bluuebunny/crossref_metadata_2025 huggingface dataset:
Correlação entre diferentes métodos de avaliação funcional da marcha de ratos com lesão por esmagamento do nervo isquiático
Authors: Gasparini Andréa Licre Pessina , Barbieri Cláudio Henrique , Mazzer Nilton
Published: January 2008

Foi realizado um estudo da correlação entre diferentes métodos de avaliação funcional do nervo ciático de ratos após lesão por esmagamento. Foram empregados no estudo 25 ratos da linhagem Wistar, de peso médio em torno de 250 g, submetidos a esmagamento controlado do nervo e avaliados por dois métodos convencionais para obtenção do índice funcional do ciático (IFC), baseados respectivamente na medida manual e computadorizada de parâmetros das impressões das pegadas dos animais, e por um novo método desenvolvido pelos autores, baseado na filmagem das pegadas e medida dos mesmos parâmetros, no 1º, 7º, 14º e 21º dias de pós-operatório, sendo feita a comparação com os valores obtidos no pré-operatório e entre os diferentes métodos nos vários períodos. Os resultados mostraram que o método da medida dos parâmetros pela filmagem das pegadas permite melhor visualização da pata acometida pela lesão do nervo e que este método se correlaciona com positivamente com os convencionais, já a partir da primeira semana de pós-operatório, desde que seja empregada a mesma fórmula para o cálculo do IFC.
Epifisiólise proximal do úmero em atleta de ginástica olímpica
Authors: Ejnisman Benno , Andreoli Carlos Vicente , Pochini Alberto de Castro , Monteiro Gustavo Cará , Faloppa Flávio , Cohen Moisés , Skaf Abdalla Youssef
Published: January 2008

CONTEXTO: Existem diversas causas de dor no ombro do atleta. Estruturas como tendões e ligamentos são freqüentemente acometidas por lesões. No atleta jovem com esqueleto imaturo, as afecções ósseas devem ser lembradas como possíveis causas de dor. RELATO DE CASO: Os autores relatam a ocorrência da epifisiólise proximal do úmero em um atleta de ginástica olímpica e discutem a literatura a respeito do assunto. CONCLUSÃO: A lesão da placa fisária proximal do úmero em atletas é pouco freqüente. O diagnóstico precoce e correto tratamento evitam que ocorra deformidades severas e déficits funcionais.
Crack users, sexual behavior and risk of HIV infection
Authors: Azevedo Renata Cruz Soares de , Botega Neury José , Guimarães Liliana Andolpho Magalhães
Published: January 2008

OBJECTIVE: To compare a sample of injecting cocaine users and crack users, assessing sexual behavior, risk for infection by HIV and its seroprevalence. METHOD: 109 injecting cocaine users and 132 crack users were assessed, using the World Health Organization questionnaire from the expanded "Cross-Site Study of Behaviors and HIV Seroprevalence among Injecting Drug Users" and HIV serology. Data were assessed by Multiple Correspondences Analysis. RESULTS: Crack users showed less time of drug consumption when compared to the injecting cocaine users. Despite this fact, they had higher rates of risky sexual activity, differences in poli-consumption of drugs, and higher rates of involvement in illegal issues. HIV seroprevalence among crack users, although lower than for injecting cocaine users (7% vs. 33%) is high when compared to the general population at the same age. CONCLUSIONS: Sexual behavior of crack users in the studied sample may be considered a risk factor for HIV infection. Crack users have access to information on HIV/ AIDS, but do not make use of it to change risk behaviors that may expose them to HIV infection and dissemination. HIV seroprevalence among crack users (7%) is concerning, which makes it necessary to create preventive strategies for HIV infection and dissemination that are specifically directed toward this population.
Psicofármacos para o tratamento de transtornos de ansiedade em crianças e adolescentes: uma revisão sistemática
Authors: Maia Carlos Renato Moreira , Rohde Luis Augusto
Published: January 2008

Os transtornos de ansiedade são muito prevalentes em crianças e adolescentes, causando sérios prejuízos quando não tratados. O tratamento farmacológico desses transtornos ainda é pouco pesquisado, não havendo consenso sobre sua indicação. O objetivo deste estudo é verificar a eficácia e a tolerabilidade dos psicofármacos indicados para esses transtornos em crianças e adolescentes, no contexto da medicina baseada em evidências. Foi realizada uma revisão sistemática da literatura, consultando-se as principais bases de dados disponíveis e contatando-se os autores. Foram encontrados, ao todo, sete artigos de qualidade A e B, conforme critérios da Colaboração Cochrane. Os resultados foram satisfatórios para os inibidores da recaptação da serotonina, pouco significativos ou desfavoráveis para benzodiazepínicos e imipramina. Alguns estudos apresentam problemas metodológicos. Sugere-se melhoria no planejamento de futuros ensaios clínicos.
Polypharmacy and suicide attempts in bipolar disorder
Authors: Gazalle Fernando Kratz , Hallal Pedro Curi , Tramontina Juliana , Rosa Adriane Ribeiro , Andreazza Ana Cristina , Zanatto Vanessa , Santin Aida , Kapczinski Flávio , Ceresér Keila Maria
Published: January 2008

