Surgical resolution of uterine prolapse in three pet rabbits.

This report describes a surgical technique for resolution of uterine prolapse in rabbits. Three pet rabbits presented within 24 hours of parturition with a red mass protruding from the vagina, which was diagnosed as uterine prolapse. In the first case, an attempt to reduce the prolapse by manual compression was ineffective. A laparotomy was used to apply internal uterine traction while simultaneously using gentle external pressure with cotton-tip applicators and resulted in successful resolution. After repositioning, an ovariohysterovaginectomy was performed in all three rabbits. All rabbits recovered uneventfully. Laparotomic repositioning of the uterus and ovariohysterovaginectomy, not previously described in rabbits, was easy to perform and permitted resolution of uterine prolapse.

All-Order Amplitudes at any Multiplicity in the Multi-Regge Limit.

We propose an all-loop expression for scattering amplitudes in planar N=4 super Yang-Mills theory in multi-Regge kinematics valid for all multiplicities, all helicity configurations, and arbitrary logarithmic accuracy. Our expression is arrived at from comparing explicit perturbative results with general expectations from the integrable structure of a closely related collinear limit. A crucial ingredient of the analysis is an all-order extension for the central emission vertex that we recently computed at next-to-leading logarithmic accuracy. As an application, we use our all-order formula to prove that all amplitudes in this theory in multi-Regge kinematics are single-valued multiple polylogarithms of uniform transcendental weight.

Production of a Higgs boson accompanied by two jets via gluon fusion.

Real-emission corrections to gg-->H, which lead to H+2 jet events, are calculated at order alpha(4)(s). Contributions include top-quark triangles, boxes, and pentagon diagrams and are evaluated analytically for arbitrary top mass m(t). This new source of H+2 jet events is compared to the weak-boson fusion cross section for a range of Higgs boson masses. The heavy top-mass approximation appears to work well for intermediate Higgs-boson masses, provided that the transverse momenta of the final-state partons are smaller than the top-quark mass.

X-ray structures of aza-proline-containing peptides.

The aza-analogue of proline (AzPro) contains a nitrogen atom in place of the CH alpha of the cognate residue. The resolution of the crystal structures of seven AzPro-containing peptides, presenting a set of ten AzPro motifs, reveals the structural properties of this particular aza-residue. Because of sterical hindrances, both nitrogen atoms are out of planarity, and the reduced electronic conjugation in the two AzPro-adjacent amide groups probably explains the longer amide bond distances and the weak proton-accepting character of the two pyrazolidine nitrogens. The absolute configuration of both AzPro nitrogens depends on the chemical nature of the sequence. In all cases, the AzPro residue assumes the same intrinsic three-dimensional structure and presents folding tendencies opposed to those induced by proline.

Conformational studies of heterochiral peptides with diastereoisomeric residues: crystal and molecular structures of linear dipeptides derived from leucine, isoleucine, and allo-isoleucine.

The x-ray diffraction analyses of three N- and C-terminally blocked L,D dipeptides, namely t-Boc-D-Leu-L-Leu-OMe (1), t-Boc-L-Ile-D-aIle-OMe (2), and t-Boc-D-aIle-L-Ile-OMe (3) containing enantiomeric or diastereomeric amino acid residues have been carried out. The structures were determined by direct methods and refined anisotropically to final Rf actors of 0.077, 0.058, and 0.072 for (1), (2), and (3), respectively. Peptides 1-3 all assume a similar U-shaped structure with phi and psi torsion angles corresponding to one of the possible calculated minimum energy regions (regions E and G for L residues, and F*, D* and H* for D residues). The peptide backbones of 1-3 are almost superimposable [provided that the appropriate inversion of the chiral centers of (2) is made]. Side-chain conformations of Leu residues in peptide (1) are g- (tg-) for the L-Leu residue and the mirrored g+ (tg+) for the D-Leu residue; however, in peptides (2) and (3) the conformations of the isoconfigurational side chains of the Ile or allo-Ile residues are (g-t) t and (tg+) t for the L-Ile and the D-allo-Ile moieties, respectively. In all cases, these conformations correspond to the more populated conformers of beta-branched residues statistically found in crystal structures of small peptides. The results seem to indicate that, at least in short peptides with enantiomeric or diastereoisomeric residues, the change in chirality in the main-chain atoms perturbs the backbone conformation to a lesser extent and the side chain conformation to a greater extent.

