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Summary Transplantation of T- and B-cell depleted allografts from haploidentical family donors was evaluated within a prospective phase II trial in children with acute lymphoblastic leukaemia, acute myeloid leukaemia and advanced myelodysplastic syndrome (n = 46). 20 patients had active disease; 19 patients received a second or third stem cell transplantation (SCT). Toxicity-reduced conditioning regimens consisted of fludarabine or clofarabine (in active disease only), thiotepa, melphalan and serotherapy. Graft manipulation was carried out with immunomagnetic microbeads. Primary engraftment occurred in 88%, with a median time to reach >1·0 × 109/l leucocytes, >20 × 109/l platelets and >0·1 × 109/l T-cells of 10, 11 and 50 days, respectively. After retransplantation, engraftment occurred in 100%. Acute graft-versus-host disease (GvHD) grade II and III-IV occurred in 20% and 7%, chronic GvHD occurred in 21%. Both conditioning regimens had comparable toxicity. Transplant-related mortality (TRM) was 8% at one year and 20% at 5 years. Event-free survival at 3 years was: 25% (whole group), 46% (first, second or third complete remission [CR], first SCT) vs. 8% (active disease, first SCT) and 20% (second or third SCT, any disease status). This approach allows first or subsequent haploidentical SCTs to be performed with low TRM. Patients in CR may benefit from SCT, whereas the results in patients with active disease were poor.

Cell surface glycosylation has important regulatory functions in the maturation, activation, and homeostasis of lymphocytes. The family of human sialic acid-binding immunoglobulin-like lectins (siglecs) comprises inhibitory as well as activating receptors intimately involved in the regulation of immune responses. Analyses of the interaction between siglecs and glycans are hampered by the low affinity of this interaction. Therefore, we expressed siglec-7 in eukaryotic cells, allowing for glycosylation, and oligomerized the protein in analogy to MHC tetramers. Using this tool, flow cytometric analysis of lymphocytes became possible. Sialic acid-dependent binding of siglec-7 tetramers was confirmed by glycan array analysis and loss of siglec tetramer binding after neuraminidase treatment of lymphocytes. In contrast to most lymphocyte subpopulations, which showed high siglec-7 ligand expression, B-cell subpopulations could be further subdivided according to different siglec-7 ligand expression levels. We also analyzed blasts from acute lymphoblastic leukemias of the B-cell lineage as well as the T-cell lineage, since malignant transformation is often associated with aberrant cell surface glycosylation. While pediatric T-ALL blasts highly expressed siglec-7 ligands, siglec-7 ligands were barely detectable on cALL blasts. Taken together, oligomerization of recombinant soluble siglec-7 enabled flow cytometric identification of physiologic lymphocyte subpopulations and malignant blasts.

The impact of human leucocyte antigen (HLA) class I expression intensity and killer-cell immunoglobulin-like receptor (KIR)-mismatch was investigated on natural killer (NK)-cell mediated lysis of B-lineage leukaemic blasts from 21 paediatric patients in vitro. Blast susceptibility to standardised NK-activity and HLA-expression differed widely. A clear association between HLA-molecules/cell (range 442 000-13 000) and specific lysis (mean 59%, range 13-98%) was observed (r(2) = 0.68). A compound model incorporating HLA-expression and KIR-ligand-mismatch provided an even stronger association (r(2) = 0.87), whereas KIR-ligand-mismatch alone was not significant. Assessment of these factors might identify patients who could benefit from NK-mediated graft-versus-leukaemia effects after mismatched stem cell transplantation.

Starting from tris(benzothiazol-2-yl)phosphane (1) an advanced Janus-head ligand, di(benzothiazol-2-yl)phosphane (2), was synthesised and structurally characterised. The heteroaryl substituents of this ligand provide both hard and soft donor sites. Surprisingly, the phosphorus atom in 2 is divalent and the hydrogen atom is directly bonded to one ring nitrogen atom and hydrogen bonded to the second. Compound 2 decomposes in any common solvent other than diethyl ether and a new preparation to improve the yields of 2 is presented. A coordination polymer, [{Cs(bth)(2)P}8] (3) (bth=benzothiazol-2-yl), was obtained when the sec-phosphane 2 was allowed to react with elemental caesium in a 1:1 ratio in diethyl ether at -78 degrees C. In 3 each anion is coordinated to four caesium cations and vice versa. The central phosphorus atom is coordinated to two metal atoms above and below the mean plane of the anion in positions in which the two lone pairs of a four-electron donor are anticipated. Two additional cations micro-bridge both ring nitrogen atoms. Hence both faces of the Janus-head ligand are coordinated to the same number of metal cations but in a different way.