OBJECTIVE: The aim of this study was to assess the association between suicide attempts and the use of multiple drugs in patients with bipolar disorder. METHOD: One hundred sixty-nine bipolar disorder outpatients diagnosed using the DSM-IV Structured Clinical Interview were included. Demographic and socioeconomic data, number of medications currently in use, history of suicide attempts, number of years undiagnosed, age of onset and current psychiatric co-morbidities were assessed using a structured questionnaire and DSM-IV criteria. The main outcome measure was the number of psychotropic drugs currently in use. RESULTS: Approximately half of all patients (48.5%) presented a history of suicide attempt; 84% were using more than one medication, and 19% were using more than three drugs. The most frequent combinations of drugs used by these patients were: lithium + valproate (17%); lithium + antipsychotics (10%); lithium + valproate + antipsychotics (9%); and antidepressants + any drug (6%). The number of suicide attempts was associated with the use of multiple drugs. CONCLUSIONS: Our findings support the notion that the use of combination therapy in bipolar disorder may be related to severity of the BD, such as number of suicide attempts.
The extinction of conditioned fear: structural and molecular basis and therapeutic use
Authors: Cammarota Martín , Bevilaqua Lia R M , Vianna Mônica R M , Medina Jorge H , Izquierdo Iván
Published: January 2008

OBJECTIVE: Through association, a large variety of stimuli acquire the property of signaling pleasant or aversive events. Pictures of a wedding or of a plane disaster may serve as cues to recall these events and/or others of a similar nature or emotional tone. Presentation of the cues unassociated with the events, particularly if repeated, reduces the tendency to retrieve the original learning based on that association. This attenuation of the expression of a learned response was discovered by Pavlov 100 years ago, who called it extinction. In this article we review some of the most recent findings about the behavioral and biochemical properties of extinction. RESULTS AND DISCUSSION: It has been shown that extinction is a new learning based on a new link formed by the cues and the absence of the original event(s) which originated the first association. Extinction does not consist of the erasure of the original memory, but of an inhibition of its retrieval: the original response reappears readily if the former association is reiterated, or if enough time is allowed to pass (spontaneous recovery). Extinction requires neural activity, signaling pathways, gene expression and protein synthesis in the ventromedial prefrontal cortex and/or basolateral amygdala, hippocampus, entorhinal cortex and eventually other areas. The site or sites of extinction vary with the task. CONCLUSIONS: Extinction was advocated by Freud in the 1920's for the treatment of phobias, and is used in cognitive therapy to treat diseases that rely on conditioned fear (phobias, panic, and particularly posttraumatic stress disorder). The treatment of learned fear disorders with medications is still unsatisfactory although some have been shown useful when used as adjuncts to behavioral therapy.
Suicide risk among inpatients at a university general hospital
Authors: Ferreira Marianne Herrera Falceti , Colombo Elisabetta Sachsida , Guimarães Paula Serra-Azul , Soeiro Rachel Esteves , Dalgalarrondo Paulo , Botega Neury José
Published: January 2008

OBJECTIVE: To estimate the proportion of inpatients at a university general hospital who are at risk of committing suicide. METHOD: A random sample of 253 patients (57% males) aged 18 years old or older, admitted to surgical and clinical wards, was assessed using the the Mini International Neuropsychiatric Interview, which has a section that evaluates the risk for suicide. Uni- and multivariate analyses were performed. RESULTS: There were 58 (23%) patients with a risk for suicide, 13 (5% of total) of whom presented a high risk. The prevalence of suicide risk was greater in young adult patients, those with no matrimonial relationship and those diagnosed with major depression (univariate analysis, Chi-squared test; p = 0.01, 0.03 and 0.0001, respectively). The multivariate analysis revealed that the risk for suicide in individuals younger than 30 years old was two fold higher than in those individuals between the ages of 30 and 59 years (OR = 0.45, 95% CI = 0.22-0.93; p = 0.03) and four fold greater than in those who were 60 years old or older (OR = 0.25, 95% CI = 0.1-0.64; p = 0.004). CONCLUSION: When young adults are admitted to general hospitals they should receive special attention due to their suicidal potential.
Is psychiatric reform a strategy for reducing the mental health budget? The case of Brazil
Authors: Andreoli Sérgio Baxter , Almeida-Filho Naomar , Martin Denise , Mateus Mário Dinis M L , Mari Jair de Jesus
Published: January 2008

OBJECTIVE: To investigate trends in the provision of mental health services and financing in Brazil. METHOD: Data from DATASUS (the Brazilian Unified Health Computerized System) with free access in the web were collected regarding the number of beds, the development of new community centers, the number of mental health professionals, and costs involved from 1995 to 2005. RESULTS: In ten years, the number of psychiatric beds decreased 41% (5.4 to 3.2 per 10,000 inhabitants) while community services have increased nine-fold (0.004 to 0.037 per 10,000 inhabitants). Psychologists and social workers have accounted for three and two-fold, respectively, as much hirings as psychiatrists. Psychiatric admissions accounted for 95.5% of the budget in 1995 and 49% in 2005, and the expenses with community services and medication have increased 15% each. As a whole, the expenses in mental health decreased by 26.7% (2.66 to 1.95 US$ per capita). CONCLUSION: There has been a clear switch from hospital to community psychiatric care in Brazil, where the system can now provide a diversity of treatments and free access to psychotropics. However, the coverage of community services is precarious, and the reform was not accompanied by an increased public investment in mental health. The psychiatric reform is not a strategy for reducing costs; it necessarily implies increasing investments if countries decide to have a better care of those more disadvantaged.
Le cœur-espace: aspects du lyrisme dans Les fleurs du mal
Authors: Collot Michel
Published: January 2008

