252 research outputs found

    Long-Term Locoregional Vascular Morbidity After Isolated Limb Perfusion and External-Beam Radiotherapy for Soft Tissue Sarcoma of the Extremity

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    Background: Isolated limb perfusion (ILP) with tumor necrosis factor alpha (TNF-alpha) and melphalan, followed by delayed surgical resection and adjuvant external-beam radiotherapy is a limb salvage treatment strategy for locally advanced soft tissue sarcomas. The long-term vascular side effects of this combined procedure were evaluated. Methods: Thirty-two patients were treated for a locally advanced sarcoma of the upper (n = 5) or lower limb (n = 27). All patients underwent a noninvasive vascular work-up. Results: Five patients underwent a leg amputation, in two cases due to critical leg ischemia 10 years after ILP. With a median follow-up of 88 (range, 17-159) months, none of the patients with a salvaged lower leg (n = 22) experienced peripheral arterial occlusive disease. Ankle-brachial index (ABI) measurements in the involved leg (median, 1.02; range, .50-1.20) showed a significant decrease compared with the contralateral leg (median, 1.09; range, .91-1.36, P = .001). Pulsatility index (PI) was decreased in the treated leg in 17 of 22 patients at the femoral level (median, 6.30; range, 2.1-23.9 vs. median, 7.35; range, 4.8-21.9; P = .011) and in 19 of 20 patients at popliteal level (median, 8.35; range, 0-21.4 vs. median, 10.95; range, 8.0-32.6; P <.0005). In patients with follow-up of > 5 years, there was more often a decrease in ABI (P = .024) and PI at femoral level (P = .011). Conclusions: ILP followed by resection and external-beam radiotherapy can lead to major late vascular morbidity that requires amputation. Objective measurements show a time-related decrease of ABI and femoral PI in the treated extremity

    Genetic analysis of the naked trait in panicles of hexaploid oat

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    The aim of this study was to estimate the number of genes that control the naked (hull-less) trait and the mode of expression of this characteristic in panicles of hexaploid white oat. Parents and the segregating population (in the F2 and F3 generations) were evaluated in regard to the presence and distribution of naked grains in panicles of individual oat plants. For each plant, a drawing of the main panicle was developed. From the drawings obtained in the progenies of the F2 population, six distinct phenotypic classes were produced. The expected phenotypic proportion of 3:9:4 (naked:segregating:hulled) was that which best fit by the Chi-square test. In the F3 generation, the results showed agreement with the hypothesis observed in the F2 generation. The naked trait in oat is passed on by two genes and the greatest expression of this trait occurs in the upper third of the panicles. Expression of this trait in oats is not complete, even in homozygous genotypes

    Protecting Endangered Species: Do the Main Legislative Tools Work?

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    It is critical to assess the effectiveness of the tools used to protect endangered species. The main tools enabled under the U.S. Endangered Species Act (ESA) to promote species recovery are funding, recovery plan development and critical habitat designation. Earlier studies sometimes found that statistically significant effects of these tools could be detected, but they have not answered the question of whether the effects were large enough to be biologically meaningful. Here, we ask: how much does the recovery status of ESA-listed species improve with the application of these tools? We used species' staus reports to Congress from 1988 to 2006 to quantify two measures of recovery for 1179 species. We related these to the amount of federal funding, years with a recovery plan, years with critical habitat designation, the amount of peer-reviewed scientific information, and time listed. We found that change in recovery status of listed species was, at best, only very weakly related to any of these tools. Recovery was positively related to the number of years listed, years with a recovery plan, and funding, however, these tools combined explain <13% of the variation in recovery status among species. Earlier studies that reported significant effects of these tools did not focus on effect sizes; however, they are in fact similarly small. One must conclude either that these tools are not very effective in promoting species' recovery, or (as we suspect) that species recovery data are so poor that it is impossible to tell whether the tools are effective or not. It is critically important to assess the effectiveness of tools used to promote species recovery; it is therefore also critically important to obtain population status data that are adequate to that task

