bluuebunny/crossref_metadata_2025 huggingface dataset:
Independent Regulation of ABCB1 and ABCC Activities in Thymocytes and Bone Marrow Mononuclear Cells during Aging
Authors: Kyle‐Cezar F. , Echevarria‐Lima J. , Rumjanek V. M.
Published: June 2007

Aging modifies a number of functional and phenotypic parameters of cells from the immune system. In this study, the activities of two members of the superfamily of ATP‐binding cassette (ABC) transport proteins, ABCB1 and ABCC (measured by rhodamine 123 efflux and Fluo‐3 efflux respectively), were compared in murine bone marrow cells and thymocytes of young (3–4 weeks old), adult (2–3 months old) and old (18 months old) mice. ABCB1 activity was shown to be age regulated in murine bone marrow mononuclear cells and thymocytes. In the bone marrow, the increased amount of cells with ABCB1 activity observed in old mice was restricted to the c‐kit−Sca‐1+ and c‐kit+Sca‐1+ subpopulations. Only a small percentage of c‐kit+ cells in the thymus had ABCB1 activity, and this subpopulation increased with age. In the thymus, old age augmented this activity in the CD4− CD8− double‐negative cells and in the CD4+ and CD8+ single‐positive populations. The activity of another ABC transporter, the ABCC‐related activity, was also modified by age in the bone marrow. However, the age‐related increase was observed in the subpopulations were ABCB1 was not modified, namely the non‐progenitor population (c‐kit−Sca‐1−cells) and c‐kit+Sca‐1− cells. Nearly, all thymocytes expressed the ABCC1 molecule in an active form and aging did not affect this pattern. This study demonstrates an independent upregulation of ABCB1 and ABCC activities during the aging process. The increases were observed in different subsets of cells but followed a developmentally regulated pattern. The functions played by these transporters and alterations in aging are discussed.
Universal Optimization of Flight Initiation Distance and Habitat‐Driven Variation in Escape Tactics in a Namibian Lizard Assemblage
Authors: Cooper William E. , Whiting Martin J.
Published: June 2007

Some aspects of escape predicted by theoretical models are intended to apply universally. For example, flight initiation distance (distance between an approaching predator and prey when escape begins) is predicted from predation risk and the costs of escaping. Escape tactics and refuge selection are not currently predicted by theoretical models, but are expected to vary with structural features of the habitat. One way of studying such variation is to compare aspects of antipredatory behavior among sympatric species that differ in habitat or microhabitat use. In an assemblage of lizards in northwestern Namibia, we conducted experiments to test predictions of escape theory for three risk factors in representatives of three families and observed escape tactics in additional species. As predicted by escape theory, flight initiation distance increased with directness of a predator's approach and predator speed in Agama planiceps, Mabuya acutilabris, and Rhotropus boultoni, and with distance from refuge in M. acutilabris. As predicted by theory, the probability of entering refuge increased with risk in R. boultoni. All available data indicate that flight initiation distance and refuge entry by lizards conform to theoretical predictions. Escape tactics varied greatly as a function of habitat type: (1) arboreal species fled up and around trees and sometimes entered tree holes; (2) saxicolous species used rock crevices as refuges, but differed in tactics prior to entering refuges; and (3) terrestrial species fled into bushes or other vegetation, often to the far sides of them. Some M. acutilabris entered small animal burrows or buried themselves in sand beneath bushes. Escape tactics varied even among congeners in Mabuya, highlighting the important effect of habitat structure on them. Although habitat partitioning has traditionally been viewed as favoring species coexistence, an interesting by‐product appears to be structuring of escape tactics in lizard communities.
The influence of exercise on foot perfusion in diabetes
Authors: Williams D. T. , Harding K. G. , Price P. E.
Published: June 2007

Aims  Diabetic foot disease is associated with both macro‐ and microvascular disease. Exercise has both positive and negative effects on the perfusion of lower limbs with peripheral arterial occlusive disease (PAOD). We aimed to measure changes in foot perfusion following a brief period of lower‐limb exercise in individuals with and without Type 2 diabetes and non‐critical PAOD.

Methods  Subjects were allocated to groups according to the presence or absence of diabetes, PAOD on colour duplex imaging and clinically detectable peripheral neuropaÍthy. Transcutaneous oxygen tension (TcPO2), transcutaneous carbon dioxide tension (TcPCO2), ankle‐brachial pressure indices, toe pressures and toe‐brachial pressure indices (TBI) were measured.

Results  One hundred and sixteen limbs were studied in 61 subjects. Post‐exercise, toe pressure and TBI increased in the non‐diabetic group with arterial disease, but not in the groups with diabetes. Foot TcPO2 values increased in groups with diabetes and TcPCO2 decreased in all groups with arterial disease. Increased chest TcPO2 and decreased TcPCO2 were demonstrated in the groups with diabetes.