Le lyrisme baudelairien ne saurait donc être confondu avec un idéalisme; la transcendance qui l’anime ne vise pas un autre monde: elle est le mouvement par lequel notre monde se révèle autre au sujet qui s’ouvre à lui.
Baudelaire: antíteses e revolução
Authors: Matos Olgária
Published: January 2008

O ensaio procura indicar o método baudelairian o das antiteses de coisas e acontecimentos, de tal forma que o maniqueísmo progressista da dialética hegeliano-marxista é substituído pelo homo duplex pascaliano, e o conceito de ação política e arte engajada é reformulado.
O papel do complexo principal de histocompatibilidade na fisiologia da gravidez e na patogênese de complicações obstétricas
Authors: Alves Crésio , Veiga Sâmia , Toralles Maria Betânia P. , Lopes Antônio Carlos Vieira
Published: January 2008

Este trabalho tem por objetivo discutir a estrutura e função dos Antígenos Leucocitários Humanos (HLA), seus métodos de detecção, nomenclatura e os mecanismos imunopatológicos que o associam com a fisiologia da gestação e morbidades obstétricas. Sabe-se que o equilíbrio imunológico entre mãe e concepto é imprescindível na manutenção da gravidez. Moléculas do HLA - notadamente o HLA-G expresso na interface materno-fetal - exercem função importante na tolerância imunológica materna, evitando rejeição fetal e algumas complicações obstétricas. Além disso, o HLA permeia diversas etapas do desenvolvimento conceptual como clivagem, formação do trofoblasto e implantação. Para revisão, foram pesquisados os bancos de dados MEDLINE e LILACS, utilizando os descritores: "HLA antigens"; "pregnancy"; "embryonic development"; "pregnancy complication"; "abortion, habitual"; "pre-eclampsia". O conhecimento sobre a influência do HLA na gravidez é necessário para melhor manejo da gestação e patologias obstétricas auto-imunes, favorecendo intervenções precoces e terapêutica específica, reduzindo a morbimortalidade materna e perinatal.
Fatores que interferem na transição alimentar de crianças entre cinco e oito meses: investigação em Serviço de Puericultura do Recife, Brasil
Authors: Santos Carmina Silva dos , Lima Luciane Soares de , Javorski Marly
Published: January 2008

OBJETIVOS: identificar os lactentes de cinco a oito meses alimentados segundo as recomendações do Ministério da Saúde, atendidos no Serviço de Puericultura do Instituto Materno Infantil Professor Fernando Figueira - IMIP; detectar os principais problemas enfrentados pelas mães no processo de introdução alimentar; identificar o tipo de orientação recebida pelas mães para iniciar a dieta de transição. MÉTODOS: estudo transversal, descritivo, formado por 101 mães de crianças entre cinco e oito meses que haviam iniciado transição alimentar no período de abril a agosto de 2003, as quais foram solicitadas a participar do estudo antes da consulta, mediante os critérios de inclusão e exclusão. As crianças foram classificadas quanto à adequação às normas do Ministério da Saúde para transição alimentar. RESULTADOS: constatou-se que 79,2% dessas crianças não se adequavam às normas do Ministério da Saúde quanto à transição alimentar. Para o não seguimento a essas normas as mães apontaram, como principais motivos: recusa da criança (23,5%); interferência da avó (19%); praticidade do preparo/oferecimento do mingau em relação à alimentação salgada (17,7%). Quanto ao tipo de orientação, 97,4% afirmaram receber as orientações verbais e escritas no serviço. Na amostra estudada o enfermeiro e a avó foram os principais orientadores da transição alimentar, com 77% e 16%, respectivamente. CONCLUSÕES: apenas 20,8% das crianças apresentaram um padrão alimentar adequado, segundo as orientações do Ministério da Saúde. A mãe, principal responsável pelos cuidados da criança, sofreu influências do seu ambiente familiar, sobretudo da avó, e da sociedade em que está inserida. Também foi observado que, para a transição alimentar das crianças, 97,4% das mães recebeu orientação escrita além da orientação verbal.
Equidade inversa e desigualdades no acesso à tecnologia no parto em Santa Catarina, Brasil, 2000 a 2004
Authors: Souza Junior Julio César de , Kunkel Nádia , Gomes Marcius de Almeida , Freitas Paulo Fontoura
Published: January 2008

