Artículos de revistas: "Behavior assays"

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Fraser, Gilles L., David E. Wennberg, John D. Dickens y Costas T. Lambrew. "Changing Physician Behavior in Ordering Digoxin Assays". Annals of Pharmacotherapy 30, n.º 5 (mayo de 1996): 449–54. http://dx.doi.org/10.1177/106002809603000502.

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OBJECTIVE: TO assess the ability to modify physicians' use of serum digoxin assays in a sustained fashion through (1) an educational intervention by a clinical pharmacist, and (2) changes in the computerized medical information system. DESIGN: A before/after methodology was used to compare test use by hospital staff physicians in two phases. Phase 1 was an educational intervention conducted by a clinical pharmacist with an 8-month follow-up. Phase 2 was a medical information system intervention with a 12-month follow-up. PATIENTS: Adult inpatients from July 1990 through December 1993 who received either digoxin therapy or at least one serum digoxin assay. MAIN OUTCOME MEASURE: Digoxin assays per patient day while receiving digoxin (assays/digoxin day), in-hospital mortality, and length of stay were compared before and after implementation of the interventions. RESULTS: A total of 9468 patients received a digoxin and/or serum digoxin assay. Baseline use of serum digoxin assays was 0.178 assays/digoxin day. Following phase 1, the educational intervention, use declined 20.2% to 0.142 assays/digoxin day (p < 0.03). After phase 2, the implementation of changes in the medical information system, digoxin assay use was maintained at 16.3% less than that at baseline (p < 0.03). Patient mortality was unaffected. CONCLUSIONS: A low-intensity educational intervention by a clinical pharmacist supplemented by medical information system modification resulted in an important decrease in the use of digoxin assays. The change in physician behavior was sustained for more than 18 months. The model presented is not labor intensive, does not require continuous maintenance by healthcare personnel for a sustained effect, and may be widely applicable to healthcare providers.

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Hira, Vashendriya VV, Barbara Breznik, Cornelis JF Van Noorden, Tamara Lah y Remco J. Molenaar. "2D and 3D in vitro assays to quantify the invasive behavior of glioblastoma stem cells in response to SDF-1α". BioTechniques 69, n.º 5 (noviembre de 2020): 339–46. http://dx.doi.org/10.2144/btn-2020-0046.

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Invasion is a hallmark of cancer and therefore in vitro invasion assays are important tools in cancer research. We aimed to describe in vitro 2D transwell assays and 3D spheroid assays to quantitatively determine the invasive behavior of glioblastoma stem cells in response to the chemoattractant SDF-1α. Matrigel was used as a matrix in both assays. We demonstrated quantitatively that SDF-1α increased invasive behavior of glioblastoma stem cells in both assays. We conclude that the 2D transwell invasion assay is easy to perform, fast and less complex whereas the more time-consuming 3D spheroid invasion assay is physiologically closer to the in vivo situation.

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Aggarwal, Aman, Heinrich Reichert y K. VijayRaghavan. "A locomotor assay reveals deficits in heterozygous Parkinson’s disease model and proprioceptive mutants in adult Drosophila". Proceedings of the National Academy of Sciences 116, n.º 49 (20 de noviembre de 2019): 24830–39. http://dx.doi.org/10.1073/pnas.1807456116.

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Severe locomotor impairment is a common phenotype of neurodegenerative disorders such as Parkinson’s disease (PD). Drosophila models of PD, studied for more than a decade, have helped in understanding the interaction between various genetic factors, such as parkin and PINK1, in this disease. To characterize locomotor behavioral phenotypes for these genes, fly climbing assays have been widely used. While these simple current assays for locomotor defects in Drosophila mutants measure some locomotor phenotypes well, it is possible that detection of subtle changes in behavior is important to understand the manifestation of locomotor disorders. We introduce a climbing behavior assay which provides such fine-scale behavioral data and tests this proposition for the Drosophila model. We use this inexpensive, fully automated assay to quantitatively characterize the climbing behavior at high parametric resolution in 3 contexts. First, we characterize wild-type flies and uncover a hitherto unknown sexual dimorphism in climbing behavior. Second, we study climbing behavior of heterozygous mutants of genes implicated in the fly PD model and reveal previously unreported prominent locomotor defects in some of these heterozygous fly lines. Finally, we study locomotor defects in a homozygous proprioceptory mutation (Trp-γ1) known to affect fine motor control in Drosophila. Moreover, we identify aberrant geotactic behavior in Trp-γ1 mutants, thereby opening up a finer assay for geotaxis and its genetic basis. Our assay is therefore a cost-effective, general tool for measuring locomotor behaviors of wild-type and mutant flies in fine detail and can reveal subtle motor defects.

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Böcker, Alexander, Pierre R. Bonneau y Paul J. Edwards. "HTS Promiscuity Analyses for Accelerating Decision Making". Journal of Biomolecular Screening 16, n.º 7 (16 de junio de 2011): 765–74. http://dx.doi.org/10.1177/1087057111407763.

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Frequent hitters are compounds that are detected as a “hit” in multiple high-throughput screening (HTS) assays. Such behavior is specific (e.g., target family related) or unspecific (e.g., reactive compounds) or can result from a combination of such behaviors. Detecting such hits while predicting the underlying reason behind their promiscuous behavior is desirable because it provides valuable information not only about the compounds themselves but also about the assay methodology and target classes at hand. This information can also greatly reduce cost and time during HTS hit profiling. The present study exemplifies how to mine large HTS data repositories, such as the one at Boehringer Ingelheim, to identify frequent hitters, gain further insights into the causes of promiscuous behavior, and generate models for predicting promiscuous compounds. Applications of this approach are demonstrated using two recent large-scale HTS assays. The authors believe this analysis and its concrete applications are valuable tools for streamlining and accelerating decision-making processes during the course of hit discovery.

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Adamkewicz, Joanne I., David C. Chen y Ido Paz-Priel. "Effects and Interferences of Emicizumab, a Humanised Bispecific Antibody Mimicking Activated Factor VIII Cofactor Function, on Coagulation Assays". Thrombosis and Haemostasis 119, n.º 07 (7 de mayo de 2019): 1084–93. http://dx.doi.org/10.1055/s-0039-1688687.

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AbstractEmicizumab bridges activated factor IX (FIX) and FX to restore the tenase function mediated by activated FVIII (FVIIIa), which is deficient in people with haemophilia A (PwHA). Unlike FVIII, emicizumab does not require activation to function; thus, in coagulation assays, the behavior of emicizumab may differ from that of FVIII. The objective of this study was to assess the effect of emicizumab on coagulation assays, including potential interference behavior that may produce inaccurate or misleading results. A variety of clotting-based, amidolytic/chromogenic, latex particle-enhanced turbidometric, and enzyme-linked immunosorbent methods were investigated. As expected based on its pharmacologic mechanism of action, emicizumab exhibited strong activity on the activated partial thromboplastin time (aPTT), which resulted in interference with several aPTT-based assays, most importantly the one-stage FVIII activity assay; these assays are not recommended for PwHA receiving emicizumab therapy. Pharmacodynamic activity of emicizumab, as measured by FVIII chromogenic assays, was species-dependent due to the binding specificity of the drug antibody. Outside of FVIII assays, emicizumab did not interfere with assays based on immunologic or chromogenic principles, nor with clotting assays based on nonintrinsic pathway activators, thus offering alternative choices where aPTT-based assays might otherwise be used. The observed interferences are in line with the unique mechanism of action of emicizumab. Potential interferences should be taken into account in the selection of coagulation assays and interpretation of coagulation assay test results for PwHA receiving emicizumab therapy.

