Workshop summary: analytical approaches to detect drugs in animal products.
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Animals↗
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The dispositions of proteins in the plasma membranes of animal cells: analytical approaches using controlled peptidolysis and protein labels.
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Acrylamides↗
Assessing adolescent health needs: a factor analytic approach.
Advances in technology are rapidly expanding health educators' resources for presenting information tailored to meet individual health needs and interests. A self-administered questionnaire was given to 510 youths in grades 6 through 9 to ascertain adolescents' health concerns and thus develop more appropriate educational programs. Smoking, diet and weight control, physical fitness, and general health items were included. Factor analysis methods identified ten concerns; smoking, weight control, exercise effects, peer approval of appearance, preparatory health behaviors, planning and maintaining a personal health program, feeling good about oneself, communication issues, comparisons with others, and resistance to negative peer influences. Sex and grade were significantly associated with particular responses. Recommendations include the value of addressing each area of the content domain as it relates to health lessons to ensure that information is relevant to the needs and interests of individual adolescents.
Adolescent↗
An analytic approach to optimized retracted missing tissue compensators.
The introduction of an attenuating medium into a photon beam serves both to reduce the intensity of the primary beam and to create secondary radiation due to scatter. When retracted missing tissue compensators are employed to compensate for irregular surface contour or internal inhomogeneities, they are often fabricated without regard to the scattered radiation that they introduce into the system. The study of a mathematically describable conical geometry has clearly demonstrated the need for improved compensator design. Experimental results obtained with this geometry can be reproduced with good agreement, using theoretical calculations based on primary and first order scattered radiation. This method of analysis may be extended to predict the shape of a compensator which will produce an optimized dose distribution at a given depth in a phantom, equivalent to that which would be obtained when an irregular surface is filled with unit density material (bolus), producing a flat surface. An optimized compensator was constructed based on these theoretical considerations and excellent agreement was observed between theory and experiment. Dramatic improvement in the restoration of bolus dose is obtained with this optimized compensator. Finally, an anthropomorphic phantom of the neck region has been constructed and the performance of a compensator designed according to current clinical methods for this geometry has been evaluated. The performance of an optimized compensator specific to this geometry is presented and good agreement between theoretical predictions and experimental results is observed. Dramatic improvement in bolus dose restoration over that obtained with the clinically designed compensator is realized.
Humans↗
Evaluation of the usefulness of bird feathers as a non-destructive biomonitoring tool for organic pollutants: a comparative and meta-analytical approach.
In this study, we investigated whether bird feathers can be used as a non-destructive biomonitor for organic pollutants. We analysed the outermost tail feathers of 8 terrestrial and aquatic bird species from Belgium (8 species, n=108) for polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and organochlorine pesticides (OCPs). Every compound class could be quantified in one single tail feather of the birds under study (sum PCBs ranging from 5.5 to 510 ng/g feather, sum PBDEs from 0.33 to 53 ng/g feather, sum DDTs from 1.5 to 730 ng/g feather), except for PBDEs in feathers of the common moorhen (Gallinula chloropus). Further, we calculated Pearson correlations between concentrations of organic pollutants in feathers and concentrations in corresponding muscle or liver tissue from the birds. Correlations were found significant in half of the cases of the terrestrial species, but were found not significant for the aquatic species, with the exception of a significant correlation of sum PCBs in the common moorhen. Only for the common buzzard (Buteo buteo) (n=43) all correlations were found significant (0.32<r<0.77). In order to cope for low statistical power, we performed a meta-analysis on all bird species together. This led to significant correlations between levels in feathers and corresponding levels in muscle or liver for all terrestrial birds (p<0.05 in all cases, effect size 0.59 (p,p'-DDE) to 0.71 (Sigma PCB) for levels in feather and muscle). When correlations were recalculated excluding the birds that had died due to starvation, correlation coefficients for the terrestrial birds were found even higher (effect size up to 0.83 (Sigma PCB)). These results have important implications for non-destructive and retrospective biomonitoring. Although our results suggest that exact concentrations in the body cannot be predicted using feathers, bird feathers can give a good estimate of contamination levels in a population and as such are a potential non-destructive biomonitoring tool for organic pollutants. Outermost tail feathers and muscle tissue were also examined for nitrogen (delta15N) and carbon (delta13C) stable isotope content in the different bird species. However, delta15N/delta13C signatures in feather or muscle were not significantly correlated with the corresponding levels of organic pollutants in these tissues. Various confounding factors (such as habitat, condition, age, sex) may have masked a relationship between delta15N values and organic pollutant levels in the birds under study.
Animals↗
Treatment of depression with atypical features: a meta-analytic approach.
