Cell death mechanisms associated with G(2) radiosensitivity in patients with prostate cancer and benign prostatic hyperplasia

Cells respond to genotoxic insults such as ionizing radiation by halting in the G(2) phase of the cell cycle. Delayed cell death (mitotic death) can occur when the cell is released from G(2), and specific spindle defects form endopolyploid cells (endoreduplication/tetraploidy). Enhanced G(2) chromosomal radiosensitivity has been observed in many cancers and genomic instability syndromes, and it is manifested by radiation-induced chromatid aberrations observed in lymphocytes of patients. Here we compare the G(2) chromosomal radiosensitivity in prostate patients with benign prostatic hyperplasia (BPH) or prostate cancer with disease-free controls. We also investigated whether there is a correlation between G(2) chromosomal radiosensitivity and aneuploidy (tetraploidy and endoreduplication), which are indicative of mitotic cell death. The G(2) assay was carried out on all human blood samples. Metaphase analysis was conducted on the harvested chromosomes by counting the number of aberrations and the mitotic errors (endoreduplication/tetraploidy) separately per 100 metaphases. A total of 1/14 of the controls were radiosensitive in G(2) compared to 6/15 of the BPH patients and 15/17 of the prostate cancer patients. Radiation-induced mitotic inhibition was assessed to determine the efficacy of G(2) checkpoint control in the prostate patients. There was no significant correlation of G(2) radiosensitivity scores and mitotic inhibition in BPH patients (P = 0.057), in contrast to prostate cancer patients, who showed a small but significant positive correlation (P = 0.029). Furthermore, there was no significant correlation between G(2) radiosensitivity scores of BPH patients and endoreduplication/ tetraploidy (P = 0.136), which contrasted with an extremely significant correlation observed in prostate cancer patients (P < 0.0001). In conclusion, cells from prostate cancer patients show increased sensitivity to the induction of G(2) aberrations from ionizing radiation exposure but paradoxically show reduced mitotic indices and aneuploidy as a function of aberration frequency.

Inhibition of S/G(2) phase CDK4 reduces mitotic fidelity

Cyclin-dependent kinase 4 (CDK4)/cyclin D has a key role in regulating progression through late G(1) into S phase of the cell cycle. CDK4-cyclin D complexes then persist through the latter phases of the cell cycle, although little is known about their potential roles. We have developed small molecule inhibitors that are highly selective for CDK4 and have used these to define a role for CDK4-cyclin D in G(2) phase. The addition of the CDK4 inhibitor or small interfering RNA knockdown of cyclin D3, the cyclin D partner, delayed progression through G(2) phase and mitosis. The G(2) phase delay was independent of ATM/ATR and p38 MAPK but associated with elevated Wee1. The mitotic delay was because of failure of chromosomes to migrate to the metaphase plate. However, cells eventually exited mitosis, with a resultant increase in cells with multiple or micronuclei. Inhibiting CDK4 delayed the expression of the chromosomal passenger proteins survivin and borealin, although this was unlikely to account for the mitotic phenotype. These data provide evidence for a novel function for CDK4-cyclin D3 activity in S and G(2) phase that is critical for G(2)/M progression and the fidelity of mitosis.

Activation of a Frizzled-2/β-adrenergic receptor chimera promotes Wnt signaling and differentiation of mouse F9 teratocarcinoma cells via Gαo and Gαt

The frizzled gene family of putative Wnt receptors encodes proteins that have a seven-transmembrane-spanning motif characteristic of G protein-linked receptors, though no loss-of-function studies have demonstrated a requirement for G proteins for Frizzled signaling. We engineered a Frizzled-2 chimera responsive to β-adrenergic agonist by using the ligand-binding domains of the β2-adrenergic receptor. The expectation was that the chimera would be sensitive both to drug-mediated activation and blockade, thereby circumventing the problem of purifying soluble and active Wnt ligand to activate Frizzled. Expression of the chimera in zebrafish embryos demonstrated isoproterenol (ISO)-stimulated, propranolol-sensitive calcium transients, thereby confirming the β-adrenergic nature of Wnt signaling by the chimeric receptor. Because F9 embryonic teratocarcinoma cells form primitive endoderm after stable transfection of Frizzled-2 chimera and stimulation with ISO, they were subject to depletion of G protein subunits. ISO stimulation of endoderm formation of F9 stem cells expressing the chimeric receptor was blocked by pertussis toxin and by oligodeoxynucleotide antisense to Gαo, Gαt2, and Gβ2. Our results demonstrate the requirement of two pertussis toxin-sensitive G proteins, Gαo and Gαt, for signaling by the Frizzled-2 receptor.

