bluuebunny/crossref_metadata_2025 huggingface dataset:
Common causes of false positive F18 FDG PET/CT scans in oncology
Authors: Carter Kevin R. , Kotlyarov Eduard
Published: February 2008

PET/CT is a common imaging modality used in the evaluation of oncology patients. While being extremely sensitive to identifying sights of malignancy F18FDG is very non-specific. We attempted to provide a brief review of some of the more common processes that a nuclear radiology physician may encounter in daily clinical practice that could result in a false positive diagnosis with F18FDG PET/CT. A fundamental understanding of the limitations of this technology by the interpreting physician is necessary to avoid making inaccurate diagnosis and potentially limiting important treatments for our patients.
Novel Tc-99m radiotracers for brain imaging
Authors: Boschi Alessandra , Pasquali Micol , Uccelli Licia , Duatti Adriano
Published: February 2008

A novel class of Tc-99m complexes able to cross the blood brain barrier has been investigated and described here. These compounds are formed by reacting the bis-substituted nitrido precusors [99mTc(N)(PS)2] (PS = phosphino-thiol ligand) with triethylborane (BEt3) under strictly anhydrous conditions and using non-aqueous solvents. The molecular structure of these tracers was not fully established, but preliminary experimental evidence suggests that they result from the interaction of the Lewis base [99mTc(N)(PS)2] with the Lewis acid BEt3, which leads to the formation of the novel -B-Nº Tc- adduct. After purification and recovery in a physiological solution, the new borane-nitrido Tc-99m derivatives were injected in rats for evaluating their in vivo biological behavior. Results showed a significant accumulation in brain tissue, thus indicating that these complexes are capable of penetrating the intact blood brain barrier. Uptake in the central nervous system was confirmed by imaging the distribution of activity on the integrated living animal using a YAP(S)SPECT small animal scanner.
Consequences of the magnetic field, sonic and radiofrequency waves and intense pulsed light on the labeling of blood constituents with technetium-99m
Authors: Meyer Patricia Froes , Santos-Filho Sebastião David , Ronzio Oscar Ariel , Bonelli Ludmila , Fonseca Adenilson de Souza da , Costa Iris do Ceu Clara , Brandão Neto José , Medeiros Aldo da Cunha , Bernardo-Filho Mario
Published: February 2008

Sources of magnetic field, radiofrequency and audible sonic waves and pulsed light have been used in physiotherapy to treat different disorders. In nuclear medicine, blood constituents(Bl-Co) are labeled with technetium-99m (99mTc) are used. This study evaluated the consequences of magnetic field, radiofrequency and audible sonic waves and intense pulsed light sources on the labeling of Bl-Co with 99mTc. Blood from Wistar rats was exposed to the cited sources. The labeling of Bl-Co with 99mTc was performed. Blood not exposed to the physical agents was used(controls). Data showed that the exposure to the different studied sources did not alter significantly (p>0.05) the labeling of Bl-Co. Although the results were obtained with animals, the data suggest that no alteration on examinations performed with Bl-Co labeled with 99mTc after exposition to the cited agents. The biological consequences associated with these agents would be not capable to interfere with some properties of the Bl-Co.
Lesões em surfistas profissionais
Authors: Base Luís Henrique , Alves Marco Antonio Ferreira , Martins Erick Oliveira , Costa Roberto Fernandes da
Published: February 2008

O objetivo do presente estudo foi verificar a ocorrência de lesões relatadas por surfistas profissionais brasileiros, integrantes do circuito brasileiro. O estudo foi realizado durante a etapa do Campeonato Brasileiro de Surfe Profissional masculino, realizado em Maresias, São Sebastião, SP, em junho de 2005. Participaram do estudo 32 surfistas profissionais; cada participante respondeu a um questionário sobre as lesões que havia sofrido durante a prática do esporte. Foram encontradas 112 lesões entre todos os participantes do estudo. O ferimento corto-contuso foi a lesão de maior ocorrência, 38 (33,9%); seguido das entorses, 29 (25,9%); das contusões, 16 (14,2%); estiramentos musculares, 14 (12,5%); queimaduras, 9 (8,0%); fraturas, 6 (5,3%). Concluímos que a maioria das lesões ocorreu durante manobras, no contato com a prancha e com o fundo, sugerindo que os fatores extrínsecos inerentes a esse esporte são potencialmente lesivos para os atletas.
A variação da acuidade visual durante esforços físicos em atletas com baixa visão, participantes de seleção brasileira de atletismo
Authors: Oliveira Filho Ciro Winckler de , Almeida José Júlio Gavião de , Vital Roberto , Carvalho Keila Miriam Monteiro de , Martins Luiz Eduardo Barreto
Published: February 2008

