Efeito do tamanho do folículo na maturação nuclear e citoplasmática de ovócitos de fêmeas zebuínas

Este estudo avaliou o efeito do tamanho do folículo na capacidade dos ovócitos de sofrerem maturação nuclear e citoplasmática. Ovários de vacas Nelore (Bos indicus) foram coletados logo após o abate, e os complexos cúmulus-ovócitos foram aspirados de folículos de diferentes categorias, e classificados de acordo com seus diâmetros em: 1-2 mm, 3-5 mm, 6-8 mm e > ou = 9 mm. A medida do diâmetro e a fixação dos ovócitos para avaliação do estádio nuclear antes da maturação foram feitas logo após a aspiração. Ovócitos morfologicamente viáveis foram maturados, fecundados e cultivados in vitro. Os ovócitos obtidos de folículos de 1-2 mm apresentaram menor diâmetro (P<0,01) do que os dos demais grupos. Antes da maturação, 89,8%, 90,1%, 85,7% e 100% dos ovócitos provenientes de folículos de 1-2, 3-5, 6-8 e > ou = 9 mm de diâmetro, respectivamente, apresentavam vesícula germinativa. O tamanho do folículo não influenciou (P<0,05) a taxa de maturação nuclear. A porcentagem de ovócitos que chegaram a metáfase II foi de 88,8%, 87,8%, 92,9% e 100% no que se refere aos ovócitos de folículos de 1-2, 3-5, 6-8 e > ou = 9 mm, respectivamente. As taxas de penetração e clivagem foram semelhantes (P>0,05) nos grupos de 1-2 mm (93,4% e 81,9%), 3-5 mm (90,7% e 79,6%), 6-8 mm (91,3% e 77,8%) e > ou = 9 mm (92,0% e 78,3%). Da mesma forma, não houve diferenças (P>0,05) entre as categorias de folículos no que se refere às taxas de polispermia, descondensação da cabeça do espermatozóide e formação de pro-núcleos. Os resultados deste estudo demonstram que na espécie B. indicus, folículos com diâmetro de 1 mm até > ou = 9 mm não influenciaram a capacidade dos ovócitos de reiniciar e completar a meiose e de clivar após maturação e fecundação in vitro.

Controle da lagarta-da-soja com aplicações de seu vírus de poliedrose nuclear por vias aérea e terrestre

De 1983 a 1988 foram conduzidos, na região de Dourados, MS, seis experimentos e três campos-piloto, objetivando controlar a lagarta Anticarsia gemmatalis Hübner, 1818, com aplicações aérea e terrestre de seu vírus de poliedrose nuclear (VPN Ag). Cem lagartas equivalentes (LE) de VPN Ag associadas a óleo de soja, melaço de cana-de-açúcar e água, foram aplicadas com avião agrícola equipado com Micronair. Os preparados oleosos (5,5 e 5 L ha-1) e com melaço (10 L ha-1) controlaram 75-89% e 79-96% das lagartas, respectivamente. A suspensão aquosa de 3 L ha-1 foi ineficaz, porém as de 15, 20 e 25 L ha-1 controlaram de 81% a 90% das lagartas. Cinqüenta LE, aplicadas com avião agrícola (3 L ha-1) ou atomizador (15 L ha-1), foram ineficientes. Aplicações da mesma dose com pulverizador de barra (134 e 150 L ha-1) proporcionaram controle de 87% e 90%, respectivamente, e com avião (15, 20 e 25 L ha-1), entre 93% e 98%. Aplicações aéreas de 50 LE com óleo de soja (5 L ha-1) ou melaço (10 L ha-1) foram eficientes (86-88% e 99%, respectivamente). Aplicações aéreas de suspensões aquosas e formulado oleoso, em campos-piloto, confirmaram os resultados experimentais.

An Evaluation of the Troxler 3241-B Nuclear Asphalt Gauge, MLR-85-11, 1986

The Troxler 3241-B Asphalt Content Gauge is intended for rapidly determining the bitumen content of bituminous paving mixtures. A 300 Millicurie Americuium 241: Beryllium source emitts neutrons which are affected by the hydrogen in the mix. The affected neutrons are detected by Helium 3 detectors, counted and computed into a percentage bitumen of the asphalt mix. The current methods of determining the bitumen content of bituminous paving mixtures requires the use of potentially hazardous chemicals and several hours of testing time. When extracted aggregates are not needed, determination of the bitumen content of a paving mixture by the nuclear method may be easier, quicker and potentially safer. The objective of the project is to study the accuracy of the Troxler 3241-B Nuclear Asphalt Content Gauge in measuring the asphalt cement (AC) content of asphalt concrete mixtures produced with different asphalt cements and different aggregates.

