bluuebunny/crossref_metadata_2025 huggingface dataset:
Produção e caracterização de microesferas de quitosana modificadas quimicamente
Authors: Torres Marco A. , Vieira Rodrigo S. , Beppu Marisa M. , Santana Cesar C.
Published: April 2006

Microesferas de quitosana podem ser empregadas na área de biomaterias, em processos biotecnológicos e como adsorventes. Neste trabalho, foi empregada a técnica de atomização e coagulação para produção dessas microesferas, que permitiu o controle dos parâmetros de operação e por conseqüência a obtenção de microesferas de tamanho e faixas de tamanho específicos. Após a sua obtenção, as microesferas foram modificadas quimicamente com objetivo de estudar as resistências térmica, mecânica e química. Para isso foram empregadas três rotas distintas: a-) reticulação com glutaraldeído; b-) reticulação com epicloridrina e c-) acetilação. As microesferas preparadas apresentaram distribuição de tamanho da ordem de 140 µm com desvio padrão de 11,9 µm. Após as modificações químicas, as microesferas apresentaram temperatura de degradação térmica em torno de 300 ºC, aumento da estabilidade química à solução de HCl, e diminuição da resistência mecânica.
Biologia e exigências térmicas de Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) em laboratório
Authors: Milanez José M. , Parra José R. P.
Published: April 2006

A biologia de Diabrotica speciosa (Germar, 1824) foi estudada em câmaras climatizadas, ajustadas para 18, 20, 22, 25, 30 e 32 ºC e fotofase de 14 h. O alimento utilizado para o desenvolvimento larval foram raízes seminais de milho pipoca, previamente tratadas com uma mistura de fungicidas (Thiabendazole: 1.0 g/kg e Captan: 1.5 g/kg). O desenvolvimento das fases de ovo, larva-adulto e ovo-adulto, na faixa de 18 a 32ºC, esteve inversamente correlacionado com a temperatura. Os limiares térmicos inferiores de desenvolvimento foram de 11,1ºC (ovo); 10,9º C (larva-adulto) e 11,04ºC (ovo-adulto). As constantes térmicas da fase de ovo, período larva-adulto e período ovo-adulto foram 119,1, 355,9 e 474,9 graus-dia, respectivamente.
Efeito da densidade e do tamanho de sauveiros sobre a produção de madeira em eucaliptais
Authors: Zanetti Ronald , Jaffé Klaus , Vilela Evaldo F. , Zanuncio José C. , Leite Hélio G.
Published: April 2006

Foram coletados os dados sobre a produção volumétrica de madeira de eucalipto dos talhões reflorestados da Mannesmann Florestal Ltda., em João Pinheiro, MG, entre 1991 e 1996. Esses dados foram associados aos de densidade de sauveiros por classe de tamanho, obtidos pelo sistema de monitoramento de formigas cortadeiras da empresa (SIMFOR), no mesmo local e período. Além disso, determinaram-se, para cada talhão, o tipo de vegetação circundante, a distância desses à vegetação nativa e a presença ou não da faixa de vegetação nativa à sua margem. Esses dados foram ordenados numa planilha, tendo o talhão como unidade amostral, e então analisados. A densidade total média de sauveiros encontrada nas áreas de estudo foi suficiente para afetar negativamente o volu -me de madeira produzida. As espécies Eucalyptus camaldulensis Dehnh, E. citriodora Hook e E. tereticornis Smith tiveram sua produção volumétrica mais afetada pelo desfolhamento provocado pelas formigas cortadeiras do que E. cloeziana F. Muell. e E. urophylla S.T. Blake.
Preferência de Diabrotica speciosa (Germar) (Coleoptera: Chrysomelidae) para oviposição em diferentes tipos e umidade de solos
Authors: Milanez José M. , Parra José R. P.
Published: April 2006

Foi estudada a preferência de oviposição de Diabrotica speciosa (Germar, 1824), em relação a diferentes tipos de solo e diferentes umidades, em teste de livre escolha. Os experimentos foram realizados em laboratório à temperatura de 25 ± 2ºC, UR de 60 ± 10% e fotofase de 14h. Os resultados evidenciaram uma acentuada preferência de oviposição por solo tipo Terra Roxa Estruturada Distrófica de cor escura, com umidade variando entre 26 a 63%.
Distribuição espacial do ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae) em cafeeiro (Coffea arabica L.)
Authors: Reis Paulo R. , Souza Júlio C. de , Sousa Elber de O. , Teodoro Adenir V.
Published: April 2006

A distribuição espacial do ácaro Brevipalpus phoenicis (Geijskes) (Acari: Tenuipalpidae), vetor da mancha-anular em cafeeiro (Coffea arabica L.), foi estudada com o objetivo de conhecer os locais preferidos pelo ácaro, e assim visando seu controle. Contagens de ácaros em todos os estádios do desenvolvimento foram realizadas nas folhas, ramos e frutos nos terços inferior, médio e superior, da parte interna e externa das plantas. Constatou-se que B. phoenicis ocorreu em maior quantidade em folhas internas, ramos e frutos dos terços inferior e médio das plantas de café. Nas folhas, os ácaros localizavam-se predominantemente na página inferior, próximos às nervuras, principalmente a central. Nos frutos, ovos e ácaros foram encontrados preferencialmente na região da coroa e pedúnculo. Nos ramos, foram frequentemente encontrados abrigados nas fendas existentes na casca, e também nos nós.
Examining plant-parasitoid interactions in tritrophic systems
Authors: De Moraes Consuelo M. , Lewis W. J. , Tumlinson James H.
Published: April 2006