INTRODUÇÃO E OBJETIVO: Esta pesquisa teve como objetivo avaliar o comportamento da acuidade visual em atletas com baixa visão, durante um protocolo de esforço contínuo. Pesquisas apontam que a acuidade visual apresenta variações de rendimento quando submetida a esforços físicos em sujeitos sem deficiência visual. MÉTODO: A população estudada foi composta por seis pessoas, praticantes de atletismo e integrantes da seleção brasileira em provas de pista. No primeiro dia aplicou-se o teste de esforço físico progressivo, realizado em esteira. No segundo dia realizou-se o teste de esforço contínuo, o qual foi dividido em três níveis, cada um com 15 minutos de duração e 30 minutos de intervalo entre eles. Como delimitador das intensidades aplicadas utilizaram-se os resultados obtidos no teste de físico progressivo (60% do VE pico, limiar de VE e 90% do VE pico). A aferição da acuidade visual aconteceu antes, durante e após cada nível de intensidade no protocolo de esforço contínuo. O teste t de Student foi utilizado para a análise estatística (p < 0,05). RESULTADOS: A acuidade visual apresentou, nos três níveis de esforço, queda de seu desempenho. A variação entre os resultados da aferição da acuidade visual estática inicial e a mensuração da mesma variável ao final da fase de corrida foi de 44,5% no primeiro nível, 52,5% no segundo e 60% no terceiro nível. Os resultados apresentaram maior degradação do componente visual durante as aferições dinâmicas. As fases de recuperação que sucediam os níveis de esforço mais intensos tiveram os melhores resultados da acuidade visual, após o déficit encontrado durante o exercício. CONCLUSÃO: Pode-se inferir que nessa população específica ocorre queda da acuidade visual durante o esforço. Tal fato implica a necessidade de a classificação esportiva ser direcionada para avaliar a funcionalidade visual de cada atleta com baixa visão durante o esforço físico, já que tais variações podem ocorrer durante o mesmo.
Associação da concentração plasmática de cobre com metaloproteínas cobre-dependentes em atletas de elite
Authors: Koury Josely Correa , Oliveira Cyntia Ferreira de , Donangelo Carmen Marino
Published: February 2008

O cobre é um elemento-traço essencial para a manutenção de vários processos biológicos, tais como metabolismo energético, homeostase de ferro e mecanismos de proteção antioxidante através da atividade da cobre-zinco superóxido dismutase (Cu-Zn SOD), da ceruloplasmina e da metalotioneína. No entanto, o cobre também participa de reações oxidativas que promovem a liberação de radicais livres, podendo prejudicar a integridade e a funcionalidade celular. A atividade física afeta a homeostase do cobre e promove maior utilização de oxigênio, favorecendo a instalação do estresse oxidativo quando mecanismos naturais de proteção antioxidante, incluindo os dependentes de cobre, não atuam adequadamente. Não há relatos na literatura sobre a associação de diferentes níveis de concentração plasmática de cobre com indicadores antioxidantes cobre-dependentes em atletas de elite. O presente estudo objetivou verificar a associação entre diferentes níveis plasmáticos de cobre e metaloproteínas cobre-dependentes, com atividade antioxidante, em atletas de elite. Os indicadores bioquímicos (metalotioneína e Cu-Zn SOD eritrocitárias, ceruloplasmina e cobre plasmáticos) foram avaliados em 50 atletas, homens e adultos, utilizando metodologias já consolidadas. Os resultados mostraram que 32% dos atletas apresentaram níveis de cobre plasmático inferiores a 11µmol/L, 38% entre 11-13µmol/L e 30% > 13µmol/L. As associações encontradas entre cobre plasmático e ceruloplasmina (r = 0,31; p = 0,04) e Cu-Zn SOD (r = 0,32, p = 0,02); metalotioneína eritrocitária e ceruloplasmina (r = 0,40, p = 0,006) e Cu-Zn SOD (0,73, p = 0,001) e entre Cu-Zn SOD e ceruloplasmina (r = 0,37, p < 0,001) demonstraram que a atividade da Cu-Zn SOD e a concentração de metalotioneína eritrocitárias são sensíveis a menor concentração, enquanto que a ceruloplasmina é sensível a elevadas concentrações plasmáticas de cobre, sugerindo que há um equilíbrio homeostático entre antioxidantes, cobre-dependentes, intra e extracelulares em atletas de elite.
Pelas vias de uma didática da obra de arte
Authors: Pougy Eliana Gomes Pereira
Published: February 2008

Trata-se de um artigo teórico, de cunho filosófico-educacional, visando analisar o dispositivo saber-poder da didática e propor a base epistemológica para a construção de uma Didática da Obra de Arte. A partir da perspectiva pós-estruturalista, com destaque para a produção de Michel Foucault, faz-se uma arqueologia dos discursos didáticos da Bíblia, da Didactica magna de Comenius, do O Emilio ou da Educação de Rousseau e do Democracia e Educação de Dewey, e percebe-se que esses discursos compartilham, a despeito de suas especificidades e seus diferentes objetos, o mesmo paradigma geral segundo o qual se estruturam os saberes científicos da comunicação. Também a partir da perspectiva pós-estruturalista, enfocando as idéias de Gilles Deleuze e Felix Guattari, propõe-se a base epistemológica para a construção de novas formas de pensar a didática ou a relação educação-comunicação. Assim como Deleuze e Guattari afirmaram que existe uma pedagogia que é do Conceito, pode-se propor a existência de uma Didática que é da Obra de Arte. Essa didática, que entende a relação didática como agenciamento e a comunicação como redundância e observação, pode ajudar-nos a compreender os momentos em que o processo de ensino e de aprendizado se processa entre o mundo do ruído e da construção de sentido, o mundo da criação.
The Full Circling Process: Leaping Into the Ethics of History Using Critical Visual Literacy and Arts‐Based Activism
Authors: Long Trisha Wies
Published: February 2008

In a time when adolescents are continually inundated by provocative multimedia campaigns that coax them to buy more, think less, and do so in a passive environment that provides little to no opportunities for them to reflect on who they are in the world, the author of this article offers one way to engage adolescents and their teachers with a process she calls full circling. Working with a variety of urban adolescents, university interns, and middle school teachers in urban settings, the author describes her four‐part process of connecting critical visual media—historically authentic photographs, paintings, drawings, and other visual documents—with more traditional fiction and non‐fiction texts, as she incorporates inquiry, reading, writing, educational drama, and “arts‐based activism.” The author explores a variety of ways to change current classroom paradigms as she reframes and repositions student learning using the tenets of her process.
Developing Academic Language: Got Words?
Authors: Flynt E. Sutton , Brozo William G.
Published: February 2008