Conclusions  Elevations in foot TcPO2 and reductions in TcPCO2 indicate improved cutaneous perfusion response to local heating post‐exercise. Elevated toe pressures in the non‐diabetes group suggest that improved perfusion may be associated with enhanced lower limb macrovascular haemodynamics. However, improvements in TcPO2 and TcPCO2 at foot and chest sites in diabetes imply a global change in cutaneous perfusion. The results suggest that brief exercise results in an improvement in cutaneous perfusion in non‐critical PAOD, particularly in individuals with diabetes.
Oral and general health behaviours among Chinese urban adolescents
Authors: Petersen Poul Erik , Jiang Han , Peng Bin , Tai Bao Jun , Bian Zhuan
Published: June 2007

Abstract –  Objectives:  The objectives of this study were to measure the association of general and oral health‐related behaviours with living conditions and to explore the interrelationships between general and oral health‐related behaviours in Chinese urban adolescents.

Methods:  A cross‐sectional survey of 2662 adolescents was conducted in eight Chinese provincial capitals. The response rate was 92%. The study population was selected through multistage cluster sampling and comprised three age groups: 11, 13 and 15 years. Data on oral and general health, lifestyles as well as living conditions were collected by means of self‐administered structured questionnaires. Several additive indices were constructed from answers to the questions on specific behaviour, and participants were categorized according to scores on each component of health‐related behaviour for statistical analyses by frequency distributions, regression analyses and factor analyses.

Results:  Oral health‐related behaviours among adolescents were associated with socioeconomic status of parents, school performance and peer relationships. The odds of a dental visit was 0.63 in adolescents of poorly educated parents and the corresponding figure for regular oral hygiene practices was 0.62. Odds of tobacco use was 3 for adolescents with poor performance in school while odds of consuming sugary foods/drinks was 1.3. Adolescents with high levels of preventive oral health practices also demonstrated general health‐promoting behaviours. In factor analysis of general and oral health‐related behaviours, three factors were isolated: (a) risk behaviours (loadings 0.48–0.66), (b) health‐promoting behaviours (loadings 0.60–0.64) and (c) help‐seeking behaviours (loadings 0.56–0.67).

Conclusion:  The findings support a multidimensional model of health behaviour. Several approaches and multiple methods should be applied in oral health education in order to modify behaviours that affect oral health.
Children's Expectations of Pain, Perceptions of Analgesic Efficacy, and Experiences With Nonpharmacologic Pain Management Strategies at Home Following Tonsillectomy
Authors: Sutters Kimberly A. , Savedra Marilyn C. , Miaskowski Christine , Holdridge‐Zeuner Danielle , Waite Steven , Paul Steven M. , Lanier Brent
Published: June 2007

PURPOSE.  To document children's (ages 6–15 years) descriptions of their pain management at home following tonsillectomy.

DESIGN AND METHODS.  Audio‐taped interviews of 80 children were transcribed and coded. Data for each response category were tabulated.

RESULTS.  Children reported they had more pain after surgery than expected, the pain medicine helped to take their pain away, taking the pain medicine was associated with a negative response by some children, and cold liquids/food by mouth provided pain relief.

PRACTICE IMPLICATIONS.  Findings provide insight into children's perspective of pain management at home following tonsillectomy and methods for relieving their pain.
Experimental and Numerical Investigation of a Swirl Stabilized Premixed Combustor Under Cold-Flow Conditions
Authors: Strakey P. A. , Yip M. J.
Published: June 2007

Planar velocity measurements under cold-flow conditions in a swirl-stabilized dump combustor typical of land-based gas turbine combustors were carried out using two-dimensional particle image velocimetry (PIV). Axial, radial, and tangential velocity components were measured sequentially using two experimental configurations. Mean and root-mean-squared velocity components are presented along with instantaneous realizations of the flowfield. A numerical study of the flowfield using large-eddy simulation (LES) and Reynolds-averaged Navier-Stokes (RANS) techniques was conducted in an effort to help understand the complex hydrodynamics observed in the experiments. The agreement between the experimental data and LES simulation was good with both showing evidence of a precessing vortex core. The results of the RANS simulation were not as encouraging. The results provide a fundamental understanding of the complex flowfield associated with the relatively simple geometry and also serve as a baseline validation dataset for further numerical simulations of the current geometry. Validation of LES models in a highly swirled, nonreacting flowfield such as the work presented here is an essential step towards more accurate prediction in a reacting environment.
Assessment and Modification of One-Equation Models of Turbulence for Wall-Bounded Flows
Authors: Elkhoury M.
Published: June 2007

This work assesses the performance of two single-equation eddy viscosity transport models that are based on Menter’s transformation of the k-ε and the k-ω closures. The coefficients of both models are set exactly the same and follow directly from the constants of the standard k-ε closure. This in turn allows a cross-comparison of the effect of two different destruction terms on the performance of single-equation closures. Furthermore, some wall-free modifications to production and destruction terms are proposed and applied to both models. An assessment of the baseline models with and without the proposed modifications against experiments, and the Spalart-Allmaras turbulence model is provided via several boundary-layer computations. Better performance is indicated with the proposed modifications in wall-bounded nonequilibrium flows.
FOURTH ORDER GRAVITY: EQUATIONS, HISTORY, AND APPLICATIONS TO COSMOLOGY
Authors: SCHMIDT HANS-JÜRGEN
Published: June 2007

