Mutations at Pro67 in the RecA protein P-loop motif differentially modify coprotease function and separate coprotease from recombination activities.

The functional significance of residues in the RecA protein P-loop motif was assessed by analyzing 100 unique mutants with single amino acid substitutions in this region. Comparison of the effects on the LexA coprotease and recombination activities shows that Pro67 is unique among these residues because only at this position did we find substitutions that caused differential effects on these functions. One mutant, Pro67-->Trp, displays high constitutive coprotease activity and a moderate inhibitory effect on recombination functions.

Identification of candidate vaccine antigens of bovine hemoparasites Theileria parva and Babesia bovis by use of helper T cell clones.

Current vaccines for bovine hemoparasites utilize live attenuated organisms or virulent organisms administered concurrently with antiparasitic drugs. Although such vaccines can be effective, for most hemoparasites the mechanisms of acquired resistance to challenge infection with heterologous parasite isolates have not been clearly defined. Selection of potentially protective antigens has traditionally made use of antibodies to identify immunodominant proteins.

Functional characterization of residues in the P-loop motif of the RecA protein ATP binding site.

We have introduced a large number of single amino acid substitutions at six positions that lie within the P-loop motif of the ATP binding site in the Escherichia coli RecA protein. The activity of each recA mutant was determined using genetic assays which assess the catalytic proficiency of the RecA protein for both homologous genetic recombination and recombinational repair of damaged DNA. The six residues displayed unique patterns of allowed versus non-allowed substitutions that define the functional and structural constraints at each position.

Tropisetron compared with a metoclopramide-based regimen in the prevention of chemotherapy-induced nausea and vomiting.

This randomised, open, parallel group study compared the antiemetic efficacy and tolerability of tropisetron with metoclopramide plus lorazepam in 102 patients receiving a first course of non-cisplatin-containing chemotherapy. Control of acute vomiting by tropisetron was significantly superior to that of the metoclopramide regimen, with total control (no vomiting) in 45% of 51 patients in the tropisetron group compared with 22% of 51 patients in the metoclopramide group (P = 0.013); total and partial control (< 5 vomits) occurred in 67 and 47% of patients, respectively (P = 0.

Mutagenesis of the P-loop motif in the ATP binding site of the RecA protein from Escherichia coli.

Using a combinatorial cassette mutagenesis procedure we have introduced a number of mutations into 10 codons that define the P-loop motif within the ATP binding site of the Escherichia coli RecA protein. The recombinational proficiency of the recA mutants was determined using three genetic assays: survival in the presence of 4-nitroquinoline-1-oxide, survival following UV irradiation and the ability to support plaque formation by a red-gam-Chi+ lambda phage. While no amino acid substitutions were allowed at the four residues that define the P-loop consensus sequence, a variety of changes at the other positions in this region were observed that allowed full or partial RecA function.

Heterogeneity in cytokine profiles of Babesia bovis-specific bovine CD4+ T cells clones activated in vitro.

The central role of T cells in the immune response against hemoprotozoan parasites, both as helper cells for T cell-dependent antibody production and as effector cells acting on intracellular parasites through the elaboration of cytokines, has prompted an investigation of the bovine cellular immune response against Babesia bovis antigens. CD4+ T helper (Th) cell clones generated from four B. bovis-immune cattle by in vitro stimulation with a soluble or membrane-associated merozoite antigen were characterized for reactivity against various forms of antigen and against different geographical isolates of B.

Electroconvulsive Therapy in Adolescents.

Because of the limited number of case reports on the use of electroconvulsive therapy (ECT) in adolescent psychiatric patients, we retrospectively reviewed the medical records of 20 young patients who underwent ECT. They constituted all the patients View Article and Find Full Text PDF

Bovine helper T cell clones recognize five distinct epitopes on Babesia bovis merozoite antigens.

Helper T cell clones from two Babesia bovis-immune cattle were characterized for use in identification of potentially protective immunogens of B. bovis merozoites. Proliferation assays with 11 CD4+ clones revealed a differential pattern of response to soluble cytosolic antigen, membrane-enriched antigen, detergent extracts of the membrane-enriched antigen, soluble culture supernatant exoantigen, and different geographical isolates of B.

Samarium-153-EDTMP: pharmacokinetic, toxicity and pain response using an escalating dose schedule in treatment of metastatic bone cancer.

Samarium-153 emits medium-energy beta particles and an imageable gamma photon with a physical half-life of 46.3 hr. When chelated to ethylenediaminetetramethylenephosphonic acid (EDTMP), it is remarkably stable in vitro and in vivo.

Babesia bovis: bovine helper T cell lines reactive with soluble and membrane antigens of merozoites.

Babesia bovis-specific T cell lines were established from cattle infected with either tick-derived or cultured parasites by stimulation of peripheral blood mononuclear cells with a crude parasite membrane fraction. Induction and enrichment of CD4+ T cells occurred over time. All cell lines responded vigorously and in a dose-dependent, MHC-restricted manner to intact merozoites, and to soluble and membrane fractions derived from merozoites by homogenization and high-speed centrifugation.