Allogeneic stem cell transplantation is for a number of patients with malignant and nonmalignant diseases the only curative approach. For those patients who do not have an HLA-identical-related or -unrelated stem cell donor, a related three-loci mismatch haploidentical stem cell transplantation with T cell-depleted stem cells is a viable option. T cell depletion either by CD34(+) positive selection or by CD3-negative depletion strategies is available and has been investigated. We have shown that reduced-intensity conditioning haploidentical transplantation using mobilized peripheral stem cells negatively depleted from T and B lymphocytes is associated with a rapid immune reconstitution, a low transplant-related mortality rate, and a favorable outcome in patients in remission at the time of transplant. For chemorefractory patients, additional posttransplant cellular and humoral immunotherapeutic strategies are needed for prevention of relapse after transplantation.

Summary A recombinant bispecific single-chain fragment variable antibody (bsscFv), directed against the B-cell antigen CD19 and the low affinity Fc-receptor FcγRIII (CD16), was designed for use in the treatment of patients with leukaemias and lymphomas. The Fc-portions of whole antibodies were deliberately eliminated in this construct to avoid undesired effector functions. A stabilised bsscFv, ds[CD19 × CD16], was generated, in which disulphide bonds bridging the respective variable light (VL) and variable heavy (VH) chains were introduced into both component single-chain (sc)Fvs. After production in 293T cells and chromatographic purification, ds[CD19 × CD16] specifically and simultaneously bound both antigens. The serum stability of ds[CD19 × CD16] was increased more than threefold when compared with the unstabilised counterpart, while other biological properties were not affected by these mutations. In antibody-dependent cellular cytotoxicity experiments, ds[CD19 × CD16] mediated specific lysis of both CD19-positive malignant human B-lymphoid cell lines and primary tumour cells from patients with B-cell chronic lymphocytic leukaemia or B-cell acute lymphoblastic leukaemia. Natural killer cells, mononuclear cells (MNCs) from healthy donors and, in some instances, MNCs isolated from patients after allogeneic stem cell transplantation, were used as effectors. Thus, ds[CD19 × CD16] holds promise for the treatment of CD19+ B-lineage malignancies.

The (2-Py)2N ligand shows much more conformational freedom than the (2-Py)2P anion in aluminium coordination. The two isomers [Al{(NPy)Py}3] (1a) and [Al{(NPy)Py}2(Py2N)] (1b) were isolated, the former containing exclusively cistrans ligands, and the latter cis-trans ligands together with a trans-trans ligand. The energy differences in the noncoordinated anions (2-Py)2E (E = N, P) were determined by computational methods to be low in the amide. While the N Al

The bis(η3-2-methallyl)ruthenium(II) complexes [Ru(η3-2-MeC3H4)2(κ2-Ph2PCH2CH2PR2)] [R = iPr (2), Cy (3)] were prepared from the cycloocta-1,5-diene derivative [Ru(η3-2-MeC3H4)2(η4-C8H12)] (1) and the unsymmetrical 1,2-bis(phosphanyl)ethanes Ph2PCH2CH2PR2. The As,P analogue [Ru(η3-2-MeC3H4)2(κ2-Ph2PCH2CH2AstBu2)] (4) was obtained by the same route. The reaction of 2 with hexafluoroacetylacetone afforded the chelate compound [Ru(κ2-[F6]acac)2(κ2-iPr2PCH2CH2PPh2)], whereas treatment of 2 and 3 with pentachlorophenol gave the related, more labile complexes [Ru(κ2-O,Cl-OC6Cl5)2(κ2-R2PCH2CH2PPh2)] [R = iPr (6), Cy (7)]. Preparation of the parent bis(acac) compound [Ru(κ2-acac)2(κ2-iPr2PCH2CH2PPh2)] (8), which could not be obtained from 2 and acacH, was achieved by ligand exchange of 6 and acetylacetone. The molecular structures of 2 and 6 were determined by X-ray crystallography.