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Wisdom, C. S., A. Gonzalez-Coloma y P. W. Rundel. "Ecological tannin assays". Oecologia 72, n.º 3 (junio de 1987): 395–401. http://dx.doi.org/10.1007/bf00377570.

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Beeler, Erik, Zachary Nobile y Gregg Homanics. "Paternal Preconception Every-Other-Day Ethanol Drinking Alters Behavior and Ethanol Consumption in Offspring". Brain Sciences 9, n.º 3 (6 de marzo de 2019): 56. http://dx.doi.org/10.3390/brainsci9030056.

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Alcohol use disorder is a devastating disease with a complex etiology. Recent preclinical studies have revealed that paternal preconception chronic intermittent ethanol (EtOH) exposure via vaporized EtOH altered drinking behaviors and sensitivity to EtOH selectively in male offspring. In the current study, we used a voluntary oral route of paternal preconception EtOH exposure, i.e., intermittent every-other-day two-bottle choice drinking, and tested offspring for behavioral alterations. Fifteen EtOH drinking sires and 10 control sires were mated to EtOH naïve females to produce EtOH-sired and control-sired offspring. These offspring were tested using the elevated plus maze, open field, drinking in the dark, and unlimited access two-bottle choice assays. We found that paternal preconception every-other-day two-bottle choice drinking resulted in reduced EtOH consumption selectively in male offspring in the drinking in the dark assay compared to control-sired offspring. No differences were detected in either sex in the unlimited access two-bottle choice and elevated plus maze assays. Open field analysis revealed complex changes in basal behavior and EtOH-induced behaviors that were sex specific. We concluded that paternal preconception voluntary EtOH consumption has persistent effects that impact the next generation. This study adds to a growing appreciation that one’s behavioral response to EtOH and EtOH drinking behavior are impacted by EtOH exposure of the prior generation.

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Piketty, M. L., M. d'Herbomez, D. Le Guillouzic, R. Lebtahi, E. Cosson, A. Dumont, A. Dilouya y B. O. Helal. "Clinical comparison of three labeled-antibody immunoassays of free triiodothyronine". Clinical Chemistry 42, n.º 6 (1 de junio de 1996): 933–41. http://dx.doi.org/10.1093/clinchem/42.6.933.

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Abstract Three labeled-antibody immunoassays of free triiodothyronine (FT3) were studied in hyperthyroid patients, patients with nonthyroidal illness, and patients being treated with amiodarone; we also studied sera presenting known interferences (n for all groups = 465). The results were compared with those of a one-step labeled-analog assay. The precision of the two automated assays were similar to that of the manual assays. The three labeled-antibody FT3 assays demonstrated a satisfactory diagnostic performance for confirming hyperthyroidism and robustness to interference; nevertheless, two assays displayed unusual behavior in some patients with nonthyroidal illness, with chronic renal failure, or after amiodarone therapy.

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Luo, Linjiao, Christopher V. Gabel, Heon-Ick Ha, Yun Zhang y Aravinthan D. T. Samuel. "Olfactory Behavior of Swimming C. elegans Analyzed by Measuring Motile Responses to Temporal Variations of Odorants". Journal of Neurophysiology 99, n.º 5 (mayo de 2008): 2617–25. http://dx.doi.org/10.1152/jn.00053.2008.

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Caenorhabditis elegans responds to chemical cues using a small number of chemosensory neurons that detect a large variety of molecules in its environment. During chemotaxis, C. elegans biases its migration in spatial chemical gradients by lengthening (/shortening) periods of forward movement when it happens to be moving toward (/away) from preferred locations. In classical assays of chemotactic behavior, a group of crawling worms is placed on an agar plate containing a point source of chemical, the group is allowed to navigate for a period of time, and aggregation of worms near the source is quantified. Here we show that swimming worms exhibit acute motile responses to temporal variations of odor in their surrounding environment, allowing our development of an automated assay of chemotactic behavior with single-animal resolution. By placing individual worms in small microdroplets and quantifying their movements as they respond to the addition and removal of odorized airstreams, we show that the sensorimotor phenotypes of swimming worms (wild-type behavior, the effects of certain mutations, and the effects of laser ablation of specific olfactory neurons) are consistent with aggregation phenotypes previously obtained in crawling assays. The microdroplet swimming assay has certain advantages over crawling assays, including flexibility and precision in defining the stimulus waveform and automated quantification of motor response during stimulus presentation. In this study, we use the microdroplet assay to quantify the temporal dynamics of the olfactory response, the sensitivity to odorant concentration, combinations, and gradients, and the contribution of specific olfactory neurons to overall behavior.

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McMeekan, John y Patricia Wadsworth. "Functional Assays to Identify and Characterize Regulators of Microtubule Behavior". BioTechniques 24, n.º 5 (mayo de 1998): 870–76. http://dx.doi.org/10.2144/98245rr04.

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Sims, Christopher E. y Nancy L. Allbritton. "Single-cell kinase assays: opening a window onto cell behavior". Current Opinion in Biotechnology 14, n.º 1 (febrero de 2003): 23–28. http://dx.doi.org/10.1016/s0958-1669(02)00002-2.

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Spivak, Marla y Danielle Laura Downey. "Field Assays for Hygienic Behavior in Honey Bees (Hymenoptera: Apidae)". Journal of Economic Entomology 91, n.º 1 (1 de febrero de 1998): 64–70. http://dx.doi.org/10.1093/jee/91.1.64.

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13

Mole, Simon, Larry G. Butler, Ann E. Hagerman y Peter G. Waterman. "Ecological tannin assays: a critique". Oecologia 78, n.º 1 (enero de 1989): 93–96. http://dx.doi.org/10.1007/bf00377202.

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Álvarez-Hernández, Juan Carlos, Javier Zaragoza Castellanos-Ramos y Cesar Leobardo Aguirre-Mancilla. "Adaptation of a Grafting Method for Carica papaya Based on Seedling Behavior". HortScience 54, n.º 6 (junio de 2019): 982–87. http://dx.doi.org/10.21273/hortsci13800-18.

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Grafting Carica papaya plants can have several benefits for productive, phytosanitary, and sexing purposes. However, the literature on the subject of papaya grafting is limited. The tongue approach and cleft grafting techniques seem to be the most adequate for C. papaya, but the quality of grafts depends on several factors. With the objective of developing and adapting a grafting method for papaya, experimental assays were carried out in the Valley of Apatzingan, Michoacan, Mexico. The physical condition of the seedlings was assessed, and the most advantageous time for grafting was determined based on the size and thickness of the stems. Three assays were then carried out. The first assay was a test of the tongue approach and cleft grafting techniques using two clamping devices. The second assay involved the same techniques with modifications and the addition of another treatment. In the third assay, the modified tongue approach grafting method was tested on three containers with papaya plants. Seedling vigor, graft survival, and graft quality were the recorded variables. The results indicated that unwanted tissue should be cut 6 days after grafting. The tongue approach grafting method using tape as the fastening device (T-T) yielded a graft survival of 80%. The modified tongue approach grafting method, in which the tongues were formed just below the stem-site cut and tape was used as the fastening device (M-T-Bc-T), yielded a graft survival of 90%. In the third assay, the previously described modified method, but with seedlings grown in plastic bags (M-T-Bc-T-B), yielded a graft survival of 92.5%. It can be concluded that the modified tongue approach grafting method with seedlings grown in plastic bags (M-T-Bc-T-B), is a reliable grafting method for papaya that does not require special handling conditions.