Concerns about how to build academic vocabulary and weave its instruction into curricula are common among classroom teachers. The column includes a review of the research and some practical suggestions for teachers.
Investigation of Episodic Flow from Unsaturated Porous Media into a Macropore
Authors: Podgorney Robert K. , Fairley Jerry P.
Published: February 2008

The recent literature contains numerous observations of episodic or intermittent flow in unsaturated flow systems under both constant flux and ponded boundary conditions. Flow systems composed of a heterogeneous porous media, as well as discrete fracture networks, have been cited as examples of systems that can exhibit episodic flow. Episodic outflow events are significant because relatively large volumes of water can move rapidly through an unsaturated system, carrying water and contaminants to depth greatly ahead of a wetting front predicted by a one‐dimensional, gravity‐driven diffusive infiltration model. In this study, we model the behavior of water flow through a sand column underlain by an impermeable‐walled macropore. Relative permeability and capillary pressure relationships were developed that capture the complex interrelationships between the macropore and the overlying porous media that control flow out of the system. The potential for episodic flow is assessed and compared to results of conventional modeling approaches and experimental data from the literature. Model results using coupled matrix–macropore relative permeability and capillary pressure relationships capture the behavior observed in laboratory experiments remarkably well, while simulations using conventional relative permeability and capillary pressure functions fail to capture some of the observed flow dynamics. Capturing the rapid downward movement of water suggests that the matrix‐macropore capillary pressure and relative permeability functions developed have the potential to improve descriptions of flow and transport processes in heterogeneous, variably saturated media.
Measuring the Electrical Properties of Soil Using a Calibrated Ground‐Coupled GPR System
Authors: Oden C. P. , Olhoeft G. R. , Wright D. L. , Powers M. H.
Published: February 2008

Traditional methods for estimating vadose zone soil properties using ground penetrating radar (GPR) include measuring travel time, fitting diffraction hyperbolae, and other methods exploiting geometry. Additional processing techniques for estimating soil properties are possible with properly calibrated GPR systems. Such calibration using ground‐coupled antennas must account for the effects of the shallow soil on the antenna's response, because changing soil properties result in a changing antenna response. A prototype GPR system using ground‐coupled antennas was calibrated using laboratory measurements and numerical simulations of the GPR components. Two methods for estimating subsurface properties that utilize the calibrated response were developed. First, a new nonlinear inversion algorithm to estimate shallow soil properties under ground‐coupled antennas was evaluated. Tests with synthetic data showed that the inversion algorithm is well behaved across the allowed range of soil properties. A preliminary field test gave encouraging results, with estimated soil property uncertainties (±σ) of ±1.9 and ±4.4 mS/m for the relative dielectric permittivity and the electrical conductivity, respectively. Next, a deconvolution method for estimating the properties of subsurface reflectors with known shapes (e.g., pipes or planar interfaces) was developed. This method uses scattering matrices to account for the response of subsurface reflectors. The deconvolution method was evaluated for use with noisy data using synthetic data. Results indicate that the deconvolution method requires reflected waves with a signal/noise ratio of about 10:1 or greater. When applied to field data with a signal/noise ratio of 2:1, the method was able to estimate the reflection coefficient and relative permittivity, but the large uncertainty in this estimate precluded inversion for conductivity.
Incorporating Aqueous Reaction Kinetics and Biodegradation into TOUGHREACT: Applying a Multiregion Model to Hydrobiogeochemical Transport of Denitrification and Sulfate Reduction
Authors: Xu Tianfu
Published: February 2008

The need to consider aqueous and sorption reaction kinetics and microbiological processes arises in many subsurface problems. By adding these processes to the TOUGH family code, more complex problems can be addressed that involve multiphase fluid and heat flow, and geochemical interaction. This paper presents a formulation for incorporating kinetic rates among primary species into mass‐balance equations. The space discretization used is based on a flexible integral finite difference approach that uses irregular gridding to model biogeologic structures. A general multiregion model for hydrological transport interacted with microbiological and geochemical processes is proposed. A one‐dimensional reactive transport problem with kinetic biodegradation and sorption was used to test the enhanced simulator, which involves the processes that occur when a pulse of water containing nitrylotriacetate (NTA) and cobalt is injected into a column. The current simulation results agree very well with those obtained with other simulators. The applicability of this general multiregion model was validated by results from a published column experiment of denitrification and sulfate reduction. The matches with measured nitrate and sulfate concentrations were adjusted with the interfacial area between mobile and immobile regions. Results suggest that TOUGHREACT not only is useful interpretative tool for biogeochemical experiments but also can produce insight into processes and parameters of microscopic diffusion and their interplay with biogeochemical reactions.
Time‐Lapse GPR Tomography of Unsaturated Water Flow in an Ice‐Contact Delta
Authors: Farmani M. Bagher , Keers Henk , Kitterød Nils‐Otto
Published: February 2008