The demonstration that parasitoids are attracted to volatile compounds released by plants in response to herbivore feeding has generated a great deal of interest over the past ten years. The release of volatile signals by plants occurs not only in response to tissue damage but is also specifically initiated by exposure to herbivore salivary secretions. Although some volatile compounds are stored in plant tissues and immediately released when damage occurs, others are induced by herbivore feeding and released not only from damaged tissue but also from undamaged leaves. Thus, damage localized to only a few leaves results in a systemic response and the release of volatiles from the entire plant. New evidence suggests that, in addition to being highly detectable and reliable indicators of herbivore presence, herbivore-induced plant volatiles may convey herbivore-specific information that allows parasitoids to discriminate even closely-related herbivore species at long range. Here we give an overview of the recent developments in the investigation of plant-parasitoid interactions.
Virulência de Beauveria bassiana (Bals.) Vuill. a Diatraea saccharalis (F.) (Lepidoptera: Crambidae) após armazenamento de conídios em baixa temperatura
Authors: Marques Edmilson J. , Alves Sergio B. , Marques Irene M.R.
Published: April 2006

Verificou-se a viabilidade e virulência de conídios puros de Beauveria bassiana (Bals.) Vuill. isolado 447, armazenado por longos períodos em baixa temperatura. O experimento iniciou-se no Laboratório de Patologia de Insetos do Departamento de Entomologia, Fitopatologia e Zoologia Agrícola da ESALQ-USP (Piracicaba, SP) e teve seqüência no Laboratório de Patologia de Insetos do Departamento de Agronomia da UFRPE (Recife, PE), durante o período de abril de 1992 a janeiro de 1999. O fungo foi produzido em arroz pré-cozido e os conídios puros, com umidade de 15,5% foram armazenados em freezer, à temperatura de -7 ± 1ºC. Após 0, 5, 8, 50, 75 e 80 meses de armazenamento, a viabilidade dos conídios foi avaliada em meio BDA e a virulência foi testada sobre larvas de Diatraea saccharalis (F.). O fungo manteve viabilidade de 100% em todos os tratamentos, com elevada virulência sobre larvas de D. saccharalis. Os resultados de TL50 e porcentagens de mortalidade foram de 3,0 dias e 92,0%; 3,86 e 96,0%; 3,97 e 92,0% ; 4,05 e 94,0% e 4,0 e 96,0 %; 4,1 dias e 94,0% , respectivamente. O armazenamento em freezer é, portanto, uma forma adequada de conservação de conídios puros de B. bassiana por pelo menos 80 meses.
Resposta funcional de Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) alimentada com Schizaphis graminum (Rondani) (Hemiptera: Aphididae)
Authors: Fonseca Alysson R. , Carvalho César F. , Souza Brígida
Published: April 2006

Estudou-se a resposta funcional de Chrysoperla externa (Hagen) alimentada com cinco densidades de Schizaphis graminum (Rondani). O delineamento experimental foi inteiramente casualizado, com cinco tratamentos e dez repetições. Os ensaios foram conduzidos em câmaras climáticas a 25 ± 1ºC, UR de 70 ± 10 % e fotofase de 12 horas. Observou-se para os três ínstares um maior consumo em função do aumento na densidade de presas oferecidas; porém, houve uma tendência de estabilização no consumo a partir da densidade média de presas pré-estabelecida, exceto para o primeiro ínstar, que apresentou um aumento constante no consumo de pulgões. A duração do primeiro e terceiro ínstares, e da fase de larva como um todo, aumentou em função do aumento na disponibilidade de presas oferecidas. Entretanto, no segundo ínstar, a duração diminuiu em função desse aumento. Os resultados evidenciaram para o 1°, 2° e 3° ínstares e toda a fase de larva uma resposta funcional do Tipo II. Para a densidade média de presas oferecida foi avaliado o tempo de busca e manuseio. O menor tempo de busca foi verificado para larvas de segundo ínstar, enquanto que o primeiro ínstar apresentou o maior tempo de busca e de manuseio. O tempo de manuseio diminuiu progressivamente com o desenvolvimento da larva.
Chemical composition of fruits of some important chestnut cultivars
Authors: Ertürk Ümran , Mert Cevriye , Soylu Arif
Published: April 2006

In this study, chemical compositions of the fruits of some important domestic chestnut types and cultivars were investigated. They contained (g/100g dry matter basis) total carbohydrates 75.32 - 86.31, total sugar 10.32 - 22.79, invert sugar 0.08 - 1.25, starch 54.45 - 69.70, sucrose 8.86 - 21.28, ash 1.02 - 3.22, crude cellulose 3.58 - 5.96, total fat 0.49 - 2.01, total protein 4.88 - 10.87. Ca, Mg, Fe, Mn, Cu, Zn, P, Na and K contents were (mg/100g) 43 - 230, 70 - 160, 0.4 - 5.7, 0.7 - 5.5, 0.6 - 3.8, 1.8 - 9.1, 107 - 191, 6 - 41, 761 - 1271, respectively.
Effects of aerial exposure on antioxidant defenses in the brown mussel Perna perna
Authors: Almeida Eduardo Alves de , Bainy Afonso Celso Dias
Published: April 2006