Targeting receptor activator of nuclear factor-kappa B as a new therapy for bone metastasis in non-small cell lung cancer.

PURPOSE OF REVIEW: The review aims at comprehensively discussing our current knowledge on bone metastases incidence in non-small cell lung cancer (NSCLC), their related complications as well as clinical impact in patients suffering from advanced disease. RECENT FINDINGS: After evoking the use of zoledronic acid as the established standard of care until recently, the new class of drugs available to prevent skeletal related events and targeting receptor activator of nuclear factor-kappa B (RANK) will be emphasized, reporting on denosumab clinical trials, a RANK-ligand (RANKL) targeting monoclonal antibody. Biological hypothesis regarding their mechanisms of action as well a potential direct impact on tumor cells are described according to the most recent laboratory as well as hypothesis-generating clinical data. SUMMARY: Targeting the RANK pathway is an efficient way to prevent complications of bone metastases in NSCLC. Interesting additional direct effects on tumor biology and evolution are being analyzed and prospectively assessed in clinical trials.

Estrogen-dependent in vitro transcription from the vitellogenin promoter in liver nuclear extracts.

One approach to analyzing the molecular mechanisms of gene expression in vivo is to reconstitute these events in cell-free systems in vitro. Although there is some evidence for tissue-specific transcription in vitro, transcriptionally active extracts that mimic a steroid hormone-dependent enhancement of transcription have not been described. In the study reported here, nuclear extracts of liver from the frog Xenopus laevis were capable of estrogen-dependent induction of a homologous vitellogenin promoter that contained the estrogen-responsive element.

Nuclear magnetic resonance

This article reviews the principles and methods of nuclear magnetic resonance spectroscopy, and gives examples of applications carried out at ourFacility, which illustrate the capabilities of the technique.

Peroxisome proliferator-activated receptors: a nuclear receptor signaling pathway in lipid physiology.

Peroxisome proliferator-activated receptors (PPARs) are lipid-activated transcription factors that belong to the steroid/thyroid/retinoic acid receptor superfamily. All their characterized target genes encode proteins that participate in lipid homeostasis. The recent finding that antidiabetic thiazolidinediones and adipogenic prostanoids are ligands of one of the PPARs reveals a novel signaling pathway that directly links these compounds to processes involved in glucose homeostasis and lipid metabolism including adipocyte differentiation. A detailed understanding of this pathway could designate PPARs as targets for the development of novel efficient treatments for several metabolic disorders.

Polychlorinated trityl radicals for dynamic nuclear polarization: the role of chlorine nuclei

Polychlorinated trityl radicals bearing carboxylate substituents are water soluble persistent radicals that can be used for dynamic nuclear polarization. In contrast to other trityl radicals, the polarization mechanism differs from the classical solid effect. DFT calculations performed to rationalize this behaviour support the hypothesis that polarization is transferred from the unpaired electron to chlorine nuclei and from these to carbon by spin diffusion. The marked differences observed between neutral and anionic forms of the radical will be discussed.

Producció de biopolímers amb cultius bacterians mixtes. Comparació de tres reactors discontinus seqüencials (SBR) amb diferents condicions operacionals