    Membrane chemical stability and seed longevity

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    Here, we investigate the relationships between the chemical stability of the membrane surface and seed longevity. Dry embryos of long-lived tomato and short-lived onion seeds were labeled with 5-doxyl-stearic acid (5-DS). Temperature-induced loss of the electron spin resonance signal caused by chemical conversion of 5-DS to nonparamagnetic species was used to characterize the membrane surface chemical stability. No difference was found between temperature plots of 5-DS signal intensity in dry onion and tomato below 345 K. Above this temperature, the 5-DS signal remained unchanged in tomato embryos and irreversibly disappeared in onion seeds. The role of the physical state and chemical status of the membrane environment in the chemical stability of membrane surfaces was estimated for model systems containing 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) dried alone or in the presence of trehalose or glucose. Fourier transform infrared spectroscopy was used to follow temperature-induced structural changes in dry POPC. Spin-label technique was used to relate the chemical stability of 5-DS with the dynamic properties of the bilayer and 5-DS motion behavior. In all the models, the decrease in 5-DS signal intensity was always observed above Tm for the membrane surface. The 5-DS signal was irreversibly lost at high temperature when dry POPC was embedded in a glucose matrix. The loss of 5-DS signal was moderate when POPC was dried alone or in the presence of trehalose. Comparison of model and in vivo data shows that the differences in longevity between onion and tomato seeds are caused by differences in the chemical status of the membrane surface rather than the degree of its immobilization

    FDG-PET Parameters as Prognostic Factor in Esophageal Cancer Patients: A Review

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    Background:18F-fluorodeoxyglucose positron emission tomography (FDG-PET) has been used extensively to explore whether FDG Uptake can be used to provide prognostic information for esophageal cancer patients. The aim of the present review is to evaluate the literature available to date concerning the potential prognostic value of FDG uptake in esophageal cancer patients, in terms of absolute pretreatment values and of decrease in FDG uptake during or after neoadjuvant therapy. Methods: A computer-aided search of the English language literature concerning esophageal cancer and standardized uptake values was performed. This search focused on clinical studies evaluating the prognostic value of FDG uptake as an absolute value or the decrease in FDG uptake and using overall mortality and/or disease-related mortality as an end point. Results: In total, 31 studies met the predefined criteria. Two main groups were identified based on the tested prognostic parameter: (1) FDG uptake and (2) decrease in FDG uptake. Most studies showed that pretreatment FDG uptake and postneoadjuvant treatment FDG uptake, as absolute values, are predictors for survival in univariate analysis. Moreover, early decrease in FDG uptake during neoadjuvant therapy is predictive for response and survival in most studies described. However, late decrease in FDG uptake after completion of neoadjuvant therapy was predictive for pathological response and survival in only 2 of 6 studies. Conclusions: Measuring decrease in FDG uptake early during neoadjuvant therapy is most appealing, moreover because the observed range of values expressed as relative decrease to discriminate responding from nonresponding patients is very small. At present inter-institutional comparison of results is difficult because several different normalization factors for FDG uptake are in use. Therefore, more research focusing on standardization of protocols and inter-institutional differences should be performed, before a PET-guided algorithm can be universally advocated

    Microbial Communication, Cooperation and Cheating: Quorum Sensing Drives the Evolution of Cooperation in Bacteria