Trimethylsilyliminotriphenylphosphoran Ph3P=NSiMe3 (1) reagiert mit metallischem Natrium in THF unter Spaltung einer P–CPhenyl-Bindung zu Natriumdiphenylphosphanyltrimethylsilylamid [(THF)3Na(Ph2PNSiMe3)] (2). Anschliesende Reaktion mit Ammoniumbromid oder Hydrolyse mit Wasser ergibt Diphenylphosphanyltrimethylsilylamin Ph2PN(H)SiMe3 (3) und bei der Hydrolyse mit Wasser in geringen Mengen das oxidierte Nebenprodukt [(THF)Na(OOPPh2)]n (4), das gezielt durch die Reaktion von Ph2POOH mit NaH in THF erhalten werden kann. Ph2PN(H)SiMe3 (3) reagiert mit einem Aquivalent Zn{N(SiMe3)2}2 zu [(Me3Si)2NZnPh2PNSiMe3]2 (5). Mit Caesium reagiert 3 unter Phosphor-Phosphor-Bindungsknupfung in einer reduktiven Substituentenkopplungsreaktion zu [(THF)Cs2{Ph(NSiMe3)P}2]n (6). Phosphor(III) wird dabei zu Phosphor(II) reduziert. Phosphor-Phosphor-Bindungsknupfung unter Oxidation der Phosphoratome von PIII zu PIV erfolgt bei der Darstellung von (Ph2PNSiMe3)2 (7) durch Lithiierung von 3 und anschliesender Umsetzung mit Bismuttrichlorid. Synthesis and Reactivity of the Diphenylphosphanyltrimethylsilylamine Ph2PN(H)SiMe3 The trimethylsilyliminotriphenylphosphoran Ph3P=NSiMe3 (1) reacts with sodium in THF under cleavage of one P–Cphenyl bond leading to the PIII-species [(THF)3Na(Ph2PNSiMe3)] (2). Reaction with NH4Br or hydrolysis with water gives the diphenylphosphanyltrimethylsilylamine Ph2PN(H)SiMe3 (3) and in low yields the oxidized byproduct [(THF)Na(OOPPh2)]n (4) that can be synthesised directly in high yields in the reaction of Ph2POOH and NaH in THF. 3 was reacted with an equimolar amount of Zn{N(SiMe3)2}2 to give [(Me3Si)2NZnPh2PNSiMe3]2 (5). 3 reacts with caesium under phosphorus-phosphorus bond formation in a reductive substituent coupling reaction to give [(THF)Cs2{Ph(NSiMe3)P}2]n (6) where phosphorus(III) is reduced to phosphorus(II). Phosphorus-phosphorus bond formation to give (Ph2PNSiMe3)2 (7) where the phosphorus(III) centres are oxidized to PIV is observed in the reaction of 3 with n-BuLi and bismuthtrichloride.

Eine Eintopfsynthese mit hohen Ausbeuten liefert unsymmetrisch substituierte 1,2-Bis(phosphanyl)ethane 2 und 1-Arsanyl-2-phosphanylethane 3 ausgehend vom cyclischen Sulfat 1. Auf analoge Weise konnen auch chirale 1,2-Bis(phosphanyl)ethane und 1,3-Bis(phosphanyl)propane enantiomerenrein hergestellt werden. R, R′=Alkyl, Phenyl.

Polymer dispersions, even in very low concentrations, can improve the performance of cholesteric liquid crystal materials necessary for their application in flat panel displays. Normal scattering mode, reverse scattering mode and reflective mode cholesteric liquid crystal materials are described. The roll of the polymer in each of these display modes is reviewed as are the unique electro-optic characteristics of the dispersions.

A one-pot reaction affords unsymmetrical 1,2-bis(phosphanyl)ethanes 2 and 1,2-arsanyl(phosphanyl)ethanes 3 from the cyclic sulfate 1 in high yield. Similarly, chiral 1,2-bis(phosphanyl)ethanes and 1,3-bis(phosphanyl)propanes could be obtained in enantiomerically pure form. R, R′=alkyl, phenyl.

A one-pot reaction affords unsymmetrical 1,2-bis(phosphanyl)ethanes 2 and 1,2-arsanyl(phosphanyl)ethanes 3 from the cyclic sulfate 1 in high yield. Similarly, chiral 1,2-bis(phosphanyl)ethanes and 1,3-bis(phosphanyl)propanes could be obtained in enantiomerically pure form. R, R′=alkyl, phenyl.

The reaction of 9-N,N-dimethylaminomethylanthracene 1 with aromatic carboxylic acids gave crystalline salts (2a, 2b, 3a and 3b), which were irradiated in the solid state. Whereas salt 3a was selectively transformed to the dimer 4a, the other salts were photoinert. The results were rationalized on the basis of X-ray structure analysis. In the presence of oxygen, solid-state irrradiation of anthracene salt 3b leads to selective photooxygenation. The selectivity of both solid-state photoreactions was not observed in solution.