OBJETIVOS: investigar a evolução temporal das taxas de cesariana e fatores associados em Santa Catarina, no período de 2000 a 2004. MÉTODOS: foram utilizados dados do Sistema de Informações de Nascidos Vivos. As variáveis analisadas foram: escolaridade, idade materna, etnia/cor da pele do recém-nascido, duração da gestação e número de consultas pré-natal. Razões de prevalência de cesariana, brutas e ajustadas para confundimento, foram estimadas para cada uma das variáveis utilizando Regressão de Poisson. RESULTADOS: as taxas encontradas para o período foram o triplo daquelas preconizadas pela Organização Mundial de Saúde e aumentaram de 43,3% em 2000 para 50,6% em 2004. Para todo o período razões de prevalência brutas e ajustadas mostraram-se positivamente associadas ao mais alto grau de escolaridade (R Paj=1,50; IC95%: 1,47-1,52), idade mais elevada (R Paj=2,10; IC95%: 2,05-2,15), maior freqüência ao pré-natal (RPaj=1,27; IC95%: 1,26-1,29), partos pré-termo (RPaj=1,10; IC95%: 1,06-1,13) e pós-termo (RPaj=1,22; IC95%: 1,14-1,30) e proteção para as etnias "indígena" (RPaj=0,79; IC95%: 0,75-0,85) e "não branca" (RPaj=1,10; IC95%: 1,06-1,14). Uma diminuição significante nas RPs ajustadas ao comparar os extremos do período (2000 e 2004) apareceu para quase todas as categorias estudadas. CONCLUSÕES: as taxas de cesariana encontradas estão bem acima daquelas justificando indicações estritamente médicas. Uma diminuição nas RPs ao comparar os extremos do período nos remete a uma redução temporal nos efeitos da "equidade inversa", provável reflexo de um maior acesso à tecnologia no parto entre as camadas de menor padrão socioeconômico, pelo menos em parte atribuível a uma maior liberalidade da prática obstétrica, incluindo uma ampliação das indicações médicas.
Interação mãe-bebê pré-termo e mudança no estado de humor: comparação do Método Mãe-Canguru com visita na Unidade de Terapia Intensiva Neonatal
Authors: Cruvinel Fernando Guimarães , Macedo Elizeu Coutinho de
Published: January 2008

OBJETIVO: avaliar mudanças nos estados de humor de mães de bebês pré-termo em função do tipo de contato com o seu filho: Método Mãe-Canguru (MMC) e visita ao filho na incubadora da Unidade de Terapia Intensiva Neonatal. MÉTODOS: foi aplicada a Escala Analógica de Humor em 60 mães divididas em 2 grupos: mães que participam do Método Mãe-Canguru (GC) e mães que acompanharam o bebê na incubadora (GI). Os grupos foram pareados em função da idade das mães, número de gestações e tipo de parto. As mães foram avaliadas antes e depois de uma das visitas ao filho na incubadora ou sessão de MMC. RESULTADOS: as mães do GC melhoraram o humor, relatando: sentirem-se mais calmas, fortes, com idéias claras, ágeis, dinâmicas, satisfeitas, tranqüilas, perspicazes, relaxadas, atentas, competentes, alegres e amistosas. As mães do GI não apresentaram melhora no estado de humor em nenhum item, mas pioraram no item "sentindo-se desajeitada". CONCLUSÕES: o Método Mãe-Canguru mostrou-se eficaz na melhora nos estados de humor de mães de bebês pré-termo, contribuindo assim para a minimização dos efeitos negativos da internação neonatal.
A expressão dos demônios de Morin
Authors: Albuquerque Maria do Socorro Veloso de , Medeiros Kátia Rejane de , Luna Karla , Almeida Sabrina Ribeiro de , Felisberto Eronildo
Published: January 2008

O objetivo deste texto é promover um diálogo com a autobiografia intelectual de Edgar Morin, com os três temas de maior relevância na sua obra "Meus demônios": a epistemologia, a ética e a política; e destacar a importância do pensamento complexo no processo de produzir saúde. A postura de indagação contínua faz Morin refletir sobre a provisoriedade das "verdades" e "conclusões". Sobretudo, que o conhecimento nunca é total, mas multidimensional. Propõe-se a construir um conhecimento que religa, que é inacabado e inacabável. Trabalha com o conceito de auto-ética, com a urgência de "constituição" de uma identidade humanitária, de uma consciência planetária, da idéia de terra pátria. Na política assinala a necessidade de uma consciência de resistência entre os homens, em todos os tempos e áreas, a forças mentais, ideológicas, culturais e históricas que possam suscitar erros e desta forma reforça a crença na necessidade imperiosa de repensar a política. A lógica do pensamento complexo de Morin tem iluminado muitas das discussões no campo da saúde, uma vez que nesse campo os fenômenos envolvendo o processo saúde e doença apresentam múltiplas dimensões, o que nos faz refletir sobre a complexidade do conceito de necessidades de saúde.
Análise crítica das indicações e resultados do tratamento cirúrgico da doença carotídea
Authors: Bonamigo Telmo P. , Lucas Márcio L.
Published: January 2008

O tratamento da doença carotídea tem ganhado enfoque nos últimos anos, principalmente com o advento da técnica endovascular, que defende o emprego da angioplastia e stent de carótida (CAS), principalmente em pacientes considerados de "alto risco" para a endarterectomia carotídea (ECA). Através da revisão bibliográfica, analisamos os resultados do tratamento da lesão carotídea em ambas as técnicas, realizando comentários embasados na experiência pessoal e nos dados da literatura, sobretudo nos pacientes de alto risco. Até o presente momento, não há evidência e justificativa para o emprego da CAS em larga escala nos pacientes com doença carotídea, inclusive nas situações de alto risco, tais como nos octogenários. No entanto, acreditamos que a CAS possa ser um coadjuvante no tratamento de pequeno número de pacientes com lesão carotídea (até 4% dos casos), como na presença de pescoço hostil, radioterapia prévia e alguns casos de estenose carotídea alta. Quando realizada com os cuidados técnicos necessários, a ECA ainda continua a melhor opção terapêutica aos doentes com lesão carotídea.
“You Can Read This Text—I'll Show You How”: Interactive Comprehension Instruction
Authors: Lapp Diane , Fisher Douglas , Grant Maria
Published: January 2008