The field equations following from a Lagrangian L(R) will be deduced and solved for special cases. If L is a non-linear function of the curvature scalar, then these equations are of fourth order in the metric. In the introduction, we present the history of these equations beginning with the paper of H. Weyl from 1918, who first discussed them as alternative to Einstein's theory. In the third part, we give details about the cosmic no hair theorem, i.e. the details of how within fourth order gravity with L= R + R2, the inflationary phase of cosmic evolution turns out to be a transient attractor. Finally, the Bicknell theorem, i.e. the conformal relation from fourth order gravity to scalar-tensor theory, will be shortly presented.
Çatalhöyük in the Context of the Middle Eastern Neolithic
Authors: Hodder Ian
Published: June 2007

This review aims to show how the new results from Çatalhöyük in central Turkey contribute to wider theories about the Neolithic in Anatolia and the Middle East. I argue that many of the themes found in symbolism and daily practice at Çatalhöyük occur very early in the processes of village formation and the domestication of plants and animals throughout the region. These themes include a social focus on memory construction; a symbolic focus on wild animals, violence, and death; and a central dominant role for humans in relation to the animal world. These themes occur early enough throughout the region that we can claim they are integral to the development of settled life and the domestication of plants and animals. Particularly the focus on time depth in house sequences may have been part of the suite of conditions, along with environmental and ecological factors, that “selected for” sedentism and domestication.
Interstitial Flow and Its Effects in Soft Tissues
Authors: Swartz Melody A. , Fleury Mark E.
Published: June 2007

Interstitial flow plays important roles in the morphogenesis, function, and pathogenesis of tissues. To investigate these roles and exploit them for tissue engineering or to overcome barriers to drug delivery, a comprehensive consideration of the interstitial space and how it controls and affects such processes is critical. Here we attempt to review the many physical and mathematical correlations that describe fluid and mass transport in the tissue interstitium; the factors that control and affect them; and the importance of interstitial transport on cell biology, tissue morphogenesis, and tissue engineering. Finally, we end with some discussion of interstitial transport issues in drug delivery, cell mechanobiology, and cell homing toward draining lymphatics.
microRNA Functions
Authors: Bushati Natascha , Cohen Stephen M.
Published: June 2007

microRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional gene regulation. In animal cells, miRNAs regulate their targets by translational inhibition and mRNA destabilization. Here, we review recent work in animal models that provide insight into the diverse roles of miRNAs in vivo.
Two Families of Chaperonin: Physiology and Mechanism
Authors: Horwich Arthur L. , Fenton Wayne A. , Chapman Eli , Farr George W.
Published: June 2007

Chaperonins are large ring assemblies that assist protein folding to the native state by binding nonnative proteins in their central cavities and then, upon binding ATP, release the substrate protein into a now-encapsulated cavity to fold productively. Two families of such components have been identified: type I in mitochondria, chloroplasts, and the bacterial cytosol, which rely on a detachable “lid” structure for encapsulation, and type II in archaea and the eukaryotic cytosol, which contain a built-in protrusion structure. We discuss here a number of issues under current study. What is the range of substrates acted on by the two classes of chaperonin, in particular by GroEL in the bacterial cytoplasm and CCT in the eukaryotic cytosol, and are all these substrates subject to encapsulation? What are the determinants for substrate binding by the type II chaperonins? And is the encapsulated chaperonin cavity a passive container that prevents aggregation, or could it be playing an active role in polypeptide folding?
The Bacillus and Myxococcus Developmental Networks and Their Transcriptional Regulators
Authors: Kroos Lee
Published: June 2007

Studies of endospore formation by Bacillus subtilis and fruiting body development of Myxococcus xanthus have revealed key features of regulatory networks that govern temporal and spatial gene expression in bacteria. In B. subtilis, σ factor cascades, modulated by other types of transcription factors, regulate genes in two cell types that form and communicate with each other during starvation-induced sporulation. In M. xanthus, starving cells also send signals that alter gene expression, but the cascade to emerge so far involves transcription factors other than σ factors. A hundred thousand cells coordinate their movements to build a fruiting body in which spores form. The two regulatory networks are compared, and questions that remain are identified.
Electron Holography: Applications to Materials Questions
Authors: Lichte Hannes , Formanek Petr , Lenk Andreas , Linck Martin , Matzeck Christopher , Lehmann Michael , Simon Paul
Published: June 2007

Impressive progress has been made in the processing and exploration of new material on an atomic scale (nanomaterials). However, the characterization of such materials by the usual transmission electron microscopy (TEM) techniques suffers from the drawback that the phase of the object-modulated electron wave is virtually lost in the recorded intensity images. Electron holography has opened possibilities for analyzing both the amplitude and phase of the electron wave, hence giving access to the object information encoded in the phase. Examples include intrinsic electric and magnetic fields, e.g. in ferroelectrics or ferromagnetics, which substantially determine the object properties and therefore are indispensable for a complete understanding of structure-properties relations.
Chlorophyll Biosynthesis in Bacteria: The Origins of Structural and Functional Diversity
Authors: Chew Aline Gomez Maqueo , Bryant Donald A
Published: June 2007

