bluuebunny/crossref_metadata_2025 huggingface dataset:
Quantification of ortholog losses in insects and vertebrates
Authors: Wyder Stefan , Kriventseva Evgenia V , Schröder Reinhard , Kadowaki Tatsuhiko , Zdobnov Evgeny M
Published: November 2007

Background

The increasing number of sequenced insect and vertebrate genomes of variable divergence enables refined comparative analyses to quantify the major modes of animal genome evolution and allows tracing of gene genealogy (orthology) and pinpointing of gene extinctions (losses), which can reveal lineage-specific traits.

Results

To consistently quantify losses of orthologous groups of genes, we compared the gene repertoires of five vertebrates and five insects, including honeybee and Tribolium beetle, that represent insect orders outside the previously sequenced Diptera. We found hundreds of lost Urbilateria genes in each of the lineages and assessed their phylogenetic origin. The rate of losses correlates well with the species' rates of molecular evolution and radiation times, without distinction between insects and vertebrates, indicating their stochastic nature. Remarkably, this extends to the universal single-copy orthologs, losses of dozens of which have been tolerated in each species. Nevertheless, the propensity for loss differs substantially among genes, where roughly 20% of the orthologs have an 8-fold higher chance of becoming extinct. Extrapolation of our data also suggests that the Urbilateria genome contained more than 7,000 genes.

Conclusion

Our results indicate that the seemingly higher number of observed gene losses in insects can be explained by their two- to three-fold higher evolutionary rate. Despite the profound effect of many losses on cellular machinery, overall, they seem to be guided by neutral evolution.
The multiple sex chromosomes of platypus and echidna are not completely identical and several share homology with the avian Z
Authors: Rens Willem , O'Brien Patricia CM , Grützner Frank , Clarke Oliver , Graphodatskaya Daria , Tsend-Ayush Enkhjargal , Trifonov Vladimir A , Skelton Helen , Wallis Mary C , Johnston Steve , Veyrunes Frederic , Graves Jennifer AM , Ferguson-Smith Malcolm A
Published: November 2007

Background

Sex-determining systems have evolved independently in vertebrates. Placental mammals and marsupials have an XY system, birds have a ZW system. Reptiles and amphibians have different systems, including temperature-dependent sex determination, and XY and ZW systems that differ in origin from birds and placental mammals. Monotremes diverged early in mammalian evolution, just after the mammalian clade diverged from the sauropsid clade. Our previous studies showed that male platypus has five X and five Y chromosomes, no SRY, and DMRT1 on an X chromosome. In order to investigate monotreme sex chromosome evolution, we performed a comparative study of platypus and echidna by chromosome painting and comparative gene mapping.

Results

Chromosome painting reveals a meiotic chain of nine sex chromosomes in the male echidna and establishes their order in the chain. Two of those differ from those in the platypus, three of the platypus sex chromosomes differ from those of the echidna and the order of several chromosomes is rearranged. Comparative gene mapping shows that, in addition to bird autosome regions, regions of bird Z chromosomes are homologous to regions in four platypus X chromosomes, that is, X1, X2, X3, X5, and in chromosome Y1.

Conclusion

Monotreme sex chromosomes are easiest to explain on the hypothesis that autosomes were added sequentially to the translocation chain, with the final additions after platypus and echidna divergence. Genome sequencing and contig anchoring show no homology yet between platypus and therian Xs; thus, monotremes have a unique XY sex chromosome system that shares some homology with the avian Z.
ERCC1 Genotype and Phenotype in Epithelial Ovarian Cancer Identify Patients Likely to Benefit From Paclitaxel Treatment in Addition to Platinum-Based Therapy
Authors: Smith Stephanie , Su Dan , Rigault de la Longrais Irene A. , Schwartz Peter , Puopolo Manuela , Rutherford Thomas J. , Mor Gil , Yu Herbert , Katsaros Dionyssios
Published: November 2007

Purpose

To investigate the effect of excision repair cross-complementation group 1 (ERCC1) on treatment response and survival of patients treated with platinum chemotherapy with or without paclitaxel.

Patients and Methods

Tumor samples from epithelial ovarian cancer patients were evaluated for ERCC1 mRNA expression and a single nucleotide polymorphism at codon 118 (C>T). Of 178 patients treated with postoperative platinum-based chemotherapy, 75 were also given paclitaxel. For all of these patients, ERCC1 expression and genotype were analyzed for associations with treatment response and survival.

Results

Among the 103 patients treated with platinum without paclitaxel, the C/C genotype, compared with C/T and T/T, was associated with greater risk of disease progression and death (hazard ratio [HR], 1.95, P = .051; HR, 2.01, P = .033, respectively); high levels of ERCC1 mRNA, compared with low levels, were associated with greater risk of disease progression (HR, 2.41; P = .014). Similarly, when the ERCC1 data were combined, patients with the C/C genotype and high ERCC1 expression had greater risk for disease progression (HR, 3.73; P = .003) compared with those with low expression and non-C/C genotype. However, for the 75 patients treated with platinum plus paclitaxel, the C/C genotype and high ERCC1 expression were not associated with poor prognosis, suggesting that paclitaxel may help to alleviate ERCC1-related platinum resistance.

Conclusion

Ovarian cancer patients with high ERCC1 expression or the C/C genotype at codon 118 may benefit from the combination of platinum and paclitaxel, while those with low ERCC1 expression or the C/T or T/T genotype may respond well to platinum without paclitaxel.
Disability in Adult Survivors of Childhood Cancer: A Swedish National Cohort Study
Authors: Hjern Anders , Lindblad Frank , Boman Krister K.
Published: November 2007

Purpose

We studied the effects of childhood or adolescent cancer and cancer treatment on disability as indicated by persistent aid needs in adult life.