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    An increasing body of empirical evidence suggests that cooperation among clone-mates is common in bacteria. Bacterial cooperation may take the form of the excretion of “public goods”: exoproducts such as virulence factors, exoenzymes or components of the matrix in biofilms, to yield significant benefit for individuals joining in the common effort of producing them. Supposedly in order to spare unnecessary costs when the population is too sparse to supply the sufficient exoproduct level, many bacteria have evolved a simple chemical communication system called quorum sensing (QS), to “measure” the population density of clone-mates in their close neighborhood. Cooperation genes are expressed only above a threshold rate of QS signal molecule re-capture, i.e., above the local quorum of cooperators. The cooperative population is exposed to exploitation by cheaters, i.e., mutants who contribute less or nil to the effort but fully enjoy the benefits of cooperation. The communication system is also vulnerable to a different type of cheaters (“Liars”) who may produce the QS signal but not the exoproduct, thus ruining the reliability of the signal. Since there is no reason to assume that such cheaters cannot evolve and invade the populations of honestly signaling cooperators, the empirical fact of the existence of both bacterial cooperation and the associated QS communication system seems puzzling. Using a stochastic cellular automaton approach and allowing mutations in an initially non-cooperating, non-communicating strain we show that both cooperation and the associated communication system can evolve, spread and remain persistent. The QS genes help cooperative behavior to invade the population, and vice versa; cooperation and communication might have evolved synergistically in bacteria. Moreover, in good agreement with the empirical data recently available, this synergism opens up a remarkably rich repertoire of social interactions in which cheating and exploitation are commonplace

    Developmental Trajectories of Body Mass Index Among Japanese Children and Impact of Maternal Factors during Pregnancy

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    Background The aims of this study were to 1) determine the distinct patterns of body mass index (BMI) trajectories in Japanese children, and 2) elucidate the maternal factors during pregnancy, which contribute to the determination of those patterns. Methodology/Principal Findings All of the children (1,644 individuals) born in Koshu City, Japan, between 1991 and 1998 were followed in a longitudinal study exploring the subjects’ BMI. The BMI was calculated 11 times for each child between birth and 12 years of age. Exploratory latent class growth analyses were conducted to identify trajectory patterns of the BMI z-scores. The distribution of BMI trajectories were best characterized by a five-group model for boys and a six-group model for girls. The groups were named “stable thin,” “stable average,” “stable high average,” “progressive overweight,” and “progressive obesity” in both sexes; girls were allocated to an additional group called “progressive average.” Multinomial logistic regression found that maternal weight, smoking, and skipping breakfast during pregnancy were associated with children included in the progressive obesity pattern rather than the stable average pattern. These associations were stronger for boys than for girls. Conclusions/Significance Multiple developmental patterns in Japanese boys and girls were identified, some of which have not been identified in Western countries. Maternal BMI and some unfavorable behaviors during early pregnancy may impact a child’s pattern of body mass development. Further studies to explain the gender and regional differences that were identified are warranted, as these may be important for early life prevention of weight-associated health problems

    Psychometric properties of the Dutch Five Facet Mindfulness Questionnaire (FFMQ) in patients with fibromyalgia

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    Mindfulness-based interventions are increasingly being used in clinical populations to reduce psychological distress and improve functioning. The Five Facet Mindfulness Questionnaire (FFMQ) is a questionnaire that measures five facets of mindfulness: observe, describe, actaware, nonjudge and nonreact. The goal of this study was to examine the psychometric properties of the FFMQ in a clinical population of fibromyalgia patients. A total of 141 patients completed an online questionnaire on mindfulness (FFMQ) and theoretically related (e.g. acceptance, openness, alexithymia) and unrelated (physical health) constructs. Thirty-eight patients filled in the FFMQ twice. A confirmatory factor analysis (CFA) was conducted to test the five-factor structure of the FFMQ. Internal consistency and test–retest reliability were respectively assessed with Cronbach’s α and intraclass correlation coefficients. Construct validity was examined by correlating FFMQ facets with theoretically related and unrelated constructs. Incremental validity in predicting mental health and psychological symptoms was examined with regression analyses. CFA confirmed the correlated five-factor structure of the FFMQ. Internal consistency of the five facets was satisfactory and test–retest reliability was good to excellent. Construct validity was excellent, as shown by the moderate to large correlations with related constructs (except observe facet) and weak correlation with a theoretically unrelated construct. Two of the five facets (actaware and nonjudge) had incremental validity over the others in predicting mental health and psychological symptoms. After controlling for related constructs, the actaware facet remained a significant predictor. This study showed satisfactory psychometric properties of the Dutch FFMQ in fibromyalgia patients. The observe facet, however, should be used with caution given its deviant relationship with theoretically related constructs
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