The present meta-analysis addressed the empirical evidence regarding the treatment of major depression with atypical features. The superiority of monoamine oxidase inhibitors (MAOIs) compared with other antidepressants in the treatment of major depression with atypical features has been frequently reported. According to the CONSORT Statement, studies included in our meta-analysis had to meet several criteria, especially a double-blind, controlled condition and an operational diagnosis according to Diagnostic and Statistical Manual of Mental Disorders (DSM)-III or DSM-IV criteria, respectively. Four databases for research-based evidence were used in a systematic review: Medline, Embase, Psyndex and PsycInfo. Only eight publications met inclusion/exclusion criteria, resulting in 11 comparisons. Our results contrast an effect size of 0.45 (95% confidence interval) for a comparison of MAOIs vs. placebo with an effect size of 0.02 (95% confidence interval: - 0.10-0.14) for a comparison of MAOIs vs. selective serotonin reuptake inhibitors. The effect size for MAOIs vs. tricyclic antidepressants was 0.27 (95% confidence interval: 0.16-0.42). MAOIs may be more effective for atypical major depressive disorder than tricyclic antidepressants. Most clinical research has been conducted on irreversible MAOIs. Additional studies testing more recently developed antidepressants (including reversible MAOIs) with an improved safety profile would be warranted. The available data are insufficient for a direct comparison between MAOIs and selective serotonin reuptake inhibitors.
Antidepressive Agents↗
Self-reported eating behaviors of extremely obese persons seeking bariatric surgery: a factor analytic approach.
OBJECTIVE: To summarize the self-reported eating behaviors of persons seeking bariatric surgery and to provide reliability data for a clinical instrument that assesses those eating behaviors. RESEARCH METHODS AND PROCEDURES: Adults (552) with extreme obesity (mean +/- standard deviation BMI = 52.4 +/- 10.1 kg/m2) completed the Weight and Lifestyle Inventory (WALI) before undergoing bariatric surgery. The WALI is a self-report instrument that includes 24 items that assess the eating behaviors to which respondents attribute their excess weight. These items were entered into a principal components analysis with promax rotation. Relationships of factor scores to demographic and psychosocial variables were examined. Test-retest reliability data were obtained from a smaller sample (n = 58) of less obese participants (BMI = 34.4 +/- 4.0 kg/m2) who completed the WALI twice within 2 weeks, before beginning a non-surgical weight loss program. RESULTS: The principal components analysis yielded five factors with acceptable internal consistency and test-retest reliability. These included: eating in response to negative affect, eating in response to positive affect and social cues, general overeating and impaired appetite regulation, overeating at early meals, and snacking. Each factor was related to symptoms of binge eating disorder, and every factor except the second one was associated with depressive symptoms. Factor scores were unrelated or weakly associated with demographic characteristics. DISCUSSION: The eating behaviors of persons seeking bariatric surgery can be assessed reliably and parsimoniously with the WALI. The predictive utility of the factors obtained in this study remains to be examined.
Adult↗
On analytical approaches to epidemics on networks.
One way to describe the spread of an infection on a network is by approximating the network by a random graph. However, the usual way of constructing a random graph does not give any control over the number of triangles in the graph, while these triangles will naturally arise in many networks (e.g. in social networks). In this paper, random graphs with a given degree distribution and a given expected number of triangles are constructed. By using these random graphs we analyze the spread of two types of infection on a network: infections with a fixed infectious period and infections for which an infective individual will infect all of its susceptible neighbors or none. These two types of infection can be used to give upper and lower bounds for R(0), the probability of extinction and other measures of dynamics of infections with more general infectious periods.
Communicable Diseases↗
A functional-analytic approach to the diagnosis of a transient tic disorder.
The diagnostic utility of functional analyses has been demonstrated with a variety of behaviors including tics. Whereas previous analyses have focused on the discovery of maintaining variables to aid in treatment prescription, we employed a functional analysis to confirm a clinical diagnosis. An 11 year old male student, who had not been previously diagnosed with a tic disorder, exhibited multiple vocal tic-like behaviors which had persisted over a period of time. Teacher reports conflicted regarding the possible etiology of these behaviors. Hence, a functional analysis was conducted in the classroom to determine if the behaviors were maintained by operant variables. Our hypothesis stated that the occurrence of vocal behaviors across experimental conditions would strongly indicate the presence of a tic disorder. The functional analysis included the following conditions: attention, escape, alone, freeplay, and high sensory stimulation. We used a multi-element design to evaluate the effects of the different stimulus conditions on vocal-behavior frequency. Data indicated the student exhibited vocal behaviors in all conditions. However, the behaviors were partially exacerbated in the attention and escape conditions. Results supported the diagnosis of a transient tic disorder affected by operant variables.
Attention↗
Functional motions of influenza virus hemagglutinin: a structure-based analytical approach.