Shared reading with think‐alouds provides adolescent students with the modeling they need to become successful readers and writers. This article provides a sample of this type of interactive comprehension instruction in a science classroom. The authors then focus on the dimensions of effective shared readings with think‐alouds that can be used across content areas to develop students' comprehension of texts.
Timed Writing and Adult English‐Language Learners: An Investigation of First Language Use in Invention Strategies
Authors: Pappamihiel N. Eleni , Nishimata Takayuki , Mihai Florin
Published: January 2008

As writing plays an increasingly important role in high‐stakes assessment, it is critical that different composition environments be explored. This article summarizes a study of the effects of native language use during the invention stage of a timed writing, similar to the type of writing demanded in such assessments as standardized tests and the Test of English as a Foreign Language (TOEFL). Results show that English‐language learners (ELLs) in the beginning levels of English writing proficiency write superior essays when they brainstorm in English rather than their native language. Results for ELLs with higher levels of English proficiency were not significant but indicate that they write slightly better essays when brainstorming in their native languages.
Improving Reading in a Middle School Science Classroom
Authors: Radcliffe Rich , Caverly David , Hand James , Franke Deanna
Published: January 2008

Middle school science teachers report using textbooks regularly although these textbooks have been criticized for not following standards‐based principles for concept learning, and student reading achievement has been stagnant for 20 years. Effective strategic reading instruction has been documented for middle school students but few teachers use these strategies. To address these issues, a quasi‐experimental research study compared middle school students (n = 23) who learned a strategic reading strategy (PLAN) for science textbooks to students (n = 27) who read silently following an audiotaped reading of the text. The strategic reading group significantly outperformed the silent reading group on a comprehension test of scientific concepts (p <. 001) and strategy use (p < .01). The teacher reported that her students gained self‐confidence in reading and found reading to be more enjoyable. This research uses a more rigorous design than prior studies of the PLAN strategy but supports previous findings and adds to an understanding of how to implement PLAN.
Making Meaning on the Screen: Digital Video Production About the Dominican Republic
Authors: Ranker Jason
Published: January 2008

As part of an inquiry and digital documentary video project, two 12‐year‐old students studied the Dominican Republic. Over the course of their research, the boys (one of whose parents moved from the Dominican Republic) focused their project on two aspects of the culture of the Dominican Republic: contemporary music (bachata and merengue) and famous baseball players who have familial ties to the country.

Through the use of digital video software available at the school, the boys produced a digital video by weaving together images from the Web with music and informational audio tracks that they wrote (based upon their research), recorded, and imported into their documentary video project. The article provides a reference point for teachers to try out digital video production in their own classrooms, as well as discussing the importance of such projects in light of the new, digital literacies that they enable students to practice.
Touchstone Texts: Fertile Ground for Creativity
Authors: Sturgell Irma
Published: January 2008

When state and local standards drive instruction, teachers often worry about compromising their creativity for a prescriptive curriculum with predictable outcomes. It is possible for creative teaching to flourish by using touchstone texts, or mentor texts, that engage both teacher and student in exploratory yet purposeful learning.
Selecting Books That Children Will Want to Read
Authors: Harris Violet J.
Published: January 2008

What kinds of books do children want to read? And how can a teacher find those books? The author provides some ideas for interesting new books in the categories of graphic novels, humorous adventures, poetry, and books about math.
Small Increases in the Level of Sox2 Trigger the Differentiation of Mouse Embryonic Stem Cells
Authors: Kopp Janel L. , Ormsbee Briana D. , Desler Michelle , Rizzino Angie
Published: February 2008

Previous studies have demonstrated that the transcription factor Sox2 is essential during the early stages of development. Furthermore, decreasing the expression of Sox2 severely interferes with the self-renewal and pluripotency of embryonic stem (ES) cells. Other studies have shown that Sox2, in conjunction with the transcription factor Oct-3/4, stimulates its own transcription as well as the expression of a growing list of genes (Sox2:Oct-3/4 target genes) that require the cooperative action of Sox2 and Oct-3/4. Remarkably, recent studies have shown that overexpression of Sox2 decreases expression of its own gene, as well as four other Sox2:Oct-3/4 target genes (Oct-3/4, Nanog, Fgf-4, and Utf1). This finding led to the prediction that overexpression of Sox2 in ES cells would trigger their differentiation. In the current study, we initially engineered mouse ES cells for inducible overexpression of Sox2. Using this model system, we demonstrate that small increases (twofold or less) in Sox2 protein trigger the differentiation of ES cells into cells that exhibit markers for a wide range of differentiated cell types, including neuroectoderm, mesoderm, and trophectoderm but not endoderm. We also demonstrate that elevating the levels of Sox2 quickly downregulates several developmentally regulated genes, including Nanog, and a newly identified Sox2:Oct-3/4 target gene, Lefty1. Together, these data argue that the self-renewal of ES cells requires that Sox2 levels be maintained within narrow limits. Thus, Sox2 appears to function as a molecular rheostat that controls the expression of a critical set of embryonic genes, as well as the self-renewal and differentiation of ES cells.