EPR and magnetic studies of a carboxylate-bridged dinuclear copper(II) compound: [cu2(flu)4(dmf)2]

We report magnetic and EPR (electron paramagnetic resonance) spectroscopy studies of [Cu2(flu)4(dmf)2] (flu = flufenamate and dmf = dimethylformamide), which has CuII ions in tetracarboxylate "paddle wheel" dinuclear units. Susceptibility measurements at 10 < T < 275 K allowed the evaluation of an antiferromagnetic intradinuclear exchange coupling J0 = -294 ± 5 cm-1 between CuII ions (Hex = "J0 S1·S2). EPR experiments at 300 K in powder and single-crystals at 9.5 and 34.4 GHz indicated g// = 2.373, g⊥ = 2.073 and zero field splitting parameters D = (-0.334 ± 0.001) cm"1 and E ca. 0. EPR signal intensity measurements at X-band in the range 4 < T < 295 K indicated that J0 = "283 ± 5 cm"1. A higher limit |J´| < 5×10-3 cm-1 for the interdinuclear exchange coupling between neighbor units at ca.14.24 Å was estimated from the angular variation of the single crystal spectra around the magic angles. The results are discussed in terms of the structure of the dinuclear unit and the bridges connecting CuII ions and compared with values reported for similar compounds.

Synthesis of [Cu-2(Me-2[9]aneN(2)S)(2)(OH)(2)] (PF6)(2), a hydroxo-bridged copper(II) complex of N,N '-dimethyl-1-thia-4,7-diazacyclononane (Me-2[9]aneN(2)S). X-ray structural analysis, magnetic susceptibility, EPR and visible spectroscopy

The bis(mu-hydroxo) complex [Cu-2(Me-2[9]aneN(2)S)(2)(OH)(2)](PF6)(2) (Me-2[9]aneN(2)S = N,N'-dimethyl-1-thia-4,7-diazacyclononane) results after reaction of [Cu(Me-2[9]aneN(2)S)(MeCN)] (PF6) with dioxygen at -78 degrees C in acetonitrile. The complex has been characterized by X-ray crystallography: orthorhombic, space group Pnma, with a 18.710(3), b 16.758(2), c 9.593(2) Angstrom, and Z = 4. The structure refined to a final R value of 0.051. The complex contains two copper(II) ions bridged by two hydroxo groups with Cu ... Cu 2.866(1) Angstrom. The solid-state magnetic susceptibility study reveals ferromagnetic coupling, the fitting parameters being J = +46+/-5 cm(-1), g = 2.01+/-0.01 and theta = -0.58+/-0.03 K. The frozen-solution e.p.r. spectrum in dimethyl sulfoxide is characteristic of a monomeric copper(II) ion (g(parallel to) 2.300, g(perpendicular to) 2.063; A(parallel to) 156.2 x 10(-4) cm(-1), A(perpendicular to) 9.0 x 10(-4) cm(-1)) with an N2O2 donor set. Thioether coordination to the copper(II) in solution is supported by the presence of an intense absorption assigned to a sigma(S)-->Cu-II LMCT transition at c. 34000 cm(-1). The single-crystal spectrum of [Cu-2(Me-2[9]aneN(2)S)(2)(OH)(2)] (PF6)(2) (273 K) reveals d-->d transitions at 14500 and 18300 cm(-1) and a weak pi(S)-->Cu-II charge-transfer band at approximately 25000 cm(-1).