Influenza virus hemagglutinin (HA), a homotrimeric integral membrane glycoprotein essential for viral infection, is engaged in two biological functions: recognition of target cells' receptor proteins and fusion of viral and endosomal membranes, both requiring substantial conformational flexibility from the part of the glycoprotein. The different modes of collective motions underlying the functional mobility/adaptability of the protein are determined in the present study using an extension of the Gaussian network model (GNM) to treat concerted anisotropic motions. We determine the molecular mechanisms that may underlie HA function, along with the structural regions or residues whose mutations are expected to impede function. Good agreement between theoretically predicted fluctuations of individual residues and corresponding x-ray crystallographic temperature factors is found, which lends support to the GNM elucidation of the conformational dynamics of HA by focusing upon a subset of dominant modes. The lowest frequency mode indicates a global torsion of the HA trimer about its longitudinal axis, accompanied by a substantial mobility at the viral membrane connection. This mode is proposed to constitute the dominant molecular mechanism for the translocation and aggregation of HAs, and for the opening and dilation of the fusion pore. The second and third collective modes indicate a global bending, allowing for a large lateral surface exposure, which is likely to facilitate the close association of the viral and endosomal membranes before pore opening. The analysis of kinetically hot residues, in contrast, reveals a localization of energy centered around the HA2 residue Asp112, which apparently triggers the solvent exposure of the fusion peptide.
Anisotropy↗
An analytical approach to ultra-small physical evidence.
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Electron Probe Microanalysis↗
Analytical approaches to measuring cospeciation of host and parasites: through a glass, darkly.
Studies of cophylogenetic associations between hosts and parasites have become increasingly common. Historically, congruence between host and parasite phylogenies has been seen as evidence for cospeciation. Analyses of such coevolutionary relationships, however, are made extremely difficult by the complex interplay of cospeciation, host switching, sorting (extinction), duplication (intrahost speciation) and inertia (lack of parasite speciation) events, all of which may produce incongruence between host and parasite phylogenies. Here we review several methods of analysing cospeciation. We illustrate these methods with an example from a Procellariiformes (seabird) and chewing louse (Halipeurus) association.
Animals↗
Relationship between worm burden and male proportion in Schistosoma mansoni experimentally infected rodents and primates. A meta-analytical approach.
This paper investigates the relationship between the worm burden and the male proportion of adult Schistosoma mansoni. This relationship was tested using data from the literature on S. mansoni experimentally infected rodents and primates. The analyses were performed within each animal model (rat, mouse, hamster and monkey) and showed positive linear relationships between worm burden and male proportion. An analysis between the four animal models showed the same positive linear relationship. The role of the genetic diversity of male and female schistosomes in this relationship is discussed.
Animals↗
Hippuric acid and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid in serum and urine. Analytical approaches and clinical relevance in kidney diseases.
Hippuric acid (HA) and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (FA) were determined in serum, plasma, ultrafiltrate and urine by gas chromatography (GC), high-performance liquid chromatography and GC with mass-selective detection, and the methods were compared. As determined by affinity chromatography and analysis of serum and ultrafiltrate, 0.5% of FA in serum occurs free and 99.5% is bound to albumin. In haemodialysed patients with chronic renal failure, the plasma levels of HA and FA are elevated in comparison with normal controls and hospital patients without kidney diseases: HA, 11.1 +/- 5.7 mg/dl (n = 86); FA, 1.9 +/- 1.2 mg/dl (n = 86). Gradual increases in HA in serum, depending on the creatinine concentrations, are found in non-dialysed patients with chronic renal failure. By haemodialysis and haemofiltration the HA levels are lowered (53-66 and 30-36%, respectively), whereas FA is not dialysable.
Chromatography, Gas↗
An analytic approach to work with families.
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Adolescent↗
Unveiling synaptic plasticity: a new graphical and analytical approach.
Short-term synaptic plasticity has a key role in information processing in the CNS, whereas memories can be formed through long-lasting changes in synaptic strength. Despite the importance of these phenomena, it remains difficult to determine whether a synaptic modulation is expressed at a presynaptic or postsynaptic site. This article describes a new approach that, in its simplest form, can identify the site of expression by direct graphical means. A more-sophisticated form of the technique can quantify functional synaptic properties and determine which of these properties is altered following a modulation of synaptic strength.
6-Cyano-7-nitroquinoxaline-2,3-dione↗
An analytical approach to the implementation of genetically modified crops.
Public scepticism towards genetically modified (GM) crops is increasing. To address this, the risks and benefits of GM crops must be examined across scientific disciplines, and be discussed with the authorities, the agricultural industry and the consumers. In a feasibility study we have systematically analysed the challenges of the development and marketing of GM crops in Europe. A life-cycle inventory was used together with established technology foresight techniques in an interdisciplinary and empirical framework. The approach taken in this study established a dialogue between stakeholders and provided a framework for discussions about the future direction of GM crops.
Agriculture↗
A meta-analytical approach for the treatment of in-stent restenosis.
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Coronary Restenosis↗