bluuebunny/crossref_metadata_2025 huggingface dataset:
Sleep and the menopause – do postmenopausal women experience worse sleep than premenopausal women?
Authors: Kalleinen Nea , Polo-Kantola Päivi , Himanen Sari-Leena , Alhola Paula , Joutsen Atte , Urrila Anna S , Polo Olli
Published: August 2008

Objective

To examine the sleep characteristics in three cross-sectional populations: young, premenopausal and postmenopausal women, and the associations between sleep, menopause, mood and cognitive performance.

Study design

Twenty-one premenopausal (45–51 years), 29 postmenopausal (59–71 years) and 11 young (20–26 years, using oral contraceptives) women were recruited. Polysomnography was used to measure objective sleep quality. Subjective sleep quality, sleepiness and mood were assessed using questionnaires. Cognitive performance was investigated by means of three attentional tests.

Results

Total sleep time in pre- and postmenopausal women was similar (404.9 and 384.7 minutes), but shorter than in young women (448.2 minutes, P = 0.030 and <0.003, respectively). Sleep efficiency followed the same pattern, being 84.3% in premenopausal ( P = 0.027), 80.2% in postmenopausal ( P < 0.003) and 93.4% in young women. Pre- and postmenopausal women had less slow wave sleep (duration or activity) and more wake time after sleep onset (duration or frequency). Insomnia complaints were more frequent after the menopause ( P = 0.023). Sleepiness and mood scores were similar in all groups. Reaction speeds slowed with increasing age. After the menopause, better cognitive performance was associated with more rapid eye movement sleep.

Conclusion

Objective sleep measures differed significantly between the young and postmenopausal groups. These differences may be more because of the physiology of ageing than the rapid changes across the menopause, since similar sleep characteristics were already present in the premenopausal women. The increase in sleep complaints after menopause was not associated with sleepiness or disturbances in objective sleep quality, mood or cognitive performance.
Patient decision aid on natural health products for menopausal symptoms: randomized controlled trial
Authors: Légaré France , Dodin Sylvie , Stacey Dawn , LeBlanc Annie , Tapp Sylvie
Published: August 2008

Objective

To evaluate the impact of a patient decision aid (PDA) regarding the use of natural health products (NHPs) at menopause on decisional conflict, knowledge of NHPs, congruence between values and choice, persistence with an option, intention to disclose the use of NHPs to a physician or a pharmacist and intention to use decision support interventions in the future.

Study design

A randomized controlled trial in which 90 women, aged 45–64 years, facing a decision about using NHPs for menopausal symptoms, received a PDA (experimental group) or a general information brochure about menopause (control group).

Main outcome

Decisional conflict.

Measures

Women were evaluated at baseline and after a two-week period using the decisional conflict scale (DCS). Analysis of covariance was used to determine the differences between both groups on the DCS.

Results

Both groups experienced a statistically significant reduction on the DCS (−0.55 ± 0.59, P < 0.0001 versus −0.52 ± 0.73, P < 0.0001). However, there was no statistically significant difference between the groups ( P = 0.32). Both groups experienced a statistically significant improvement in knowledge of NHPs (0.86 ± 1.77, P = 0.002 versus 0.51 ± 1.47, P = 0.031). However, there was no statistically significant difference between the groups ( P = 0.162).

Conclusion

A PDA regarding the use of NHPs for menopausal symptoms impacted favourably on women's decisional conflict, but was not superior to a general information brochure on menopause.
Factors in Tissue Handling and Processing That Impact RNA Obtained From Formalin-fixed, Paraffin-embedded Tissue
Authors: Chung Joon-Yong , Braunschweig Till , Williams Reginald , Guerrero Natalie , Hoffmann Karl M. , Kwon Mijung , Song Young K. , Libutti Steven K. , Hewitt Stephen M.
Published: August 2008

Formalin-fixed, paraffin-embedded (FFPE) tissue is the most common specimen available for molecular assays on tissue after diagnostic histopathological examination. RNA from FFPE tissue suffers from strand breakage and cross-linking. Despite excellent extraction methods, RNA quality from FFPE material remains variable. To address the RNA quality factors within FFPE tissues, we studied RNA quality, isolating individual elements of the tissue fixation and processing including length of fixation in formalin and the type of buffer incorporated in the fixative. We examined the impact of the length of the tissue processing cycle as well. The optimal fixation period of 12-24 hr in phosphate-buffered formalin resulted in better-quality RNA. Longer tissue processing times were associated with higher quality RNA. We determined that the middle region of gene suffers less damage by these processes as shown by real-time quantitative RT-PCR. These data provide key information for the development of methods of analysis of gene expression in archival FFPE tissues and contribute to the establishment of objective standards for the processing and handling of tissue in surgical pathology. This manuscript contains online supplemental material at www.jhc.org . Please visit this article online to view these materials.
Cancer cells, adipocytes and matrix metalloproteinase 11: a vicious tumor progression cycle
Authors: Motrescu Elena Roza , Rio Marie-Christine
Published: August 2008

This brief review focuses on the emerging role of matrix metalloproteinase 11 (MMP-11) in cancer progression. It has recently been shown that MMP-11 is induced in adipose tissue by cancer cells as they invade their surrounding environment. MMP-11 negatively regulates adipogenesis by reducing pre-adipocyte differentiation and reversing mature adipocyte differentiation. Adipocyte dedifferentiation in turn leads to the accumulation of non-malignant peritumoral fibroblast-like cells, which favor cancer cell survival and tumor progression. This MMP-11-mediated bi-directional cross-talk between invading cancer cells and adjacent adipocytes/pre-adipocytes highlights the central role that MMP-11 plays during tumor desmoplasia and represents a molecular link between obesity and cancer.
Contribution of the C30/C75 disulfide bond to the biological properties of onconase
Authors: Torrent Gerard , Benito Antoni , Castro Jessica , Ribó Marc , Vilanova Maria
Published: August 2008