Cross‐well ground penetrating radar (GPR) data sets were collected in the vadose zone of an ice‐contact delta near Oslo's Gardermoen Airport (Norway) before, during, and after snowmelt in 2005. The observed travel times were inverted using curved‐ray travel time tomography. The tomograms are in good agreement with the local geologic structure of the delta. The tomographic results were confirmed independently by surface GPR reflection data and x‐ray images of core samples. In addition to structure, the GPR tomograms also show a strong time dependency due to the snowmelt. The time‐lapse tomograms were used to estimate volumetric soil water content using Topp's equation. The volumetric soil water content was also observed independently by using a neutron meter. Comparison of these two methods revealed a strong irregular wetting process during the snowmelt. This was interpreted to be due to soil heterogeneity as well as a heterogeneous infiltration rate. The geologic structure and water content estimates obtained from the GPR tomography can be used in forward and inverse flow modeling. Finally, the water balance in the vadose zone was calculated using snow accumulation data, precipitation data, porosity estimates, and observed changes in the groundwater table. The amount of water stored in the vadose zone obtained from the water balance is consistent with the amount estimated using GPR tomography. Alternatively, the change in water storage in the vadose zone can be estimated using GPR tomography. This may then permit estimates of evapotranspiration to be made, provided other components of the water balance are known.
Inferring the Subsurface Structural Covariance Model Using Cross‐Borehole Ground Penetrating Radar Tomography
Authors: Hansen Thomas M. , Looms Majken C. , Nielsen Lars
Published: February 2008

We address a fundamental problem inherent in least squares based ground penetrating radar tomography problems, and linear inverse Gaussian problems in general: how should the a priori covariance model be chosen? The choice of such a prior covariance model is most often a very subjective task that has major implications on the result of the inversion. We present a method that allows quantification of the likelihood that a given choice of prior covariance model is consistent with the observed tomography data. This is done by comparing statistical properties of samples of the prior and posterior probability density function of the tomographic inverse problem. In essence, if samples of the posterior are unlikely samples of the prior, then such a choice of a priori covariance model is deemed unlikely. This enables one to quantify the consistency of a number of equally probable prior covariance models to data observations. A synthetic data set was used to describe and validate the approach. We determined how a known covariance model could be inferred from a synthetic tomography problem. The methodology was then applied to a nonlinear ground penetrating radar tomography case study. The covariance model deemed most likely was consistent with nearby ground penetrating radar reflection profiles. The method provides useful results even if just a subset as small as 10% of the available data is considered.
Identifying Unsaturated Hydraulic Parameters Using an Integrated Data Fusion Approach on Cross‐Borehole Geophysical Data
Authors: Looms Majken C. , Binley Andrew , Jensen Karsten H. , Nielsen Lars , Hansen Thomas M.
Published: February 2008

Cross‐borehole geophysical data can provide valuable information concerning hydrologic properties of the unsaturated zone. Such data are most often used sequentially, where images of soil physical properties are obtained through numerical inversion and then converted to hydrologic state properties using petrophysical relationships. If not accounted for, inversion artifacts are transferred to the resulting hydrologic images. We propose a framework in which multiple geophysical data sets can be incorporated using an integrated data fusion approach. The geophysical data collected are integrated in a forward modeling approach to evaluate a series of plausible hydrologic models. The approach permits an evaluation of the sensitivity of geophysical data for constraining hydrologic model parameters. We illustrate the approach using geophysical data collected during a dual water and solute tracer experiment in the unsaturated zone. Cross‐borehole ground penetrating radar and electrical resistivity tomography, measuring electromagnetic travel time and electrical transfer resistances, respectively, were collected during a 20‐d period. As a first approximation, one‐dimensional flow was considered and three models (one, two, and five layers) of the subsurface were evaluated. The five‐layered model was found to be the only model capable of mimicking the infiltration pattern satisfactorily. The results showed that only the hydraulic conductivity and one of the parameters (empirical parameter n) describing the soil moisture release curve for three of the five layers could be constrained by the data, illustrating the nonuniqueness of the problem. The data fusion approach proved, however, that application of multiple geophysical methods may reduce hydraulic parameter uncertainty.
Downregulation of Thymosin β4 Expression by Androgen in Prostate Cancer LNCaP Cells
Authors: Iguchi Kazuhiro , Ito Mai , Usui Shigeyuki , Mizokami Atsushi , Namiki Mikio , Hirano Kazuyuki
Published: February 2008

ABSTRACT: Androgen ablation therapy is an effective treatment for advanced prostate cancer, but the tumor often progresses toward a more aggressive phenotype. We determined the changes in genes associated with the malignant progression and found increased thymosin β4, involved in tumor metastasis, in androgen‐sensitive LNCaP cells grown in the medium with androgen‐deficient, charcoal‐stripped fetal calf serum. The mRNA expression of thymosin β4 was determined by real‐time polymerase chain reaction analysis. The transcriptional activity of thymosin β4 was measured by luciferase assay using reporter plasmid containing 5′‐flanking region of thymosin β4. Thymosin β4 mRNA expression was increased in LNCaP cells in the androgen‐deficient condition and decreased by dihydrotestosterone treatment. Androgen receptor antagonist bicalutamide inhibited thymosin β4 expression in a dose‐dependent manner. In androgen receptor—negative PC‐3 cells, no significant effects on thymosin β4 gene expression were observed. The regulation of thymosin β4 mRNA expression by androgen is due to the transcriptional activation. Deletion analysis revealed that the region between −83 bp and −46 bp of the thymosin β4 gene is responsible for the regulation of the transcriptional activity by androgen. Thymosin β4 expression is negatively controlled at the transcriptional level by androgen.
Prevalence of the Metabolic Syndrome Among U.S. Adolescents Using the Definition From the International Diabetes Federation
Authors: Ford Earl S. , Li Chaoyang , Zhao Guixiang , Pearson William S. , Mokdad Ali H.
Published: February 2008

OBJECTIVE—Our objective was to estimate the prevalence of the metabolic syndrome using the 2007 pediatric International Diabetes Federation (IDF) definition among adolescents in the U.S.