Disclosure of potential conflicts of interest is found at the end of this article.
Expanding Criteria for Resectability of Colorectal Liver Metastases
Authors: Pawlik Timothy M. , Schulick Richard D. , Choti Michael A.
Published: January 2008

Learning Objectives

After completing this course, the reader will be able to: Identify the criteria for hepatic resection of colorectal metastases.Describe strategies for expanding the number of patients who may potentially benefit from hepatic resection.List the factors associated with poor prognosis following hepatic resection.

CME Access and take the CME test online and receive 1 AMA PRA Category 1 Credit™ at CME.TheOncologist.com

Surgical resection is the treatment of choice in patients with colorectal liver metastases, with 5-year survival rates reported in the range of 40%–58%. Over the past 10 years, there has been an impetus to expand the criteria for defining resectability for patients with colorectal metastases. In the past, such features as the number of metastases (three to four), the size of the tumor lesion, and a mandatory 1-cm margin of resection dictated who was “resectable.” More recently, the criteria for resectability have been expanded to include any patient in whom all disease can be removed with a negative margin and who has adequate hepatic volume/reserve. Specifically, instead of resectability being defined by what is removed, decisions concerning resectability now center around what will remain after resection. Under this new paradigm, the number of patients with resectable disease can be expanded by increasing/preserving hepatic reserve (e.g., portal vein embolization, two-stage hepatectomy), combining resection with ablation, and decreasing tumor size (preoperative chemotherapy). The criteria for resectability have also expanded to include patients with extrahepatic disease. Rather than being an absolute contraindication to surgery, patients with both intra- and extrahepatic disease should potentially be considered for resection based on strict selection criteria. The expansion of criteria for resectability of colorectal liver metastases requires a much more nuanced and sophisticated approach to the patient with advanced disease. A therapeutic approach that includes all aspects of multidisciplinary and multimodality care is required to select and treat this complex group of patients.
CT Screening for Lung Cancer: Update 2007
Authors: Henschke Claudia I. , Yankelevitz David F.
Published: January 2008

Editor's Note

This article is not available for CME
Keeping Pace
Authors: John Simone , Niederhuber John E.
Published: January 2008

The future role of continuing medical education in preparing physicians for the research-driven transformation of the practice of oncology is proposed.
TIME TO COMPLETION OF WEB‐BASED PHYSICS PROBLEMS WITH TUTORING
Authors: Warnakulasooriya Rasil , Palazzo David J. , Pritchard David E.
Published: February 2008

We studied students performing a complex learning task, that of solving multipart physics problems with interactive tutoring on the web. We extracted the rate of completion and fraction completed as a function of time on task by retrospectively analyzing the log of student—tutor interactions. There was a spontaneous division of students into three groups, the central (and largest) group (about 65% of the students) being those who solved the problem in real time after multiple interactions with the tutorial program (primarily receiving feedback to submitted wrong answers and requesting hints). This group displayed a sigmoidal fraction‐completed curve as a function of logarithmic time. The sigmoidal shape is qualitatively flatter for problems that do not include hints and wrong‐answer responses. We argue that the group of students who respond quickly (about 10% of the students) is obtaining the answer from some outside source. The third group (about 25% of the students) represents those who interrupt their solution, presumably to work off line or to obtain outside help.
Racial/Ethnic and Gender Differences in Individual Workplace Injury Risk Trajectories: 1988–1998
Authors: Berdahl Terceira A.
Published: January 2008

Objectives. I examined workplace injury risk over time and across racial/ethnic and gender groups to observe patterns of change and to understand how occupational characteristics and job mobility influence these changes.

Methods. I used hierarchical generalized linear models to estimate individual workplace injury and illness risk over time (“trajectories”) for a cohort of American workers who participated in the National Longitudinal Survey of Youth (1988–1998).

Results. Significant temporal variation in injury risk was observed across racial/ethnic and gender groups. At baseline, White men had a high risk of injury relative to the other groups and experienced the greatest decline over time. Latino men demonstrated a pattern of lower injury risk across time compared with White men. Among both Latinos and non-Latino Whites, women had lower odds of injury than did men. Non-Latino Black women's injury risk was similar to Black men's and greater than that for both Latino and non-Latino White women. Occupational characteristics and job mobility partly explained these differences.

Conclusions. Disparities between racial/ethnic and gender groups were dynamic and changed over time. Workplace injury risk was associated with job dimensions such as work schedule, union representation, health insurance, job hours, occupational racial segregation, and occupational environmental hazards.
I Think Therefore I Am: Perceived Ideal Weight as a Determinant of Health
Authors: Muennig Peter , Jia Haomiao , Lee Rufina , Lubetkin Erica
Published: January 2008

Objectives. We examined whether stress related to negative body image perception and the desire to lose weight explained some of the body mass index–health gradient.

Methods. We used 2003 Behavioral Risk Factor Surveillance System data to examine the impact of desired body weight, independent of actual body mass index, on the amount of physically and mentally unhealthy days by race, ethnicity, and gender.

Results. The difference between actual and desired body weight was a stronger predictor than was body mass index (BMI) of mental and physical health. When we controlled for BMI and age, men who wished to lose 1%, 10%, and 20% of their body weight respectively suffered a net increase of 0.1, 0.9, and 2.7 unhealthy days per month relative to those who were happy with their weight. For women, the corresponding numbers were 0.1, 1.6, and 4.3 unhealthy days per month. The desire to lose weight was more predictive of unhealthy days among women than among men and among Whites than among Blacks or Hispanics.