The use of photochemical reaction centers to convert light energy into chemical energy, chlorophototrophy, occurs in organisms belonging to only five eubacterial phyla: Cyanobacteria, Proteobacteria, Chlorobi, Chloroflexi, and Firmicutes. All chlorophototrophs synthesize two types of pigments: (a) chlorophylls and bacteriochlorophylls, which function in both light harvesting and uniquely in photochemistry; and (b) carotenoids, which function primarily as photoprotective pigments but can also participate in light harvesting. Although hundreds of carotenoids have been identified, only 12 types of chlorophylls (Chl a, b, d; divinyl-Chl a and b; and 81-hydroxy-Chl a) and bacteriochlorophylls (BChl a, b, c, d, e, and g) are currently known to occur in bacteria. This review summarizes recent progress in the identification of genes and enzymes in the biosynthetic pathways leading to Chls and BChls, the essential tetrapyrrole cofactors of photosynthesis, and addresses the mechanisms for generating functional diversity for solar energy capture and conversion in chlorophototrophs.
Microbial Metabolism of Reduced Phosphorus Compounds
Authors: White Andrea K. , Metcalf William W.
Published: June 2007

The field of bacterial phosphorus (P) metabolism has undergone a significant transformation in the past decade owing to the elucidation of widespread and diverse pathways for the metabolism of reduced P compounds. The characterization of these pathways dramatically changes the current and narrow view of P metabolism and our understanding of the forms in which P is produced and available in the environment. In this review, recent investigations into the biochemical pathways and molecular genetics of reduced P metabolism in bacteria are discussed. Particular attention is paid to recently elucidated metabolic reactions and the genetic characterization of biosynthesis of organic reduced P compounds and to the pathways for oxidation of the inorganic reduced P compounds hypophosphite and phosphite.
40 Years with Bacteriophage ø29
Authors: Salas Margarita
Published: June 2007

I have dedicated the past 46 years of my life to science and I expect to be active in research for many more years. I have been lucky in my professional life. During my postdoctoral years I discovered two proteins that I showed to be involved in the initiation of protein synthesis. Working with bacteriophage ø29 for the past 40 years, we have made many interesting findings. Among them is the discovery of a protein covalently linked to the 5′ ends of ø29 DNA that we later showed to be the primer for the initiation of ø29 DNA replication. Also, the finding of the ø29 DNA polymerase with its properties of high processivity, strand displacement, and high fidelity has been very rewarding. The ø29 DNA polymerase has become the ideal enzyme for DNA amplification, both rolling circle and whole-genome amplification. I also am happy because I have worked with many brilliant students and collaborators over the years, most of whom have become excellent scientists.
Glauber Modeling in High-Energy Nuclear Collisions
Authors: Miller Michael L. , Reygers Klaus , Sanders Stephen J. , Steinberg Peter
Published: June 2007

We review the theoretical background, experimental techniques, and phenomenology of what is known in relativistic heavy ion physics as the Glauber model, which is used to calculate geometric quantities. A brief history of the original Glauber model is presented, with emphasis on its development into the purely classical, geometric picture used for present-day data analyses. Distinctions are made between the optical limit and Monte Carlo approaches, which are often used interchangeably but have some essential differences in particular contexts. The methods used by the four RHIC experiments are compared and contrasted, although the end results are reassuringly similar for the various geometric observables. Finally, several important RHIC measurements are highlighted that rely on geometric quantities, estimated from Glauber calculations, to draw insight from experimental observables. The status and future of Glauber modeling in the next generation of heavy ion physics studies is briefly discussed.
Physics of String Flux Compactifications
Authors: Denef Frederik , Douglas Michael R. , Kachru Shamit
Published: June 2007

We provide a qualitative review of flux compactifications of string theory, focusing on broad physical implications and statistical methods of analysis.
Regulation of Lipolysis in Adipocytes
Authors: Duncan Robin E. , Ahmadian Maryam , Jaworski Kathy , Sarkadi-Nagy Eszter , Sul Hei Sook
Published: June 2007

Lipolysis of white adipose tissue triacylglycerol stores results in the liberation of glycerol and nonesterified fatty acids that are released into the vasculature for use by other organs as energy substrates. In response to changes in nutritional state, lipolysis rates are precisely regulated through hormonal and biochemical signals. These signals modulate the activity of lipolytic enzymes and accessory proteins, allowing for maximal responsiveness of adipose tissue to changes in energy requirements and availability. Recently, a number of novel adipocyte triacylglyceride lipases have been identified, including desnutrin/ATGL, greatly expanding our understanding of adipocyte lipolysis. We have also begun to better appreciate the role of a number of nonenzymatic proteins that are critical to triacylglyceride breakdown. This review provides an overview of key mediators of lipolysis and the regulation of this process by changes in nutritional status and nutrient intakes.
Vitamin E Regulatory Mechanisms
Authors: Traber Maret G.
Published: June 2007

Dietary and supplemental vitamin E is absorbed and delivered to the liver, but of the various antioxidants with vitamin E activity, only α-tocopherol is preferentially recognized by the α-tocopherol transfer protein (α-TTP) and is transferred to plasma, while the other vitamin E forms (e.g., γ-tocopherol or tocotrienols) are removed from the circulation. Hepatic α-TTP is required to maintain plasma and tissue α-tocopherol concentrations. The liver is the master regulator of the body's vitamin E levels in that it not only controls α-tocopherol concentrations, but also appears to be the major site of vitamin E metabolism and excretion. Vitamin Es are metabolized similarly to xenobiotics; they are initially ω-oxidized by cytochrome P450s, undergo several rounds of β-oxidation, and then are conjugated and excreted. As a result of these various mechanisms, liver α-tocopherol and other vitamin E concentrations are closely regulated; thus, any potential adverse vitamin E effects are limited.
Structure and Function of Resistance Proteins in Solanaceous Plants
Authors: van Ooijen Gerben , van den Burg Harrold A. , Cornelissen Ben J. C. , Takken Frank L. W.
Published: June 2007