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Grimsey, Natasha L., Kriebashne S. Moodley, Michelle Glass y E. Scott Graham. "Sensitive and Accurate Quantification of Human Leukocyte Migration Using High-Content Discovery-1 Imaging System and ATPlite Assay". Journal of Biomolecular Screening 17, n.º 3 (1 de diciembre de 2011): 386–93. http://dx.doi.org/10.1177/1087057111428985.

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Migration is a fundamental aspect of leukocyte behavior and represents a significant therapeutic target clinically. However, most migration assays used in research are relatively low throughput and not easily compatible with rapid analysis or high-throughput screening (HTS) protocols required for drug screening assays. We therefore investigated the quantification of the migration of human leukocytes using the Molecular Devices high-content Discovery-1 platform or PerkinElmer ATPlite assay compared to manual counting. We have conducted extensive assay validation, investigating the detection limits, sensitivity, and precision of each method to count human leukocytes. Leukocyte migration assays were conducted using 96-well HTS-Transwell plates and the potent chemokine stromal cell–derived factor-1 (SDF-1). We reveal that the Discovery-1 and ATPlite methods developed here provide useful approaches to quantify leukocyte migration in an HTS manner with high levels of detection, sensitivity, and precision.

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Audira, Gilbert, Bonifasius Sampurna, Stevhen Juniardi, Sung-Tzu Liang, Yu-Heng Lai y Chung-Der Hsiao. "A Versatile Setup for Measuring Multiple Behavior Endpoints in Zebrafish". Inventions 3, n.º 4 (7 de noviembre de 2018): 75. http://dx.doi.org/10.3390/inventions3040075.

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The measurement of multiple behavior endpoints in zebrafish can provide informative clues within neurobehavioral field. However, multiple behavior evaluations usually require complicated and costly instrumental settings. Here, we reported a versatile setting that applied ten acrylic tanks arranging into five vertical layers and two horizontal columns to perform multiple behavior assays simultaneously, such as the novel tank diving test, mirror-biting test, social interaction, shoaling, and predator escape assay. In total, ten behavioral performance were collected in a single video, and the XY coordination of fish locomotion can be tracked by using open source software of idTracker and ImageJ. We validated our setting by examining zebrafish behavioral changes after exposure to low dose ethanol (EtOH) for 96 h. Fish were observed staying longer time at bottom of the tank, less mirror biting interest, higher freezing time, less fear in predator test, and tight shoaling behaviors which indicated the anxiogenic effect was induced by low dosage exposure of EtOH in zebrafish. In conclusion, the setting in this study provided a simple, versatile and cost-effective way to assess multiple behavioral endpoints in zebrafish with high reliability and reproducibility for the first time.

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Moore, Rebecca S., Rachel Kaletsky y Coleen T. Murphy. "Protocol for transgenerational learned pathogen avoidance behavior assays in Caenorhabditis elegans". STAR Protocols 2, n.º 1 (marzo de 2021): 100384. http://dx.doi.org/10.1016/j.xpro.2021.100384.

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Ganguly, Payel, Landiso Madonsela, Jesse T. Chao, Christopher J. R. Loewen, Timothy P. O’Connor, Esther M. Verheyen y Douglas W. Allan. "A scalable Drosophila assay for clinical interpretation of human PTEN variants in suppression of PI3K/AKT induced cellular proliferation". PLOS Genetics 17, n.º 9 (7 de septiembre de 2021): e1009774. http://dx.doi.org/10.1371/journal.pgen.1009774.

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Gene variant discovery is becoming routine, but it remains difficult to usefully interpret the functional consequence or disease relevance of most variants. To fill this interpretation gap, experimental assays of variant function are becoming common place. Yet, it remains challenging to make these assays reproducible, scalable to high numbers of variants, and capable of assessing defined gene-disease mechanism for clinical interpretation aligned to the ClinGen Sequence Variant Interpretation (SVI) Working Group guidelines for ‘well-established assays’. Drosophila melanogaster offers great potential as an assay platform, but was untested for high numbers of human variants adherent to these guidelines. Here, we wished to test the utility of Drosophila as a platform for scalable well-established assays. We took a genetic interaction approach to test the function of ~100 human PTEN variants in cancer-relevant suppression of PI3K/AKT signaling in cellular growth and proliferation. We validated the assay using biochemically characterized PTEN mutants as well as 23 total known pathogenic and benign PTEN variants, all of which the assay correctly assigned into predicted functional categories. Additionally, function calls for these variants correlated very well with our recent published data from a human cell line. Finally, using these pathogenic and benign variants to calibrate the assay, we could set readout thresholds for clinical interpretation of the pathogenicity of 70 other PTEN variants. Overall, we demonstrate that Drosophila offers a powerful assay platform for clinical variant interpretation, that can be used in conjunction with other well-established assays, to increase confidence in the accurate assessment of variant function and pathogenicity.

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Subbotin, Sergei A. y Julie Burbridge. "Sensitive, Accurate and Rapid Detection of the Northern Root-Knot Nematode, Meloidogyne hapla, Using Recombinase Polymerase Amplification Assays". Plants 10, n.º 2 (10 de febrero de 2021): 336. http://dx.doi.org/10.3390/plants10020336.

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Rapid and reliable diagnostics of root-knot nematodes are critical for selections of effective control against these agricultural pests. In this study, recombinase polymerase amplification (RPA) assays were developed targeting the IGS rRNA gene of the northern root-knot nematode, Meloidogyne hapla. The RPA assays using TwistAmp® Basic, TwistAmp® exo and TwistAmp® nfo kits (TwistDx, Cambridge, UK) allowed for the detection of M. hapla from crude extracts of females, eggs and juveniles without a DNA extraction step. The results of the RPA assays using real-time fluorescence detection (real-time RPA) in series of crude nematode extracts showed reliable detection after 13 min with a sensitivity of 1/100 of a second-stage juvenile and up to 1/1000 of a female in reaction tubes. The results of the RPA assays using lateral flow dipsticks (LF-RPA) showed reliable detection within 30 min with a sensitivity of 1/10 of a second-stage juvenile and 1/1000 of a female in reaction tubes. The RPA assay developed here is a successful tool for quick, accurate and sensitive diagnostics of M. hapla. The application of the LF-RPA assay has great potential for diagnosing infestation of this species in the lab, field or in areas with a minimal laboratory infrastructure.

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Wu, Shang-Ying, Yung-Shin Sun, Kuan-Chen Cheng y Kai-Yin Lo. "A Wound-Healing Assay Based on Ultraviolet Light Ablation". SLAS TECHNOLOGY: Translating Life Sciences Innovation 22, n.º 1 (10 de julio de 2016): 36–43. http://dx.doi.org/10.1177/2211068216646741.

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Collective cell migration plays important roles in many physiological processes such as embryonic development, tissue repair, and angiogenesis. A “wound” occurs when epithelial cells are lost and/or damaged due to some external factors, and collective cell migration takes place in the following wound-healing process. To study this cellular behavior, various kinds of wound-healing assays are developed. In these assays, a “wound,” or a “cell-free region,” is created in a cell monolayer mechanically, chemically, optically, or electrically. These assays are useful tools in studying the effects of certain physical or chemical stimuli on the wound-healing process. Most of these methods have disadvantages such as creating wounds of different sizes or shapes, yielding batch-to-batch variation, and damaging the coating of the cell culture surface. In this study, we used ultraviolet (UV) lights to selectively kill cells and create a wound out of a cell monolayer. A comparison between the current assay and the traditional scratch assay was made, indicating that these two methods resulted in similar wound-healing rates. The advantages of this UV-created wound-healing assay include fast and easy procedure, high throughput, and no direct contact to cells.