Conclusions. Our results raise the possibility that some of the health effects of the obesity epidemic are related to the way we see our bodies.
Longitudinal Patterns of Health Insurance Coverage Among a National Sample of Children in the Child Welfare System
Authors: Raghavan Ramesh , Aarons Gregory A. , Roesch Scott C. , Leslie Laurel K.
Published: January 2008

Objectives. We sought to describe health insurance coverage over time among a national sample of children who came into contact with child welfare or child protective services agencies.

Methods. We used data from 4 waves of the National Survey of Child and Adolescent Well-Being to examine insurance coverage among 2501 youths. Longitudinal insurance trajectories were identified using latent class analyses, a technique used to classify individuals into groupings of observed variables, and survey-weighted logistic regression was used to identify variables associated with class membership.

Results. We identified 2 latent insurance classes—1 contained children who gained health insurance, and the other contained children who stably maintained coverage over time. History of sexual abuse, and race/ethnicity other than White, Black, and Hispanic, were associated with membership in the “gainer” class. Foster care placement and poorer health status were associated with membership in the “maintainer” class. Caregiver characteristics were not associated with class membership.

Conclusions. The majority of children in child welfare had stable health insurance coverage over time. Given this vulnerable population’s dependence upon Medicaid, protection of existing entitlements to Medicaid is essential to preserve their stable insurance coverage.
Climate Change: The Public Health Response
Authors: Frumkin Howard , Hess Jeremy , Luber George , Malilay Josephine , McGeehin Michael
Published: January 2008

There is scientific consensus that the global climate is changing, with rising surface temperatures, melting ice and snow, rising sea levels, and increasing climate variability. These changes are expected to have substantial impacts on human health. There are known, effective public health responses for many of these impacts, but the scope, timeline, and complexity of climate change are unprecedented. We propose a public health approach to climate change, based on the essential public health services, that extends to both clinical and population health services and emphasizes the coordination of government agencies (federal, state, and local), academia, the private sector, and nongovernmental organizations.
The effect of temperature on the performance and stability of thermophilic anaerobic digestion
Authors: Wilson C. A. , Murthy S. M. , Fang Y. , Novak J. T.
Published: February 2008

Sustainable operation of an anaerobic sewage sludge digester requires the effective shuttling of carbon from complex organic material to methane gas. The accumulation of intermediates and metabolic products such as volatile fatty acids and hydrogen gas not only reveal inefficiency within the digestion process, but can be detrimental to reactor operation at sufficiently high levels. Eight anaerobic digesters (1 mesophilic and 7 thermophilic) were operated in order to determine the effect of steady-state digestion temperature on the operational stability and performance of the digestion process. Replicate reactors operated at 57.5 °C, the highest temperature studied, were prone to accumulation of volatile fatty acids (4052 and 3411 mg/L as acetate) and gaseous hydrogen. Reactors operated at or below 55 °C showed no such accumulation of intermediate metabolites. Overall methanogenesis was also greatly reduced at 57.5 °C (0.09 L CH4/g VS fed) versus optimal methane formation at 53 °C (0.40 L CH4/g VS fed). Microbial community assessment and free energy calculations suggest that the accumulation of fatty acids and hydrogen, and relatively poor methanogenic performance at 57.5 °C are likely due to temperature limitations of thermophilic aceticlastic methanogens.
Changes in pH of peritoneal fluid associated with carbon dioxide insufflation during laparoscopic surgery in dogs
Authors: Duerr Felix M. , Twedt David C. , Monnet Eric
Published: February 2008

Objective—To evaluate changes in pH of peritoneal fluid associated with CO2 insufflation during laparoscopy in dogs.

Animals—13 client-owned dogs and 10 purpose-bred teaching dogs.

Procedures—Laparotomy was performed on control dogs; peritoneal fluid pH was mea-sured at time of incision of the abdominal cavity (time 0) and 30 minutes later. Laparoscopic insufflation with CO2 was performed and routine laparoscopic procedures conducted on the teaching dogs. Insufflation pressure was limited to 12 mm Hg. Intraperitoneal fluid pH was measured by use of pH indicator paper at 4 time points. Arterial blood gas analysis was performed at the same time points.

Results—Peritoneal fluid pH did not change significantly between 0 and 30 minutes in the control dogs. For dogs with CO2 insufflation, measurements obtained were a mean of 8.5, 24.5, 44.5, and 72.0 minutes after insufflation. The pH of peritoneal fluid decreased signifi-cantly between the first (7.825 ± 0.350) and second (7.672 ± 0.366) time point. Blood pH decreased significantly between the first (7.343 ± 0.078), third (7.235 ± 0.042), and fourth (7.225 ± 0.038) time points. The PaCO2 increased significantly between the first (39.9 ± 9.8 mm Hg) and fourth (54.6 ± 4.4 mm Hg) time points. Base excess decreased significantly between the first and all subsequent time points.