Onconase, a member of the pancreatic type ribonuclease family, is currently used as a chemotherapeutic agent for the treatment of different types of cancer. It is widely accepted that one of the properties that renders this enzyme cytotoxic is its ability to evade the cytosolic ribonuclease inhibitor (RI). In the present work, we produced and characterized an onconase variant that lacks the disulfide bond C30/C75. This variant mimics the stable unfolding intermediate des(30–75) produced in the reductive unfolding pathway of onconase. We found that the reduction of the C30/C75 disulfide bond does not significantly alter the cytotoxic properties of onconase, although the variant possesses a notably reduced conformational stability. Interestingly, both its catalytic activity and its ability to evade RI are comparable to wild-type onconase under mild reductive conditions in which the three disulfide containing intermediate des(30–75) is present. These results suggest that the C30/C75 disulfide bond could easily be reduced under physiological redox conditions.
Bauhinia Kunitz-type proteinase inhibitors: structural characteristics and biological properties
Authors: Vilela Oliva Maria Luiza , Sampaio Misako Uemura
Published: August 2008

Plant proteinase inhibitors are involved in the regulation of the activity of many proteinases and, in consequence, in biological processes driven by proteolysis. In this review, we summarize recent results on the activity of native Bauhinia inhibitors and synthetic derivatives. Structural and functional characteristics and the potential therapeutic use of these inhibitors are also discussed.
In vivo analysis reveals substrate-gating mutants of a rhomboid intramembrane protease display increased activity in living cells
Authors: Urban Sinisa , Baker Rosanna P.
Published: August 2008

Intramembrane proteases hydrolyze peptide bonds within cell membranes. Recent crystal structures revealed that rhomboid intramembrane proteases contain a hydrated active site that opens to the outside of the cell, but is protected laterally from membrane lipids by protein segments. Using Escherichia coli rhomboid (GlpG) structures as a guide, we previously took a mutational approach to identify the GlpG gating mechanism that allows substrates to enter the active site laterally from the membrane. Mutations that weaken contacts keeping the gate closed increase enzyme activity and implicate transmembrane segment 5 as the substrate gate. Since these analyses were performed in vitro with pure proteins in detergent micelles, we have now examined GlpG in its natural environment, within the membrane of live E. coli cells. In striking congruity with in vitro analysis, gate-opening mutants in transmembrane segment 5 display up to a 10-fold increase in protease activity in living cells. Conversely, mutations in other parts of the protease, including the membrane-inserted L1 loop previously thought to be the gate, decrease enzyme activity. These observations provide evidence for the existence of both closed and open forms of GlpG in cells, and show that inter-conversion between them via substrate gating is rate limiting physiologically.
Isoaspartate residues dramatically influence substrate recognition and turnover by proteases
Authors: Böhme Livia , Bär Joachim Wolfgang , Hoffmann Torsten , Manhart Susanne , Ludwig Hans-Henning , Rosche Fred , Demuth Hans-Ulrich
Published: August 2008

Posttranslational modifications influence the structure, stability and biological activity of proteins. Most of the reactions are enzyme-catalyzed, but some, such as asparagine (Asn) and glutamine (Gln) deamidation and the isoaspartate (isoAsp) formation within peptide chains, occur spontaneously. It has been previously shown that certain peptide sequences form isoAsp quite fast if the Asp stretches are exposed to the protein surface, thereby potentially changing susceptibility to proteolysis at these sites. This tempted us to investigate the activity of exo- and endopeptidases against Asp- or isoAsp-containing substrates. Members of the prolyl oligopeptidase family were unable to cleave substrates after proline if isoAsp was placed in the P2-position. Caspases, usually accepting Asp at P1-position of their substrates, did not cleave isoAsp-containing sequences. Similarly, the metal-dependent aminopeptidase amino peptidase N did not turnover N-terminal isoAsp-containing substrates, nor could the endopeptidase matrix metalloproteinase 3 (MMP 3) hydrolyze a serum amyloid A protein-like substrate if the sequence contained isoAsp instead of Asp. Also, the highly specific enterokinase, usually clipping after a stretch of four Asp residues and a lysine in the P1 position, could not turnover substrates if the P2 amino acid was replaced by isoAsp. In contrast, acylamino acid-releasing enzyme and dipeptidyl peptidases 1, 2 and 4 hydrolyzed substrates containing the isoAsp-Ala motif.
Molecular mechanisms of aromatase inhibition by new A, D-ring modified steroids
Authors: Cepa Margarida , Correia-da-Silva Georgina , Tavares da Silva Elisiário J. , Roleira Fernanda M.F. , Hong Yanyan , Chen Shiuan , Teixeira Natércia A.
Published: August 2008