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Albert, Keith J. y John Thomas Bradshaw. "Importance of Integrating a Volume Verification Method for Liquid Handlers: Applications in Learning Performance Behavior". JALA: Journal of the Association for Laboratory Automation 12, n.º 3 (junio de 2007): 172–80. http://dx.doi.org/10.1016/j.jala.2006.10.005.

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Nearly all assays performed within a microtiter plate are volume dependent. In turn, all concentrations of biological and chemical components in these assays, as well as the associated dilution protocols, are volume dependent. Therefore, it is imperative to quantify the volumes transferred to and from an assay. A volume verification method, which can be used to quantify the amount of transferred volume, is an essential component that enables proper interpretation of experimental results. A volume verification method can be used to help an operator optimize volume transfers as well as troubleshoot automated methods. Moreover, these methods can be used to compare performance between liquid handlers, show dispense drift over time, compare channel-to-channel (tip-to-tip) reproducibility, or statistically compare individual dispenses from a multisequential dispense. The focus of this paper, in part, is to discuss some of the many situations where a volume verification method should be implemented. This paper addresses important factors and their associated applications in understanding liquid handler behavior and is not meant to be specific to the volume verification process or the specific liquid handlers used. A robust and reliable volume verification method allows for measurement of transferred volumes at all levels in assay development, from a pure research level to a highly regulated laboratory environment. The goal is to achieve liquid delivery quality assurance through accurate and precise measurement of critical volume transfers. (JALA 2007;12:172–80)

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Wynne, FJ, R. Puschendorf, ME Knight y SJ Price. "Choice of molecular assay determines ranavirus detection probability and inferences about prevalence and occurrence". Diseases of Aquatic Organisms 141 (24 de septiembre de 2020): 139–47. http://dx.doi.org/10.3354/dao03518.

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Ranaviruses are emerging pathogens that can cause morbidity, mortality and population declines in ectothermic hosts; however, there is no standardized approach to diagnostics. Here, we compared the inter-assay variation and intra-assay precision among 2 commonly used quantitative PCRs (qPCRs), a conventional and a nested PCR assay (used as a gold standard), using laboratory-propagated ranavirus (FV3 and CMTV) and field-collected samples. A qPCR assay (‘Leung’) detected viral DNA in dilutions 2 orders of magnitude lower than other assays regardless of the viral lineage of the cultured isolate (FV3/CMTV). The second qPCR (‘Brunner’) was slightly more sensitive than the conventional PCR (‘Mao’ assay). For field samples, the Leung qPCR detected all known positives, while the Mao assay PCR only detected 2.5% of the positive samples. Amplicon sequences from the 2 conventional PCRs were shown to be useful for inferring viral lineage. Inaccurate results will bias estimates of the distribution and prevalence of ranaviruses, and together these findings emphasize that molecular assays should be chosen carefully in the context of study aims.

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Schiewe, Michael H., Eric G. Hawk, David I. Actor y Margaret M. Krahn. "Use of a Bacterial Bioluminescence Assay to Assess Toxicity of Contaminated Marine Sediments". Canadian Journal of Fisheries and Aquatic Sciences 42, n.º 7 (1 de julio de 1985): 1244–48. http://dx.doi.org/10.1139/f85-154.

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A bacterial bioluminescence assay was evaluated for assessing the toxicity of contaminated marine sediments. Preliminary assays established the feasibility of testing methanol–dichloromethane sediment extracts and demonstrated the advantages of solvent-exchanging the extracts into ethanol before testing. Bioluminescence assays were then conducted on extracts of 18 marine sediments varying in nature and degree of chemical contamination. Statistical analyses revealed significant associations between acute toxicity expressed as a 15-min EC50 (the concentration of extract causing a 50% reduction in bioluminescence after a 15-min exposure) and concentrations of sums of measured aromatic hydrocarbons, naphthalenes, and chlorinated hydrocarbons. We conclude that the bioluminescence assay is useful as a rapid method of comparing and ranking the toxicity of organic extracts of contaminated sediments.

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Morote, Juan, Inma Comas, Jacques Planas, Ana Celma, Roser Ferrer y Lucas Regis. "Behavior of chemiluminescent assays to measure serum testosterone during androgen deprivation therapy". International Journal of Urology 23, n.º 11 (3 de agosto de 2016): 957–58. http://dx.doi.org/10.1111/iju.13180.

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Llewellyn, Lyndon E. "The Behavior of Mixtures of Paralytic Shellfish Toxins in Competitive Binding Assays". Chemical Research in Toxicology 19, n.º 5 (mayo de 2006): 661–67. http://dx.doi.org/10.1021/tx050277i.

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White, P. J., R. A. Garrott y D. M. Heisey. "Variability in snow-urine assays". Canadian Journal of Zoology 73, n.º 3 (1 de marzo de 1995): 427–32. http://dx.doi.org/10.1139/z95-048.

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Urea nitrogen: creatinine ratios in snow urine have become popular for assessing the extent of winter nutritional deprivation in ungulates. During winter 1992 – 1993, we collected 10–17 sequential snow-urine samples (402 total) from 27 individually identifiable free-ranging adult female elk. Within-animal variance accounted for 91% of the total variance (351.66 mg2/dL2) in creatinine, 86% of the total variance (637.03 mg2/dL2) in urea nitrogen, and 82% of the total variance (0.56) in urea nitrogen: creatinine ratios. This substantial within-animal variability was unexpected and led to experiments that examined whether the variability was due to sample collection and measurement technique or actually reflected biological variability. Factors examined included dilution effects, measurement (assay) repeatability, and short-term (<24 h) within-animal constancy in metabolite excretion. No dilution effects were detected when the initial concentrations of snow-urine samples were diluted <75% with water. Measurement variability accounted for 0.78, 0.37, and 27.7% of the total variance in creatinine, urea nitrogen, and urea nitrogen: creatinine ratios, respectively. Within-animal metabolite excretion was reasonably constant within 24 h, suggesting that creatinine provides a valid index for comparing urinary metabolites. We conclude that variability in urea nitrogen: creatinine ratios due to dilution, measurement variability, and short-term temporal variability in metabolite excretion was small compared with the total within-animal variance. Urea nitrogen: creatinine ratios should provide an accurate estimate of the true ratios of these metabolites in an elk's bladder urine. However, the interpretation of urea nitrogen: creatinine ratios is often complex, since they reflect the immediate dynamics between fat depletion, protein catabolism, and dietary intake. Differences in ratios between collections may be partially due to variations in recent dietary intake or restriction, in addition to true differences in long-term nutritional status. The best method for statistically analyzing snow-urine data remains unresolved.

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Carlson, Bradley E. y Tracy Langkilde. "No evidence of selection by predators on tadpole boldness". Behaviour 151, n.º 1 (2014): 23–45. http://dx.doi.org/10.1163/1568539x-00003121.