Gene-for-gene resistance in plants is based on the presence of a resistance (R) gene in the host and a matching Avirulence (Avr) gene in the pathogen. Many R genes have been cloned over the past two decades, mostly from the Solanaceae. The gene products, called R proteins, display modular domain structures. R protein function has recently been shown to require dynamic interactions between the various domains. In addition to these intramolecular interactions, R proteins interact with other proteins to form signaling complexes that are able to activate an innate immune response that arrests proliferation of the invading pathogen, thereby conferring disease resistance. In this review, we summarize current understanding of R protein structure and function, as well as the molecular mechanisms underlying the activation of defense signaling processes. As well as being a rich source for R genes, Solanaceae are a leading model system in which to study inter- and intramolecular interactions of R proteins.
Bourdieu in American Sociology, 1980–2004
Authors: Sallaz Jeffrey J. , Zavisca Jane
Published: June 2007

This article traces the transatlantic diffusion of Pierre Bourdieu's ideas into American sociology. We find that rather than being received as abstract theory, Bourdieu has been actively put to use to generate new empirical research. In addition, American sociologists have used their findings to problematize and extend his theory. Bourdieu's sociology, in other words, has inspired a progressive research program in the United States. We trace this process in the two main forums for presenting research: journal articles and books. Content analysis of articles published in four major sociology journals reveals that, far from a recent fad, Bourdieu's ideas steadily diffused into American sociology between 1980 and 2004. Case studies of four influential books in turn illustrate how researchers have used Bourdieu's key concepts (capital, field, habitus, and symbolic power) to inform debates in four core subfields (political, economic, cultural, and urban sociology).
Hispanic Families: Stability and Change
Authors: Landale Nancy S. , Oropesa R.S.
Published: June 2007

Spurred in part by the rapid growth of the Hispanic population, considerable progress has been made over the past several decades in documenting the family behavior of Hispanics. Scholars increasingly recognize the importance of disaggregating the Hispanic population by national origin and generation, but the literature remains inconsistent in this regard. With an emphasis on demographic indicators of family behavior, this review summarizes trends in marriage, fertility, and family/household structure among the major Hispanic subgroups and identifies key issues in the literature that attempts to explain existing patterns. The role of generation is systematically addressed, as are the shortcomings of the standard practice of using cross-sectional data on generation to draw inferences about assimilation. We conclude that new research designs are needed to address the complexities of the migration process and their links to family patterns. In addition, future research should push toward greater integration of cultural and structural perspectives on how Hispanic families are shaped.
Toward a Historicized Sociology: Theorizing Events, Processes, and Emergence
Authors: Clemens Elisabeth S.
Published: June 2007

Since the 1970s, historical sociology in the United States has been constituted by a configuration of substantive questions, a theoretical vocabulary anchored in concepts of economic interest and rationalization, and a methodological commitment to comparison. More recently, this configuration has been destabilized along each dimension: the increasing autonomy of comparative-historical methods from specific historical puzzles, the shift from the analysis of covariation to theories of historical process, and new substantive questions through which new kinds of arguments have been elaborated. Although the dominant responses have centered on methodological elaboration and epistemological debate, greater attention to historical process also informs new strategies for defining cases and framing puzzles, thereby highlighting different categories of empirical questions: social caging, group formation, and multiple orders. The most striking shift is from the imagery of systems-and-crises, which highlighted revolution and state-building, to multidimensional understandings of emergence and destabilization.
From prediction error to psychosis: ketamine as a pharmacological model of delusions
Authors: Corlett P.R. , Honey G.D. , Fletcher P.C.
Published: June 2007

Recent cognitive neuropsychiatric models of psychosis emphasize the role of attentional disturbances and inappropriate incentive learning in the development of deLusions. These models highlight a pre-psychotic period in which the patient experiences perceptual and attentional disruptions. Irrelevant details and numerous associations between stimuli, thoughts and percepts are imbued with inappropriate significance and the attempt to rationalize and account for these bizarre experiences results in the formation of delusions. The present paper discusses delusion formation in terms of basic associative learning processes. Such processes are driven by prediction error signaLs. Prediction error refers to mismatches between an organism's expectation in a given environment and what actually happens and it is signalled by both dopaminergic and glutamatergic mechanisms. Disruption of these neurobiological systems may underie delusion formation. We review similarities between acute psychosis and the psychotic state induced by the NMDA receptor antagonist drug ketamine, which impacts upon both dopaminergic and glutamatergic function. We conclude by suggesting that ketamine may provide an appropriate model to investigate the formative stages of symptom evolution in schizophrenia, and thereby provide a window into the earliest and otherwise inaccessible aspects of the disease process.
A case of primary squamous cell colon cancer
Authors: Landau Danny , Garrett Chris , Chodkiewicz Catherine
Published: June 2007