Patients and Methods

A group of 2,503 survivors of childhood cancer diagnosed before their 16th birthday were studied with data from registers in a national cohort of 1.91 million Swedish residents. Disability indicators were created from information in national registers about income (sickness pension, handicap allowance), personal assistance, and family situation in 2002. Multivariate logistic regression on the log scale was used to estimate relative risk (RR) ratios.

Results

A total of 7.6% of survivors received handicap allowance indicating permanent disability, including brain tumors (14.0%), other solid tumors (6.3), and leukemias/lymphomas (2.9%), compared with 0.6% in the general population. Twenty-six percent of survivors of CNS tumor and 10% of survivors of solid tumors had at least one indication of a disability. Younger age at diagnosis suggested a higher risk for disability. CNS tumor survivors had an RR of 10.7 (95% CI, 9.3 to 12.8) for having at least one disability indication compared with the noncancer population, whereas leukemia and lymphoma survivors had an RR of 3.0, and survivors of other cancers had an RR of 3.8. Survivors of CNS tumor only had an increased RR for living in the parental household (RR = 1.6; 95% CI, 1.4 to 1.9).

Conclusion

Childhood cancer survivors more often have persistent needs of supportive measures provided by community and/or the parental household. The survivors of CNS tumors were at particular risk, indicating a need of safer treatment protocols, and tailored follow-up, prevention, and rehabilitation to address this persistent social disability.
Preparation of Nanostructured Conjugated Polymers Using Template Electrochemical Polymerization in Supercritical Fluids
Authors: Atobe Mahito , Iizuka Shinya , Fuchigami Toshio , Yamamoto Hikaru
Published: November 2007

The electrochemical coating and filling with conjugated polymers in porous templates were carried out in supercritical fluids. The use of the special properties of the fluids such as higher diffusivity and lower viscosity enabled the effective monomer transport into the porous template and the nanoprecise coating and filling with the polymers.
New Facile Preparation of a Poly(vinyl chloride)/Layered Double Hydroxide Nanocomposite via Solution Intercalation
Authors: Liu Jun , Chen Guangming , Yang Jiping , Ma Yongmei
Published: November 2007

A poly(vinyl chloride)/layered double hydroxide (PVC/LDH) nanocomposite was successfully prepared via solution intercalation for the first time. Its microstructure was characterized by XRD, TEM, TGA, and IR, which clearly demonstrates that LDH particles were exfoliated into nanometer scale and homogeneously dispersed in the PVC matrix.
One-dimensional Strands of Trigonellinium Constructed by Intermolecular Strong O–H···O and Weak C–H···O Hydrogen Bonds in the Crystal of Partially Oxidized Ni(dmit)2 Salt
Authors: Tomono Kazuaki , Miyamura Kazuo
Published: November 2007

The trigonellinium cations in the partially oxidized Ni(dmit)2 complex salt 1 formed strong O–H···O hydrogen-bridged dimers, and the dimers are held together by the weak C(sp2 and sp3)–H···O hydrogen bond to form 1D strands. Further assembly through weak C(sp3)–H···O hydrogen bond and π···π interaction resulted in the formation of Ni(dmit)2 column structure.
A Group of Friends: The Las Americas Network, Virtual Studios, and Distance Education in Architecture
Authors: de Velasco Guillermo Vásquez
Published: November 2007

This paper celebrates the human factor by describing how our collective vocation towards innovation in design education has inspired the development of an active network across the Americas. Ten years after its creation, the Las Americas Digital Research Network has generated a stream of innovative implementations. This is the first time that the main stream of these research activities is articulated into a peer-reviewed journal publication. The narrative of the paper follows a time-line that starts with the creation of the Las Americas Digital Research Network in 1996. Supported by such a framework the paper continues to describe the implementation of virtual design studios as collaborations nested at the core of the network. Finally, the paper explains how the virtual design studios provide fundamental feasibility for the development of network-mediated distance education curricula in architecture and the opening of a new dimension in the development and deployment of collaborative networks.
Integrating Approximation and Interactive Decision Making in Multicriteria Optimization
Authors: Klamroth Kathrin , Miettinen Kaisa
Published: November 2007

We present a new interactive hybrid approach for solving multicriteria optimization problems where features of approximation methods and interactive approaches are incorporated. We produce rough approximations of the nondominated set and let the decision maker indicate with the help of reference points where to refine the approximation. In this way, (s)he iteratively directs the search toward the best nondominated solution. After the decision maker has identified the most interesting region of the nondominated set, the final solution can be fine-tuned with existing interactive methods. We suggest different ways of updating the reference point as well as discuss visualizations that can be used in comparing different nondominated solutions. The new method is computationally relatively inexpensive and easy to use for the decision maker.
Hormonal, pH, and Calcium Regulation of Connexin 43–Mediated Dye Transfer in Osteocytes in Chick Calvaria
Authors: Ishihara Yoshihito , Kamioka Hiroshi , Honjo Tadashi , Ueda Hirotaka , Takano-Yamamoto Teruko , Yamashiro Takashi
Published: November 2007

Gap junctional intercellular communication among osteocytes in chick calvaria, their natural 3D environment, was examined using FRAP analysis. Cell–cell communication among osteocytes in chick calvaria was mediated by Cx43 and was regulated by extracellular pH, extracellular calcium ion concentration, and PTH.

Introduction: The intercellular network of communication among osteocytes is mediated by gap junctions. Gap junctional intercellular communication (GJIC) is thought to play an important role in integration and synchronization of bone remodeling. We hypothesized that extracellular pH (pHo) and extracellular calcium ion concentration ([Ca2+]e), both of which are dynamically altered by osteoclasts during bone remodeling, affect GJIC among osteocytes. Using fluorescence replacement after photobleaching (FRAP) analysis, we examined the effect of changes in pHo and [Ca2+]e and addition of PTH on GJIC in osteocytes in chick calvaria. Additionally, we examined the role of intracellular calcium on the regulation of GJIC among osteocytes.