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Animals typically exhibit adaptive behaviors that reduce their risk of predation. The term ‘boldness’ describes individual variation in the propensity to exhibit risk-reducing behavior and is the subject of much research attention. Predators should select against boldness, and this has been supported by empirical studies and behavioral ecology theory. We tested whether a standardized assay of three boldness-associated behaviors in wood frog (Lithobates sylvaticus) tadpoles predicted survival when faced with a predator. Tadpole behavior was assayed in an open field and then tadpoles were placed, in pairs, in an enclosure with a predator (newt or larval dragonfly). Survival did not depend on differences in measured boldness, and this result held when we accounted for interactions between different boldness behaviors and between behavior and size or predator identity. The absence of selection by predators against bolder tadpoles is counterintuitive and inconsistent with our understanding of the behavioral ecology of these animals. Two possible explanations are offered for this result. First, selection against boldness may be minimized by other phenotypic traits, such as escape ability. Alternatively, the potential lack of consistency between standardized boldness assays and natural encounters with predators may limit our capacity to study the evolution of boldness, cautioning against this approach. These results highlight the complexities of the relationships between behavioral traits and fitness and the challenges associated with their study.

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Silva-Comar, Francielli Maria de Souza, Luiz Alexandre Marques Wiirzler, Saulo Euclides Silva-Filho, Raquel Kummer, Raissa Bocchi Pedroso, Ricardo Alexandre Spironello, Expedito Leite Silva, Ciomar Aparecida Bersani-Amado y Roberto Kenji Nakamura Cuman. "Effect of Estragole on Leukocyte Behavior and Phagocytic Activity of Macrophages". Evidence-Based Complementary and Alternative Medicine 2014 (2014): 1–7. http://dx.doi.org/10.1155/2014/784689.

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Estragole, a chemical constituent of the essential oils of many aromatic plants, is used as flavoring in beverage and food industries.In vivoandin vitroexperimental assays have shown that EST has sedative, anticonvulsant, antioxidant, antimicrobial, and anesthetic activity. In this work, we evaluate the effect of EST on leukocyte behavior and phagocytic activity of macrophages. In the peritonitis model, EST (500 and 750 mg/kg) decreased the infiltration of peritoneal exudate leukocytes.In vitrochemotaxis assay showed that EST (3, 10, 30, and 60 μg/mL) inhibited neutrophil migration toward fMLP. In thein vivomicrocirculation assay, EST at doses of 250, 500, and 750 mg/kg significantly reduced the number of rolling and adherent leukocytes and at doses of 250 and 500 mg/kg decreased number of leukocyte migrated to perivascular tissue. The results showed that EST (3, 10, and 30 μg/mL) was able to stimulate the macrophages phagocytosis but only at concentration of 10 μg/mL promoted an increase in nitric oxide (NO) production. In conclusion, this study showed that EST had potential anti-inflammatory effects, likely by inhibiting leukocyte migration and by stimulating macrophages phagocytosis.

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29

Watanabe, Tsuneo, Manabu Kanno, Masahiro Tagawa, Hideyuki Tamaki y Yoichi Kamagata. "Primary simple assays of cellulose-degrading fungi". Mycoscience 53, n.º 1 (enero de 2012): 45–48. http://dx.doi.org/10.1007/s10267-011-0132-5.

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Nisogi, Kenta, Satoshi Okano, Sengo Kobayashi, Kensuke Kuroda y Takeaki Okamoto. "Effects of Titanium Surface Wettability on Osteoblast Behavior In Vitro". Materials Science Forum 985 (abril de 2020): 64–68. http://dx.doi.org/10.4028/www.scientific.net/msf.985.64.

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Surface wettability is thought to influence the osteoconductivity of bone-substituting materials; however, the effects of surface wettability on osteoblast behavior are not well understood. In this study, we prepared both an as-polished pure titanium with a water contact angle (WCA) of 57° and heat-treated pure titanium with more hydrophobic surface and WCAs of 68°-98°. The effects of the surface wettability of pure titanium on osteoblast behaviors were evaluated by in vitro assays. Compared with the as-polished titanium, the proliferation rate of osteoblast increased on heat-treated titanium. This suggested that surface wettability affects osteoblast behaviors, meaning osteoconductivity is influenced by surface wettability.

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31

Garcia, Jeison y Fernando Lizcano. "Kdm4c is Recruited to Mitotic Chromosomes and Is Relevant for Chromosomal Stability, Cell Migration and Invasion of Triple Negative Breast Cancer Cells". Breast Cancer: Basic and Clinical Research 12 (1 de enero de 2018): 117822341877307. http://dx.doi.org/10.1177/1178223418773075.

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Members of the jumonji-containing lysine demethylase protein family have been associated with cancer development, although their specific roles in the evolution of tumor cells remain unknown. This work examines the effects of lysine demethylase 4C (KDM4C) knockdown on the behavior of a triple-negative breast cancer cell line. KDM4C expression was knocked-down by siRNA and analyzed by Western blot and immunofluorescence. HCC38 cell proliferation was examined by MTT assay, while breast cancer cells’ migration and invasion were tested in Transwell format by chemotaxis. Immunofluorescence assays showed that KDM4C, which is a key protein for modulating histone demethylation and chromosome stability through the distribution of genetic information, is located at the chromosomes during mitosis. Proliferation assays demonstrated that KDM4C is important for cell survival, while Transwell migration and invasion assays indicated that this protein is relevant for cancer progression. These data indicate that KDM4C is relevant for breast cancer progression and highlight its importance as a potential therapeutic target.

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32

Subbotin, Sergei A. "Recombinase polymerase amplification assay for rapid detection of the root-knot nematode Meloidogyne enterolobii". Nematology 21, n.º 3 (2019): 243–51. http://dx.doi.org/10.1163/15685411-00003210.

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Summary Rapid diagnosis tools for detection of root-knot nematodes play an important role in the disease control and eradication programme. Recombinase polymerase amplification (RPA) assays were developed targeting the IGS rRNA gene of the pacara earpod tree root-knot nematode, Meloidogyne enterolobii. The RPA assays using TwistAmp® Basic and TwistAmp® exo kits allowed detection of M. enterolobii from gall tissues and crude nematode extracts of all stages of target species without a DNA extraction step. The results of real-time RPA assays using a real-time fluorescent detection of a series of crude nematode extracts showed reliable detection with sensitivity of 1/10 of a second-stage juvenile in a RPA reaction tube after 15-20 min. The RPA assay provides affordable, simple, fast and sensitive detection of M. enterolobii.

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33

Yoon, Jinsoo, Christopher R. Parish y Lucy A. Coupland. "A Rapid and Accurate Bioluminescence-Based Migration Assay Permitting Analysis of Tumor Cell/Stromal Cell Interactions". Methods and Protocols 3, n.º 1 (23 de enero de 2020): 10. http://dx.doi.org/10.3390/mps3010010.

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Bioluminescent tumor cell lines are used extensively in vivo to monitor tumor growth and metastasis but rarely used in vitro to follow tumor cell behavior. Tumor cell migration is frequently studied in vitro using transwell assays, however, current methods do not permit the co-incubation of tumor cells with different stromal cell types for analysis of the effects of intercellular cross-talk on tumor cell migration. We describe a novel migration assay using bioluminescent tumor cell lines that is rapid, accurate, and permits the study of the effects of tumor cell-stromal cell interactions on tumor cell migratory behavior.

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34

Shahandeh, Michael P., Cameryn Brock y Thomas L. Turner. "Light dependent courtship behavior in Drosophila simulans and D. melanogaster". PeerJ 8 (16 de julio de 2020): e9499. http://dx.doi.org/10.7717/peerj.9499.