Carcinomas of the colon are a common cancer seen in both inpatient and outpatient settings with approximately 145 000 new cases being diagnosed every year in the USA. Despite the frequency of these cancers being seen, it continues to be a rarity to see a primary squamous cell cancer of the colon. In this article, such a case is presented. While the exact aetiology of this rare tumour is currently still not completely understood, various aetiologies include chronic irritation leading to squamous differentiation, embryonic migration of ectodermal cells to the colon, or adenomas undergoing squamous transformation. J Oncol Pharm Practice (2007) 13: 47-48.
Concentração de fluoreto em arroz, feijão e alimentos infantis industrializados
Authors: Casarin Renato C V , Fernandes Daniel R M , Lima-Arsati Ynara B O , Cury Jaime A
Published: June 2007

OBJETIVO: Determinar a concentração de fluoreto na refeição brasileira típica (arroz e feijão) e em alimentos infantis industrializados e estimar suas contribuições para fluorose dental. MÉTODOS: Os alimentos foram adquiridos de supermercados das cidades de Piracicaba e Campinas, SP, Brasil. Os alimentos infantis industrializados foram comprados em 2001 e o arroz e feijão em 2003, e imediatamente analisados. Foram analisadas três marcas de arroz, três de feijão e 36 amostras de alimentos infantis divididos em cinco grupos: prontos para o consumo; mingaus; alimentos formulados; leites em pó e outros alimentos. No arroz e feijão, foram determinadas as concentrações de fluoreto nas sementes "in natura" e após cozimento com água destilada ou fluoretada (0,7 ppm). Todas as análises de fluoreto foram feitas com eletrodo específico. Considerou-se 0,07 mg/kg/dia como a dose limite de exposição a fluoreto para risco de fluorose. RESULTADOS: A concentração de fluoreto encontrada nos grãos de arroz e feijão foi baixa. Porém, a concentração aumentou 100-200 vezes após cozimento em água fluoretada e mesmo assim, foi menor que a encontrada em alguns alimentos industrializados. Uma refeição com arroz e feijão preparada com água fluoretada seria responsável por 29% da dose limite de ingestão de fluoreto em termos de fluorose aceitável; a contribuição de alguns alimentos industrializados atingiria 45%. CONCLUSÕES: A alimentação típica brasileira, mesmo preparada com água fluoretada, é mais segura em termos de risco de fluorose dental que alguns alimentos infantis industrializados.
Vulnerabilidade e vida nua: bioética e biopolítica na atualidade
Authors: Arán Márcia , Peixoto Júnior Carlos Augusto
Published: June 2007

O trabalho teve por objetivo analisar a noção de vulnerabilidade utilizada pela bioética para debater as pesquisas com seres humanos na atualidade, a partir de uma reflexão acerca da biopolítica na cultura contemporânea. Para isto, partiu-se da leitura de Giorgio Agamben dos modelos de poder foucaultianos - Soberania e Biopolítica - para, em seguida, analisar a noção de vida nua - "vida sem nenhum valor". Se os dispositivos de poder nas democracias modernas conjugam estratégias biopolíticas com a emergência da força do poder soberano que transforma a vida em vida nua, é fato que a bioética deve ser um instrumento de proteção das pessoas vulneradas. No entanto, além do território do estado do direito, a bioética também deve poder penetrar nas zonas de indiferenciação, onde soberania e técnica se misturam, profanando a fronteiras biopolíticas e problematizando a própria condição de vulnerabilidade.
Child health and nutrition in the Western Brazilian Amazon: population-based surveys in two counties in Acre State
Authors: Muniz Pascoal Torres , Castro Teresa Gontijo de , Araújo Thiago Santos de , Nunes Nara Barros , Silva-Nunes Mônica da , Hoffmann Erika Hellena Esther , Ferreira Marcelo Urbano , Cardoso Marly Augusto
Published: June 2007

The article presents prevalence rates for malnutrition, intestinal parasitic infections, anemia, and iron deficiency in under-five children in a population-based cross-sectional survey performed in the urban area of two counties in the Western Brazilian Amazon, Assis Brasil (n = 200) and Acrelandia (n = 477). Available data included: (a) weight and height measurements, standardized as z-scores using the 1977 NCHS reference population, (b) diagnosis of current intestinal parasitic infection, (c) blood hemoglobin levels, and (d) plasma ferritin and soluble transferrin receptor levels. Overall prevalence rates of low weight-for-height, low weight-for-age, and low height-for-age were 3.7%, 8.7%, and 7.5%, respectively, with similar figures in the two towns. Intestinal parasites were detected in 32.5% children; helminths were uncommon. Anemia and iron deficiency were diagnosed in 30.6% and 43.5% of the children, respectively. Evidence of anemia was found in only 47.6% of the children with depleted iron reserves, indicating that hemoglobin measurement alone would severely underestimate the magnitude of iron deficiency in this population. In both towns, anemia and malnutrition were significantly more prevalent among children in the lowest socioeconomic stratum.
Reflexos das políticas de saúde sobre as tendências da mortalidade infantil no Brasil: revisão da literatura sobre a última década
Authors: Duarte Cristina Maria Rabelais
Published: June 2007