Materials and Methods: Anti-Connexin43 (Cx43) immunolabeling was used to localize gap junctions in chick calvaria. GJIC among osteocytes in chick calvariae was assessed using FRAP.

Results: Cx43 immunoreactivity was detected in most of the osteocyte processes. FRAP analysis showed dye-coupling among osteocytes in chick calvariae. In untreated osteocytes, fluorescence intensity recovered 43.7 ± 2.2% within 5 min after photobleaching. Pretreatment of osteocytes with 18 α-GA, a reversible inhibitor of GJIC, significantly decreased fluorescence recovery to 10.7 ± 2.2%. When pHo was decreased from 7.4 to 6.9, fluorescence recovery significantly decreased from 43.3 ± 2.9% to 19.7 ± 2.3%. Conversely, when pHo was increased from 7.4 to 8.0, fluorescence recovery was significantly increased to 61.9 ± 4.5%. When [Ca2+]e was increased from 1 to 25 mM, fluorescence recovery was significantly decreased from 47.0 ± 6.1% to 16.1 ± 2.1%. In bone fragments exposed to 1.0–10 nM rPTH for 3 h, replacement of fluorescence was significantly increased to 60.7 ± 7.2%. Chelating intracellular calcium ions affected GJIC regulation by [Ca2+]e and PTH.

Conclusions: Our study of cell–cell communication between osteocytes in chick calvaria showed for the first time that GJIC among osteocytes is regulated by the extracellular environment and by hormonal stimulation during bone remodeling. This method may be more biologically relevant to living bone than current methods.
Plasma Concentration of Heat Shock Protein 27 and Risk of Cardiovascular Disease: A Prospective, Nested Case-Control Study
Authors: Kardys Isabella , Rifai Nader , Meilhac Olivier , Michel Jean-Baptiste , Martin-Ventura Jose Luis , Buring Julie E , Libby Peter , Ridker Paul M
Published: November 2007

Background: Heat shock protein 27 (HSP27) has been hypothesized to be a potential biomarker of atherothrombosis. However, no prospective studies have yet been performed to investigate the association between HSP27 plasma concentration and incident cardiovascular events among initially healthy individuals.

Methods: We evaluated plasma concentrations of HSP27 at baseline among 255 initially healthy participants in the Women’s Health Study who subsequently developed myocardial infarction, ischemic stroke, or cardiovascular death during a follow-up period of up to 5.9 years and among an equal number of women matched for age and smoking but who remained free of cardiovascular disease over the same time period.

Results: Overall, HSP27 plasma concentrations were inversely associated with age (Spearman correlation coefficient r = −0.258, P <0.001), but not with other established cardiovascular risk factors. Conditional logistic regression analysis showed no significant association of baseline HSP27 plasma concentration with future cardiovascular disease; the odds ratio for upper vs lower tertile of HSP27 concentration at baseline was 0.99 (95% CI 0.62–1.57, P for trend = 0.99).

Conclusion: In this prospective study of initially healthy women, baseline HSP27 plasma concentration was not associated with incident cardiovascular events.
Analytical Determination of the Surface Area of a Threaded Fastener
Authors: Rammer Douglas R. , Zelinka Samuel L.
Published: November 2007

Accurate determination of corrosion rates for threaded fasteners hinges on the ability to determine the surface area on which corrosion is occurring. Currently, no general analytical expression of surface area exists for the threaded fastener types. A recent voluntary withdrawal of chromated copper arsenate as the primary, long-standing preservative treatment for wood resulted in the need to determine the corrosion rates of threaded fasteners. This paper developed general analytical surface area equations for a wedge-shaped thread and the area between the threads for three cases: (1) an increasing thread root and crest diameter, (2) constant thread root and crest diameters, and (3) a constant thread root but a decreasing thread crest diameter. The expressions are applied, numerically verified, and compared to simplified models for a No. 10–2.54 cm (1-in.) long wood screw.
Measurement and Evaluation of Asphalt Concrete Thermal Expansion and Contraction
Authors: Xu Qinwu , Solaimanian Mansour
Published: November 2007

Thermal expansion and contraction (TE/TC) of asphalt concrete (AC) play a significant role in both the thermal fatigue and low-temperature cracking of AC pavements. This paper discusses a test method and procedure developed to determine the AC coefficients of thermal expansion and contraction (CTE and CTC, respectively). Cylindrical specimens were subjected to temperature variations in an environmental chamber and specimen deformations were measured using extensometers. Temperature was applied in the range of −5°C to 40°C during both expansion and contraction phases. A specimen made from ceramic with very low CTE/CTC was also tested so that the influence of the self TE/TC of extensometers could be accounted for, and therefore, the measured deformation of an AC specimen was properly adjusted. A finite element (FE) model was developed to simulate the thermal stresses and strains inside the specimen, and to provide means for reliable computation of CTE/CTC. For this FE model, required AC viscoelastic properties were determined from the dynamic modulus test. The CTE/CTC of AC were then determined by using the calibrated deformation-temperature relationship. The standard aluminum and rubber specimens were also tested for TE/TC within a temperature range to validate the developed test method and computation approach. It was found that the CTE/CTC of AC were nonlinear and temperature dependent. The CTE/CTC determined for the aluminum and rubber specimens were found to be close to the standard values, therefore, validating the proposed approach for determination of CTE/CTC of AC.
Suitability of Dynamic and Relaxation Tests for the Evaluation of Moisture Susceptibility of Asphalt Mixtures
Authors: Arambula Edith , Masad Eyad , Martin Amy Epps , Lytton Robert L.
Published: November 2007