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Differences in courtship signals and perception are well-known among Drosophila species. One such described difference is the dependency on light, and thus presumably vision, for copulation success. Many studies have described a difference in light-dependent copulation success between D. melanogaster and D. simulans, identifying D. simulans as a light-dependent species, and D. melanogaster as a light-independent one. However, many of these studies use assays of varying design and few strains to represent the entire species. Here, we attempt to better characterize this purported difference using 11 strains of each species, paired by collection location, in behavioral assays conducted at two different exposure times. We show that, while there is a species-wide difference in magnitude of light-dependent copulation success, D. melanogaster copulation success is, on average, still impaired in the dark at both exposure times we measured. Additionally, there is significant variation in strain-specific ability to copulate in the dark in both species across two different exposure times. We find that this variation correlates strongly with longitude in D. melanogaster, but not in D. simulans. We hypothesize that differences in species history and demography may explain behavioral variation. Finally, we use courtship assays to show that light-dependent copulation success in one D. simulans strain is driven in part by both males and females. We discuss potential differences in courtship signals and/or signal importance between these species and potential for further comparative studies for functional characterization.

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35

Akarapipad, Patarajarin, Kattika Kaarj, Yan Liang y Jeong-Yeol Yoon. "Environmental Toxicology Assays Using Organ-on-Chip". Annual Review of Analytical Chemistry 14, n.º 1 (5 de junio de 2021): 155–83. http://dx.doi.org/10.1146/annurev-anchem-091620-091335.

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Adverse effects of environmental toxicants to human health have traditionally been assayed using in vitro assays. Organ-on-chip (OOC) is a new platform that can bridge the gaps between in vitro assays (or 3D cell culture) and animal tests. Microenvironments, physical and biochemical stimuli, and adequate sensing and biosensing systems can be integrated into OOC devices to better recapitulate the in vivo tissue and organ behavior and metabolism. While OOCs have extensively been studied for drug toxicity screening, their implementation in environmental toxicology assays is minimal and has limitations. In this review, recent attempts of environmental toxicology assays using OOCs, including multiple-organs-on-chip, are summarized and compared with OOC-based drug toxicity screening. Requirements for further improvements are identified and potential solutions are suggested.

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Marples, Nicola M. "Toxicity assays of ladybirds using natural predators". Chemoecology 4, n.º 1 (marzo de 1993): 33–38. http://dx.doi.org/10.1007/bf01245894.

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Parkinson, Rachel H., Sinan Zhang y John R. Gray. "Neonicotinoid and sulfoximine pesticides differentially impair insect escape behavior and motion detection". Proceedings of the National Academy of Sciences 117, n.º 10 (24 de febrero de 2020): 5510–15. http://dx.doi.org/10.1073/pnas.1916432117.

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Insect nervous systems offer unique advantages for studying interactions between sensory systems and behavior, given their complexity with high tractability. By examining the neural coding of salient environmental stimuli and resulting behavioral output in the context of environmental stressors, we gain an understanding of the effects of these stressors on brain and behavior and provide insight into normal function. The implication of neonicotinoid (neonic) pesticides in contributing to declines of nontarget species, such as bees, has motivated the development of new compounds that can potentially mitigate putative resistance in target species and declines of nontarget species. We used a neuroethologic approach, including behavioral assays and multineuronal recording techniques, to investigate effects of imidacloprid (IMD) and the novel insecticide sulfoxaflor (SFX) on visual motion-detection circuits and related escape behavior in the tractable locust system. Despite similar LD50 values, IMD and SFX evoked different behavioral and physiological effects. IMD significantly attenuated collision avoidance behaviors and impaired responses of neural populations, including decreases in spontaneous firing and neural habituation. In contrast, SFX displayed no effect at a comparable sublethal dose. These results show that neonics affect population responses and habituation of a visual motion detection system. We propose that differences in the sublethal effects of SFX reflect a different mode of action than that of IMD. More broadly, we suggest that neuroethologic assays for comparative neurotoxicology are valuable tools for fully addressing current issues regarding the proximal effects of environmental toxicity in nontarget species.

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38

Eltz, Thomas. "Spatio-temporal variation of apine bee attraction to honeybaits in Bornean forests". Journal of Tropical Ecology 20, n.º 3 (21 de abril de 2004): 317–24. http://dx.doi.org/10.1017/s0266467403001196.

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The abundance and species richness of highly social bees (Apinae: Meliponini, Apini) were studied at 12 dipterocarp forest sites in Sabah, northern Borneo, using standardized honey-water baiting assays. The 12 sites were grouped in five localities varying in the degree and history of disturbance from selective logging. A baiting assay consisted of spraying diluted honey on vegetation along transects and recording bee arrival on the same day. Repeated assays of the same sites were run in two consecutive years, 1998 and 1999. One-way repeated-measures ANOVAs were calculated on bee abundance and species richness, with locality and year as independent factors. There were significant or marginally significant effects of forest locality on all measures of bee abundance and species richness. However, there were also significant interactions between year and locality on these variables, thwarting conclusions on the effects of logging on bee communities. The diverging results of the two years are likely related to spatio-temporal variation of flowering activity prior to and during the assays, with between-year differences being amplified by pronounced differences in climatic conditions (ENSO). Local or regional differences in flowering phenology complicate the application of resource-based baiting techniques for between-site comparisons of bee diversity.

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Lance, Richard F. y Xin Guan. "Variation in inhibitor effects on qPCR assays and implications for eDNA surveys". Canadian Journal of Fisheries and Aquatic Sciences 77, n.º 1 (enero de 2020): 23–33. http://dx.doi.org/10.1139/cjfas-2018-0263.

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Aquatic environmental DNA (eDNA) surveys are sometimes impacted by polymerase chain reaction (PCR) inhibitors. We tested varying concentrations of different inhibitors (humic, phytic, and tannic acids; crude leaf extracts) for impacts on quantitative PCR (qPCR) assays designed for eDNA surveys of bighead and silver carp (Hypophthalmichthys nobilis and Hypophthalmichthys molitrix). We also tested for inhibition by high concentrations of exogenous DNA, hypothesizing that DNA from increasingly closely related species would be increasingly inhibitory. All tested inhibitors impacted qPCR, though only at very high concentrations — likely a function, in part, of having used an inhibitor-resistant qPCR solution. Closer phylogenetic relatedness resulted in inhibition at lower exogenous DNA concentrations, but not at relatively close phylogenetic scales. Inhibition was also influenced by the qPCR reporter dye used. Importantly, different qPCR assays responded differently to the same inhibitor concentrations. Implications of these results are that the inclusion of more than one assay for the same target taxa in an eDNA survey may be an important countermeasure against false negatives and that internal positive controls may not, in the absence of efforts to maximize inhibition compatibility, provide useful information about the inhibition of an eDNA assay.

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40

Gaire, Sudip, Coby Schal, Russell Mick y Zachary DeVries. "The Role of Antennae in Heat Detection and Feeding Behavior in the Bed Bug (Hemiptera: Cimicidae)". Journal of Economic Entomology 113, n.º 6 (31 de octubre de 2020): 2858–63. http://dx.doi.org/10.1093/jee/toaa250.

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Abstract The common bed bug (Cimex lectularius L.) is an obligate hematophagous ectoparasite that has significant impacts on human health and well-being. All life stages of bed bugs (except eggs) feed solely on blood, which is required to molt and reproduce. Bed bugs use multiple cues to locate their hosts, including heat, CO2, and body odors. Of these cues, detection of heat appears limited to a short distance of <3 cm. However, it remains unclear if bed bugs can detect radiant heat, what structure(s) are responsible for heat detection, and if heat detection via the antennae is required for feeding. In this study, bed bug response to radiant heat was evaluated using the two-choice T-maze assay with the heat source either in contact with the surface (i.e., conduction) or not in contact (i.e., radiation) in nonantennectomized bed bugs. Further, we systematically ablated the bed bug’s antennal segments (distal tip, first segment, and all four segments) and assessed their responses to heat and feeding in a unique two-choice T-maze assay and individual feeding assays, respectively. Our two-choice assays with contact to or no contact with the surface indicated that bed bugs cannot detect radiant heat. Later, we found that the distal tip of the terminal antennal segment is responsible for orientation toward a heat source. However, >50% of the bed bugs fed even when the entire antenna was removed, suggesting redundancy in sensory cues that drive feeding. These results will be used to better understand the role heat plays in bed bug host attraction and design of traps.