A mortalidade infantil tem sido considerada um bom indicador das condições de vida. É simples de ser calculada e reflete o estado de saúde da parcela mais vulnerável da população: os menores de um ano. A divulgação de dados oficiais que estimaram uma queda de 31% no indicador pareceu surpreendente num contexto de deterioração dos níveis de crescimento econômico, renda e trabalho e do aumento da taxa de desemprego. Entretanto, a década foi marcada por decisões políticas importantes, especialmente a implantação da Estratégia de Saúde da Família e dos incentivos da NOB-96. Este estudo objetivou avaliar como a literatura nacional analisou o comportamento da mortalidade infantil na década e sua possível associação com as mudanças na organização e financiamento do SUS. Foi realizada uma revisão sistemática de artigos científicos publicados entre 1998 e 2006. Concluiu-se que os estudos produzidos até o momento não possibilitam avaliar com clareza o possível impacto das alterações produzidas na organização e financiamento do SUS. Ficou evidente a necessidade de monitoramento do indicador e a importância dos estudos locais, especialmente nos municípios com informações incipientes.
Nutrição e promoção da saúde: perspectivas atuais
Authors: Ferreira Vanessa A. , Magalhães Rosana
Published: June 2007

A promoção da saúde tem ao longo dos últimos anos se apresentado como uma estratégia promissora para o campo da Saúde Pública. Este estudo propõe articular o tema da nutrição no debate contemporâneo da promoção da saúde, analisando o papel dos nutricionistas neste processo. Frente ao reconhecimento da complexidade do quadro alimentar brasileiro advindo da transição nutricional em curso no país, a proposta de promoção da saúde aponta perspectivas, mas também desafios ao campo da alimentação e nutrição. Em linhas gerais, novas exigências relacionadas à formação acadêmica e ao modelo de atenção tendem a fortalecer a busca de parcerias, inovação das práticas alimentares à educação nutricional voltada à construção da cidadania alimentar.
Leishmaniose Tegumentar Americana (LTA) em uma vila de exploração de minérios - Pitinga, município de Presidente Figueiredo, Amazonas, Brasil
Authors: Chagas Andrezza Campos , Pessoa Felipe Arley Costa , Medeiros Jansen Fernandes de , Py-Daniel Victor , Mesquita Éder C. , Balestrassi Dultevir Antônio
Published: June 2007

A Vila de Pitinga, Presidente Figueiredo/AM, é uma área de exploração de minérios e endêmica para leishmaniose tegumentar americana (LTA). A vila é a sede administrativa e local de moradia de seus funcionários. O comportamento epidemiológico da endemia, avaliado para o período de 2000 a 2004, foi relacionado com as medidas de controle adotadas para reduzir a incidência da doença na área e comparado com o registrado para o município e o Estado do Amazonas. A maior proporção dos casos detectados no período ocorreu no gênero masculino, com atividades laborais de contato com a floresta. O declínio na incidência de casos de LTA na área do estudo, não foi observado como ocorrido no Município e Estado e foi considerado resultante das medidas de controle para a doença, aplicadas na área.
Totalsynthese komplexer Cyclotryptaminalkaloide: stereokontrollierter Aufbau quartärer Kohlenstoffstereozentren
Authors: Steven Alan , Overman Larry E.
Published: June 2007

Die Cyclotryptamine sind eine Familie von Alkaloiden mit sehr unterschiedlichen biologischen Aktivitäten. Die komplexeren Mitglieder dieser Naturstoffklasse sind durch benachbarte quartäre Kohlenstoffzentren charakterisiert und wegen der schwierig aufzubauenden, oligomeren Polyindolinstruktur schwer zugänglich. In den letzten Jahren konnten wir eine Reihe von Methoden entwickeln, die einen einfachen Zugang zu Polyindolinen ermöglichen; einige dieser Methoden nutzen Palladiumkatalysatoren zum Aufbau von Kohlenstoff‐Kohlenstoff‐Bindungen mit beeindruckenden Regio‐ und Stereoselektivitäten. In diesem Aufsatz schildern wir die Entwicklung eines Repertoires an Synthesemethoden und deren Anwendung in den Totalsynthesen einiger strukturell komplexer Cyclotryptamine. Insbesondere zeigen wir auf, wie es gelingen kann, mithilfe asymmetrischer Katalysen komplexe, hochfunktionalisierte Moleküle aufzubauen.
Quantitative Separation of As(III) and As(V) from a Synthetic Water Solution Using Ion Exchange Columns in the Presence of Fe and Mn Ions
Authors: Mondal Prasenjit , Balomajumder Chandrajit , Mohanty Bikash
Published: June 2007

The quantitative separation of As(III) from a water sample containing As(III) and As(V) in the presence of Fe and Mn in an ion exchange resin (AG1 X8) column for the speciation of arsenic is described. Individual and combined effects of Fe and Mn on the separation of As(III) from the solution have been studied separately. In absence of Fe and Mn, the ratio between the As(T) concentration in the eluent and the As(III) concentration in the original sample has been found to be 0.9717 under optimum process conditions. The presence of Fe(II) in the water sample increased the As(T) concentration in the eluent whereas Mn(II) decreased it. Combined effects of Fe and Mn on the percentage increment in the eluent arsenic concentration have been expressed by additive and interactive models. The interactive model has been developed by a statistical software with a 95 % confidence level. In most of the cases the error on the determination of the As(III) concentration had a minimum when using the interactive model.
Cost‐effectiveness of switching to exemestane versus continued tamoxifen as adjuvant therapy for postmenopausal women with primary breast cancer
Authors: Risebrough Nancy A. , Verma Shailendra , Trudeau Maureen , Mittmann Nicole
Published: June 2007

BACKGROUND.