The presence of waIn ter in asphalt pavements deteriorates their condition and causes distresses that result in high maintenance costs to state and federal agencies. The objective of this research was to execute dynamic and relaxation tests and evaluate their effectiveness in assessing moisture susceptibility of asphalt mixture specimens with different air void structures determined using X-ray computed tomography (CT) and conditioned using the modified Lottman procedure. The dynamic test consisted of the application of a sinusoidal cyclic compressive load on the specimen while maintaining the strain within a specified range. The relaxation test, performed in both direct tension and compression, consisted of the application of a constant static strain. A statistical analysis was used to study the effectiveness of the tests in evaluating the moisture susceptibility of the asphalt mixtures. The results showed that none of the tests (dynamic or relaxation) were consistent in differentiating between the moisture conditioned and unconditioned specimens or between the responses of the different mixtures within each condition. In addition, the results of the dynamic and relaxation tests were compared after applying different methods to convert frequency-domain data to time-domain data.
Characterization of defect structures in nanocrystalline materials by X-ray line profile analysis
Authors: Gubicza Jenõ , Ungár Tamás
Published: November 2007

X-ray line profile analysis is a powerful alternative tool for determining dislocation densities, dislocation type, crystallite and subgrain size and size-distributions, and planar defects, especially the frequency of twin boundaries and stacking faults. The method is especially useful in the case of submicron grain size or nanocrystalline materials, where X-ray line broadening is a well pronounced effect, and the observation of defects with very large density is often not easy by transmission electron microscopy. The fundamentals of X-ray line broadening are summarized in terms of the different qualitative breadth methods, and the more sophisticated and more quantitative whole pattern fitting procedures. The efficiency and practical use of X-ray line profile analysis is shown by discussing its applications to metallic, ceramic, diamond-like and polymer nanomaterials.
Grazing exit small angle X-ray scattering on grain formation in polycrystalline metal films
Authors: Zhang Wei , Robinson Ian K.
Published: November 2007

We recently proposed a new grazing exit geometry for measuring the small-angle scattering from thin film materials, which we call GESAXS, to contrast with the successful grazing incidence version, GISAXS. The technique is particularly useful for probing nanostructured thin film materials, especially when the coherence properties of the beam are employed. Here we demonstrate the application of GESAXS to evaporated metal films, prepared using an in-situ diffraction chamber, to investigate how their structure evolves upon annealing. Contrasting behavior is seen for Au, which preserves a roughly exponential distribution of domain sizes, and Fe for which the size distribution narrows by an Ostwald ripening process.
Solving the 3D structure of metal nanoparticles
Authors: Frenkel Anatoly
Published: November 2007

We discuss methods of Extended X-ray Absorption Fine-Structure (EXAFS) analysis that provide three-dimensional structural characterization of metal nanoparticles, both mono- and bi-metallic. For the bimetallic alloys, we use short range order measurements to discriminate between random and non-random inter-particle distributions of atoms. We also discuss the application of EXAFS to heterogeneous nanoparticle systems.
Quantitative structural analysis of individual nanotubes by electron diffraction
Authors: Zuo Jian-Min , Kim Taekyung , Celik-Aktas Ayten , Tao Jing
Published: November 2007

A general method for quantitative structure analysis of individual, cylindrical, carbon nanotubes is described here. The method is based on electron diffraction of individual nanotubes and analysis using a combination of helical diffraction theory and diffraction geometry of the underlying lattice. Experimental recording of nanotube diffraction is achieved using a nanometer-sized electron beam. Procedures are developed for 1) the measurement of chiral angles in both single- and multi-wall nanotubes and 2) structure determination based on Bessel function fitting of layer line intensity oscillations. The accuracy of the method is demonstrated for the structure determination of a single- and double-wall carbon nanotubes and partial structural analysis of a multiwall carbon nanotube. The results show that the single-, double- and incommensurate multi-wall tubes are well described by the cylindrical tube model. However, a large Debye-Waller factor in the radial direction is obtained. The method developed here is general and can be applied to other cylindrical nanotubes.
Vibrational properties of metallic nanoparticles
Authors: Meyer Ralf , Entel Peter
Published: November 2007

This brief overview discusses the structure and vibrational dynamics of metallic nanoparticles. The theoretical results are derived from molecular dynamics simulations using empirical tight-binding potentials. The vibrational densities of states of nanoparticles with sizes from 4 to 20 nm are shown. A method to identity surface, subsurface and core atoms is presented and it is shown that the average vibrational density of states of the atoms in these regions is fairly independent of the particle size.
Annual Fecundity of Tautog in Long Island Sound: Size Effects and Long‐Term Changes in a Harvested Population
Authors: LaPlante Lori Hosaka , Schultz Eric T.
Published: November 2007

Few studies estimate the impact of individual size on annual reproductive output, which is an important consideration where size‐selective harvest may truncate size distributions and sharply reduce populationwide reproductive potential. We conducted a 2‐year study of reproduction in field‐collected and captive tautog Tautoga onitis from Long Island Sound to investigate the influence of individual size on components that constitute annual fecundity: Batch fecundity, spawning frequency, and season duration. Estimates of spawning frequency in field‐caught females relied on time‐varying features of postovulatory follicles that we validated in experiments conducted on captive spawners. Mature females collected in the wild demonstrated midseason peaks in spawning frequency and batch size. Both spawning frequency and batch fecundity increased significantly with size. As a result, annual fecundity increased sharply with size: Large (500‐mm) females produced 24‐86 times as many eggs as did small (250‐mm) females. Average (400‐mm) females spawned 10‐16 million eggs over a season, or about 10,000 eggs/g of whole body mass. We estimated temporal changes in populationwide egg production with data from a 22‐year trawl survey in Long Island Sound. Over this period, an index of abundance declined by a factor of six and size distributions shifted to smaller fish. Despite the shift in size distribution, estimated annual egg production declined no more than the index of abundance because the sex ratio of the population has become female biased. Estimates of tautog annual fecundity were higher than those reported previously in the southern portion of the species' range, reflecting genetic differentiation or phenotypic responses to environmental effects. Given the relatively large reproductive output of large females, their abundance is likely to influence the rate of population recovery in Long Island Sound.
A microcirculação no diabetes: implicações nas complicações crônicas e tratamento da doença
Authors: Aguiar Luiz Guilherme K. de , Villela Nivaldo Ribeiro , Bouskela Eliete
Published: November 2007