A recent approach for treatment and prevention of estrogen-dependent breast cancer focuses on the inhibition of aromatase, the enzyme that catalyzes the final step of estrogen biosynthesis. Some synthetic steroids, such as formestane and exemestane, resembling the natural enzyme substrate androstenedione, revealed to be potent and useful aromatase inhibitors (AIs) and were approved for the treatment of estrogen-dependent breast cancer in postmenopausal women. Recently, we found that five newly synthesized steroids with chemical features in the A- and D-rings considered important for drug-receptor interaction efficiently inhibit aromatase derived from human placental microsomes. In this work, these steroids showed a similar pattern of anti-aromatase activity in several aromatase-expressing cell lines. 5α-androst-3-en-17-one and 3α,4α-epoxy-5α-androstan-17-one were revealed to be the most potent inhibitors. These compounds induced a time-dependent inhibition of aromatase, showing to be irreversible AIs. The specific interactions of these compounds with aromatase active sites were further demonstrated by site-directed mutagenesis studies and evaluated by computer-aided molecular modeling. Both compounds were able to suppress hormone-dependent proliferation of MCF-7aro cells in a dose-dependent manner. These findings are important for the elucidation of a structure-activity relationship on aromatase, which may help in the development of new AIs.
HIV-1 at the immunological and T-lymphocytic virological synapse
Authors: Haller Claudia , Fackler Oliver T.
Published: August 2008

Cell-cell transmission of human immunodeficiency virus type 1 (HIV-1) is considered the most effective mode of viral spread in T-lymphocyte cultures. Evidence has accumulated that HIV-1 assembles polarized synaptic-like structures, referred to as virological synapses, as specialized sites of viral transfer. Interestingly, it was recently also discovered that HIV-1 impairs the formation of the structurally similar immunological synapse, thereby modulating exogenous T-lymphocyte stimulation to yield an optimal activation state for productive HIV-1 infection. The careful dissection of these opposing effects will contribute to our understanding of retroviral spread and cellular signal transduction machineries.
Taxonomy and molecular phylogeny of Arthrobotrys mangrovispora, a new marine nematode-trapping fungal species
Authors: Swe Aung , Jeewon Rajesh , Pointing Stephen B. , Hyde Kevin D.
Published: August 2008

Arthrobotrys mangrovispora sp. nov. (fungi) isolated from decaying submerged wood in mangroves of Hong Kong is described and illustrated. The species closely resembles A. scaphoides and A. microscaphoides, but is distinguished by its conidial shape and size and septum number. Conidia vary in shape; they are broadly turbinate to elongate-fusoid, range from 25–(38.9)–50×12– (17.3)–24 μm, and possess 0–3 septa. The proportions of conidia with 0, 1, 2 or 3 septa are 6%, 23.5%, 50% and 20.5%, respectively. The new species forms adhesive network trapping devices. Phylogenetic analyses of nuclear and protein-coding DNA sequences (28S, ITS and a combined ITS+β-tubulin dataset) indicate that the new taxon should be assigned to Arthrobotrys.
Mutagenic and Recombinagenic Responses to Defective DNA Polymerase δ Are Facilitated by the Rev1 Protein in pol3-t Mutants of Saccharomyces cerevisiae
Authors: Mito Erica , Mokhnatkin Janet V , Steele Molly C , Buettner Victoria L , Sommer Steve S , Manthey Glenn M , Bailis Adam M
Published: August 2008

Defective DNA replication can result in substantial increases in the level of genome instability. In the yeast Saccharomyces cerevisiae, the pol3-t allele confers a defect in the catalytic subunit of replicative DNA polymerase δ that results in increased rates of mutagenesis, recombination, and chromosome loss, perhaps by increasing the rate of replicative polymerase failure. The translesion polymerases Pol η, Pol ζ, and Rev1 are part of a suite of factors in yeast that can act at sites of replicative polymerase failure. While mutants defective in the translesion polymerases alone displayed few defects, loss of Rev1 was found to suppress the increased rates of spontaneous mutation, recombination, and chromosome loss observed in pol3-t mutants. These results suggest that Rev1 may be involved in facilitating mutagenic and recombinagenic responses to the failure of Pol δ. Genome stability, therefore, may reflect a dynamic relationship between primary and auxiliary DNA polymerases.
Tilting at Quixotic Trait Loci (QTL): An Evolutionary Perspective on Genetic Causation
Authors: Weiss Kenneth M
Published: August 2008

Recent years have seen great advances in generating and analyzing data to identify the genetic architecture of biological traits. Human disease has understandably received intense research focus, and the genes responsible for most Mendelian diseases have successfully been identified. However, the same advances have shown a consistent if less satisfying pattern, in which complex traits are affected by variation in large numbers of genes, most of which have individually minor or statistically elusive effects, leaving the bulk of genetic etiology unaccounted for. This pattern applies to diverse and unrelated traits, not just disease, in basically all species, and is consistent with evolutionary expectations, raising challenging questions about the best way to approach and understand biological complexity.
Epidemiology of Highly Endemic Multiply Antibiotic-Resistant Shigellosis in Children in the Peruvian Amazon
Authors: Kosek Margaret , Yori Pablo Peñataro , Pan William K. , Olortegui Maribel Paredes , Gilman Robert H. , Perez Juan , Chavez Cesar Banda , Sanchez Graciela Meza , Burga Rosa , Hall Eric
Published: August 2008

OBJECTIVE. Our goal was to estimate the impact of a Shigella vaccine in an area where shigellosis is endemic by characterizing the disease burden and antibiotic-resistance profiles of isolates and by determining the prevalence of Shigella flexneri serotypes.

PATIENTS AND METHODS. We conducted a 43-month-long prospective, community-based diarrheal disease surveillance in 442 children <72 months of age in the Peruvian Amazon between October 1, 2002, and April 15, 2006.