The polypeptide 3(10)-helix as a template for molecular recognition studies. Structural characterization of a side-chain functionalized octapeptide.

A N alpha-blocked, Aib-rich octapeptide methylamide containing two N omega-benzoylated L-Lys residues at positions 3 and 6 was synthesized by solution methods and fully characterized. A solution and crystal-state conformational analysis, performed by using FT-IR, 1H NMR, CD, and X-ray diffraction techniques, showed that the peptide is folded into a regular, right-handed 3(10)-helix stabilized by seven consecutive N-H...O=C intramolecular H-bonds of the beta-turn III type. The two benzamidobutyl L-Lys side chains, located on the same side of the helix after one complete turn, generate a cleft the minimal width of which was found to be 3.47 A.

Conformation and structure of linear peptides with regularly alternating L- and D-residues: structure of the blocked hexapeptide tert-butyloxycarbonyl-(D-alloisoleucyl-L-isoleucyl)3 methyl ester monohydrate.

Peptides with a regular sequence of enantiomeric residues (L and D) along the chain have received considerable attention because of their accessibility to unique conformations and because they are model compounds for the naturally occurring peptide gramicidin A, which shows monovalent cation selective transmembrane transport. The solid-state structure of the linear hexapeptide t-Boc-(D-alle-L-Ile)3-OMe has been determined by X-ray diffraction techniques and refined to a final R factor of 0.068. The molecule shows a bent U-shaped conformation stabilized by three intramolecular H-bonds of the N-H...O = C type: a type II beta-bend (4-->1 bend or C10 ring structure) with L-Ile2 and D-aIle3 at positions 2 and 3 of the bend, an alpha-turn (5-->1 bend or C13 ring structure) and a 1-->5 bend or C17 ring structure. The first two 10-membered and 13-membered bends are enclosed in the latter 17-membered hydrogen-bonded ring structure. This structural motif is common to hepta- and octa-peptide cyclic molecules, showing that ring closure is not required to achieve a particular topology in the molecular design of specific bended conformations.

T-cell lymphoblastic lymphoma with eosinophilia associated with subsequent myeloid malignancy.

Three patients with T-cell lymphoblastic lymphoma and peripheral blood eosinophilia are reported. At the time of diagnosis, all patients had lymphadenopathy, and one had a mediastinal mass. Lymph node biopsies revealed lymphoblastic lymphoma admixed with a variable number of mature eosinophils. Immunophenotypic studies demonstrated that each lymphoma had an immature T-cell immunophenotype. Bone marrow biopsies were hypercellular with myeloid hyperplasia and eosinophilia but were negative for lymphoma. All patients received multiagent chemotherapy; one patient achieved a complete remission, and two patients had partial remissions. All patients subsequently developed a myeloid malignancy. Two died of acute myeloid leukemia within 18 months of the diagnosis of lymphoblastic lymphoma. The third patient relapsed with a lymphoma that had histologic and immunophenotypic features of both T-cell lymphoblastic lymphoma and granulocytic sarcoma and also developed a poorly defined myeloproliferative disorder. These findings suggest that T-cell lymphoblastic lymphoma associated with eosinophilia may represent a distinct clinico-pathologic entity with a high risk of subsequent myeloid neoplasia.

Vincristine, prednisone and L-asparaginase in the induction of remission in children with acute lymphoblastic leukemia following relapse.

Two hundred and twenty-seven children with recurrent acute lymphoblastic leukemia were treated with various combinations of vincristine, prednisone, cyclophosphamide and L-asparaginase in an approach to the induction of remission. The combination of L-asparaginase 1,000 mu/kg iv q.d. x 10, vincristine 2.0 mg/m2iv q.w. x 4 and prednisone 40 mg/m2 p.o.q.d. x 28 days was found to be highly effective. The incidence of remission was 73%. No significant improvement was achieved when cyclophosphamide was added to this regimen. Various combinations of cytosine arabinoside, cyclophosphamide, vincristine, prednisone, BCNU or CCNU failed to maintain remission duration for more than two or three months. Neither BCNU nor CCNU prevented the development of CNS leukemia.