A microangiopatia diabética ainda é responsável por importante taxa de morbidade e mortalidade relacionada à doença. O dano endotelial parece ser o fator desencadeante na patogênese das complicações microvasculares. O diabetes mellitus e outras doenças metabólicas estão associados à disfunção endotelial, que é o marcador mais precoce conhecido da aterosclerose. Alterações da reatividade microvascular estão presentes tanto em portadores de diabetes mellitus quanto em indivíduos com fatores de risco para essa doença. A avaliação das funções endotelial e microvascular é possível através de diferentes métodos invasivos ou não. O controle adequado do diabetes mellitus é capaz de retardar ou talvez mesmo prevenir a doença microvascular. A disfunção microvascular, quando expressa somente por alterações da reatividade microvascular, pode ser melhorada com a correção de fatores de risco ou uso de drogas.
Impacto do diabetes mellitus na mortalidade em síndromes coronarianas agudas
Authors: Braga Juarez R. de , Santos Ítalo S.O. , Flato Uri P. , Guimarães Hélio P. , Avezum Álvaro
Published: November 2007

O diabetes mellitus (DM) é uma das grandes causas de morte no mundo, principalmente em decorrência das doenças cardiovasculares. Atualmente, sabe-se que não somente o DM, como também os demais estados hiperglicêmicos, determinam um risco aumentado de doença arterial coronariana. No contexto das síndromes coronarianas agudas (SCA), o DM determina um pior prognóstico, tanto a curto quanto a longo prazo. Sendo o risco absoluto de mortalidade maior em diabéticos, as intervenções nessa população trazem maior impacto quanto aos benefícios. Estudos têm comprovado um maior benefício em diabéticos contra não-diabéticos na adoção de medidas como controle rigoroso da hiperglicemia intra-hospitalar, terapia de reperfusão (seja por trombólise, seja por intervenção percutânea), uso de inibidores da glicoproteína IIb/IIIa e de inibidores da enzima conversora da angiotensina (ECA). Apesar dos benefícios da adoção de intervenções baseadas em evidências no tratamento das SCA em diabéticos, chama atenção a sub-utilização dessas medidas. Tendo em vista o aumento da prevalência do diabetes mellitus previsto para os próximos anos e levando-se em conta que as síndromes coronarianas agudas serão a principal causa de mortalidade nessa população, torna-se cada vez mais necessário que cardiologistas e endocrinologistas passem a interagir, de maneira a modificar o panorama previsto.
Cirurgia de revascularização miocárdica no diabetes mellitus
Authors: Kalil Renato A.K.
Published: November 2007

Diabetes mellitus está presente em 25 a 30% de pacientes com doença arterial coronariana que necessitam cirurgia. Os pacientes diabéticos têm prognóstico distinto dos não-diabéticos, tanto na evolução clínica como nos resultados cirúrgicos. A cirurgia de revascularização está indicada em lesões de 2 ou mais coronárias, nos diabéticos. Porém, pode ser preferida, em relação à intervenção percutânea, em lesões de 1 artéria, quando esta for a descendente anterior ou houver área extensa sob isquemia. Diabéticos candidatos a transplante renal devem ser submetidos à cinecoronariografia e, se necessário, à revascularização. Pacientes diabéticos apresentam maior morbidade, como internação prolongada, infecções, insuficiência respiratória, complicações renais e cerebrais. No entanto, não há maior mortalidade, exceto nos pacientes sem diagnóstico prévio. Na evolução tardia, diabetes representa fator de risco para oclusões de enxertos e mortalidade, tanto de causa cardíaca como de outras causas. Embora os riscos sejam maiores, a cirurgia de revascularização resulta em melhor qualidade de vida e sobrevida em relação ao tratamento clínico e à angioplastia percutânea, especialmente nos usuários de insulina ou com enxertos de artérias mamárias.
Efeitos do índice glicêmico no balanço energético
Authors: Guttierres Ana P.M. , Alfenas Rita de Cássia G.
Published: November 2007

A prevalência da obesidade vem crescendo nas últimas décadas. Associado a este fato, tem-se observado uma mudança no padrão dietético da população em geral, no que diz respeito a um maior consumo de carboidratos. Segundo alguns autores, o índice glicêmico (IG) dos alimentos afeta a composição e o peso corporal. A presente revisão de literatura teve como objetivo avaliar os efeitos do IG sobre apetite, saciedade e composição corporal. A partir das evidências científicas analisadas, foi possível constatar que a maioria dos estudos que atribuem efeitos positivos ao IG é cercada de limitações metodológicas. Estudos bem delineados não observaram benefícios do IG sobre os parâmetros citados acima. Diante disso, conclui-se que o IG apresenta pouca aplicabilidade na prática clínica, como uma ferramenta capaz de controlar a saciedade, reduzir o apetite e, conseqüentemente, a prevalência de obesidade.
Nefropatia e retinopatia em diabéticos do tipo 1 de um programa de atendimento multiprofissional universitário
Authors: Sampaio Emerson , Almeida Henriqueta G.G. , Delfino Vinicius Daher Alvares
Published: November 2007