Single photon scatter compensation by photopeak energy distribution analysis.

Scattered photons degrade nuclear medicine image contrast and resolution, and preclude simple attenuation corrections. Current scatter correction methods utilize detected events with energies below pulse height analyzer (PHA) window levels, making attenuation corrections source position dependent. This new scatter rejection technique analyzes only the photon signals occurring within the range of standard PHA windows.

Cell-mediated immune responses to Babesia bovis merozoite antigens in cattle following infection with tick-derived or cultured parasites.

Peripheral blood mononuclear cells from cattle experimentally infected with Babesia bovis were examined for parasite-specific cell-mediated immune responses. Unfractionated merozoites and soluble and membrane fractions derived from merozoites were all antigenic for immune cattle, although the membrane fraction was the most stimulatory. Cattle responded to different antigenic fractions in a differential manner, and only that animal immunized with autologous cultured parasites responded to parasitized erythrocyte culture supernatants.

Feline immunodeficiency virus infects both CD4+ and CD8+ T lymphocytes.

Monoclonal populations of feline T cells, derived from a specific-pathogen-free cat and expressing either the CD4 or CD8 surface antigen, were infected in vitro with two geographically distinct isolates of feline immunodeficiency virus (FIV). Both infected T-cell subsets exhibited decreased cell viability, expressed FIV-encoded proteins, and generated reverse transcriptase activity. All clones examined retained their original surface phenotype after infection.

Titration of human immunodeficiency virus type 1 (HIV-1) and quantitative analysis of virus expression in vitro using liquid RNA-RNA hybridization.

An assay is described for titration of human immunodeficiency virus type 1 (HIV-1) and for quantitative analysis of virus expression in vitro. The assay utilizes a liquid RNA-RNA hybridization method coupled with reversible target capture (RTC) on oligo(dT) derivatized magnetic particles. The assay provides a rapid, specific, and sensitive method for quantitation of HIV-1 RNA molecules present either in cells or in viral particles from cell-free culture media.

Early events of RNA polymerase II transcription initiation.

We have investigated the earliest stages of assembly of an RNA polymerase II transcription complex. General transcription factors from HeLa cells were partially purified and assayed using the adenovirus-2 major late promoter. Preincubation of either all the transcription factors (TF) with the DNA or only the subset consisting of TFIIA, TFIID, and DNA overcame the 15-20 min lag normally observed.

Drug inhibitors of RNA polymerase II transcription.

Transcription by RNA polymerase II occurs after formation of a transcription complex. This complex is assembled in stages by the interaction of transcription factors with the template and/or with each other. We report on the ability of six drugs to inhibit the assembly of the RNA polymerase II transcription complex.

Arterial oxygen desaturation following intravenous injection of midazolam.

The water soluble benzodiazepine derivative, midazolam, is used almost exclusively at our institution to produce sedation for numerous surgical procedures. Mild arterial oxygen desaturation has been reported in patients who have received as little as .04 mg/kg.

Aneurysmectomy prognosticators by equilibrium multi-gated cardiac blood pool scintigraphy.

Non-invasive assessment of left ventricular aneurysm (LVA) resection prognosticators was obtained in 13 multigated cardiac blood pool scintigrams by applying Fourier analysis to identify regions of interest. Results were compared to contrast ventriculograms performed at recent cardiac catheterization. Excellent correlation of the contractile section ejection fraction (CSEF) was found between the two techniques, r = .

Biliary obstruction after cholecystectomy: diagnosis with quantitative cholescintigraphy.

Fifty patients with recurrent post-cholecystectomy pain underwent hepatobiliary scintigraphy. Time-activity curves were generated from regions of interest over the liver, bile duct, duodenum, and bowel. Patients were divided into obstructed and unobstructed groups with endoscopic retrograde cholangiopancreatography criteria.

Effects of antibiotics on RNA polymerase III transcription.

We investigated the effects of six drugs on an RNA polymerase III in vitro transcription system. Adriamycin, daunorubicin, heparin, rifamycin AF/013, streptolydigin, and streptovaricin all inhibit RNA synthesis from a tRNA gene or the adenovirus 2 (AD2) VA1 RNA gene. The completed RNA polymerase III transcription complex is formed by the sequential, ordered addition of protein factors.

Histones H1(0) and H5 share common epitopes with RNA polymerase II.

We report here the cross-reaction of RNA polymerase II antiserum with histones H1(0) and H5 and the complementary cross-reactions of antisera to the globular domain of histone H1(0) (GH1(0)) and histone H5 (GH5) with RNA polymerase II. Immunoblotting of RNA polymerase II antiserum with fragments of histone H1(0) localized the cross-reaction at the junction of the globular and C-terminal domains of histone H1(0). The structural homology implied by these cross-reactions is interesting in light of reports that suggest H1(0) may play a role in differentiation and development.