RESULTS. The incidence of diarrheal disease was 4.38 episodes per child-year. The incidence rate for shigellosis was 0.34 episodes per child-year in children <72 months of age and peaked in children between 12 and 23 months at 0.43 episodes per child-year. Maternal education at or beyond the primary grade level, piped water supply, weight-for-age z score, and improved water-storage practices were the most significant determinants of disease in this community with living conditions comparable to many rural areas in the developing world.

CONCLUSIONS. Children living in this region had a 20-fold higher rate of disease incidence detected by active surveillance as those recently estimated by passive detection. Most symptomatic disease was caused by S flexneri, although the diversity of serotypes will require a multivalent vaccine to have a significant impact on the burden of disease caused by shigellosis. Several other public health disease-control interventions targeted at water source and improved storage, nutritional interventions, and improved maternal education seem to have a greater impact than a univalent S flexneri 2a vaccine.
Estigma, discriminação e HIV/Aids no contexto brasileiro, 1998 e 2005
Authors: Garcia Sandra , Koyama Mitti Ayako Hara
Published: August 2008

OBJETIVO: Identificar a prevalência de atitudes discriminatórias em dois momentos da epidemia brasileira de HIV/Aids e possíveis mudanças ocorridas. MÉTODOS: O Índice de Intenção de Discriminação foi obtido por pontuação, somando 1 para situações de discriminação ou 0, para o caso contrário. As faixas de intenção de discriminação foram estabelecidas por meio da técnica de cluster, compatibilizadas entre os estudos de 1998 e 2005. Para verificar associação entre o índice e as variáveis sociodemográficas, utilizou-se comparações de médias, teste qui-quadrado, e modelos ajustados de regressão logito ordenado. RESULTADOS: Houve redução estatisticamente significante na proporção de pessoas entre as pesquisas de 1998 e 2005 que responderam sim à obrigatoriedade do teste anti-HIV para: a admissão no emprego, antes do casamento, ingresso nas forças armadas, usuários de drogas, entrada de estrangeiros no país, profissionais do sexo e para todas as pessoas. Possuir menor escolaridade, ser do sexo feminino, ter acima de 45 anos e residir na região Norte/Nordeste são fatores associados ao maior nível de intenção de discriminação. CONCLUSÕES: O crescimento da intenção de discriminação mostra que as informações sobre formas de transmissão e não transmissão da Aids ainda necessitam de melhor elaboração e divulgação, principalmente entre as populações de menor escolaridade, residentes nos estados do Norte/Nordeste, do sexo feminino e pertencentes à faixa etária acima de 45 anos.
Mudanças no âmbito da testagem anti-HIV no Brasil entre 1998 e 2005
Authors: França Junior Ivan , Calazans Gabriela , Zucchi Eliana Miura
Published: August 2008

OBJETIVO: Analisar mudanças na realização de teste anti-HIV, as razões alegadas entre as pessoas que foram ou não testadas e o recebimento de aconselhamento. MÉTODOS: Estudos transversais conduzidos com homens e mulheres de 16 a 65 anos, com amostras representativas do Brasil urbano em 1998 (n=3.600) e 2005 (n=5.040). Características sociodemográficas, sexuais, reprodutivas e de experiências de vida e saúde foram consideradas na análise. A avaliação das possíveis diferenças nas distribuições das variáveis baseou-se nos testes qui-quadrado de Pearson e F design-based (±<5%). RESULTADOS: Em 1998, 20,2% dos entrevistados haviam realizado o teste e 33,6% em 2005. Foram testadas 60% das mulheres na faixa 25-34 anos, mas as que iniciaram a vida sexual antes dos 16 anos e reportaram quatro ou mais parceiros sexuais nos cinco anos anteriores à entrevista foram menos testadas. Não se observou aumento significativo da testagem entre homens, exceto para os de 55-65 anos, renda per capita entre 1-3 e 5-10 salários mínimos, aposentados, protestantes históricos e adeptos de cultos afro-brasileiros, moradores da região Norte/Nordeste e os que declararam parceria homo/bissexual ou não tiveram relações sexuais nos cinco anos anteriores à entrevista. Não aumentou a freqüência de testagem entre pessoas auto-avaliadas como sob alto risco para o HIV. Entre as mulheres, a freqüência de testagem pré-natal aumentou e a testagem por trabalho diminuiu entre os homens. Em 2005, metade dos testados não recebeu orientação antes ou após o teste. CONCLUSÕES: Houve expansão desigual na testagem, atingindo principalmente mulheres em idade reprodutiva, adultas e pessoas com melhores condições sociais. A testagem parece estar aumentando no País sem a devida atenção à decisão autônoma das pessoas e sem o provimento de maior e melhor oferta de aconselhamento.
Consumo de álcool e drogas: principais achados de pesquisa de âmbito nacional, Brasil 2005
Authors: Bastos Francisco I , Bertoni Neilane , Hacker Mariana A
Published: August 2008