RESEARCH DESIGN AND METHODS—We used data from 2,014 participants aged 12–17 years of the National Health and Nutrition Examination Survey 1999–2004.

RESULTS—The prevalence of the metabolic syndrome for the period 1999–2004 was ∼4.5% (∼1.1 million adolescents aged 12–17 years in 2006). It increased with age, was higher among males (6.7%) than females (2.1%) (P = 0.006), and was highest among Mexican-American adolescents (7.1%). The prevalence of the metabolic syndrome was relatively stable across the 6-year period: 4.5% for 1999–2000, 4.4–4.5% for 2001–2002, and 3.7–3.9% for 2003–2004 (P for linear trend >0.050).

CONCLUSIONS—Our results provide the first estimates of the prevalence of the metabolic syndrome using the pediatric IDF definition among adolescents in the U.S.
Influence of Elevated Cardiometabolic Risk Factor Levels on Treatment Changes in Type 2 Diabetes
Authors: Voorham Jaco , Haaijer-Ruskamp Flora M. , Stolk Ronald P. , Wolffenbuttel Bruce H.R. , Denig Petra ,   the Groningen Initiative to Analyze Type 2 Diabetes Treatment (GIANTT) Group
Published: February 2008

Undertreatment of risk factors in patients with type 2 diabetes is common. We assessed the influence of elevated levels of blood pressure, total cholesterol, and A1C on decisions of Dutch general practitioners to change drug treatment in a cohort of 3,029 patients during a 1-year period. Respectively, 58, 71, and 21% of patients remained untreated despite poor blood pressure, lipid levels, and glycemic control. Of poorly controlled but already drug-treated patients, 52% did not receive intensification for antihypertensive medication, 81% not for lipid-lowering medication, and 43% not for glucose-lowering medication. We observed a significantly lower treatment intervention rate in moderately than in poorly controlled patients for blood pressure. This was not seen for decisions on cholesterol or A1C results. The low overall action rates observed for blood pressure and especially lipid management cannot sufficiently be explained by the use of treatment thresholds higher than those indicated by guidelines.
Should Nonalcoholic Fatty Liver Disease Be Included in the Definition of Metabolic Syndrome?
Authors: Musso Giovanni , Gambino Roberto , Bo Simona , Uberti Barbara , Biroli Giampaolo , Pagano Gianfranco , Cassader Maurizio
Published: February 2008

OBJECTIVE—The ability of the Adult Treatment Panel III (ATP III) criteria of metabolic syndrome to identify insulin-resistant subjects at increased cardiovascular risk is suboptimal, especially in the absence of obesity and diabetes. Nonalcoholic fatty liver disease (NAFLD) is associated with insulin resistance and is emerging as an independent cardiovascular risk factor. We compared the strength of the associations of ATP III criteria and of NAFLD to insulin resistance, oxidative stress, and endothelial dysfunction in nonobese nondiabetic subjects.

RESEARCH DESIGN AND METHODS—Homeostasis model assessment of insulin resistance (HOMA-IR) >2, oxidative stress (nitrotyrosine), soluble adhesion molecules (intracellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin), and circulating adipokines (tumor necrosis factor-α, leptin, adiponectin, and resistin) were cross-sectionally correlated to ATP III criteria and to NAFLD in 197 unselected nonobese nondiabetic subjects.

RESULTS—NAFLD more accurately predicted insulin resistance than ATP III criteria: sensitivity 73 vs. 38% (P = 0.0001); positive predictive value: 81 vs. 62% (P = 0.035); negative predictive value 87 vs. 74% (P = 0.012); positive likelihood ratio 4.39 vs. 1.64 (P = 0.0001); and negative likelihood ratio 0.14 vs. 0.35 (P = 0.0001). Adding NAFLD to ATP III criteria significantly improved their diagnostic accuracy for insulin resistance. Furthermore, NAFLD independently predicted HOMA-IR, nitrotyrosine, and soluble adhesion molecules on logistic regression analysis; the presence of NAFLD entailed more severe oxidative stress and endothelial dysfunction, independent of adiposity or any feature of the metabolic syndrome in insulin-resistant subjects.

CONCLUSIONS—NAFLD is more tightly associated with insulin resistance and with markers of oxidative stress and endothelial dysfunction than with ATP III criteria in nonobese nondiabetic subjects and may help identify individuals with increased cardiometabolic risk in this population.
Relationship of Retinal Vascular Caliber With Diabetes and Retinopathy
Authors: Nguyen Thanh Tan , Wang Jie Jin , Sharrett A. Richey , Islam F.M. Amirul , Klein Ronald , Klein Barbara E.K. , Cotch Mary Frances , Wong Tien Yin
Published: February 2008

OBJECTIVE—To examine the relationship of retinal vascular caliber with diabetes, glycemia, and diabetic retinopathy.

RESEARCH DESIGN AND METHODS—Population-based study using data from the Multi-Ethnic Study of Atherosclerosis (MESA), comprising 5,976 individuals (whites, blacks, Hispanics, and Chinese) residing in six U.S. communities who were free of clinical cardiovascular disease at baseline. Retinal vascular caliber was measured from digital retinal photographs.