Mu-Chlorido-Bridged Dimanganese(II) complexes of the schiff base derived from [2+2] condensation of 2,6-diformyl-4-methylphenol and 1,3-bis(3-aminopropyl)tetramethyldisloxane: structure, magnetismo, electrochemical behaviour, and catalytic oxidation of secondary alcohols

The reaction of 2,6-diformyl-4-methylphenol with 1,3-bis(3-aminopropyl)tetramethyldisiloxane in the presence of MnCl2 in a 1:1:2 molar ratio in methanol afforded a dinuclear -chlorido-bridged manganese(II) complex of the macrocyclic [2+2] condensation product (H2L), namely, [Mn2Cl2(H2L)(HL)]Cl center dot 3H(2)O (1). The latter afforded a new compound, namely, [Mn2Cl2(H2L)(2)][MnCl4]center dot 4CH(3)CN center dot 0.5CHCl(3 center dot)0.4H(2)O (2), after recrystallisation from 1:1 CHCl3/CH3CN. The co-existence of the free and complexed azomethine groups, phenolato donors, mu-chlorido bridges, and the disiloxane unit were well evidenced by ESI mass spectrometry and FTIR spectroscopy and confirmed by X-ray crystallography. The magnetic measurements revealed an antiferromagnetic interaction between the two high-spin (S = 5/2, g = 2) manganese(II) ions through the mu-chlorido bridging ligands. The electrochemical behaviour of 1 and 2 has been studied, and details of their redox properties are reported. Both compounds act as catalysts or catalyst precursors in the solvent-free low-power microwave-assisted oxidation of selected secondary alcohols, for example, 1-phenylethanol, cyclohexanol, 2- and 3-octanol, to the corresponding ketones in the absence of solvent. The highest yield of 72% was achieved for 1-phenylethanol by using a maximum of 1% molar ratio of catalyst relative to substrate.

µ-Chlorido-bridged dimanganese(II) complexes of the schiff base derived from [2+2] condensation of 2,6-diformyl-4-methylphenol and 1,3-bis(3-aminopropyl)tetramethyldisiloxane: structure, magnetismo, electrochemical behaviour, and catalytic oxidation of secondary alcohols

The reaction of 2,6-diformyl-4-methylphenol with 1,3-bis(3-aminopropyl)tetramethyldisiloxane in the presence of MnCl2 in a 1:1:2 molar ratio in methanol afforded a dinuclear -chlorido-bridged manganese(II) complex of the macrocyclic [2+2] condensation product (H2L), namely, [Mn2Cl2(H2L)(HL)]Cl center dot 3H(2)O (1). The latter afforded a new compound, namely, [Mn2Cl2(H2L)(2)][MnCl4]center dot 4CH(3)CN center dot 0.5CHCl(3 center dot)0.4H(2)O (2), after recrystallisation from 1:1 CHCl3/CH3CN. The co-existence of the free and complexed azomethine groups, phenolato donors, mu-chlorido bridges, and the disiloxane unit were well evidenced by ESI mass spectrometry and FTIR spectroscopy and confirmed by X-ray crystallography. The magnetic measurements revealed an antiferromagnetic interaction between the two high-spin (S = 5/2, g = 2) manganese(II) ions through the mu-chlorido bridging ligands. The electrochemical behaviour of 1 and 2 has been studied, and details of their redox properties are reported. Both compounds act as catalysts or catalyst precursors in the solvent-free low-power microwave-assisted oxidation of selected secondary alcohols, for example, 1-phenylethanol, cyclohexanol, 2- and 3-octanol, to the corresponding ketones in the absence of solvent. The highest yield of 72% was achieved for 1-phenylethanol by using a maximum of 1% molar ratio of catalyst relative to substrate.

Microbiologia da carne moida = 2. Avaliação da qualidade por método modificado, baseado na redução da resazurina

Quarenta amostras de carne (bovina) moida, provenientes de quatro supermercados da cidade de Piracicaba, SP, foram analisados quanto à contagem total de bactérias, segundo as recomendações da "American Public Health Associaton" (incubação das placas a 32°C por 48 horas). As mesmas amostras foram utilizadas em estudo de modificação de teste baseado na redução da resazurina, proposto para a avaliação da qualidade, sob o ponto-de-vista, microbiológico, do alimento em questão. Os resultados podem ser resumidos como segue: 1) As contagens totais foram elevadas, em geral, com diversas amostras na faixa de 10(7) a 10(9) bactérias/g: a média obtida foi de 3,0 x 10(7) bactérias/g. 2) Não foi constatada diferença significativa, quanto à contagem total de bactérias, entre os quatro estabelecimentos onde as amostras foram obtidas. 3) Uma correlação altamente significativa (r=-0,91) foi verificada entre a contagem total de bactérias e o tempo necessário à redução da resazurina até a descoloração, pelo método modificado estudado.