OBJETIVO: Analisar os padrões de consumo de álcool e drogas de uma amostra representativa da população urbana brasileira na sua inter-relação com a saúde sexual e reprodutiva. MÉTODOS: Dados de inquérito de base populacional, de abrangência nacional, com plano amostral complexo, realizado em 2005. Foram entrevistados 5.040 indivíduos de ambos os sexos, na faixa etária de 16 a 65 anos. Analisaram-se questões relativas consumo de álcool e drogas e comportamento sexual. Utilizou-se análise bivariada e multivariada. RESULTADOS: O álcool foi a substância mais freqüentemente utilizada, com relato de uso regular, na vida, por 18% dos entrevistados. O consumo de drogas ilícitas foi referido por 9% dos entrevistados, especialmente, maconha e cocaína aspirada, com uso de drogas injetáveis infreqüente. Observou-se declínio do consumo de cocaína aspirada e incremento do uso de maconha (nos últimos 12 meses), comparados a resultados de pesquisa similar realizada em 1998. Histórico de abuso sexual constituiu fator de risco do consumo de drogas e uso regular de álcool. A referência por parte do entrevistado ao papel da religião na sua formação, ser branco e do sexo feminino se mostraram protetores frente ao consumo regular de álcool, particularmente prevalente entre homens mais velhos. As opções de lazer e a ausência de práticas religiosas atuais se mostraram associadas ao consumo de drogas. CONCLUSÕES: O consumo de álcool, regular ou não, é prevalente na população urbana brasileira, enquanto o uso de drogas injetáveis se mostrou raro. Ao longo da última década observou-se declínio no consumo de cocaína. Histórico de abuso sexual se mostrou central ao consumo posterior de drogas e álcool.
Estimativa de áreas de risco para hepatite A
Authors: Braga Ricardo Cerqueira Campos , Valencia Luís Iván Ortiz , Medronho Roberto de Andrade , Escosteguy Claudia Caminha
Published: August 2008

Este estudo estimou áreas de risco de hepatite A e de variáveis associadas em região de Duque de Caxias, Rio de Janeiro, Brasil. Foi realizado um inquérito soroepidemiológico para hepatite A e domiciliar em 19 setores censitários. Destes, foram selecionados 11 setores contíguos com diferentes cotas altimétricas e todas as 1.298 crianças com idade menor que dez anos foram incluídas no estudo. Construiu-se semivariogramas para a hepatite A, não uso de filtro, número de pontos de água e tempo de encanamento de água. A estimativa espacial foi obtida por krigagem indicadora e ordinária. O ajuste dos modelos foi avaliado por meio de validação cruzada. Os quatro modelos ajustados de semivariogramas do desfecho e das três variáveis sócio-econômicas apresentaram um padrão isotrópico; mapas do risco estimado segundo a krigagem para hepatite A e para as variáveis sócio-econômicas foram construídos; a validação cruzada mostrou um bom ajuste. A utilização do método de estimativa espacial usando-se a krigagem possibilitou a detecção de áreas com maior probabilidade de ocorrência da hepatite A, independentemente da divisão político-administrativa dos setores censitários.
Dor nos dentes e gengivas e fatores associados em adolescentes brasileiros: análise do inquérito nacional de saúde bucal SB-Brasil 2002-2003
Authors: Borges Carolina Marques , Cascaes Andreia Morales , Fischer Tatiana Konrad , Boing Antonio Fernando , Peres Marco Aurélio , Peres Karen Glazer
Published: August 2008

Estimou-se a prevalência de dor nos dentes e gengivas e fatores associados em adolescentes brasileiros de 15 a 19 anos de idade. Foram utilizadas informações de 16.126 adolescentes participantes do levantamento epidemiológico nacional de saúde bucal - SB Brasil 2002-2003. O desfecho foi o relato de dor nos dentes e gengivas nos últimos seis meses. As variáveis exploratórias foram: renda per capita, escolaridade, condição de estudo, sexo, cor da pele, idade, localização geográfica da residência, tipo de serviço odontológico utilizado pela última vez, tempo decorrido da última consulta odontológica, índice CPO-D e seus componentes, cálculo dentário e o índice de estética dental. Foram realizadas análises brutas e múltiplas utilizando a regressão de Poisson. A prevalência da dor de dentes e gengivas foi de 35,6% (IC95%: 34,8-36,4). A prevalência de dor foi maior nas meninas, naqueles pertencentes a famílias com baixa renda per capita, nos não estudantes e estudantes de escola pública e naqueles com baixa escolaridade para a idade. Indivíduos que apresentaram altos níveis de cárie e cálculo dentário também apresentaram maiores prevalências do desfecho. A dor nos dentes e gengivas em adolescentes pode ser considerada um problema relevante em saúde pública sugerindo a necessidade de ações preventivas e de promoção da saúde.
Desenvolvimento de pré-escolares na educação infantil em Cuiabá, Mato Grosso, Brasil
Authors: Souza Sandra Coenga de , Leone Claudio , Takano Olga Akiko , Moratelli Hélio Borba
Published: August 2008

O objetivo foi avaliar o desenvolvimento neuropsicomotor de pré-escolares na educação infantil. Estudo de corte transversal, utilizando 38 itens do teste de Denver II. Foram avaliados todos os pré-escolares com idade entre quatro e seis anos incompletos matriculados na Rede Pública Municipal de Ensino de Cuiabá, Mato Grosso, Brasil, no período de agosto 2002 a novembro 2003. Nesse período havia 960 pré-escolares matriculados em 27 creches e duas escolas públicas. Para a análise estatística foi aplicado o teste Ç2 com intervalo de 95% de confiança e ± = 5%. Para calcular os percentis da idade em que os pré-escolares passaram em cada prova foi realizada uma regressão logística. Dos 960 pré-escolares avaliados, 67% apresentaram desempenho normal, 30,2% questionável e 2,8% anormal. Em 27/38 itens avaliados, o percentual de acertos ultrapassou 90%. O desempenho alterado predominou no sexo masculino, no grupo de cinco a seis anos. O desempenho dessa população foi muito semelhante ao dos pré-escolares norte-americanos de Denver, Colorado. O melhor resultado segundo o gênero ocorreu no sexo feminino e segundo a idade no grupo de quatro anos.
Perfil das vítimas de trauma por acidente de moto atendidas em um serviço público de emergência
Authors: Santos Ana Maria Ribeiro dos , Moura Maria Eliete Batista , Nunes Benevina Maria Vilar Teixeira , Leal Clara Francisca dos Santos , Teles João Batista Mendes
Published: August 2008