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41

Walenga, Jeanine M., Amanda F. Drenth, Myttle Mayuga, Debra A. Hoppensteadt, Margaret Prechel, Sebastian Harder, Hikari Watanabe, Masanori Osakabe y Hans-Klaus Breddin. "Transition From Argatroban to Oral Anticoagulation With Phenprocoumon or Acenocoumarol: Effect on Coagulation Factor Testing". Clinical and Applied Thrombosis/Hemostasis 14, n.º 3 (19 de junio de 2008): 325–31. http://dx.doi.org/10.1177/1076029607308867.

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Treatment with the thrombin inhibitor argatroban is often followed by vitamin K-antagonist treatment. In this study, the behavior of coagulation factors measured under these treatment regimens is shown. Healthy subjects received infusions of 1.0, 2.0, or 3.0 µg/kg/hr argatroban before and during phenprocoumon or acenocoumarol dosing. Quantitation of factors II, VII, IX, and X by clot-based assays resulted in dose dependent, approximately 20%, lower than expected values in the presence of argatroban. On the contrary, values for the inhibitors, protein C and protein S, were higher. Cotherapy exaggerated the effect by vitamin K-antagonist alone. However, testing by immunologic and chromogenic assays did not show any effect by argatroban. Coupled with a lack of bleeding in the subjects, these data suggests that argatroban does not affect coagulation proteins and that the observations are only an assay artifact. Assay interferences must be considered when measuring coagulation proteins in patients receiving thrombin inhibitors.

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42

Alcalde, Berta, Mercè Granados y Javier Saurina. "Exploring the Antioxidant Features of Polyphenols by Spectroscopic and Electrochemical Methods". Antioxidants 8, n.º 11 (31 de octubre de 2019): 523. http://dx.doi.org/10.3390/antiox8110523.

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This paper evaluates the antioxidant ability of polyphenols as a function of their chemical structures. Several common food indexes including Folin-Ciocalteau (FC), ferric reducing antioxidant power (FRAP) and trolox equivalent antioxidant capacity (TEAC) assays were applied to selected polyphenols that differ in the number and position of hydroxyl groups. Voltammetric assays with screen-printed carbon electrodes were also recorded in the range of −0.2 to 0.9 V (vs. Ag/AgCl reference electrode) to investigate the oxidation behavior of these substances. Poor correlations among assays were obtained, meaning that the behavior of each compound varies in response to the different methods. However, we undertook a comprehensive study based on principal component analysis that evidenced clear patterns relating the structures of several compounds and their antioxidant activities.

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Moseid, Camilla V. S., Tone Falkenhaug y Audun Slettan. "Development of a TaqMan PCR assay for the identification of the non-native copepod Acartia tonsa, and detection of this species in Norwegian coastal waters". Journal of Plankton Research 43, n.º 3 (30 de abril de 2021): 497–99. http://dx.doi.org/10.1093/plankt/fbab029.

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Abstract Molecular based assays for detection of species are a powerful tool to supplement morphological methods that may be time and labor intensive. Here we describe a sensitive TaqMan real time polymerase chain reaction assay that specifically detects the presence of Acartia tonsa in mixed plankton samples. The assay is used to find this non-native copepod in samples collected in Norwegian coastal waters.

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44

Money, David Andrus, Spencer J. Ingley y Jerald B. Johnson. "Divergent predation environment between two sister species of livebearing fishes (Cyprinodontiformes: Poeciliidae) predicts boldness, activity, and exploration behavior". Revista de Biología Tropical 65, n.º 1 (1 de noviembre de 2016): 267. http://dx.doi.org/10.15517/rbt.v65i1.23861.

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Predators can influence a variety of prey traits, including behavior. Traits such as boldness, activity rate, and tendency to explore can all be shaped by predation risk. Our study examines the effects of predation on these behaviors by considering a natural system in which two sister species of livebearing fishes, Brachyrhaphis roseni and B. terrabensis, experience divergent predation environments. In February of 2013, we collected fish in the Río Chiriquí Nuevo drainage, Chiriquí, Panama, and conducted behavioral assays. Using open-field behavioral assays, we evaluated both juveniles and adults, and males and females, to determine if there were differences in behavior between ontogenetic stages or between sexes. We assessed boldness as ‘time to emerge’ from a shelter into a novel environment, and subsequently measured activity and exploration within that novel environment. We predicted that B. roseni (a species that co-occurs with predators) would be more bold, more active, and more prone to explore, than B. terrabensis (a species that does not co-occur with predators). In total, we tested 17 juveniles, 21 adult males, and 20 adult females of B. roseni, and 19 juveniles, 19 adult males, and 18 adult females of B. terrabensis. We collected all animals from streams in Chiriquí, Panama in February 2013, and tested them following a short acclimation period to laboratory conditions. As predicted, we found that predation environment was associated with several differences in behavior. Both adult and juvenile B. roseni were more active and more prone to explore than B. terrabensis. However, we found no differences in boldness in either adults or juveniles. We also found a significant interaction between ‘sex’ and ‘species’ as predictors of boldness and exploration, indicating that predation environment can affect behaviors of males and females differently in each species. Our work demonstrates the importance of considering sex and life history stage when evaluating the evolution of behavior.

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Burckhardt, Bjoern B., Jutta Tins, Sergej Ramusovic y Stephanie Läer. "Tailored Assays for Pharmacokinetic and Pharmacodynamic Investigations of Aliskiren and Enalapril in Children: An Application in Serum, Urine, and Saliva". Journal of Pediatric Pharmacology and Therapeutics 20, n.º 6 (1 de noviembre de 2015): 431–52. http://dx.doi.org/10.5863/1551-6776-20.6.431.

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OBJECTIVES: Drugs that are effectively used to treat hypertension in adults (e.g., enalapril) have not been sufficiently investigated in children. Studies required for pediatric approval require special consideration regarding ethics, study design, and conduct and are also associated with special demands for the bioanalytic method. Pediatric-appropriate assays can overcome these burdens and enable systematic investigations of pharmacokinetics and pharmacodynamic in all pediatric age groups. METHODS: Tailored assays were developed for pharmacokinetic investigation of a drug in 100 μL of serum, saliva, and urine. All assays were applied in a proof-of-concept study to 22 healthy volunteers who had been given 300 mg aliskiren hemifumarate or 20 mg enalapril maleate and allowed for dense sampling. Changes in humoral parameters of the renin-angiotensin-aldosterone system were also evaluated with 6 parameters in 2.1 mL blood per time point. RESULTS: The pharmacokinetic results of aliskiren and enalapril obtained by low-volume assays in serum and urine were comparable to that noted in the literature. The dense sampling enabled very detailed concentration-time profiles that showed high intersubject variability and biphasic absorption behavior of aliskiren. The replacement of invasive sampling by saliva collection appears inappropriate for both drugs because the correlations of drug concentrations in both fluids were low. A low-volume assay was also used to determine values for in the renin-angiotensin-aldosterone system and to compare those results with the published literature. CONCLUSION: These results support both the use of low-volume assays in pediatric research and the systematic investigation of their use in neonates and infants. Use of this assay methodology will increase information about drug pharmacokinetics and pharmacodynamics in this vulnerable population and might contribute to safe and effective use of pharmacotherapy.