Adsorção do complexo H[Ru(III)Cl2(H2EDTA)] sobre a superfície da sílica gel modificada com [3-(2-aminoetil) aminopropil]trimetoxissilano em soluções etanólicas

Silica gel was functionalized with [3-(2-aminoethyl)aminopropyl]trimethoxysilane group (SF-AEATS) and the characterization by chemical analysis (N) and infrared spectroscopy confirmed the functionalization. The capacity of the modified silica to adsorb the complex Ru(III)-EDTA from ethanolic solution was studied. The selectivity coefficients of the complex formed on the support obtained was (Gñ), 2,07 x 10(4) L/mol and the average number of ligand bonded by one metal ion on the support (ñ) was ~ 1.

[Lettre autographe signée d'A. G. André à Camille Du Locle (sans date)]

Problèmes pour des loges demandées pour la Messe de Requiem

Modelo de evaluación aplicado al currículum de Biología de la carrera de Agronomía en la Escuela Internacional de Agricultura y Ganadería (E.I.A.G.) de Rivas, Nicaragua.

1.- Ofrecer un modelo de evaluación para el currículum de Biología que permita la valoración de su funcionalidad, eficiencia y eficacia en la formación de Técnicos Superiores en Agronomía a través de un análisis reflexivo y crítico de la realidad educativa. 2.- Proponer la evaluación del Currículum de Biología como alternativa a la mejora de la calidad de los procesos de enseñanza-aprendizaje que permitan respaldar los procesos de desarrollo nacional. 3.- Contribuir a la autonomía y toma de decisiones del docente utilizando un modelo de evaluación adaptado al contexto de la educación agrícola y que permita el conocimientos de los valores, características, posibilidades y necesidades que identifican. Treinta y tres sujetos: el director del Instituto de Bachillerato, la profesora de Biología de COU, 30 alumnos del curso de COU y el Coordinador de Biología de los COU de Salamanca. El modelo utilizado para la evaluación del currículo de Biología es el modelo CIPP (contexto, entrada, proceso, producto) de Stufflebeam, integrando las aportaciones y valoraciones de la Dra. Margarita Bartolomé Pina. Entrevistas semiestructuradas con los participantes y observación participante. Análisis arbóreo funcional y triangulación. La investigación realiza una propuesta de evaluación del currículum de Biología, del Plan de estudios de la carrera de Agronomía en la Escuela Internacional de Agricultura y Ganadería de Rivas, eligiendo el modelo CIPP de Stufflebean. Para probar el modelo se aplica el mismo a los alumnos de Biología de un Instituto de Bachillerato de Salamanca con el objeto de realizar los ajustes necesarios sobre el modelo para posteriormente poderlo aplicar en los estudios de Agronomía de la facultad de Rivas, en Nicaragua. El estudio realizado fue de 6 días, tiempo brevísimo para obtener resultados fiables y válidos, pero adecuado para familiarizarse con la aplicación del modelo, a la vez que conocer la realidad educativa española. Se consiguió un ambiente adecuado de trabajo donde se desarrolló adecuadamente el proceso. La aplicación parcial del modelo CIPP al currículum de Biología de un grupo de alumnos de un Instituto de Bachillerato de Salamanca se deducen las siguientes relaciones entre las diferentes categorías: el contexto, la entrada, el proceso y el producto. El contexto donde se desarrolla la acción educativa es adecuado, las instalaciones son adecuadas para la tarea. La elaboración del currículo de Biología no parte de las necesidades del alumnado, sino que parte de las propuestas del MEC en estrecha relación con el programa de Biología de la Universidad, es elaborado por el coordinador de Biología de los COU de Salamanca en colaboración con el profesorado que imparte esta materia. La ventaja que ofrece el currículum es la adecuación a la realidad científica contextual, adecuándolo a los cambios propios del medio y utilizando los recursos necesarios; los problemas aparecen en la vinculación de la teoría y la práctica. Durante el proceso se debería informar al alumno de la utilidad de cada uno de los temas y los objetivos que se persiguen para incrementar la motivación y expectativas. Durante el proceso es importante que el Director del Centro y el Coordinador de los COU realicen un seguimiento al desarrollo del currículo para buscar alternativas de solución de problemas. El último producto de la enseñanza debe ser la satisfacción de haber formado hombres y mujeres críticos y creativos que respondan a las demandas de la sociedad. De los resultados obtenidos en la aplicación del modelo CIPP en el centro educativo español, puede extraerse las siguientes conclusiones en su extrapolación al contexto nicaragüense al currículo de Biología de la carrera de Agronomía: 1.- La evaluación ha de partir del estudio exhaustivo sobre la realidad educativa de la E.I.A.G. 2.- La evaluación ha de ser práctica y se han de obtener los datos necesarios en el tiempo estipulado. 3.- Se ha de prestar atención a la influencia ejercida por los directivos y docentes, para modificar los resultados a su favor una vez realizada la evaluación. 4.- Las entrevistas dirigidas hacia el alumnado serán de fácil comprensión, para que puedan responder a las diferentes cuestiones; se les presentará los resultados de las mismas para su análisis. 5.- Se tratará de aplicar la evaluación con los menores costes posibles, atendiendo a los presupuestos asignados por la administración. 6.- La aplicación del Modelo CIPP de evaluación del currículum de Biología de la E.I.A.G. deberá permitir la extrapolación o adecuación del modelo a la evaluación de otras materias y a la evaluación del centro de manera integral.

