28-day Mortality
28-day Mortality - Related Videos
03:57
Assessing Pathogenic Bacteria–Induced Mortality in C. elegans Larvae
0 Views •
2025
Source: Anderson, Q. L., et al. A High-throughput, High-content, Liquid-based C. elegans Pathosystem. J. Vis. Exp. (2018)The video demonstrates a liquid-based assay where genetically modified C. elegans larvae are exposed to pathogenic bacteria in a microplate. Bacterial toxins secreted into the medium induce host stress and death. A fluorescent dye stains dead worms, allowing imaging-based quantification of mortality to assess genetic susceptibility or resistance.
03:56
Mosquito Feeding Assay: A Method to Evaluate Test Compound Effects on Mortality and Fecundity of Adult Female Mosquitoes
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2025
This video demonstrates a blood-feeding assay to evaluate the mortality and fecundity of test compounds with novel modes of action on female mosquitoes. This technique helps in screening new classes of insecticides to kill the resistant population of mosquitoes and control disease spread.
07:03
Reliable Method for Assessing Seed Germination, Dormancy, and Mortality under Field Conditions
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Cited by 5 •
2016
Here we present a protocol for assessing seed survivorship, germination and dormancy under field conditions using buried, labeled seed strips and tetrazolium chloride (TZ) viability testing.
11:16
Isolation of Protoplasts from Tissues of 14-day-old Seedlings of Arabidopsis thaliana
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Cited by 59 •
2009
This video shows a procedure for isolating intact protoplasts from tissues of 14-day-old seedlings of Arabidopsis. Given that the isolated protoplasts remain intact for at least 96h and are isolated from seedlings instead of one-month-old mature plants, this procedure expedites assays requiring intact protoplasts.
03:55
Larval Contact Assay: A Procedure to Evaluate Mosquito Larval Mortality following Direct Contact with Test Larvicidal Compound
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2025
In this video, we describe the larval contact assay to evaluate the toxicity of the dopamine receptor antagonist amitriptyline on the third instar stage larvae of mosquitoes, known vectors of several human infectious diseases. Assessing the larval mortality upon incubation with different amitriptyline concentrations over different time intervals helps determine its lethal concentration 50.
FAQs
Selecting time zero determines when the observation clock begins and therefore which deaths are attributed to the 28-day outcome. A diagnosis-based start differs conceptually from one anchored to admission, treatment, or onset of an acute illness. Consistent selection within a study helps ensure that participants have comparable opportunity for follow-up and that reported results answer the intended clinical question.
The percentage alone does not establish that one intervention is superior. Interpretation depends on who was enrolled, the acute disease being studied, the chosen starting point, and whether the groups were observed and assessed in comparable ways. A higher or lower 28-day mortality may reflect differences in population or clinical context rather than the treatment effect the comparison seeks to measure.
Recording whether deaths occurred, and how completely outcomes were ascertained, affects what the endpoint represents. Cause of death can help distinguish the clinical relevance of observed deaths, while incomplete ascertainment can make the reported proportion less dependable. These considerations are especially important when studies compare prognosis or treatment performance across populations or settings.
Standardized follow-up applies the same 28-day observation rule to each participant, making proportions more directly comparable across study groups. It also clarifies whether a reported difference reflects variation in outcomes rather than variation in how long or consistently participants were monitored. This supports clearer evaluation of acute illness prognosis and interventions.
A study should specify the event that counts as death, the clinical starting point, and the 28-day follow-up period. Investigators then track participants through that window and document deaths using a consistent approach to outcome ascertainment. Stating these elements allows readers to understand what the measure captures and judge whether comparisons between groups are appropriate.
The measure is expressed as the proportion of participants who die during the defined 28-day window. To compare groups, investigators calculate that proportion separately for each group and examine the resulting difference in the context of the study population and starting point. This provides a concise short-term outcome for clinical trials and acute-disease studies.
In medicine, this endpoint is used in clinical trials, critical care, and research on acute diseases. It can summarize short-term prognosis or support assessment of treatment effectiveness, provided investigators interpret it alongside the population, starting point, cause of death, and completeness of outcome ascertainment information.