No Brasil, observa-se um aumento dos acidentes envolvendo motocicletas. Este estudo objetivou caracterizar as vítimas desse tipo de acidente atendidas em um serviço de emergência no Piauí. Pesquisa quantitativa com amostra de 430 vítimas. A análise mostrou predominância do sexo masculino, na faixa etária de 15 a 24 anos e procedentes do próprio estado. Observou-se que 301 dessas vítimas eram condutores da motocicleta, 81 passageiros e 48 foram atropelados por moto. Verificou-se que 76,05% das vítimas sofreram acidente de quinta-feira a domingo, 80,75% apresentaram seqüelas temporárias e 52,33% dos acidentes ocorreram no período noturno. Os tipos de lesão corresponderam em 69,3% dos casos a ferimentos; 51,4% a fraturas; 27,44% a hematomas; e 20,7% a traumatismos cranioencefálicos. Entre as vítimas de acidente, condutores da moto e suspeitos de ingestão de álcool, 52,07% não utilizavam capacete no momento do acidente. A maioria das vítimas recebeu alta hospitalar e 14 foram a óbito. Conclui-se que o trauma provocado pelos acidentes envolvendo motocicletas merece atenção, especialmente em relação ao planejamento de ações preventivas, assim como controle de sua ocorrência no estado.
Cofactor Biosynthesis
Authors: Haase Ilka , Fischer Markus , Bacher Adelbert , Eisenreich Wolfgang , Rohdich Felix
Published: August 2008

Whereas plants and certain microorganisms can generate all required coenzymes from CO2or simple organic precursors, animals must obtain precursors (designated as vitamins) for a major fraction of their coenzymes from nutritional sources. Still, most vitamins must be converted into the actual coenzymes by reactions catalyzed by animal enzymes. The structures and biosynthetic pathways of some coenzymes are characterized by extraordinary complexity. Enzymes for coenzyme biosynthesis have frequently low catalytic rates, and some of them catalyze reactions with highly unusual mechanisms.
DNA
Helicases: Chemistry and Mechanisms
Authors: Pugh Robert A. , Spies Maria
Published: August 2008

DNA helicases are members of a larger class of enzymes composed of molecular motors that couple the energy of NTP binding and hydrolysis to directional translocation along a nucleic acid lattice. Structurally and mechanistically related helicases perform drastically different roles in DNA metabolism by associating with various macromolecular machineries that orchestrate DNA processing events. Within these macromolecular ensembles, DNA helicase translocation is coupled to separation of duplex DNA into two single strands, which is necessary for DNA replication, repair, recombination and transcription. Translocation by DNA helicases can also result in the disassembly of protein–nucleic acid complexes formed during DNA metabolism. One major consequence of cellular dependence on DNA helicases is that defects in these enzymes result in a broad spectrum of disorders usually characterized by premature aging, susceptibility to cancer, and other diseases normally associated with aging.
Fluorescence to Study Nucleic Acids
Authors: Asseline Ulysse
Published: August 2008

The power of fluorescence spectroscopy in the study of nucleic acids relies on the availability of hundreds of different fluorophores that span the visible spectrum of light and the possibility of using them to label oligonucleotides (short fragments of DNA or RNA obtained by chemical synthesis) specifically. Any sequence can be obtained with one or more fluorophores and fluorophore quenchers attached at preselected positions by linkages with suitable parameters to ensure the optimal properties for the fluorescent oligonucleotides. Fluorescent labeling of long DNA or RNA fragments is also possible by enzymatic methods. Fluorescence‐based studies of nucleic acids are widely used in different areas such as basic research, molecular and clinical diagnostics, disease monitoring, therapeutic development, food technology, environmental sciences, and biotechnology. After a few words on biological and fluorescence backgrounds, the main labeling strategies will be developed and examples of biological questions that can be addressed with fluorescent oligonucleotides and the major types of fluorescence spectroscopy techniques will be reported.
Starch Biosynthesis in Plants
Authors: Preiss Jack
Published: August 2008

Starch is a major storage compound in plants that is present both in leaves and in storage tissues. Biochemical and molecular biological data show that ADP‐glucose is the glucosyl donor for plant starch synthesis, and its synthesis is catalyzed by ADP‐glucose pyrophosphorylase. Subsequently, starch synthases catalyze the transfer of the glucosyl residue from ADP‐glucose to the oligosaccharide chains of the starch components amylose and amylopectin to form new α‐1,4‐glucosidic residues. After elongation of these α‐1,4‐glucosidic chains, the branching enzyme catalyzes a cleavage of the elongated chain and transfers the cleaved portion of the oligosaccharide chain to either another region in the amylopectin molecule or to a new amylopectin and forms a new α‐1,6‐glucosidic linkage. Amylose synthesis is catalyzed by the granule‐bound starch synthase. Regulation of starch synthesis occurs at the ADP‐glucose pyrophosphorylase step. The enzyme from higher plants, green algae, and cyanobacteria is activated allosterically by 3‐phosphoglycerate and inhibited by inorganic phosphate. Isolation of mutants and control analyses indicate that the allosteric activation and inhibition are of physiological and functional importance in the regulation of starch synthesis. Furthermore, evidence indicates that ADP‐glucose pyrophosphorylases can also be regulated by a redox mechanism. The current knowledge of the enzyme structures and critical amino acids necessary for substrate binding, allosteric effector binding, regulation, and catalysis for the ADP‐glucose pyrophosphorylase is reviewed.
High Throughput Screening (HTS) Techniques: Applications in Chemical Biology
Authors: Inglese James , Auld Douglas S.
Published: August 2008