Investigations were carried out to evaluate the antioxidant defenses in digestive gland of mussels Perna perna held in air for 4 hours, exposed to air for 4 hours followed by submersion in water for 30 minutes, and constantly submerged for 4.5 hours. No differences were observed in CAT and GPx activities and in the levels of total GSH. Mussels exposed to air had significantly higher SOD activity, possibly related to a preparative mechanism of defense against oxidative stress during reoxygenation.
Expression pattern and ontogenesis of thyroid hormone receptor isoforms in the mouse heart
Authors: Stoykov I , Zandieh-Doulabi B , Moorman A F M , Christoffels V , Wiersinga W M , Bakker O
Published: April 2006

Nuclear thyroid hormone (T3) receptors (TR) play a critical role in mediating the effects of T3 on development, differentiation and normal physiology of many organs. The heart is a major target organ of T3, and recent studies in knockout mice demonstrated distinct effects of the different TR isoforms on cardiac function, but the specific actions of TR isoforms and their specific localization in the heart remain unclear. We therefore studied the expression of TRα1, TRα2 and TRβ1 isoforms in the mouse heart at different stages of development, using monoclonal antibodies against TRα1, TRα2 and TRβ1. In order to identify distinct components of the embryonic heart, in situ hybridization for cardiac-specific markers was used with the expression pattern of sarcoplasmic reticulum calcium-ATPase 2a as a marker of myocardial structures, while the pattern of expression of connexin40 was used to indicate the developing chamber myocardium and peripheral ventricular conduction system. Here we show that in the ventricles of the adult heart the TRβ1 isoform is confined to the cells that form the peripheral ventricular conduction system. TRα1, on the other hand, is present in working myocardium as well as in the peripheral ventricular conduction system. In the atria and in the proximal conduction system (sinoatrial node, atrio-ventricular node), TRα1 and TRβ1 isoforms are co-expressed. We also found the heterogeneous expression of the TRα1, TRα2 and TRβ1 isoforms in the developing mouse heart, which, in the case of the TRβ1 isoform, gradually revealed a dynamic expression pattern. It was present in all cardiomyocytes at the early stages of cardiogenesis, but from embryonic day 11.5 and into adulthood, TRβ1 demonstrated a gradual confinement to the peripheral ventricular conduction system (PVCS), suggesting a specific role of this isoform in the formation of PVCS. Detailed knowledge of the distribution of TRα1 and TRβ1 in the heart is of importance for understanding not only their mechanism of action in the heart but also the design and (clinical) use of TR isoform-specific agonists and antagonists.
Increasing plasma thyroxine levels during late embryogenesis and hatching in the chicken are not caused by an increased sensitivity of the thyrotropes to hypothalamic stimulation
Authors: De Groef Bert , Grommen Sylvia V H , Darras Veerle M
Published: April 2006

The hatching process in the chicken is accompanied by dramatic changes in plasma thyroid hormones. The cause of these changes, though crucial for hatching and the onset of endothermy, is not known. One hypothesis is that the pituitary gland becomes more sensitive to hypothalamic stimulation during this period. We have tested whether the responsiveness of the thyrotropes to hypothalamic stimuli changes throughout the last week of embryonic development and hatching by studying the mRNA expression of receptors involved in the control of the secretory activity of this cell type. We used a real-time PCR set-up to quantify whole pituitary mRNA expression of the β subunit of thyrotrophin (TSH-β), type 1 thyrotrophin-releasing hormone receptor (TRH-R1), corticotrophin-releasing hormone receptors (CRH-R1 and CRH-R2) and somatostatin subtype receptor 2 (SSTR2) on every day of the last week of embryonic development, including the day of hatch and the first day of posthatch life. The thyrotrope-specific expression was investigated by a combination of in situ hybridization with immunohistochemistry at selected ages. Although TSH-β mRNA levels increased towards day 19 of incubation (E19), the expression of CRH-R2 and TRH-R1 mRNA by the thyrotropes tended to decrease during this period, suggesting a lower sensitivity of the thyrotropes to the stimulatory factors CRH and TRH. CRH-R1, which is not involved in the control of TSH secretion, increased steadily throughout the period tested. The expression of SSTR2 mRNA by the thyrotropes was low during embryonic development and increased just before hatching. We have concluded that the sensitivity of the pituitary thyrotropes to hypothalamic stimulation decreases throughout the last week of embryonic development, so that the higher expression of TSH-β mRNA around E16–E19, and hence the increasing plasma thyroxine level, is unlikely to be the result of an increased stimulation by either TRH or CRH.
The restricted potential for recovery of growth plate chondrogenesis and longitudinal bone growth following exposure to pro-inflammatory cytokines
Authors: MacRae V E , Farquharson C , Ahmed S F
Published: April 2006

Childhood chronic inflammatory disease can be associated with transient and permanent growth retardation. This study examined the potential for spontaneous growth recovery following pro-inflammatory cytokine exposure. Murine ATDC5 chondrogenic cells and postnatal metatarsals were exposed to interleukin (IL)-1β, IL-6 and tumour necrosis factor-α (TNFα), and their growth and proliferative capacity were determined following recovery. TNFα and IL-1β reduced chondrocyte proliferation and aggrecan and collagen types II and X expression at minimum concentrations of 10 ng/ml and 0.1 ng/ml respectively. TNFα but not IL-1β exposure led to increased caspase-3 activity and altered cellular morphology, consistent with reduced viability. Cytokine exposure particularly inhibited proteoglycan synthesis. This effect was dose and duration dependent. Compared with the control, IL-1β and TNFα led to a 71% and 45% reduction in metatarsal growth after 8 days of exposure respectively (P < 0.05). An additive effect of IL-1β combined with TNFα was observed (110% decrease; P < 0.05). Metatarsals exposed to IL-1β or TNFα individually for a 2-day period, and allowed to recover spontaneously in the absence of cytokines for a further 6 days, showed normal growth trajectories. In combination, growth was 59% lower (P < 0.01) compared with control metatarsals at the end of the recovery period. Exposure to the combination for 4 days followed by a 4-day recovery period resulted in 87% decrement compared with controls (P < 0.05). IL-6 did not alter any parameter studied. IL-1β and TNFα exert diverse inhibitory effects on ATDC5 chondrocyte dynamics and metatarsal growth. The extent of recovery following cytokine exposure depends on the duration of exposure, and may be incomplete following longer periods of exposure.
FSH regulates the formation of adherens junctions and ectoplasmic specialisations between rat Sertoli cells in vitro and in vivo
Authors: Sluka P , O’Donnell L , Bartles J R , Stanton P G
Published: April 2006