RESULTS—There were 4,585 individuals with normal fasting glucose (NFG), 499 with impaired fasting glucose (IFG), 165 with diabetes with retinopathy signs, and 727 with diabetes without retinopathy signs. After multivariate analysis, retinal arteriolar caliber increased from 143.8 μm in subjects with NFG to 144.5 μm in IFG and 146.1 μm in diabetes (P < 0.001 for trend). Retinal venular caliber increased from 214.4 μm in NFG to 216.7 μm in IFG and 218.0 μm in diabetes (P < 0.001 for trend). Retinal venular caliber was significantly larger with increasing levels of fasting glucose and A1C. In a subgroup analysis by ethnicity, the association between wider arteriolar caliber and diabetes was evident in whites only, whereas wider venular caliber and diabetes was evident in Hispanics and Chinese only. In people with diabetes, eyes with retinopathy had larger retinal venular but not arteriolar caliber.

CONCLUSIONS—Retinal arteriolar and venular calibers are larger in individuals with diabetes, but the pattern of associations appears to vary by ethnicity. Retinal venular caliber is additionally associated with retinopathy signs. These findings add further to the concept that variations in retinal vascular caliber may reflect early diabetic microvascular damage.
A Prospective Study of Cardiorespiratory Fitness and Risk of Type 2 Diabetes in Women
Authors: Sui Xuemei , Hooker Steven P. , Lee I-Min , Church Timothy S. , Colabianchi Natalie , Lee Chong-Do , Blair Steven N.
Published: February 2008

OBJECTIVE—The purpose of this study was to determine the independent and joint associations of cardiorespiratory fitness (CRF) and BMI with the incidence of type 2 diabetes in women.

RESEARCH DESIGN AND METHODS—An observational cohort of 6,249 women aged 20–79 years was free of baseline cardiovascular disease, cancer, and diabetes. CRF was measured using a maximal treadmill exercise test. BMI was computed from measured height and weight. The incidence of type 2 diabetes was identified primarily by 1997 American Diabetes Association criteria.

RESULTS—During a 17-year follow-up, 143 cases of type 2 diabetes occurred. Compared with the least fit third, the multivariate (including BMI)-adjusted hazard ratio (HR) (95% CI) was 0.86 (0.59–1.25) for the middle third and 0.61 (0.38–0.96) for the upper third of CRF. For BMI, the multivariate (including CRF)-adjusted HR (95% CI) was 2.34 (1.55–3.54) for overweight individuals and 3.70 (2.12–6.44) for obese individuals, compared with normal-weight patients. In the combined analyses, overweight/obese unfit (the lowest one-third of CRF) women had significantly higher risks compared with normal-weight fit (the upper two-thirds of CRF) women.

CONCLUSIONS—Low CRF and higher BMI were independently associated with incident type 2 diabetes. The protective effect of CRF was observed in individuals who were overweight or obese, but CRF did not eliminate the increased risk in these groups. These findings underscore the critical importance of promoting regular physical activity and maintaining normal weight for diabetes prevention.
Association Between Serum Bioavailable Testosterone Concentration and the Ratio of Glycated Albumin to Glycated Hemoglobin in Men With Type 2 Diabetes
Authors: Fukui Michiaki , Tanaka Muhei , Hasegawa Goji , Yoshikawa Toshikazu , Nakamura Naoto
Published: February 2008

OBJECTIVE—Testosterone stimulates erythropoiesis and thus glycated hemoglobin (A1C) values may be relatively low in male diabetic patients with hypogonadism. We therefore investigated relationships between serum bioavailable testosterone concentration and the ratio of glycated albumin (GA) to A1C and between serum bioavailable testosterone and hemoglobin concentrations in men with type 2 diabetes.

RESEARCH DESIGN AND METHODS—The above relationships were investigated in 222 consecutive men with type 2 diabetes. We also investigated how the ratio of GA to A1C is related to other variables such as age, BMI, and degree of diabetic microangiopathy.

RESULTS—Mean ratio of GA to A1C was 2.94 ± 0.38. Serum bioavailable testosterone concentration correlated positively with hemoglobin concentration (r = 0.368, P < 0.0001) and negatively with the ratio of GA to A1C (r = −0.278, P < 0.0001). Multiple regression analyses identified serum bioavailable testosterone concentration (β = 0.187, P = 0.0062), age (β = −0.204, P = 0.0075), BMI (β = 0.151, P = 0.0302), systolic blood pressure (β = 0.173, P = 0.0090), and plasma total cholesterol (β = 0.155, P = 0.0141) as independent determinants of hemoglobin concentration; moreover, serum bioavailable testosterone concentration (β = −0.155, P = 0.0381) and plasma total cholesterol (β = −0.170, P = 0.0144) were identified as independent determinants of the ratio of GA to A1C.

CONCLUSIONS—Serum bioavailable testosterone concentration correlated positively with hemoglobin concentration and negatively with the ratio of GA to A1C in men with type 2 diabetes, which may lead to underestimation of A1C in hypogonadal men with type 2 diabetes.
Insulin Restriction and Associated Morbidity and Mortality in Women with Type 1 Diabetes
Authors: Goebel-Fabbri Ann E. , Fikkan Janna , Franko Debra L. , Pearson Kimberly , Anderson Barbara J. , Weinger Katie
Published: February 2008

OBJECTIVE—To determine whether insulin restriction increases morbidity and mortality in women with type 1 diabetes.