O diabetes mellitus (DM) tipo 1 é associado a complicações crônicas micro e macrovasculares. Propusemo-nos a estudar a associação entre nefropatia (ND) e retinopatia diabéticas (RD), e destas com variáveis clínico-laboratoriais em portadores de DM tipo 1 acompanhados em um centro universitário. Realizou-se um estudo transversal através de análise de prontuários. Foram estudados 81 pacientes; a prevalência de RD foi 21,0% e de ND, 35,8%; houve associação entre ambas. Os portadores de ND e RD possuíam maior tempo de DM, maior prevalência de hipertensão, pior controle glicêmico e LDL colesterol mais elevado. A taxa de filtração glomerular (TFG) foi associada ao tempo de DM, hipertensão e albuminúria. Identificou-se menor TFG nos portadores de complicações microvasculares, principalmente naqueles com lesões avançadas. Concluímos que, em nosso estudo com portadores de DM tipo 1, houve associação entre RD, ND e TFG, sendo tempo de DM e hipertensão variáveis associadas de forma independente.
Substituição da insulina NPH por insulina glargina em uma coorte de pacientes diabéticos: estudo observacional
Authors: Maia Frederico F.R. , Melo Fabrício J. , Araújo Isabella M. , Araújo Levimar R.
Published: November 2007

Este estudo avaliou o impacto da introdução da insulina glargina na terapia basal/bólus em pacientes com diabetes mellitus do tipo 1 (DM1) e do tipo 2 (DM2), com controle inadequado (A1c > 6,9%) em uso prévio de insulina basal NPH. Foi realizado um estudo retrospectivo, não-controlado, com 49 pacientes (28F/21M), idade média 24,7 ± 16,5 anos, tempo de diabetes de 13,2 ± 10,1, sendo 93,1% dos pacientes com DM1, que receberam insulina glargina combinada com insulina ultra-rápida (aspart/lispro) pré-refeições, durante 90 dias de seguimento. Foram analisados dose total de insulina, incidência de hipoglicemias, crises convulsivas, complicações hiperglicêmicas (cetoacidose) e níveis de A1c antes e após três meses do uso da insulina glargina. Os valores de A1c foram determinados pelo método HPLC, com valores de referência de 4,3% a 6,9%. Após 3 meses da modificação do esquema basal para insulina glargina, observou-se redução significativa dos níveis de A1c (10,2 ± 2,0 vs. 9,1 ± 1,8%; p= 0,019). Além disso, verificou-se redução de 0,11 U/kg/dia na dose total de insulina utilizada (NPH: 0,75 U/kg para 0,64 U/kg de insulina glargina; p< 0,05). O uso da insulina glargina associou-se com redução das crises hipoglicêmicas (p= 0,02), crises convulsivas por hipoglicemia grave (p= 0,023) e nenhum caso de cetoacidose (p= 0,001). Este estudo corrobora a eficácia da introdução da insulina glargina em pacientes diabéticos mal controlados, em uso prévio de insulina NPH, com redução importante dos níveis de A1c. Estima-se uma melhora da qualidade de vida desses pacientes, marcada pela redução de eventos hipoglicêmicos (inclusive os graves), episódios de cetoacidose e utilização de menor dose diária de insulina, com provável impacto em políticas de saúde pública.
Avaliação morfológica e dos mecanismos de mobilização de Ca2+ pela glicose e acetilcolina em células pancreáticas humanas
Authors: Cardoso Daniela Espinha , França Lucimar Pereira de , Chinen Elisângela , Moraes Andréa A.F. Souza , Ferreira Alice Teixeira , França Jerônimo Pereira de
Published: November 2007

OBJETIVOS: Avaliar a morfologia das organelas e do citoesqueleto em células pancreáticas humanas cultivadas e a mobilização de Ca2+ em resposta à glicose e ACh por medidas fluorimétricas. MATERIAL E MÉTODOS: As células foram semeadas em lamínulas, fixadas e marcadas com uma combinação de fluoróforos: o núcleo foi corado com DAPI e as mitocôndrias, com Mytotracker Red. Foram utilizados faloidina e anticorpos secundários conjugados com Alexa Fluor verde e vermelho fluorescentes (488 e 594) para identificar proteína actina F e receptor muscarínico tipo M3, respectivamente. Para estudar a mobilização de Ca2+, as células foram incubadas com fura-2/AM. RESULTADOS: As células pancreáticas humanas apresentaram morfologia preservada com grande quantidade de mitocôndrias. Na região de maior densidade celular, evidenciou-se as pseudo-ilhotas e os receptores muscarínicos M3. Por meio da elevação da [Ca2+]c, devido à ação da glicose e ACh, mostrou-se preservação da capacidade responsiva a esses estímulos e foi dependente de concentração desses agonistas. A glicose promoveu uma resposta sustentada e a ACh induziu uma resposta bifásica. CONCLUSÃO: As células pancreáticas humanas cultivadas conservaram sua morfologia. A mobilização de Ca2+ em resposta à glicose e a ACh confirma a sua funcionalidade. Os receptores muscarínicos M3 estão presentes nessas células.
Prevalência da deficiência, insuficiência de vitamina D e hiperparatiroidismo secundário em idosos institucionalizados e moradores na comunidade da cidade de São Paulo, Brasil
Authors: Saraiva Gabriela Luporini , Cendoroglo Maysa Seabra , Ramos Luiz Roberto , Araújo Lara Miguel Quirino , Vieira José Gilberto H. , Maeda Sérgio Setsuo , Borba Victória Z.C. , Kunii Ilda , Hayashi Lillian F. , Lazaretti-Castro Marise
Published: November 2007