Spermatogenesis is dependent on the ability of Sertoli cells to form mature junctions that maintain a unique environment within the seminiferous epithelium. Adjacent Sertoli cells form a junctional complex that includes classical adherens junctions and testis-specific ectoplasmic specialisations (ES). The regulation of inter-Sertoli cell junctions by the two main endocrine regulators of spermatogenesis, FSH and testosterone, is unclear. This study aimed to investigate the effects of FSH and testosterone on inter-Sertoli cell adherens junctions (as determined by immunolocalisation of cadherin, catenin and actin) and ES junctions (as determined by immunolocalisation of espin, actin and vinculin) in cultured immature Sertoli cells and GnRH-immunised adult rat testes given FSH or testosterone replacement in vivo. When hormones were absent in vitro, adherens junctions formed as discrete puncta between interdigitating, finger-like projections of Sertoli cells, but ES junctions were not present. The adherens junction puncta included actin filaments that were oriented perpendicularly to the Sertoli cell plasma membrane, but were not associated with the intermediate filament protein vimentin. When FSH was added in vitro, ES junctions formed, and adjacent adherens junction puncta fused into extensive adherens junction belts. After hormone suppression in vivo, ES junctions were absent, while FSH replacement restored ES junctions, as confirmed by electron microscopy and confocal analysis of ES-associated proteins. Testosterone alone did not affect adherens junctions or ES in vitro or in vivo. We conclude that FSH can regulate the formation of ES junctions and stimulate the organisation and orientation of extensive adherens junctions in Sertoli cells.
Prenatal influences on leptin sensitivity and susceptibility to diet-induced obesity
Authors: Krechowec Stefan O , Vickers Mark , Gertler Arieh , Breier Bernhard H
Published: April 2006

Obesity and type 2 diabetes are world wide health issues and their incidence is rapidly increasing. Currently the biological factors responsible for the development of obesity are only partially understood. Recent research has shown that maternal nutrition during pregnancy may have long-term metabolic consequences in offspring. In the present study we investigated interactions between prenatal and postnatal nutrition on leptin sensitivity and obesity development. Wistar rats were time-mated and randomly assigned to either ad-libitum (AD) or to 30% of ad-libitum (UN) food intake throughout pregnancy. After weaning, female offspring were fed standard chow, a high-fat diet or a calorie restricted diet. Female offspring of UN dams were growth retarded at birth and showed increased susceptibility to diet-induced obesity on a high-fat diet. At 142 ± 5 days of age, leptin sensitivity was measured as a response to 14 days of leptin treatment (2.5 μg/g/day, s.c.). In UN offspring fed chow, leptin treatment failed to reduce food intake and weight loss was diminished. This leptin resistance observed in UN offspring was independent of diet-induced obesity and was associated with fasting hyperinsulinemia and hypertriglyceridemia. Our study suggests that prenatal nutrition can shape future susceptibility to obesity through alterations in leptin sensitivity and changes in energy metabolism during adult life.
Mechanisms of long-term decay of tension stiffening
Authors: Beeby A. W. , Scott R. H.
Published: April 2006

Details of an extensive collaborative project to study tension stiffening have been recently published in a number of papers. Among other factors, the project investigated the loss of tension stiffening with time. It has been concluded that the reduction of tension stiffening to a constant long-term value is fairly rapid, being complete in 10–30 days. This paper explores the mechanisms that may operate to cause the reduction of tension stiffening with time. It is concluded that the loss is mainly attributed to cumulative damage resulting from either the formation of additional surface cracks or the formation or extension of internal cracks. It would appear that the final tension stiffening is only minimally dependent on concrete strength.
Key design issues for autostereoscopic 2‐D/3‐D displays
Authors: Woodgate Graham J. , Harrold Jonathan
Published: April 2006

Abstract— Flat‐panel 2‐D/3‐D autostereoscopic displays are now being commercialized in a variety of applications, each with its own particular requirements. The autostereoscopic display designer has two key considerations to address in order to meet customer needs — the optical output of the display (defined by the output window structure) and the choice of optical components. Window structure determines 3‐D image resolution, achievable lateral and longitudinal viewing freedom, crosstalk, and 3‐D fringe contrast. Optical‐component selection determines the quality of the imaging of such windows, viewing distances, device ruggedness, thickness, and brightness. Trade‐offs in window design are described, and a comparison of the leading optical component technologies is given. Selection of Polarisation Activated Microlenses™ architectures for LCD and OLED applications are described. The technology delivers significant advantages particularly for minimising nominal viewing distances in high pixel density panels and optimizing device ruggedness while maintaining display brightness.
Recent advances in phosphorescent OLEDs for small‐ and large‐area‐display sizes
Authors: Weaver M. S. , Kwong R. C. , Adamovich V. A. , Hack M. , Brown J. J.
Published: April 2006