RESEARCH DESIGN AND METHODS—This is an 11-year follow-up study of women with type 1 diabetes. A total of 234 women (60% of the original cohort) participated in the follow-up. Mean age was 45 years and mean diabetes duration was 28 years at follow-up. Mean BMI was 25 kg/m2 and mean A1C was 7.9%. Measures of diabetes self-care behaviors, diabetes-specific distress, fear of hypoglycemia, psychological distress, and eating disorder symptoms were administered at baseline. At follow-up, mortality data were collected through state and national databases. Follow-up data regarding diabetes complications were gathered by self-report.

RESULTS—Seventy-one women (30%) reported insulin restriction at baseline. Twenty-six women died during follow-up. Based on multivariate Cox regression analysis, insulin restriction conveyed a threefold increased risk of mortality after controlling for baseline age, BMI, and A1C. Mean age of death was younger for insulin restrictors (45 vs. 58 years, P < 0.01). Insulin restrictors reported higher rates of nephropathy and foot problems at follow-up. Deceased women had reported more frequent insulin restriction (P < 0.05) and reported more eating disorder symptoms (P < 0.05) at baseline than their living counterparts.

CONCLUSIONS—Our data demonstrate that insulin restriction is associated with increased rates of diabetes complications and increased mortality risk. Mortality associated with insulin restriction appeared to occur in the context of eating disorder symptoms, rather than other psychological distress. We propose a screening question appropriate for routine diabetes care to improve detection of this problem.
Clonal diversity and distribution in Stenocereus eruca (Cactaceae), a narrow endemic cactus of the Sonoran Desert
Authors: Clark‐Tapia Ricardo , Alfonso‐Corrado Cecilia , Eguiarte Luis E. , Molina‐Freaner Francisco
Published: February 2008

Stenocereus eruca (Cactaceae), a prostrate cactus endemic to the Sonoran Desert, is thought to be highly clonal. We examined its clonal diversity and distribution: (1) at the population level, in four distinct populations along its distribution range; and (2) at a micro scale level, within a single population. Our objective was to evaluate the importance of sexual versus clonal recruitment through the use of RAPD markers. Contrary to previous field observations, clonal diversity was relatively high across the distribution range. This finding suggests that sexual recruitment is an important regeneration mechanism. The proportions of distinguishable genotypes (G/N = 0.83) and genotypic diversity (D = 0.987) were greater than in other clonal cacti, suggesting that clonal propagation is not the major regeneration mechanism. Autocorrelation analyses revealed a spatial genetic structure that may be the result of restricted gene flow (via pollen or seeds) and clonal propagation. A molecular variance analysis (AMOVA) indicated that most of the variation (66.3%) was found within and not across populations. Future studies on pollen and seed dispersal are needed to understand the role of the clonal habit in the mating system of S. eruca.
Phylogenetic relationships in subfamily Tillandsioideae (Bromeliaceae) based on DNA sequence data from seven plastid regions
Authors: Barfuss Michael H. J. , Samuel Rosabelle , Till Walter , Stuessy Tod F.
Published: February 2008

Molecular phylogenetic studies of seven plastid DNA regions were used to resolve circumscriptions at generic and infrageneric levels in subfamily Tillandsioideae of Bromeliaceae. One hundred and ten tillandsioid samples were analyzed, encompassing 10 genera, 104 species, and two cultivars. Two species of Bromelioideae, eight species of the polymorphic Pitcairnioideae, and two species of Rapateaceae were selected as outgroups. Parsimony analysis was based on sequence variation of five noncoding (partial 5′ and 3′trnKintron,rps16intron,trnLintron,trnL‐trnFintergenic spacer,atpB‐rbcLintergenic spacer) and two coding plastid regions (rbcLandmatK). Phylogenetic analyses of individual regions produced congruent, but mostly weakly supported or unresolved clades. Results of the combined data set, however, clearly show that subfamily Tillandsioideae is monophyletic. The earliest divergence separates a lineage comprised ofGlomeropitcairniaandCatopsisfrom the “core” tillandsioids. In their present circumscriptions, generaVrieseaandTillandsia, and their subgenera or sections, as well asGuzmaniaandMezobromelia, are poly‐ and/or paraphyletic. GeneraAlcantarea,Werauhia,Racinaea, andViridanthaappear monophyletic, but separation of these fromVrieseaandTillandsiamakes the remainder paraphyletic. Nevertheless, Tillandsioideae separates into four main clades, which are proposed as tribes, viz., Catopsideae, Glomeropitcairnieae, Vrieseeae, and Tillandsieae.
Molecular phylogeny of the Caryophyllaceae (Caryophyllales) inferred from chloroplast matK and nuclear rDNA ITS sequences
Authors: Fior Simone , Karis Per Ola , Casazza Gabriele , Minuto Luigi , Sala Francesco
Published: February 2008

Caryophyllaceae is a principally holarctic family including around 2200 species often classified into the three subfamilies Alsinoideae, Caryophylloideae, and Paronychioideae. Complex and possibly homoplasious morphological characters within the family make taxa difficult to delimit and diagnose. To explore part of the morphological evolution within the family, we investigated the phylogeny of the Caryophyllaceae by means of analyzing plastid and nuclear sequence data with parsimony and Bayesian methods. We describe a mode of tracing a stable phylogenetic signal in ITS sequences, and a significant common signal is shared with the plastid data. Parsimony and Bayesian analyses yield some differences in tree resolution. None of the subfamilies appear monophyletic, but the monophyly of the Caryophylloideae is not contradicted. Alsinoideae are paraphyletic, with Arenaria subg. Eremogone and Minuartia subg. Spergella more closely related to the Caryophylloideae. There is strong support for the inclusion of Spergula‐Spergularia in an Alsinoideae‐Caryophylloideae clade. Putative synapomorphies for these groupings are twice as many stamens as number of sepals and a caryophyllad‐type of embryogeny. Paronychioideae form a basal grade, where tribe Corrigioleae are sister to the rest of the family. Free styles and capsules with simple teeth are possibly plesiomorphic for the family.
Rare plants are common where you find them
Authors: Lesica Peter , Yurkewycz Raymond , Crone Elizabeth E
Published: February 2008