A ocorrência de fraturas osteoporóticas em idosos está relacionada às concentrações reduzidas de vitamina D e conseqüente hiperparatiroidismo secundário, sendo os institucionalizados de maior risco. No Brasil, por seu alto grau de insolação, infere-se que a quantidade de vitamina D da população seja adequada. Neste estudo, objetivamos avaliar as concentrações plasmáticas de 25-hidroxivitamina D (25OHD), paratormônio (PTH) e cálcio ionizado (Cai), assim como analisar a prevalência de hipovitaminose D e de hiperparatiroidismo secundário em idosos moradores da cidade de São Paulo. Estudamos 177 pacientes institucionalizados (125 mulheres e 52 homens) com idade média (DP) de 76,6 (9,0) anos, e 243 idosos ambulatoriais (168 mulheres e 75 homens) com 79,1 (5,9) anos. Nesta avaliação, 71,2% do grupo institucionalizado e 43,8% do ambulatorial possuíam valores de 25OHD menores do que o mínimo recomendado (50 nmol/l), sendo que as mulheres apresentaram valores consideravelmente mais baixos que os homens. O hiperparatiroidismo secundário ocorreu em 61,7% dos pacientes institucionalizados e em 54% dos ambulatoriais. Considerando os resultados obtidos, recomendamos a suplementação com doses eficientes de vitamina D para a população idosa brasileira, alem de sugerir uma discussão para a implementação de políticas de fortificação alimentar com vitamina D, especialmente direcionada àqueles com maior risco.
Bone density and bone turnover markers in patients with epilepsy on chronic antiepileptic drug therapy
Authors: Kulak Carolina A.M. , Borba Victória Z.C. , Silvado Carlos Eduardo , Paola Luciano de , Seibel Markus J. , Bilezikian John P. , Boguszewski César L.
Published: November 2007

In this comparative, cross-sectional study, we evaluated 55 patients with epilepsy on chronic use of antiepileptic drugs (AED); [(38 females and 17 males, 35 ± 6 years (25 to 47)] and compared to 24 healthy subjects (17 females/7 males). Laboratorial evaluation of bone and mineral metabolism including measurements of bone specific alkaline phosphatase (BALP) and carboxyterminal telopeptide of type I collagen (CTX-I) were performed. Bone mineral density (BMD) was measured by DXA. BALP and CTX-I levels did not differ significantly between the groups. CTX-I levels were significantly higher in patients who were exposed to phenobarbital (P< 0.01) than those who were not. Patients presented BMD of both sites significantly lower than the controls (0.975 ± 0.13 vs. 1.058 ± 0.1 g/cm²; p= 0.03; 0.930 ± 0.1 vs. 0.988 ± 0.12 g/cm²; p= 0.02, respectively). Total hip BMD (0.890 ± 0.10 vs. 0.970 ± 0.08 g/cm²; p< 0.003) and femoral neck (0.830 ± 0.09 vs. 0.890 ± 0.09 g/cm²; p< 0.03) were significantly lower in patients who had been exposed to phenobarbital, in comparison to the non-phenobarbital users. In conclusion, patients on AED demonstrate reduced BMD. Among the AED, phenobarbital seems to be the main mediator of low BMD and increases in CTX-I.
The importance of sodium/iodide symporter (NIS) for thyroid cancer management
Authors: Carvalho Denise P. , Ferreira Andrea C.F.
Published: November 2007

The thyroid gland has the ability to uptake and concentrate iodide, which is a fundamental step in thyroid hormone biosynthesis. Radioiodine has been used as a diagnostic and therapeutic tool for several years. However, the studies related to the mechanisms of iodide transport were only possible after the cloning of the gene that encodes the sodium/iodide symporter (NIS). The studies about the regulation of NIS expression and the possibility of gene therapy with the aim of transferring NIS gene to cells that normally do not express the symporter have also become possible. In the majority of hypofunctioning thyroid nodules, both benign and malignant, NIS gene expression is maintained, but NIS protein is retained in the intracellular compartment. The expression of NIS in non-thyroid tumoral cells in vivo has been possible through the transfer of NIS gene under the control of tissue-specific promoters. Apart from its therapeutic use, NIS has also been used for the localization of metastases by scintigraphy or PET-scan with 124I. In conclusion, NIS gene cloning led to an important development in the field of thyroid pathophysiology, and has also been fundamental to extend the use of radioiodine for the management of non-thyroid tumors.
Expressão das iodotironinas desiodases nas neoplasias tireoidianas
Authors: Meyer Erika L. Souza , Wagner Márcia S. , Maia Ana Luiza
Published: November 2007

As iodotironinas desiodases formam uma família de selenoenzimas com propriedades catalíticas distintas que ativam ou inativam os hormônios tireoidianos via desiodação do anel fenólico ou tirosínico da molécula do T4. As desiodases tipo I e II (D1 e D2) são as enzimas responsáveis pela geração do T3 e são amplamente expressas na tireóide normal. A transformação neoplásica benigna ou maligna da glândula tireóide está associada a alterações na expressão dessas isoenzimas, sugerindo um possível papel da D1 e da D2 como marcadores de diferenciação celular. Anormalidades na expressão de ambas enzimas e da desiodase tipo III (D3), inativadora do hormônios tireoidianos, são também encontradas em outras neoplasias humanas. Os mecanismos ou implicações do aumento ou diminuição das desiodases na patogênese neoplásica são pouco compreendidas. No entanto, é importante observar que a expressão anormal da D2 pode ser responsável por um quadro de tireotoxicose em pacientes com metástases de carcinoma folicular de tireóide, enquanto que o aumento da D3 em hemangiomas pode causar hipotireoidismo de difícil tratamento.
Carcinoma de tireóide na infância e adolescência
Authors: Monte Osmar , Calliari Luis Eduardo P. , Kochi Cristiane , Scalisse Nilsa Maria , Marone Marilia , Longui Carlos Alberto
Published: November 2007