Abstract— State‐of‐the‐art phosphorescent organic light‐emitting diode (PHOLED™) lifetime and efficiency performances for a range of emission colors are reported. Lifetimes in excess of 100,000 hours were demonstrated at display luminance levels for yellow‐green and NTSC deep‐red emission. In addition, external quantum efficiencies close to the theoretical maximum are demonstrated for long‐lived PHOLEDs.
A method for reproducing apparent continuous depth in a stereoscopic display using “Depth‐Fused 3D” technology
Authors: Kuribayashi Hidenori , Date Munekazu , Suyama Shiro , Hatada Toyohiko
Published: April 2006

Abstract— A new method that can present fine depth increments in a stereoscopic display is proposed. In typical stereoscopic displays, depth can be presented by binocular disparity, but binocular disparity of less than one pixel cannot be displayed because, in general, electronic displays have discrete pixels. We combined binocular disparity and modulation of the edge luminance in DFD (depth‐fused 3D) displays. In an experiment, the perceived depth could be continuously changed by modulating the edge luminance only. Therefore, continuous depth can be produced by combining binocular disparity and modulation of edge luminance distribution.
A comparison of alcohol ethoxylate environmental monitoring data using different analytical procedures
Authors: McAvoy Drew C. , Eckhoff William S. , Begley William M. , Pessler Daniel G.
Published: April 2006

Several analytical methods have been developed for analyzing alcohol ethoxylates (AE) in aqueous environmental samples. These methods differ widely in their selectivity and sensitivity for measuring the AE components; that is, they vary in their resolution of alkyl chain length homologs and ethoxymer distributions (degree of ethoxylation for each homolog). Given these differences, AE monitoring results from different studies often are inconsistent and, sometimes, are deemed to be incomparable. To address these differences, three currently available methods for determining AE concentrations in environmental matrices were compared among a common set of wastewater treatment plant samples. These methods included the detection of hydrogen bromide-derivatized homologs by gas chromatography/mass spectrometry, the detection of aqueous homologs by high-pressure liquid chromatography/electrospray mass spectrometry, and the detection of pyridinium-derivatized homologs by high-pressure liquid chromatography/electrospray mass spectrometry. Results from the present study showed that all three methods responded differently in determining the complex suite of chemical species that comprise AE in the environment. The collective information, however, allowed a consistent comparison among the methods. This comparison was then used to reevaluate results from previous AE monitoring studies. Results from this reevaluation provided a more realistic profile of both historical AE removal during wastewater treatment as well as the occurrence of AE in U.S. surface waters.
Short-term responses to cadmium exposure in the estuarine polychaete Laeonereis acuta (Polychaeta, Nereididae): Subcellular distribution and oxidative stress generation
Authors: Sandrini Juliana Zomer , Regoli Francesco , Fattorini Daniele , Notti Alessandra , Inácio Alan Ferreira , Linde-Arias Ana Rosa , Laurino Jomar , Bainy Afonso Celso Dias , Marins Luis Fernando Fernandes , Monserrat José María
Published: April 2006

Some effects of cadmium exposure (100 μg/L for 4, 8, 12, and 24 h) on the estuarine polychaete Laeonereis acuta (Nereididae) were evaluated. This polychaete was able to accumulate cadmium in the body, with the metal stored mainly in the cytosolic fraction (>10 kDa). Activity of the antioxidant enzymes superoxide dismutase, glutathione S-transferase, and glutathione reductase (GR) as well as the total oxyradical scavenger capacity, the glutamate cysteine ligase catalytic subunit gene expression, and the metallothionein-like proteins content were not affected by cadmium at any exposure time tested. Catalase (CAT) activity, however, was significantly lower (p < 0.05) in worms treated with cadmium compared with that in controls after 8 h of exposure. At the same exposure time, lipid peroxide levels were increased (p < 0.05) in worms exposed to cadmium compared with those in control worms. Interestingly, CAT and GR activities decreased over time (p < 0.05) independent of cadmium treatment, which is a result that could be attributed to starvation. The effects caused by cadmium in the present study were observed only after 8 h of exposure, demonstrating that cadmium can generate oxidative stress.
Weathering and toxicity of marine sediments contaminated with oils and polycyclic aromatic hydrocarbons
Authors: Jonker Michiel T. O. , Brils Jos M. , Sinke Anja J. C. , Murk Albertinka J. , Koelmans Albert A.
Published: April 2006

Many sediments are contaminated with mixtures of oil residues and polycyclic aromatic hydrocarbons (PAH), but little is known about the toxicity of such mixtures to sediment-dwelling organisms and the change in toxicity on weathering. In the present study, we investigated the effects of a seminatural, two-year weathering period on PAH/oil chemistry and toxicity in a marine sediment that had been spiked with three different oils (a gas oil, a lubricating oil, and a crude oil; all tested at five concentrations). Toxicity of bioavailable, pore water-accommodated oil/PAH fractions was quantified using a bacterial (Vibrio fischeri) assay and the in vitro chemical-activated luciferase expression assay (DR-CALUX; using conditions to detect PAHs). Results of chemical analyses pointed to (microbial) degradation of all three oils: Sediment oxygen demand during weathering increased with increasing oil concentration, total oil concentrations decreased to between 17 and 29% of initial levels, and resolved n-alkanes were depleted in weathered oil fractions. Furthermore, a shift in the relative importance of different boiling-point fraction ranges of the oils was observed on weathering. Generally, the lowest fraction range (C10-C16) disappeared, whereas the relative proportion of the highest (C28-C40) fraction range increased considerably. Remarkably, for the gas oil, this fraction shift was dependent on the oil concentration in sediment. Similarly, degradation of PAHs was strongly affected by the sedimentary oil content, indicating that the presence of oil stimulated PAH degradation. This phenomenon applied to both low- and high-molecular-weight PAHs, although the first group (3- and 4-ring PAHs) was degraded most. Results from the V. fischeri and DR-CALUX assay showed that in most cases, pore-water toxicity decreased on weathering. Combining the assay responses with chemical data indicated that the observed toxicity probably was not caused by the analyzed PAHs but, rather, by specific oil constituents instead.
Toxic effects of uranium on Desulfovibrio desulfuricans G20
Authors: Sani Rajesh K. , Peyton Brent M. , Dohnalkova Alice
Published: April 2006

