Use In Different Laboratories Research Articles

Wave analysis based on genetic algorithms using data collected from laboratories at different scales

This paper presents the results of a comparative study of waves generated in water channels and in shaking tank systems with the aim of standardizing the use of different laboratories’ facilities and establishing scales for analyzing the evolution of waves under deep water conditions. For this purpose, experimental models are built. The experiments encompass a collection of free surface level measurements obtained from progressive waves in a hydraulic channel and from stationary waves generated by imposing controlled motion to a rectangular tank. The experimental results are also evaluated by contrasting them with analytical correlations. In addition, a model based on a genetic algorithm is proposed to extrapolate the evolution of waves under other physical conditions not measured in the laboratory. The present analysis confirms the viability of wave height comparison between waves generated in a hydraulic channel and those generated by sloshing in a rectangular tank when its natural frequency coincides with the frequency of the progressive wave. Finally, a methodology for establishing a plausible scale for wave comparisons is described and applied.

Interlaboratory Validation of a Detection Method for Hepatitis E Virus RNA in Pig Liver

Background: In the last years, the number of notified hepatitis E cases in humans has continuously increased in Europe. Foodborne infection with the zoonotic hepatitis E virus (HEV) genotype 3 is considered the major cause of this disease. Undercooked liver and raw sausages containing the liver of pigs and wild boar are at high risk of containing HEV. However, so far, no standardized method for the detection of HEV-RNA in pig liver is available. Methods: An international collaborative study on method reproducibility involving 11 laboratories was performed for an HEV-RNA detection method, which consists of steps of sample homogenization, RNA extraction and real-time RT-PCR detection, including a process control. Naturally contaminated pork liver samples containing two different amounts of HEV and a HEV-negative pork liver sample were tested by all laboratories using the method. Results: Valid results were retrieved from 10 laboratories. A specificity of 100% and a sensitivity of 79% were calculated for the method. False negative results were only retrieved from the sample containing very low HEV amounts near the detection limit. Conclusions: The results show that the method is highly specific, sufficiently sensitive and robust for use in different laboratories. The method can, therefore, be applied to routine food control as well as in monitoring studies.

Gut-lymph-lung pathway mediates sepsis-induced acute lung injury.

This review attempts to unveil the possible mechanisms underlying how gut lymph affects lung and further gives rise to acute respiratory distress syndrome, as well as potential interventional targets under the condition of ischemia-reperfusion injury. We searched electronic databases including PubMed, MEDLINE, Cochrane Central Register of Controlled Trials, Google Scholar, Web of Science, and Embase to identify relevant literatures published up to December 2019. We enrolled the literatures including the Mesh Terms of “gut lymph or intestinal lymph and acute lung injury or acute respiratory distress syndrome.” Gut is considered to be the origin of systemic inflammation and the engine of multiple organ distress syndrome in the field of critical care medicine, whereas gut lymph plays a pivotal role in initiation of ischemia-reperfusion injury-induced acute respiratory distress syndrome. In fact, in the having been established pathologic model of sepsis leading to multiple organ dysfunction named by Gut Lymph theory, a variety of literatures showed the position and role of changes in gut lymph components in the initiation of systemic inflammatory response, which allows us to screen out potential intervention targets to pave the way for future clinic and basic research.