Sequential tamoxifen/exemestane therapy reportedly improves disease‐free survival in women with primary breast cancer compared with continued tamoxifen therapy. The objective of the current study was to assess the cost‐effectiveness of switching to exemestane after 2 to 3 years of tamoxifen versus continued tamoxifen in postmenopausal women with primary breast cancer for a total of 5 years of adjuvant therapy.

METHODS.

A Markov model based on the Intergroup Exemestane Study (IES) population compared switching to exemestane versus continued tamoxifen for 2.5 years of therapy and 5 years of postadjuvant therapy follow‐up. Disease progression and hazards ratios (HR) for recurrence and survival were determined from datasets (IES and the Surveillance, Epidemiology, and End Results program of the National Cancer Institute) and from the published literature. An expert panel validated treatment patterns, outcomes, and resource utilization. Direct medical costs were included based on published sources. Cost‐effectiveness ratios were determined, and extensive sensitivity analyses were conducted.

RESULTS.

Exemestane was found to be more effective than tamoxifen alone with regard to disease‐free survival (2.6% absolute improvement), life‐years gained (0.1028 LY), and quality‐adjusted life‐years gained (0.1195 QALY), at an additional cost of Can$2889 per person over 7.5 years. Incremental cost‐effectiveness ratios were Can$28,119/LY gained and Can$24,185/QALY gained. The model was most sensitive to distant recurrence HR but was robust to variations in clinical, cost, and utility parameters.

CONCLUSIONS.

Switching to adjuvant exemestane after 2 to 3 years of tamoxifen is cost‐effective in postmenopausal women with primary breast cancer. Cancer 2007. © 2007 American Cancer Society.
Influence of buffer substances and urea on the β‐cyclodextrin‐mediated chiral separation of dipeptides in CE
Authors: Hammitzsch‐Wiedemann Manuela , Scriba Gerhard K. E.
Published: June 2007

The influence of buffering substances and urea on the β‐CD‐mediated chiral separations of the dipeptides Ala–Phe and Ala–Tyr was studied in the pH range of 2.5–3.8. Only minor effects of the buffer substances on the chiral separation selectivity α were observed at a β‐CD concentration of 15 mg/mL. In contrast, the selectivity improved at pH 2.5 but decreased at pH 3.8 upon the addition of 2 M urea. Complexation by β‐CD resulted in a shift of the pKa values toward higher values which was more pronounced for the DD‐enantiomers of both dipeptides than for the LL‐enantiomers. Addition of urea further increased the pKa shift. The consequence of this pKa shift is an increase of the fraction of the protonated, positively charged form of the peptides which explained the improved chiral separation at pH 2.5 and the reduced selectivity at pH 3.8. A pKa shift by the addition of urea was also observed for N‐tert‐butyloxycarbonyl phenylalanine (BOC‐Phe) as a model compound that is strongly complexed by β‐CD. This effect was not stereospecific. Addition of urea resulted in a decrease of the apparent complexation constants between β‐CD and the BOC‐Phe enantiomers to the same extent but this did not affect the separation selectivity α. For chiral separations that display strong pH dependence such as peptide enantioseparations close to the pKa values of the compounds, urea may not solely be regarded as a solubility enhancer for β‐CD but may also influence the separation.
Cytoprotective effects of anthocyanins and other phenolic fractions of Boysenberry and blackcurrant on dopamine and amyloid β‐induced oxidative stress in transfected COS‐7 cells
Authors: Ghosh Dilip , McGhie Tony K , Fisher Derek R , Joseph James A
Published: June 2007

There is growing interest both from consumers and researchers in the role that berries play in human health. In the experiments reported here, we assessed the ability of anthocyanins and phenolic fractions of Boysenberry and blackcurrant to ameliorate the deleterious effect of the amyloid β25–35 (100 µmol L−1, 24 h) and dopamine (1 mmol L−1, 4 h) on calcium buffering (recovery) of M1 muscarinic receptor‐transfected COS‐7 cells. Cell viability was also studied. Our results demonstrate that extracts of Boysenberry and blackcurrant showed significant protective effect and restored the calcium buffering ability of cells that had been subjected to oxidative stress induced by dopamine and the amyloid β25–35. Blackcurrant polyphenolics showed slightly higher protective effect against dopamine, whereas Boysenberry polyphenolics had a higher effect against the amyloid β25–35. In viability studies, all extracts showed significant protective effects against dopamine and amyloid β25–35‐induced cytotoxicity. Our results provide further evidence for the protective effects of berries against the neurotoxic effect of dopamine and amyloid β25–35 in brain cells. Copyright © 2007 Society of Chemical Industry