The toxic effects of U(VI) were studied using Desulfovibrio desulfuricans G20 in a medium containing bicarbonate or 1,4-piperazinediethane sulfonic acid disodium salt monohydrate (PIPES) buffer (each at 30 mM and pH 7). Uranium(VI) toxicity was dependent on the medium buffer and was observed in terms of longer lag times and, in some cases, no measurable growth. The minimum inhibiting concentration was 140 μM U(VI) in PIPES-buffered medium. This is 36-fold lower than that reported previously for D. desulfuricans. For all cases in which D. desulfuricans G20 grew in the presence of U(VI), the final cell protein yield was equivalent to that of the U(VI)-free control. In 24 h, D. desulfuricans G20 (total cell protein, 40 mg/L) removed 50 μM U(VI) from solution in PIPES buffer, as compared to 96 μM U(VI) in bicarbonate buffer under anaerobic, nongrowth conditions. Even though the solubility of U(VI) was significantly lower in PIPES buffer than in bicarbonate buffer, U(VI) was much more toxic in PIPES buffer than in bicarbonate buffer. Analysis of thin sections of D. desulfuricans G20 treated with 90 μM U(VI) in medium containing PIPES buffer revealed that only a very small fraction of cells had reduced U precipitates in the periplasmic spaces. In the presence of bicarbonate buffer, however, reduced U was observed not only in the periplasm but also in the cytoplasm. Selected-area electron diffraction patterns and crystallographic analysis of transmission-electron microscopic lattice fringe images confirmed the structure of precipitated U in the cell periplasm and cytoplasm as being that of uraninite. These results suggest that U(VI) toxicity and the detoxification mechanisms of D. desulfuricans G20 depend greatly on the chemical forms of U(VI) that are present.
The efficacy and safety of rituximab in patients with active rheumatoid arthritis despite methotrexate treatment: Results of a phase IIB randomized, double‐blind, placebo‐controlled, dose‐ranging trial
Authors: Emery Paul , Fleischmann Roy , Filipowicz‐Sosnowska Anna , Schechtman Joy , Szczepanski Leszek , Kavanaugh Arthur , Racewicz Artur J. , van Vollenhoven Ronald F. , Li Nicole F. , Agarwal Sunil , Hessey Eva W. , Shaw Timothy M.
Published: April 2006

Objective

To examine the efficacy and safety of different rituximab doses plus methotrexate (MTX), with or without glucocorticoids, in patients with active rheumatoid arthritis (RA) resistant to disease‐modifying antirheumatic drugs (DMARDs), including biologic agents.

Methods

A total of 465 patients were randomized into 9 treatment groups: 3 rituximab groups (placebo [n = 149], 500 mg [n = 124], or 1,000 mg [n = 192] on days 1 and 15) each also taking either placebo glucocorticoids, intravenous methylprednisolone premedication, or intravenous methylprednisolone premedication plus oral prednisone for 2 weeks. All patients received MTX (10–25 mg/week); no other DMARDs were permitted.

Results

Significantly more patients who received 2 500‐mg or 2 1,000‐mg infusions of rituximab met the American College of Rheumatology 20% improvement criteria (achieved an ACR20 response) at week 24 (55% and 54%, respectively) compared with placebo (28%; P < 0.0001). ACR50 responses were achieved by 33%, 34%, and 13% of patients, respectively (P < 0.001), and ACR70 responses were achieved by 13%, 20%, and 5% of patients (P < 0.05). Changes in the Disease Activity Score in 28 joints (−1.79, −2.05, −0.67; P < 0.0001) and moderate to good responses on the European League Against Rheumatism criteria (P < 0.0001) reflected the ACR criteria responses. Glucocorticoids did not contribute significantly to the primary efficacy end point, ACR20 response at 24 weeks. Intravenous glucocorticoid premedication reduced the frequency and intensity of first infusion–associated events; oral glucocorticoids conferred no additional safety benefit. Rituximab was well tolerated; the type and severity of infections was similar to those for placebo.

Conclusion

Both rituximab doses were effective and well tolerated when added to MTX therapy in patients with active RA. The primary end point (ACR20 response) was independent of glucocorticoids, although intravenous glucocorticoid premedication improved tolerability during the first rituximab infusion.
Benefit of taxanes as adjuvant chemotherapy for early breast cancer
Authors: Bria Emilio , Nistico Cecilia , Cuppone Federica , Carlini Paolo , Ciccarese Mariangela , Milella Michele , Natoli Guido , Terzoli Edmondo , Cognetti Francesco , Giannarelli Diana
Published: April 2006

BACKGROUND

The magnitude of the survival benefit of taxanes as adjuvant chemotherapy for early breast cancer is still unclear. A pooled analysis of Phase III trials was performed to assess the advantages that adjuvant taxane chemotherapy has over standard chemotherapy.