Aproximadamente 10% das neoplasias de tireóide aparecem abaixo dos 21 anos e representam 3% das neoplasias da infância, com predomínio em meninas (2F:1M). São papilíferos em 90% casos e mais freqüentemente bilaterais, multifocais e de maior dimensão. Invasão de cápsula e metástases ganglionar ou pulmonar são mais freqüentes que no adulto. O efeito carcinogênico da radiação é especialmente importante na criança pré-púbere. Em 5% dos casos de PTC existe história familial. Genes como o RET/PTC, RAS e BRAF estão habitualmente envolvidos na gênese do processo. A apresentação clínica pode ser nódulo cervical (90% casos) sem que represente um fator de pior prognóstico. O US e a PAAF são procedimentos diagnósticos valiosos. O tratamento deve ser cirúrgico (tireoidectomia total com esvaziamento ganglionar) seguido de PCI e radioterapia ablativa. A substituição com L-tiroxina deve objetivar a supressão crônica do TSH. O prognóstico ao longo prazo é melhor que no adulto. A quantificação da Tg plasmática também é útil na detecção da doença residual.
Microcarcinoma da tireóide: experiência e conduta em clínica privada
Authors: Friguglietti Celso U.M. , Kulcsar Marco Aurélio V.
Published: November 2007

OBJETIVO: Estudar o microcarcinoma papilífero observado nas tireoidectomias realizadas em nossa clínica privada. MATERIAL E MÉTODOS: Revisamos clínica e histologicamente 1.930 pacientes submetidos a tireoidectomias no período de 2002 a 2006, tendo 606 carcinomas e, desses, 332 como microcarcinomas papilíferos. Avaliamos sexo, idade, tipo histológico, tamanho da neoplasia, multifocalidade, freqüência do esvaziamento cervical, resultados da PCI e tireoglobulina sérica. RESULTADOS: Dos 332 pacientes, 48 eram do sexo masculino e 146 tinham idade superior a 45 anos. Todos foram submetidos a tireoidectomia total, 19 concomitantemente a esvaziamento cervical de necessidade (5,72%), e 313 a iodoterapia (94,27%). Tivemos metástase a distância em 5 pacientes (1,5%). Após 1 ano, de 170 pacientes submetidos à PCI, temos 141 considerados livres de doença, 21 com anti-tireoglobulina positivo, 6 com tireoglobulina superior a 2 ng/ml, sendo 1 com metástase pulmonar e outro com recidiva linfonodal (0,3%). CONCLUSÃO: Recomendamos que seja realizada a tireoidectomia total, esvaziamento cervical de necessidade e iodoterapia ablativa na presença de fatores clínicos e anátomo-patológicos de risco.
Repercussão clínica da reclassificação dos carcinomas diferenciados de tireóide de acordo com a 6ª edição do TNM
Authors: Varandas Vanessa M. , Coelho Sabrina Mendes , Soeiro Ana Paula V. , Coeli Cláudia Medina , Carvalho Denise Pires de , Buescu Alexandru , Vaisman Mário
Published: November 2007

A classificação TNM segundo a UICC é usada para avaliar os resultados do acompanhamento do carcinoma de tireóide. A 6ª edição modificou a descrição do tumor primário (T), dos linfonodos regionais (N) e dos grupos de estadiamento. O objetivo deste estudo foi comparar a habilidade das 5ª e 6ª edições em predizer resultados. As duas classificações foram aplicadas em uma análise retrospectiva de 90 pacientes do HUCFF. Sessenta e nove pacientes apresentavam carcinoma papilífero, 14 folicular, 4 células de Hürthle e 3 misto. Os pacientes foram acompanhados por um período médio de 58,3 meses. Ao final do acompanhamento, 49 pacientes estavam em remissão, 23 com doença persistente, 4 com recorrência tumoral, 11 com metástases e 3 evoluíram para o óbito. De acordo com a 6ª edição, 19 pacientes foram classificados como T1, comparado com 7 pela 5ª edição; 19 pacientes T2 comparado com 30; 14 classificados como T3 comparado com 10; 22 como T4 comparado com 27, e 16 pacientes como Tx. Ambas as edições mostraram remissões comparáveis para os estágios I, II e III. Para o estágio IV houve uma mudança significativa na remissão, entretanto não houve diferença comparando IV e IV C.
Boron neutron capture therapy in cancer: past, present and future
Authors: Pisarev Mario A. , Dagrosa Maria Alejandra , Juvenal Guilermo J.
Published: November 2007

Undifferentiated thyroid cancer (UTC) is a very aggressive tumor with no effective treatment, since it lacks iodine uptake and does not respond to radio or chemotherapy. The prognosis of these patients is bad, due to the rapid growth of the tumor and the early development of metastasis. Boron neutron capture therapy (BNCT) is based on the selective uptake of certain boron non-radioactive compounds by a tumor, and the subsequent irradiation of the area with an appropriate neutron beam. 10B is then activated to 11B, which will immediately decay releasing alpha particles and 7Li, of high linear energy transfer (LET) and limited reach. Clinical trials are being performed in patients with glioblastoma multiforme and melanoma. We have explored its possible application to UTC. Our results demonstrated that a cell line of human UTC has a selective uptake of borophenylalanine (BPA) both in vitro and after transplantation to nude mice. Treatment of mice by BNCT led to a complete control of growth and cure of 100% of the animals. Moreover dogs with spontaneous UTC also have a selective uptake of BPA. At the present we are studying the biodistribution of BPA in patients with UTC before its application in humans.