The rapid testing of chemical libraries for biological activity is the primary aim of high throughput screening (HTS). Advances in HTS have paralleled those in molecular biology, instrumentation and automation, and informatics, and the increased availability of arrayed compound libraries. Sophisticated high sensitivity assays and the associated technologies required to implement these assays in HTS have been largely developed within the pharmaceutical industry for the identification of new chemical matter for drug development. However, HTS approaches are now widely applied to the broader questions within biological research. By way of introduction, we will describe the components of HTS and provide examples of strategies used to identify novel chemtypes for specific biological targets using large chemical libraries. We then will illustrate how more narrowly defined compound collections (e.g., targeted libraries or bioactive compounds) have been profiled against related targets or cell types for the purpose of discovering or defining, compound class/gene family selectivity, off‐target activity or “hidden phenotypes”, toxic fingerprints, or any other relationship between chemical structure and bioactivity. In this way, HTS systems can expand the scope of an experimental hypothesis to address questions of chemical biology, be they at the level of an isolated enzymatic activity or that of a complex cellular phenotype.
Membrane Compartments in Immune Cell Signaling and Trafficking
Authors: Hammond Stephanie , Holowka David , Baird Barbara
Published: August 2008

Cells of the immune system detect and respond to the presence of foreign antigens by signaling through an array of receptors, which include the multichain immune recognition receptor (MIRR) family. Stimulated changes in membrane architecture, which includes protein and lipid segregation within membranes as well as membrane trafficking, regulate these cellular responses. We provide a brief overview of MIRR signaling, which focuses on signaling through the IgE receptor in mast cells, and we highlight specific examples in which membrane compartmentalization plays a role in this signaling pathway. We summarize biochemical methods used to isolate and characterize membrane subdomains. Finally, we discuss cross‐correlation microscopy methods, application of antigen‐patterned surfaces, and fluorescence‐based trafficking assays to study dynamics of stimulated proteins interactions and membrane trafficking.
Membrane Potentials in Living Systems
Authors: O'Shea Paul
Published: August 2008

Membrane potentials are a ubiquitous feature of all living cells and play different roles in manifold cellular processes. Three different membrane potentials are known to exist that include the transmembrane potential difference, the surface electrostatic potential and the membrane dipole potential. Each of these are discussed in terms of their different physical origins and characteristics together with representative examples of how they feature in cell biology as well as some examples in physiology. Techniques for the quantitative measurement of each of these potentials are described in both model systems as well as with living systems. As many of these practices involve the use of spectroscopic technologies (particularly fluorescence) they lend themselves to spatial (single cell) imaging applications and examples of the biological roles that spatial variation or localisation of each of these potentials are also outlined.
Neurotransmission: Measuring Chemical Events
Authors: Jacobs Christopher B. , Vickrey Trisha L. , Venton B. Jill
Published: August 2008

Measuring chemical events in neurotransmission is challenging because fast measurements of small amounts of neurotransmitters and neuromodulators are needed to track the dynamics of chemical changes accurately. In this article, we outline the basics of three popular methods for measuring neurochemical changes: electrophysiology, microdialysis, and electrochemistry. Electrophysiological techniques measure changes in membrane potentials associated with neurotransmission. These methods are often used to measure receptor‐gated ion channel currents and are popular for neuropharmacology studies. Microdialysis is a sampling technique that can be used to monitor basal levels of neurotransmitters directly. When coupled to a separation technique, microdialysis is advantageous because it can be used to detect virtually any compound in the brain. Electrochemical techniques are popular because microelectrodes allow rapid, direct detection of neurotransmitters with minimal tissue disturbance. Although the analytes must be electroactive, electrochemistry has been used successfully to monitor neurochemical changes in various preparations, from single cells to behaving animals. Future research in monitoring neurochemical events will include improving the temporal resolution, spatial resolution, and selectivity of measurements.
Combinatorial Libraries: Applications in Chemical Biology
Authors: Nestler H. Peter
Published: August 2008

The sequencing of genomes gave access to the complete set of building blocks for organisms of various species. A plethora of “‐omics” technologies has been developed to investigate the dynamic interactions of the building blocks to understand the functioning of living organisms. Synthetic molecules have proven to be powerful tools to modulate that states of biological systems, but the challenges to find suitable probes are tremendous. Combinatorial libraries allow preparing and testing diverse sets of molecules with high efficiency. In this article, we will discuss how combinatorial chemistry enables to investigate and modulate biochemical function in the quest to chart chemical and biological spaces.
Origins of Life: Emergence of the
RNA
World
Authors: Robertson Michael P.
Published: August 2008