Broad patterns in distribution and abundance can elucidate processes of evolution. A positive association between local abundance and the size of the geographic range has been demonstrated for closely related species across many taxa. This pattern is usually explained by assuming that species with smaller ranges are ecologically inferior (e.g., poor competitors or dispersers). Many areas of high endemism support local species that have evolved recently. The distribution of these neoendemics may reflect historical processes not accounted for by ecological, equilibrium hypotheses. We asked whether such traditional macroecological hypotheses also applied to the local abundance of seven narrowly endemic species and ecologically similar widespread congeners in the northern Rocky Mountains. For each of the 14 species, we estimated abundance of five randomly chosen populations by counting plants in 10 randomly located plots. The association between range size and local abundance was not positive. Instead, all seven narrow endemics were more abundant than their widespread congeners. Ecological specialization or differences in dispersal ability are not likely explanations for our results. We believe the local abundance of narrowly endemic species may be a sign of recent speciation. Most or all of our narrowly distributed species have probably not yet had time to spread to their full potential. Furthermore, theory predicts that speciation is more likely to occur in locally abundant populations. Our results suggest that strictly ecological mechanisms cannot explain abundance and distribution in regions with high neoendemism.
A modular approach to biomass allocation in an invasive annual (Microstegium vimineum;Poaceae)
Authors: Cheplick Gregory P.
Published: February 2008

The invasive grassMicrostegium vimineumgrows in low light beneath the canopy of eastern forests in North America by reiteration of modules (phytomers) along a tiller. Basal phytomers are vegetative; terminal phytomers produce a raceme of chasmogamous (CH) spikelets plus an axillary raceme of cleistogamous (CL) spikelets. Additional subterminal phytomers with CL racemes mature basipetally. Allocation to culms, leaves, and CH and CL within phytomers was examined in relation to light conditions for a population in New Jersey, USA. Plants were reared in a greenhouse from seed families of parents in deep shade (2–8% full sun) or sunny, edge habitats. Primary tillers were subdivided into phytomers, dried, and weighed. Tillers from field habitats were similarly treated. For vegetative and subterminal phytomers, allocation to leaves and CH was greatest for the shady habitat. CL allocation decreased from terminal to reproductively immature subterminal phytomers. CH and CL mass was positively correlated with leaf mass, suggesting that reproduction is determined by available photosynthate. CH mass showed a genetic correlation with leaf mass. Developmental plasticity in modular allocation allowsMicrostegiumto maximize fitness when conditions are favorable (e.g., high light along forest edges) by continual maturation of CL caryopses on axillary racemes.
Development of a comprehensive detection method for medicinal and toxic plant species
Authors: Barthelson Roger A. , Sundareshan Padma , Galbraith David W. , Woosley Raymond L.
Published: February 2008

Pharmacologically active ingredients in plants can cause significant morbidity through their increasingly common use in herbal alternative medicines and dietary supplements. Monitoring consumer products for the presence of toxic plants is encumbered by the lack of rapid and specific assays. To create a sensitive, reliable, fast, and broad‐spectrum assay for medicinal or toxic plant species, we tested multiplexed ligation‐dependent probe amplification (MLPA), which requires partial genomic DNA sequences from species of plants that are not well represented in currently available genetic databases. Genomic DNA was obtained from 21 species of medicinal and/or toxic plants. The PCR products were amplified from these plants and cloned for sequencing. The MLPA method was successful with DNA samples from many different species. The use of a microarray to facilitate screening of potentially thousands of plants in a single assay also was successful. The combination of the specificity of the MLPA assay with the broad‐scale capabilities of microarray technology should make this an especially useful tool in screening in foods and commercial herbal preparations to identify the plant compounds actually present. Other applications could potentially extend to the identification of any plant species in samples for academic botanical studies and for biodefense and forensics applications.
Genetic variation and reproductive system among North American species ofNuttallanthus(Plantaginaceae)
Authors: Crawford Phillip T. , Elisens Wayne J.
Published: February 2008

We examined the effect of reproductive and life history strategies on the amount and partitioning of genetic variation in three annual species ofNuttallanthus. The North American speciesN. canadensis,N. floridanus, andN. texanushave regional to widespread ranges that overlap in the southeastern USA, are characterized by homogeneous populations and high fecundity, and possess showy, fragrant flowers seemingly adapted for insect pollination and outbreeding. Field and greenhouse studies on plants from 25 populations indicated that reproductive strategies were similar among species and showed predominant self‐fertilization via cleistogamy and self‐pollination prior to anthesis in chasmogamous flowers. Species were reproductively isolated and demonstrated complete cross‐incompatibility after experimental crosses and no evidence for hybridization in mixed populations. Genetic variation was assessed using starch gel electrophoresis to resolve 15 isozyme loci in 50 populations. Conspecific genetic identity (I) values were high (0.819–0.936), but interspecific comparisons indicated many qualitative allelic differences and correspondingly lowIvalues (0.516–0.623). Low levels of polymorphism and observed heterozygosity within populations and the disproportionate amount of gene diversity distributed among populations were concordant with reproductive data. The pattern of genetic differentiation was most similar to that observed in species with a predominantly inbreeding mating system.