Effect of the piperazine unit and metal-binding site position on the solubility and anti-proliferative activity of ruthenium(II)- and osmium(II)- arene complexes of isomeric indolo[3,2-c]quinoline-piperazine hybrids.

In this study, the indoloquinoline backbone and piperazine were combined to prepare indoloquinoline-piperazine hybrids and their ruthenium- and osmium-arene complexes in an effort to generate novel antitumor agents with improved aqueous solubility. In addition, the position of the metal-binding unit was varied, and the effect of these structural alterations on the aqueous solubility and antiproliferative activity of their ruthenium- and osmium-arene complexes was studied. The indoloquinoline-piperazine hybrids L(1-3) were prepared in situ and isolated as six ruthenium and osmium complexes [(η(6)-p-cymene)M(L(1-3))Cl]Cl, where L(1) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-2-N-amine, M = Ru ([1a]Cl), Os ([1b]Cl), L(2) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-4-N-amine, M = Ru ([2a]Cl), Os ([2b]Cl), L(3) = 6-(4-methylpiperazin-1-yl)-N-(pyridin-2-yl-methylene)-11H-indolo[3,2-c]quinolin-8-N-amine, M = Ru ([3a]Cl), Os ([3b]Cl). The compounds were characterized by elemental analysis, one- and two-dimensional NMR spectroscopy, ESI mass spectrometry, IR and UV-vis spectroscopy, and single-crystal X-ray diffraction. The antiproliferative activity of the isomeric ruthenium and osmium complexes [1a,b]Cl-[3a,b]Cl was examined in vitro and showed the importance of the position of the metal-binding site for their cytotoxicity. Those complexes containing the metal-binding site located at the position 4 of the indoloquinoline scaffold ([2a]Cl and [2b]Cl) demonstrated the most potent antiproliferative activity. The results provide important insight into the structure-activity relationships of ruthenium- and osmium-arene complexes with indoloquinoline-piperazine hybrid ligands. These studies can be further utilized for the design and development of more potent chemotherapeutic agents.

Localization pattern of conjugation machinery in a Gram-positive bacterium.

Conjugation is an efficient way for transfer of genetic information between bacteria, even between highly diverged species, and a major cause for the spreading of resistance genes. We have investigated the subcellular localization of several conserved conjugation proteins carried on plasmid pLS20 found in Bacillus subtilis. We show that VirB1, VirB4, VirB11, VirD2, and VirD4 homologs assemble at a single cell pole, but also at other sites along the cell membrane, in cells during the lag phase of growth. Bimolecular fluorescence complementation analyses showed that VirB4 and VirD4 interact at the cell pole and, less frequently, at other sites along the membrane. VirB1 and VirB11 also colocalized at the cell pole. Total internal reflection fluorescence microscopy showed that pLS20 is largely membrane associated and is frequently found at the cell pole, indicating that transfer takes place at the pole, which is a preferred site for the assembly of the active conjugation apparatus, but not the sole site. VirD2, VirB4, and VirD4 started to localize to the pole or the membrane in stationary-phase cells, and VirB1 and VirB11 were observed as foci in cells resuspended in fresh medium but no longer in cells that had entered exponential growth, although at least VirB4 was still expressed. These data reveal an unusual assembly/disassembly timing for the pLS20 conjugation machinery and suggest that specific localization of conjugation proteins in lag-phase cells and delocalization during growth are the reasons why pLS20 conjugation occurs only during early exponential phase.

Olanzapine versus placebo in adolescents with schizophrenia: a 6-week, randomized, double-blind, placebo-controlled trial.

OBJECTIVE: To assess olanzapine's efficacy and tolerability in adolescents with schizophrenia. METHOD: One hundred seven inpatient and outpatient adolescents (olanzapine, n = 72, mean age 16.1 years; placebo, n = 35, mean age 16.3 years) with schizophrenia participated in this randomized (2:1), international, multisite, industry-sponsored trial. All patients met DSM-IV-TR criteria for schizophrenia, and they were treated for up to 6 weeks with flexible doses of olanzapine (2.5-20.0 mg/day) or placebo. Last-observation-carried-forward mean changes from baseline to endpoint on the anchored version of the Brief Psychiatric Rating Scale for Children, Clinical Global Impression Scale-Severity of Illness, and Positive and Negative Syndrome Scale (PANSS) were assessed. RESULTS: More olanzapine-treated versus placebo-treated patients completed the trial (68.1% versus 42.9%, p =.020). Compared with placebo-treated patients, olanzapine-treated adolescents had significantly greater improvement in Brief Psychiatric Rating Scale for Children total (p =.003), Clinical Global Impressions Scale-Severity of Illness (p =.004), PANSS total (p =.005), and PANSS positive scores (p =.002). Olanzapine-treated patients gained significantly more baseline-to-endpoint weight (4.3 kg versus 0.1 kg, p <.001). Significantly more olanzapine-treated versus placebo-treated patients gained 7% or greater of their body weight at any time during treatment (45.8% versus 14.7%, p =.002). Prolactin and triglyceride mean baseline-to-endpoint changes were significantly higher in olanzapine-treated versus placebo-treated adolescents. The incidence of treatment-emergent significant changes in fasting glucose, cholesterol, or triglycerides did not differ between the groups at endpoint, but significantly more olanzapine-treated patients had high triglycerides at any time during treatment. CONCLUSIONS: Olanzapine-treated adolescents with schizophrenia experienced significant symptom improvement. Significant increases in weight, triglycerides, uric acid, most liver function tests, and prolactin were observed during olanzapine treatment.Clinical trial registration information-Olanzapine Versus Placebo in the Treatment of Adolescents With Schizophrenia. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00051298.

Iron-sulfur cluster N7 of the NADH:ubiquinone oxidoreductase (complex I) is essential for stability but not involved in electron transfer.

The NADH:ubiquinone oxidoreductase (complex I) from Escherichia coli is composed of 13 subunits called NuoA through NuoN. It catalyzes the electron transfer from NADH to ubiquinone by a chain of redox groups consisting of one FMN and seven iron-sulfur clusters. The function of the additional, nonconserved cluster N7 located on NuoG is not known. It has been speculated that it is not involved in electron transfer, due to its distance of more than 20 A from the electron transfer chain. Dithionite-reduced minus NADH-reduced EPR difference spectra of complex I and of a soluble fragment containing NuoG revealed for the first time the EPR spectrum of N7 in the complex. Individual mutation of the cysteines ligating this cluster to alanine led to a decreased amount of complex I in the membrane without affecting the electron transfer activity. Sucrose gradient centrifugation revealed that the complex from the C230A and C233A mutants decayed in detergent solution while the C237A and C265A mutant complex was stable. Cluster N7 was detectable in the latter mutants but with shifted g-values, indicating a different ligation of N7. Thus, N7 is essential for the stability of the complex but is not involved in electron transfer.