La producció de biopolímers (polihidroxialcanoats (PHA) i substàncies polimèriques extracel·lulars (EPS)) a nivell industrial, resulta una nova àrea d’investigació que recull diverses disciplines, entre elles les Ciències Ambientals. Aquest projecte final de carrera amb el títol: “Producció de biopolímers amb cultius bacterians mixtes”, s’ha desenvolupat sota la supervisió de la directora de projecte Dra. María Eugenia Suárez Ojeda del Departament d’Enginyeria Química de la Universitat Autònoma de Barcelona (UAB) i s’ha dut a terme per l’estudiant Jordi Pérez i Forner de la Llicenciatura de Ciències Ambientals, Facultat de Ciències de la UAB, en el Departament d’Enginyeria Química de la mateixa universitat. L’objectiu d’aquest projecte ha estat produir biopolímers simultàniament amb l’eliminació de fòsfor i matèria orgànica en aigües residuals per obtenir un residu final amb un alt valor afegit. Aquests biopolímers reuneixen les característiques necessàries per a poder competir amb els plàstics convencionals i així, reduir l’elevat consum del petroli i la generació de residus no biodegradables. En aquest projecte s’ha dut a terme la posta en marxa d’un reactor discontinu seqüencial (SBR) per a l’acumulació de biopolímers amb cultius bacterians mixtes. Diferents investigadors han estudiat que aquests tipus de cultius bacterians arriben a nivells de fins el 53-97% [Pijuan et al., 2009] de contingut de biopolímers a la biomassa, sometent als microorganismes a diferents situacions d’estrés ja sigui per dèficit de nutrients o per variacions en les fases de feast-famine (festí-fam). Durant el projecte, s’ha realitzat el monitoratge del reactor alimentat amb una aigua sintètica, elaborada en el laboratori, amb les característiques d’un aigua residual provinent de la industria làctica. S’ha sotmès als microorganismes a diferents condicions operacionals, una d’elles amb limitació de fòsfor com a nutrient i una tercera condició amb una variació a les fases feast-famine. D’altra banda, com a segon objectiu, s’ha analitzat el contingut de biopolímers a la biomassa de dos SBRs més, del grup de recerca Bio-GLS del Departament d’Enginyeria Química de la UAB, alimentats amb diferents fonts de carboni, glicerol i àcids grassos de cadena llarga (AGCLL), per observar les influències que té el tipus de substrat en l’acumulació de biopolímers. Els resultats obtinguts en la primera part d’aquest projecte han estat similars als resultats d’altres investigadors [Pijuan et al., 2009; Guerrero et al., 2012]. S’ha determinat que sotmetre als microorganismes a situacions d’estrés té un efecte directe pel que fa a l’acumulació de biopolímers. També s’ha observat com al mateix temps que acumulaven aquests compostos, els microorganismes desenvolupaven la seva tasca de depurar l’aigua residual, obtenint al final del cicle una aigua amb un baix contingut en matèria orgànica i altres contaminants com amoni i fòsfor, en aquest cas. En la segona part del projecte, s’ha observat com el tipus de substrat té un efecte directe pel que fa a l’acumulació de biopolímers i també a l’activitat metabòlica dels microorganismes. Per tant, s’ha conclòs que la producció de biopolímers mitjançant la depuració d’aigües residuals es una via d’investigació molt prometedora pel que fa als resultats obtinguts. Alhora que es tracta un residu, s’obté una producte residual amb un alt valor afegit que pot ser utilitzat per la producció de bioplàstics 100% biodegradables.

A nuclear defect in the 4p16 region predisposes to multiple mitochondrial DNA deletions in families with Wolfram syndrome.

Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the family, the percentages of deleted mitochondrial DNA genomes were only 1-10%. Recently, a Wolfram syndrome gene has been linked to markers on 4p16. In both families linkage between the disease locus and 4p16 markers gave a maximum multipoint lod score of 3.79 at theta = 0 (Pi<0.03) with respect to D4S431. In these families, the syndrome was caused by mutations in this nucleus-encoded gene which deleteriously interacts with the mitochondrial genome. This is the first evidence of the implication of both genomes in a recessive disease.

A nuclear defect in the 4p16 region predisposes to multiple mitochondrial DNA deletions in families with Wolfram syndrome.

Wolfram syndrome is a progressive neurodegenerative disorder transmitted in an autosomal recessive mode. We report two Wolfram syndrome families harboring multiple deletions of mitochondrial DNA. The deletions reached percentages as high as 85-90% in affected tissues such as the central nervous system of one patient, while in other tissues from the same patient and from other members of the family, the percentages of deleted mitochondrial DNA genomes were only 1-10%. Recently, a Wolfram syndrome gene has been linked to markers on 4p16. In both families linkage between the disease locus and 4p16 markers gave a maximum multipoint lod score of 3.79 at theta = 0 (Pi<0.03) with respect to D4S431. In these families, the syndrome was caused by mutations in this nucleus-encoded gene which deleteriously interacts with the mitochondrial genome. This is the first evidence of the implication of both genomes in a recessive disease.