The RNA World hypothesis refers to a period during the evolution of life on Earth, preceding the DNA/RNA/protein‐based systems of modern biology, during which RNA alone directed and catalyzed the chemistry of life. The concept is an elegant solution to the problem of devolving our intertwined 3‐biopolymer biochemistry toward its origins as the simplest system imaginable. In support of this idea, a scattering of molecular clues within our cells point suggestively toward an RNA‐only period leading up to the ribozyme‐mediated invention of protein synthesis. Indeed, the RNA World hypothesis is a very sensible scenario when considered from the perspective of trying to simplify life's complexity. The alternative perspective, however, imagining a sterile, primordial Earth and trying to assemble abiotically produced precursors into the RNA World is an extremely difficult problem. Certain steps along the logical chemical pathway to the RNA World have been demonstrated in the laboratory, but many others remain problematic. The exploration of RNA's catalytic properties has been encouraging, but complex ribozymes are extremely scarce in RNA populations. If the RNA World did once exist, it came about by a mechanism that has not yet been adequately elucidated, including the possibility that a different, unknown, biopolymer system may have preceded the RNA World.
Polyketide Biosynthesis: Fungi
Authors: Simpson Thomas J. , Cox Russell J.
Published: August 2008

Fungi produce a wide variety of biologically active compounds. Among these compounds, the polyketides form a large and structurally diverse group. These compounds are synthesized by highly programmed, large iterative multifunctional proteins, which are called the polyketide synthases. This review describes the structure and biosynthesis of polyketide fungal metabolites and highlights recent work on the links between gene sequence, protein architecture, and biosynthetic programming for fungal polyketide synthases.
Serine Proteases and Serine Protease Inhibitors
Authors: Page Michael J. , Cera Enrico Di
Published: August 2008

Serine proteases are among the largest group of proteolytic enzymes in the human genome that play vital roles in health and disease. Regulation of their activityin vivois mediated by a diverse group of serine protease inhibitors. An overview of the interplay between serine proteases and their inhibitors is provided. In addition, approaches to characterize this relationship are discussed with subsequent emphasis on how such measures apply to pathologies that result from defect of serine proteases or their inhibitors.
Protein Misfolding and Disease
Authors: Scheinost Johanna C. , Boldt Grant E. , Wentworth Paul
Published: August 2008

The amyloidoses are a class of conformational diseases that arise from the conversion of normally unfolded or globular proteins into fibrillar aggregates that are either pathogenic or non‐functional. At present there are more than 20 proteins that are associated with human amyloid diseases. This review focuses on three natively unfolded proteins that form fibrillar aggregates; amyloid‐β, islet amyloid polypeptide (‘amylin’), and α‐synuclein, the diseases they contribute to and chemical and biophysical approaches that are used to investigate these proteins' aggregation.
Chromosome Formation
Authors: Potts Patrick Ryan , Yu Hongtao
Published: August 2008

Chromosomes are large molecules of DNA that organize genetic materials of an organism. Chromosomes need to be properly organized, packaged, and compacted to ensure their integrity and segregation to daughter cells during mitosis. In eukaryotic cells, chromosomes associate with histones and other proteins to form chromatin within the nucleus. The basic packaging unit of chromatin is the nucleosome. The nucleosome core particle consists of 147 base pairs of DNA that wrap around a core histone octamer. A linear array of nucleosomes is further folded into high‐order chromatin structures. In addition, chromosomes are regulated during mitosis by the structural maintenance of chromosomes (SMC) family of proteins. Sister chromatids are physically tethered during DNA replication by the SMC1/3 cohesin complex to ensure equal segregation of chromosomes to daughter cells. These sister chromatids are compacted by the SMC2/4 condensin complex to form metaphase chromosomes.
Membrane Protein Structure: Techniques
Authors: King Gavin , Dixon Ann M.
Published: August 2008

The biological importance of membrane proteins has been recognized worldwide for many years, but historically these proteins have proved difficult to characterize structurally because of a variety of experimental challenges. Recently, technological advances across several disciplines have prompted considerable progress in three‐dimensional structure determination of membrane proteins. This review describes the state‐of‐the‐art methods that have successfully produced high‐resolution membrane protein structures to date. Most notably, X‐ray crystallography will be discussed, as this technique has made by far the largest contribution to our current knowledge of membrane protein structure. This is followed by discussion of nuclear magnetic resonance spectroscopy and cryo‐electron microscopy, both techniques that have also been successful in producing high‐resolution structures for membrane proteins, albeit to a lesser degree than X‐ray crystallography. Finally, we will discuss atomic force microscopy. Although this technique cannot be used for atomic level structural determination, it offers distinct advantages for investigation of membrane protein oligomerization, dynamics, and large‐scale conformational changes. Recent notable membrane protein structures are included throughout to illustrate progress in the field as well as the strengths and weaknesses of each method.
Metabolome
Authors: Griffin Julian L. , Atherton Helen J. , Pears Michael R.
Published: August 2008

With the development of systems biology, several approaches have been developed to profile a tier of organization in a cell, tissue, or organism globally. Metabolomics, also referred to as metabonomics, is an approach that attempts to profile all the small‐molecule metabolites in a biological matrix. One major challenge of this approach, as with other “‐omic” technologies, is that the metabolome is context dependent and varies with developmental stage/age, genetic modification, disease, and environment. Thus, by definition, the metabolome of an organism must take into consideration all the effects of these manipulations. Despite these challenges, the approach has already been applied to understand metabolism in a range of animal models and has more recently started to be applied to clinical studies. In this article, we will discuss some common approaches currently used in metabolomics and the results that they have produced. In particular, we will focus on the two most common analytical approaches, nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry, and some biological problems they have been used to address.