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46

Jamalova, Dilafruz N., Haidy A. Gad, Davlat K. Akramov, Komiljon S. Tojibaev, Nawal M. Al Musayeib, Mohamed L. Ashour y Nilufar Z. Mamadalieva. "Discrimination of the Essential Oils Obtained from Four Apiaceae Species Using Multivariate Analysis Based on the Chemical Compositions and Their Biological Activity". Plants 10, n.º 8 (26 de julio de 2021): 1529. http://dx.doi.org/10.3390/plants10081529.

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The chemical composition of the essential oils obtained from the aerial parts of four Apiaceae species, namely Elaeosticta allioides (EA), E. polycarpa (EP), Ferula clematidifolia (FC), and Hyalolaena intermedia (HI), were determined using gas chromatography. Altogether, 100 volatile metabolites representing 78.97, 81.03, 85.78, and 84.49% of the total components present in EA, EP, FC, and HI oils, respectively, were reported. allo-Ocimene (14.55%) was the major component in FC, followed by D-limonene (9.42%). However, in EA, germacrene D (16.09%) was present in a high amount, while heptanal (36.89%) was the predominant compound in HI. The gas chromatographic data were subjected to principal component analysis (PCA) to explore the correlations between these species. Fortunately, the PCA score plot could differentiate between the species and correlate Ferula to Elaeosticta species. Additionally, the antioxidant activity was evaluated in vitro using the 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH), 2,2-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) (ABTS), and the ferric reducing power (FRAP) assays. In addition, the antimicrobial activity using the agar diffusion method was assessed, and the minimum inhibitory concentrations (MICs) were determined. Furthermore, the cell viability MTT assay was performed to evaluate the cytotoxicity of the essential oils against hepatic (HepG-2) and cervical (HeLa) cancer cell lines. In the DPPH assay, FC exhibited the maximum activity against all the antioxidant assays with IC50 values of 19.8 and 23.0 μg/mL for the DPPH and ABTS assays, respectively. Ferula showed superior antimicrobial and cytotoxic activities as well. Finally, a partial least square regression model was constructed to predict the antioxidant capacity by utilizing the metabolite profiling data. The model showed excellent predictive ability by applying the ABTS assay.

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Min, Yu Yu, Keita Goto, Koki Toyota y Erika Sato. "A multiplex real-time PCR assay for the simultaneous quantification of the major plant-parasitic nematodes in Japan". Nematology 13, n.º 6 (2011): 713–20. http://dx.doi.org/10.1163/138855410x543175.

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AbstractMultiplex real-time PCR assays were developed to quantify multiple species of Meloidogyne incognita, Pratylenchus penetrans, Globodera rostochiensis and Heterodera glycines in soil. The probes specific for P. penetrans and H. glycines are labelled with a fluorescence molecule, FAM, and those for M. incognita and G. rostochiensis with ROX. The primers and probes are species-specific to P. penetrans, but group-specific to the other species. DNA was extracted from suspensions containing each nematode and multiplex Cycleave® PCR assays were done for pairs of P. penetrans and M. incognita, P. penetrans and G. rostochiensis, or G. rostochiensis and H. glycines. The results revealed that the target nematode, except for H. glycines, was quantified in the presence of less than 100 times that of the other nematode (competitor), but underestimated in the presence of 1000 times the competitor. Such underestimation was solved by the use of SYBR Green I real time PCR assays targeting a single species. Multiplex PCR assay for P. penetrans and M. incognita was done using environmental DNA (eDNA) extracted from a soil naturally infested with the nematodes. Results quantified both species. Multiplex assay using eDNA may enable a sensitive and simultaneous detection of P. penetrans and M. incognita or P. penetrans and G. rostochiensis in soil although caution is needed in case the existing ratio is biased to one of the species.

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Majeed, Zana, Felicitas Koch, Joshua Morgan, Heidi Anderson, Jennifer Wilson y Robin L. Cooper. "A novel educational module to teach neural circuits for college and high school students: NGSS-neurons, genetics, and selective stimulations". F1000Research 6 (8 de febrero de 2017): 117. http://dx.doi.org/10.12688/f1000research.10632.1.

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This report introduces various approaches to target defined neural pathways for stimulation and to address the effect of particular neural circuits on behavior in a model animal, the fruit fly (Drosophila melanogaster). The objective of this novel educational module described can be used to explain and address principle concepts in neurobiology for high school and college level students. A goal of neurobiology is to show how neural circuit activity controls corresponding behavior in animals. The fruit fly model system provides powerful genetic tools, such as the UAS-Gal4 system, to manipulate expression of non-native proteins in various populations of defined neurons: glutamergic, serotonergic, GABAergic, and cholinergic. The exhibited behaviors in the examples we provide allows teachers and students to address questions from behaviors to details at a cellular level. We provided example sets of data, obtained in a research lab, as well as ideas on ways to present data for participants and instructors. The optogenetic tool, channelrhodpsin 2 (ChR2), is employed to increase the activity of each population of neurons in a spatiotemporal controlled manner in behaving larvae and adult flies. Various behavioral assays are used to observe the effect of a specific neuron population activation on crawling behavior in larvae and climbing behavior in adult flies. Participants using this module become acquainted with the actions of different neurotransmitters in the nervous system. A pre- and post- assessment survey on the content is provided for teachers, as templates, to address learning of content and concepts.

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Liu, Hua, Zhongju Ye, Xin Wang, Lin Wei y Lehui Xiao. "Molecular and living cell dynamic assays with optical microscopy imaging techniques". Analyst 144, n.º 3 (2019): 859–71. http://dx.doi.org/10.1039/c8an01420e.

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Compared with the conventional ensemble averaged measurements, single object analysis with optical microscopy can obtain the heterogeneous behavior of many individual objects, avoiding false judgment. Moreover, higher spatial and temporal resolution has been achieved by various optical imaging technologies.

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50

Wotton, Janine M., Emma Peterson, Laura Anderson, Stephen A. Murray, Robert E. Braun, Elissa J. Chesler, Jacqueline K. White y Vivek Kumar. "Machine learning-based automated phenotyping of inflammatory nocifensive behavior in mice". Molecular Pain 16 (enero de 2020): 174480692095859. http://dx.doi.org/10.1177/1744806920958596.

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The discovery and development of new and potentially nonaddictive pain therapeutics requires rapid, yet clinically relevant assays of nociception in preclinical models. A reliable and scalable automated scoring system for nocifensive behavior of mice in the formalin assay would dramatically lower the time and labor costs associated with experiments and reduce experimental variability. Here, we present a method that exploits machine learning techniques for video recordings that consists of three components: key point detection, per frame feature extraction using these key points, and classification of behavior using the GentleBoost algorithm. This approach to automation is flexible as different model classifiers or key points can be used with only small losses in accuracy. The adopted system identified the behavior of licking/biting of the hind paw with an accuracy that was comparable to a human observer (98% agreement) over 111 different short videos (total 284 min) at a resolution of 1 s. To test the system over longer experimental conditions, the responses of two inbred strains, C57BL/6NJ and C57BL/6J, were recorded over 90 min post formalin challenge. The automated system easily scored over 80 h of video and revealed strain differences in both response timing and amplitude. This machine learning scoring system provides the required accuracy, consistency, and ease of use that could make the formalin assay a feasible choice for large-scale genetic studies.

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