Espectros de duas formas de lignina obtidos por ressonância magnética nuclear

O conteúdo de lignina pode ser útil na estimativa da digestão da fibra de plantas forrageiras. A determinação quantitativa da lignina pelo método espectrofotométrico pressupõe a existência de um padrão de referência satisfatório. O objetivo deste trabalho foi avaliar, por meio da ressonância magnética nuclear (RMN), duas ligninas, uma extraída com brometo de acetila (LBrAc) e outra com solução ácida de dioxano (LDiox), para utilização como padrão de referência em análises espectrofotométricas. A ressonância de próton acusou altos teores de carboidratos contaminantes nas amostras de LBrAc. Como a cromatografia líquida já havia indicado menor presença de carboidratos contaminantes na LDiox, os espectros por ressonância de carbono, mais rica em detalhes do que a espectroscopia anterior, porém mais demorada, foram realizados somente nas ligninas LDiox. Este espectro revelou picos típicos, comuns à maioria das ligninas. Os achados da RMN foram condizentes com a análise química, a qual identificou que o carboidrato da parede celular que acompanha a LBrAc seria possivelmente a celulose, ao passo que a pequena contaminação da LDiox teria origem nas pentosanas. A LDiox pode ser considerada melhor padrão de referência para as análises espectrofotométricas do que a LBrAc.

Proton NMR of (15)N-choline metabolites enhanced by dynamic nuclear polarization.

Chemical shifts of protons can report on metabolic transformations such as the conversion of choline to phosphocholine. To follow such processes in vivo, magnetization can be enhanced by dynamic nuclear polarization (DNP). We have hyperpolarized in this manner nitrogen-15 spins in (15)N-labeled choline up to 3.3% by irradiating the 94 GHz electron spin resonance of admixed TEMPO nitroxide radicals in a magnetic field of 3.35 T during ca. 3 h at 1.2 K. The sample was subsequently transferred to a high-resolution magnet, and the enhanced polarization was converted from (15)N to methyl- and methylene protons, using the small (2,3)J((1)H,(15)N) couplings in choline. The room-temperature lifetime of nitrogen polarization in choline, T(1)((15)N) approximately 200 s, could be considerably increased by partial deuteration of the molecule. This procedure enables studies of choline metabolites in vitro and in vivo using DNP-enhanced proton NMR.

Nuclear factor I-C regulates TGF-{beta}-dependent hair follicle cycling.

Skin appendages such as teeth and hair share several common signaling pathways. The nuclear factor I C (NFI-C) transcription factor has been implicated in tooth development, but a potential role in hair growth had not been assessed. In this study we found that NFI-C regulates the onset of the hair growth cycle. NFI-C(-/-) mice were delayed in the transition from the telogen to anagen phase of the hair follicle cycle after either experimental depilation or spontaneous hair loss. Lack of NFI-C resulted in delayed induction of the sonic hedgehog, Wnt5a, and Lef1 gene expression, which are key regulators of the hair follicle growth initiation. NFI-C(-/-) mice also showed elevated levels of transforming growth factor β1 (TGF-β1), an inhibitor of keratinocyte proliferation, and of the cell cycle inhibitor p21 at telogen. Reduced expression of Ki67, a marker of cell proliferation, was noted at the onset of anagen, indicating impaired activation of the hair progenitor cells. These findings implicate NFI-C in the repression of TGF-β1 signaling during telogen stage, resulting in the delay of progenitor cell proliferation and hair follicle regeneration in NFI-C-deficient mice. Taken together with prior observations, these findings also designate NFI-C as a regulator of adult progenitor cell proliferation and of postnatal tissue growth or regeneration.

A nuclear factor I-like activity and a liver-specific repressor govern estrogen-regulated in vitro transcription from the Xenopus laevis vitellogenin B1 promoter.

A hormone-controlled in vitro transcription system derived from Xenopus liver nuclear extracts was exploited to identify novel cis-acting elements within the vitellogenin gene B1 promoter region. In addition to the already well-documented estrogen-responsive element (ERE), two elements were found within the 140 base pairs upstream of the transcription initiation site. One of them, a negative regulatory element, is responsible for the lack of promoter activity in the absence of the hormone and, as demonstrated by DNA-binding assays, interacts with a liver-specific transcription factor. The second is required in association with the estrogen-responsive element to mediate hormonal induction and is recognized by the Xenopus liver homolog of nuclear factor I.