Prospective Evaluation of Self-Reported Aggression in Transgender Persons

BackgroundAlthough research on the relation between testosterone and aggression in humans is inconclusive, guidelines (including the World Professional Association for Transgender Health Standards of Care, edition 7) have warned for an increase in aggression in transgender men taking testosterone treatment. AimsTo investigate the association between levels of testosterone and aggression in treatment-seeking transgender people and explore the role of mental health psychopathology (anxiety and depressive symptoms) and social support in aggression in this population. MethodsEvery transgender person invited for assessment at a national transgender health clinic in the United Kingdom during a 3-year period (2012–2015) completed self-report measures for interpersonal problems, including levels of aggression (Inventory of Interpersonal Problems [IIP-32]), symptoms of anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), social support (Multidimensional Scale of Perceived Social Support), and experiences of transphobia before and 1 year after the initiation of gender-affirming hormonal therapy. Correlations between prospective scores for the IIP-32 factor “too aggressive” and prospective levels of sex steroids, prospective psychological (HADS), and baseline psychosocial measurements were tested. OutcomesProspective scores for the factor “too aggressive” were not correlated to prospective serum testosterone levels. ResultsResults of 140 people (56 transgender men, 84 transgender women) were analyzed. A prospective increase in scores for the factor “too aggressive” of the IIP-32 in transgender men 1 year after being treated with testosterone treatment or a decrease of the IIP-32 aggression scores in transgender women 1 year after gender-affirming hormonal therapy was not found. However, a positive correlation was found between increasing HADS anxiety scores and increasing scores for the IIP-32 “too aggressive” score in the entire study population and a positive correlation with lower support from friends in transgender women. Clinical ImplicationsHormone-prescribing physicians can be reassured that the long-term administration of testosterone in transgender men does not increase aggressive behavior. Strengths and LimitationsThis is the 1st prospective study to assess the effect of gender-affirming hormonal care on aggression. Limitations included the use of different laboratories, the use of a patient-reported outcome measure, and the lack of aggression subtypes. ConclusionsTestosterone therapy was not associated with an increase in levels of aggression in transgender men or a decrease in aggressive behavior in transgender women on antiandrogen and estrogen therapy, but other psychological and/or social factors, such as anxiety levels, appear to contribute to self-reported aggression in transgender people.Defreyne J, T'Sjoen G, Bouman WP, et al. Prospective Evaluation of Self-Reported Aggression in Transgender Persons. J Sex Med 2018;15:768–776.

Long-term environmental monitoring for assessment of change: measurement inconsistencies over time and potential solutions

The importance of long-term environmental monitoring and research for detecting and understanding changes in ecosystems and human impacts on natural systems is widely acknowledged. Over the last decades, a number of critical components for successful long-term monitoring have been identified. One basic component is quality assurance/quality control protocols to ensure consistency and comparability of data. In Norway, the authorities require environmental monitoring of the impacts of the offshore petroleum industry on the Norwegian continental shelf, and in 1996, a large-scale regional environmental monitoring program was established. As a case study, we used a sub-set of data from this monitoring to explore concepts regarding best practices for long-term environmental monitoring. Specifically, we examined data from physical and chemical sediment samples and benthic macroinvertebrate assemblages from 11 stations from six sampling occasions during the period 1996-2011. Despite the established quality assessment and quality control protocols for this monitoring program, we identified several data challenges, such as missing values and outliers, discrepancies in variable and station names, changes in procedures without calibration, and different taxonomic resolution. Furthermore, we show that the use of different laboratories over time makes it difficult to draw conclusions with regard to some of the observed changes. We offer recommendations to facilitate comparison of data over time. We also present a new procedure to handle different taxonomic resolution, so valuable historical data is not discarded. These topics have a broader relevance and application than for our case study.

The comet assay as a tool for human biomonitoring studies: The ComNet Project

The comet assay is widely used in human biomonitoring to measure DNA damage as a marker of exposure to genotoxic agents or to investigate genoprotective effects. Studies often involve small numbers of subjects, and design may be sub-optimal in other respects. In addition, comet assay protocols in use in different laboratories vary significantly. In spite of these difficulties, it is appropriate to carry out a pooled analysis of all available comet assay biomonitoring data, in order to establish baseline parameters of DNA damage, and to investigate associations between comet assay measurements and factors such as sex, age, smoking status, nutrition, lifestyle, etc. With this as its major objective, the ComNet project has recruited almost 100 research groups willing to share datasets. Here we provide a background to this project, discussing the history of the comet assay and practical issues that can critically affect its performance. We survey its diverse applications in biomonitoring studies, including environmental and occupational exposure to genotoxic agents, genoprotection by dietary and other factors, DNA damage associated with various diseases, and intrinsic factors that affect DNA damage levels in humans. We examine in depth the quality of data from a random selection of studies, from an epidemiological and statistical point of view.

Interlaboratory Comparison of Real-Time Polymerase Chain Reaction Methods to Detect Coxiella Burnetii, The Causative Agent of Q Fever

The bacterium Coxiella burnetii, which has a wide host range, causes Q fever. Infection with C. burnetii can cause abortions, stillbirth, and the delivery of weak offspring in ruminants. Coxiella burnetii infection is zoonotic, and in human beings it can cause chronic, potentially fatal disease. Real-time polymerase chain reaction (PCR) is increasingly being used to detect the organism and to aid in diagnosis both in human and animal cases. Many different real-time PCR methods, which target different genes, have been described. To assess the comparability of the C. burnetii real-time PCR assays in use in different European laboratories, a panel of nucleic acid extracts was dispatched to 7 separate testing centers. The testing centers included laboratories from both human and animal health agencies. Each laboratory tested the samples using their in-house real-time PCR methods. The results of this comparison show that the most common target gene for real-time PCR assays is the IS1111 repeat element that is present in multiple copies in the C. burnetii genome. Many laboratories also use additional real-time PCR tests that target single-copy genes. The results of the current study demonstrate that the assays in use in the different laboratories are comparable, with general agreement of results for the panel of samples.