Synthesis, crystal structure, magnetic behavior and thermal property of three polynuclear complexes: [M(dca)(2)(H2O)2](n)center dot(hmt)(n) [M = Mn(II), Co(II)] and [Co(dca)(2)(bpds)](n) [dca, dicyanamide; hint, hexamethylenetetramine; bpds, 4,4 '-bipyridyl disulfide]

Three mu(1.5)-dicyanamide bridged Mn(II) and Co(II) complexes having molecular formula [Mn(dca)(2)(H2O)(2)](n)center dot(hmt)(n) (1), [Co(dca)(2) (H2O)(2)](n)center dot(hmt)(n) (2) and [Co(dca)(2)(bpds)](n) (3) [dca = dicyanamide; hmt = hexamethylenetetramine; bpds = 4,4'-bipyridyl disulfide] have been synthesized and characterized by single crystal X-ray diffraction study, low temperature (300-2 K) magnetic measurement and thermal behavior. The X-ray diffraction analysis of 1 and 2 reveals that they are isostructural, comprising of 1D coordination polymers [M(dca)(2)(H2O)(2)](n) [M = Mn(II), Co(II) for 1 and 2. respectively] with uncoordinated hmt molecules located among the chains. The [M(dca)(2)(H2O)(2)](n) chains and the lattice hint molecules are connected through H-bonds resulting in a 3D supramolecular architecture. The octahedral N4O2 chromophore surrounding the metal ion forms via two trans located water oxygens and four nitrogens from four nitrile dca. Complex 3 is a 1D chain formed by two mu(1.5)-dca and one bridging bpds. The octahedral N-6 coordination sphere surrounding the cobalt ions comprises four nitrogens from dca and two from bpds. Low temperature magnetic study indicates small antiferromagnetic coupling for all the complexes. Best fit parameters for 1: J = -0.17 cm(-1), g = -2.03 with R = 6.1 x 10(-4), for 2, J = -0.50 cm(-1), and for 3, J = -0.95 cm(-1). (c) 2005 Elsevier B.V. All rights reserved.

Structural and spectroscopic properties of Ru(II) complexes of 4-(aryl)thiosemicarbazones of thiophen-2-carbaldehyde

Six Ru(II) complexes of formula [Ru(L)(2)(PPh3)(2)] have been prepared where LH = 4-(aryl)thiosemicarbazones of thiophen-2-carbaldehyde. X-ray crystal structures of five of the complexes are reported. In all the complexes ruthenium is six coordinate with a distorted octahedral cis-P-2, cis-N-2, trans-S-2 donor environment, and each of the two thiosemicarbazone ligands are coordinated in a bidentate fashion forming a four membered chelate ring. The complexes undergo a one-electron oxidation at similar to 0.5 V vs. Ag/AgCl. The EPR spectrum of the electrochemically oxidized solution at 100 K shows a rhombic signal, with transitions at g(1) = 2.27, g(2) = 2.00 and g(3) = 1.80. DFT calculations on one of the complexes suggest that there is 35% ruthenium and 17% sulfur orbital contribution to the HOMO. These results suggest that the assignment of metal atom oxidation states in these compounds is not unambiguous. (C) 2009 Elsevier Ltd. All rights reserved.