Conclusions and Clinical Relevance—Pneumoperitoneum attributable to CO2 insufflation caused a mild and transient decrease in peritoneal fluid pH in dogs. Changes in peritoneal fluid associated with CO2 insufflation in dogs were similar to those in other animals.
Outcome of cats with low-grade lymphocytic lymphoma: 41 cases (1995–2005)
Authors: Kiselow Michael A. , Rassnick Kenneth M. , McDonough Sean P. , Goldstein Richard E. , Simpson Kenneth W. , Weinkle Tristan K. , Erb Hollis N.
Published: February 2008

Objective—To evaluate factors associated with response to treatment, remission duration, and survival in cats with low-grade lymphoma affecting various organ systems.

Design—Retrospective case series.

Sample Population—41 cats with histologically confirmed low-grade lymphocytic lymphoma.

Procedures—Medical records and biopsy specimens of cats with histologically confirmed low-grade lymphocytic lymphoma of various organ systems treated with prednisone and chlorambucil between 1995 and 2005 were reviewed. The Kaplan-Meier method was used to estimate remission duration and survival. Factors potentially associated with prognosis were compared.

Results—Common clinical signs were weight loss (83%), vomiting (73%), anorexia (66%), and diarrhea (58%). Seventy-eight percent of cats tested had low serum cobalamin concentrations. Lymphoma was confined to the gastrointestinal tract in 68% of cats. Fifty-six percent of cats achieved a complete response to treatment, and 39% achieved a partial response. Five percent of cats had no response. No association was found between any risk factors (including anatomic site) and response to treatment. Partial response was associated with shorter remission duration, compared with complete response; median remission duration was 428 days for cats achieving a partial response, compared with 897 days for cats achieving a complete response. No other factors were associated with remission duration. Overall median survival time was 704 days. No factors were significantly associated with survival time.

Conclusions and Clinical Relevance—Most cats with lymphocytic lymphoma responded to treatment with prednisone and chlorambucil, and most factors evaluated were not associated with outcome.
Experimental demonstration of distance measurement with a femtosecond frequency comb laser
Authors: Cui M. , Schouten R. N. , Bhattacharya N. , van den Berg S.A.
Published: January 2008

NMi Van Swinden Laboratory, Thijsseweg 11, 2629 JA Delft, The Netherlands We experimentally demonstrate that a stabilized femtosecond frequency comb can be applied as a tool for distance measurement in an interferometric scheme. A proof of principle of this method, as proposed by Ye [5], is provided by measuring a displacement of about 15 cm in air and comparing it to a reference value from a calibrated laser interferometer. The experiment shows that the new scheme easily achieves an accuracy better than one optical fringe.
Efficient Implementation of Method of Successive Averages in Simulation-Based Dynamic Traffic Assignment Models for Large-Scale Network Applications
Authors: Sbayti Hayssam , Lu Chung-Cheng , Mahmassani Hani S.
Published: February 2008

The method of successive averages remains by far the most widely used solution heuristic in simulation-based dynamic traffic assignment. Its simplicity and the nonrequirement of derivative information for the flow-cost mapping function are the main reasons for its widespread use, especially in the realm of dynamic traffic assignment (DTA). However, its convergence properties in real-life networks have been inconclusive, especially because (a) simulation-based models typically are not well behaved mathematically, and therefore their solution properties are not guaranteed, and (b) predetermined step sizes do not exploit local information in searching for a solution and therefore tend to have sluggish performance properties. An effort was made to improve on the performance of the method of successive averages heuristic for user-equilibrium and system-optimal DTA problems on large congested networks through novel implementations that derive their efficiency from exploiting local information made available in the results of vehicle-based simulation models used to provide the mapping between a feasible path flow assignment and the experienced travel cost in a DTA solution framework. The results of extensive numerical tests on actual networks are reported, confirming the performance improvements attainable with the new approach.
Exploring spatiotemporal patterns in early stages of primary succession on former lignite mining sites
Authors: Felinks Birgit , Wiegand Thorsten
Published: February 2008

Questions:1. Does random colonization predominate in early stages of primary succession? 2. Do pioneer species facilitate the establishment of later arriving species? 3. Does an initially random distribution change to an aggregated pattern with ongoing succession?

Location:Lignite mining region of Lower Lusatia, eastern Germany.

Methods:Individual plants were mapped along a 2 m × 28 m transect during three successive years and classified into two groups (1) the pioneerCorynephorus canescensand (2)‘all other species’. Using the pair‐correlation function, univariate point pattern analysis was carried out by applying a heterogeneous Poisson process as null model. Bivariate analysis and a toroidal shift null model were applied to test for independence between the spatial patterns of the two groups separately for each year, as well by exploring spatiotemporal patterns from different years.

Results:In the first yearCorynephorusand ‘all other species’ showed an aggregated pattern on a spatial scale > 40 cm and in the second and third years a significant attraction for distances between 4 and 12 cm, with an increasing radius in the third year. The analyses of interspecific spatiotemporal dynamics revealed a change from independence to attraction between distances of 4 cm and 16 cm when usingCorynephorusas focal species. However, applying ‘all other species’ as focal points results in a significant attraction at distances up to 60 cm in the first year and a diminishing attraction in the second and third years with distances ≤ 6 cm.

Conclusions:Facilitative species‐species interactions are present in early stages of primary succession, resulting mainly from pioneer species acting as physical barriers and their ability to capture diaspores being drifted by secondary dispersal along the substrate surface. However, due to gradual establishment of perennial species and their ability of lateral extension by vegetative dispersal, facilitation may influence spatial pattern formation predominantly on short temporal and fine spatial scales.