METHODS

All Phase III trials were considered eligible. A pooled analysis was accomplished and event‐based relative risk ratios (RR) with 95% confidence intervals (95% CI) were derived. The significant differences in disease‐free survival (DFS) and overall survival (OS) were explored. Magnitude outcome measures were absolute benefits and the number of patients needed to treat. A heterogeneity test was applied as well. A sensitivity analysis in 6 subpopulations was also performed.

RESULTS

Nine trials designed to assess if paclitaxel or docetaxel improve survival (15,598 patients) were gathered. One of the 9 trials did not report OS results. Significant differences in favor of taxanes were seen in DFS in the overall (RR: 0.86; 95% CI, 0.81–0.90 [P<.00001]) and lymph node‐positive population (RR: 0.84; 95% CI, 0.79–0.89 [P<.0001]), and in OS in the overall (RR: 0.87; 95% CI, 0.81–0.83 [P<.0001]) and lymph node‐positive population (RR: 0.84; 95% CI, 0.77–0.92 [P<.0001]). The absolute benefits in DFS and OS in favor of taxanes ranged from 3.3% to 4.6% and from 2.0% to 2.8%, respectively.

CONCLUSIONS

Considering all the available Phase III trials, taxane‐based adjuvant chemotherapy for early breast cancer seems to add a significant benefit in both DFS and OS over standard chemotherapy. The lack of significant heterogeneity in the sensitivity analysis underscores the homogeneous effect across all trials. Cancer 2006. © 2006 American Cancer Society.
Quality of life in long‐term survivors of bladder cancer
Authors: Allareddy Veerasathpurush , Kennedy Julianna , West Michele M. , Konety Badrinath R.
Published: April 2006

BACKGROUND

The quality of life (QOL) of long‐term survivors of bladder cancer in a population‐based registry was assessed.

METHODS

The Functional Assessment of Cancer Therapy (FACT‐BL) instrument was used to evaluate QOL in a population‐based sample of bladder cancer patients. QOL scores were compared between those undergoing radical cystectomy (RC) or those with an intact bladder (BI) and between continent and conduit urinary diversion groups. The influence of current age and time since diagnosis of cancer on QOL were also examined. Multivariate regression analyses were performed to examine the influence of age, time since diagnosis, current condition, treatment, stage of cancer, and comorbid conditions on QOL.

RESULTS

A total of 259 patients participated in the study who had undergone RC (n = 82) or other therapy (BI) (n = 177). There were no differences in general QOL scores between RC and BI groups and between the 2 urinary diversion groups, but patients undergoing RC had worse sexual function scores. QOL scores for BI patients tended to decrease with increasing age (P = .01). Presence of comorbid conditions lowered QOL (P<.05).

CONCLUSIONS

General QOL does not vary among long‐term bladder cancer survivors regardless of treatment, but sexual functioning can be adversely affected in those undergoing cystectomy. Long‐term QOL declines even in those with intact bladders, particularly in those with comorbidities. Cancer 2006. © 2006 American Cancer Society.
Controlling delivery properties of a waterborne, in‐situ‐forming biomaterial
Authors: McLemore Ryan , Preul Mark C. , Vernon Brent L.
Published: April 2006

This study details efforts to transition an in‐situ‐gelling polymer for endovascular embolization from the bench‐top to preclinical cerebral arteriovenous malformation animal model studies. The in‐situ‐forming gel is based on waterborne, reverse emulsion materials. For controlled embolization of vascular defects, it is crucial to understand the delivery properties of an in‐situ‐forming gel. Directing a liquid into a small cavity requires both precise control of the fluid flow, and depends upon minimal variability in the materials behavior. A 23 factorial experiment performed in the laboratory revealed that temperature, mixing time, and buffer strength are all significant factors affecting the gelation time of the specific system studied. All three factors were also seen to reduce the standard deviation on the gel times. Changing the temperature from 21.3 to 37.0°C reduced the cross population variability from 6.0 ± 3.3 min to 3.4 ± 1.6 min. At 30‐s premixing, the protocol produced an average gel time of 5.3 ± 3.0 min, which was reduced to 3.3 ± 1.2 min with 90 s. Finally, a 50 mM buffer solution provided a gel time of 6.5 ± 3.2 min, which was reduced to 2.95 ± 0.6 min at 100 mM. Viscosity data was analyzed to suggest a model for injection volume and viscosity. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
Diffusion‐induced water movement within resin–dentin bonds during bonding
Authors: Hashimoto Masanori , Tay Franklin R. , Sano Hidehiko , Kaga Masayuki , Pashley David H.
Published: April 2006

It is thought that water‐filled channels and nanovoids in resin–dentin bonds represent potential sites for degradation of bonds or hydrolysis of collagen or both. How water gains access to bonded interfaces is not clear. This study evaluated the diffusion‐induced water uptake through resin–dentin interfaces during bonding. Two light‐cured total‐etch adhesive systems (Excite and One‐Step Plus) and a chemical‐cured adhesive (Amalgambond Plus) were used in this study. Dentin disks were placed in a split‐chamber device, and the fluid movement across dentin was measured, with and without a physiological pressure, during bonding procedures and 24 h after bonding. For light‐cured adhesives in the experimental groups, a 6 min interval of dark storage was conducted prior to light‐curing, to evaluate the diffusion of water through the uncured resin monomers, and to test the effect of prolonged infiltration time of adhesives on water permeability of bonds. Prolonged adhesive infiltration reduced the water permeability of resin–dentin bonds for light‐cured adhesives. Water gradients produced by bonding systems contribute to water movement across the dentin–adhesive interfaces during bonding procedures. Differences in chemical formulations for adhesive systems may lead to differences in the extent of diffusion‐induced water movement and the amount of water within the resin–dentin bonds. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2006
The role of fMRI in drug discovery
Authors: Wise Richard G. , Tracey Irene
Published: April 2006