Preanalytical treatment of EDTA-anticoagulated blood to ensure stabilization of the mean platelet volume and component measured with the ADVIA counters

The mean platelet component (MPC) parameter calculated by the ADVIA blood cell analyzers provides direct information on density, or granularity, of platelets and could become a useful biomarker to detect in vivo platelet activation. Unfortunately, it is largely affected by time and storage conditions in standard anticoagulants based on EDTA. The present study was designed to improve the stability of the MPC in blood specimens to facilitate a more standardized use in different laboratories. Blood from healthy controls was collected into EDTA plus additives, and stored at different conditions. MPC and the mean platelet volume (MPV) were assessed at 30 min and at 1, 3, 6 and 24 hours after blood drawing on the ADVIA 2120 system. Flow cytometry was used to evaluate platelet-activation proteins. Ultrastructural morphology of platelets was assessed using electron microscopy. Storage in EDTA increased MPV, decreased MPC, reduced the number of α-granules, and induced changes in the phosphorylation patterns of platelet proteins. A solution based on EDTA containing wortmanin and tyrphostin (ED-WORTY), both inhibitors of signaling pathways, provided good stability for most of the parameters tested up to 6 hours at room temperature. Storage at lower temperatures produced more favorable results. ED-WORTY solutions preserved adequate morphology and had minimal influence on other parameters provided by the ADVIA 2120 system. Thus, the additives included in ED-WORTY may be useful for maintaining the stability of MPC for prolonged periods and to facilitate the transport and exchange of samples among institutions and laboratories.

Effects of methodological variation on assessment of riboflavin status using the erythrocyte glutathione reductase activation coefficient assay

Riboflavin status is usually measured as the in vitro stimulation with flavin adenine dinucleotide of the erythrocyte enzyme glutathione reductase, and expressed as an erythrocyte glutathione reductase activation coefficient (EGRAC). This method is used for the National Diet and Nutrition Surveys (NDNS) of the UK. In the period between the 1990 and 2003 surveys of UK adults, the estimated prevalence of riboflavin deficiency, expressed as an EGRAC value > or = 1.30, increased from 2 to 46 % in males and from 1 to 34 % in females. We hypothesised that subtle but important differences in the detail of the methodology between the two NDNS accounted for this difference. We carried out an evaluation of the performance of the methods used in the two NDNS and compared against an 'in-house' method, using blood samples collected from a riboflavin intervention study. Results indicated that the method used for the 1990 NDNS gave a significantly lower mean EGRAC value than both the 2003 NDNS method and the 'in-house' method (P < 0.0001). The key differences between the methods relate to the concentration of FAD used in the assay and the duration of the period of incubation of FAD with enzyme. The details of the EGRAC method should be standardised for use in different laboratories and over time. Additionally, it is proposed that consideration be given to re-evaluating the basis of the EGRAC threshold for riboflavin deficiency.

Computational Laboratories for Organization Science: Questions, Validity and Docking

A computational laboratory is a “place” where we can: ask a question about an organization and its processes, build a computational experiment, design and conduct an experiment, and answer or comment on the question. The questions can be: what is, what might be, and what should be. Validation is a fundamental concern in sciences the validity of a laboratory and model depends upon the question being addressed. A laboratory for a descriptive what is question may not be valid for a what should be design question. Docking—the alignment of two models—goes beyond validity. Docking juxtaposes two models to investigate whether they proceed in like manner or yield similar results. I argue that docking provides a guide in the use of different laboratories to address organization questionss and, further computational and non computational models can be docked to deepen and broaden our understanding of organization science.

A New Rapid Method for Penicillin Assay

VARIOUS methods of testing penicillin are in use in different laboratories, and while the accuracy of some of them is quite high, they all suffer from the disadvantage that some 12–18 hr. are required to obtain a result of any accuracy. Such a time-lag is a serious disadvantage in studying the production of penicillin—as the rapid change of pH which occurs under certain conditions makes it essential that harvesting should be carried out with the least delay if serious loss of activity is to be avoided.