IL-6 by activated monocytes. These results suggest that FKN might preferentially mediate migration and recruitment of CD16+ monocytes, and might contribute to synovial tissue inflammation.</p

Induction of tumour necrosis factor receptor-expressing macrophages by interleukin-10 and macrophage colony-stimulating factor in rheumatoid arthritis

Despite its potent ability to inhibit proinflammatory cytokine synthesis, interleukin (IL)-10 has a marginal clinical effect in rheumatoid arthritis (RA) patients. Recent evidence suggests that IL-10 induces monocyte/macrophage maturation in cooperation with macrophage-colony stimulating factor (M-CSF). In the present study, we found that the inducible subunit of the IL-10 receptor (IL-10R), type 1 IL-10R (IL-10R1), was expressed at higher levels on monocytes in RA than in healthy controls, in association with disease activity, while their expression of both type 1 and 2 tumour necrosis factor receptors (TNFR1/2) was not increased. The expression of IL-10R1 but not IL-10R2 was augmented on monocytes cultured in the presence of RA synovial tissue (ST) cell culture supernatants. Cell surface expression of TNFR1/2 expression on monocytes was induced by IL-10, and more efficiently in combination with M-CSF. Two-color immunofluorescence labeling of RA ST samples showed an intensive coexpression of IL-10R1, TNFR1/2, and M-CSF receptor in CD68(+ )lining macrophages. Adhered monocytes, after 3-day preincubation with IL-10 and M-CSF, could produce more IL-1β and IL-6 in response to TNF-α in the presence of dibutyryl cAMP, as compared with the cells preincubated with or without IL-10 or M-CSF alone. Microarray analysis of gene expression revealed that IL-10 activated various genes essential for macrophage functions, including other members of the TNFR superfamily, receptors for chemokines and growth factors, Toll-like receptors, and TNFR-associated signaling molecules. These results suggest that IL-10 may contribute to the inflammatory process by facilitating monocyte differentiation into TNF-α-responsive macrophages in the presence of M-CSF in RA

Resonance-enhanced multiphoton ionization spectroscopy oflaser-ablated copper atoms

Resonance-enhanced multiphoton ionization (REMPI) spectra of laser-ablated copper atoms entrainedin a supersonic free jet expansion are reported. Depending on the ionization scheme employed, andthe conditions under which the copper atoms are produced, very different spectra are produced, whichare discussed. In some circumstances, high proportions of metastable atoms survive the ablation andexpansion process and are clearly seen in the spectra. The spectroscopic transitions for the observedlines are identified, and it is noted that some caution is merited in the assumption that only ground statecopper atoms are present following laser ablation