Pharmacological functional (phMRI) studies are making a significant contribution to our understanding of drug‐effects on brain systems. Pharmacological fMRI has an additional contribution to make in the translation of disease models and candidate compounds from preclinical to clinical investigation and in the early clinical stages of drug development. Here it can demonstrate a proof‐of‐concept of drug action in a small human cohort and thus contribute substantially to decision‐making in drug development. We review the methods underlying pharmacological fMRI studies and the links that can be made between animal and human investigations. We discuss the potential fMRI markers of drug effect, experimental designs and caveats in interpreting hemodynamic fMRI data as reflective of changes in neuronal activity. Although there are no current published examples of fMRI applied to novel compounds, we illustrate the potential of fMRI across a range of applications and with specific reference to processing of pain in the human brain and pharmacological analgesia. Pharmacological fMRI is developing to meet the neuroscientific challenges. Electrophysiological methods can be used to corroborate the drug effects measured hemodynamically with fMRI. In future, pharmacological fMRI is likely to extend to examinations of the spinal cord and into pharmacogenetics to relate genetic polymorphisms to differential responses of the brain to drugs. J. Magn. Reson. Imaging 2006. © 2006 Wiley‐Liss, Inc.
Opioid peptides and receptors in joint tissues: Study in the rat
Authors: Bergström Jonas , Ahmed Mahmood , Li Jian , Ahmad Tashfeen , Kreicbergs Andris , Spetea Mariana
Published: April 2006

Using immunohistochemical and biochemical techniques, the occurrence of endogenous opioid peptides and their receptors in normal rat bone and joint tissues was investigated. Opioid receptors were detected, quantified, and characterized in homogenates from capsule/synovium and periosteum using radioligand binding assays. Receptor binding of the nonselective opioid [3H]naloxone to tissue homogenates was stereospecific and saturable, showing similar characteristics to that of brain tissue, although with lower binding capacities. By immunohistochemistry, the neuronal occurrence of four different enkephalins was demonstrated in synovium, bone marrow, periosteum, and juxta‐articular bone, whereas no neuronal dynorphin immunoreactivity was detected. Double‐staining studies disclosed that enkephalins coexisted with substance P in primary afferent fibers. The applied techniques can be used to assess changes in the distribution of endogenous opioids and their receptors in joint tissues in conditions associated with pain and inflammation. The endogenous opioid system now demonstrated might be targeted and exploited therapeutically to obtain peripheral control of symptoms in joint disorders. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Correlation of swelling pressure and intrafibrillar water in young and aged human intervertebral discs
Authors: Sivan Sarit , Merkher Yulia , Wachtel Ellen , Ehrlich Shlomit , Maroudas Alice
Published: April 2006

Fluid balance in the intervertebral disc under applied load is determined primarily by its swelling pressure, that is, the external pressure at which it neither loses nor gains water. This depends on the composition of the tissue, in particular on its proteoglycan concentration. Proteoglycans develop a high osmotic pressure due to their fixed negatively charged groups. Because of their size, proteoglycans are excluded from the collagen's intrafibrillar volume; hence their osmotic activity is determined only by the extrafibrillar water. Here, we show that in order to evaluate correctly the swelling pressure in the annuli fibrosi of human intervertebral disc, it is essential to evaluate its proportion of intrafibrillar water. We used low‐angle X‐ray scattering and osmotic stress techniques to determine the lateral packing of the collagen molecules in the fibrils of the annuli fibrosi (ages: 25–77). It was found that the lateral packing and, hence, the intrafibrillar water content depends on age, external osmotic pressure, and location in the tissue. Subtracting intrafibrillar water from total hydration yields the amount of extrafibrillar water, from which the true fixed charge density of the tissue could be estimated. From a force balance, it would appear that collagen tension plays only a minor role in the equilibrium of the human intervertebral disc under load, in contrast to articular cartilage, where collagen tension is important for load bearing. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res
Analysis of carbohydrates and glycoconjugates by matrix‐assisted laser desorption/ionization mass spectrometry: An update covering the period 1999–2000
Authors: Harvey David J.
Published: April 2006

This review describes the use of matrix‐assisted laser desorption/ionization (MALDI) mass spectrometry for the analysis of carbohydrates and glycoconjugates and continues coverage of the field from the previous review published in 1999 (D. J. Harvey, Matrix‐assisted laser desorption/ionization mass spectrometry of carbohydrates, 1999, Mass Spectrom Rev, 18:349–451) for the period 1999–2000. As MALDI mass spectrometry is acquiring the status of a mature technique in this field, there has been a greater emphasis on applications rather than to method development as opposed to the previous review. The present review covers applications to plant‐derived carbohydrates, N‐ and O‐linked glycans from glycoproteins, glycated proteins, mucins, glycosaminoglycans, bacterial glycolipids, glycosphingolipids, glycoglycerolipids and related compounds, and glycosides. Applications of MALDI mass spectrometry to the study of enzymes acting on carbohydrates (glycosyltransferases and glycosidases) and to the synthesis of carbohydrates, are also covered. © 2006 Wiley Periodicals, Inc., Mass Spec Rev 25:595–662, 2006