Expansion Pathology
Expansion Pathology - Related Videos
04:14
Expansion Pathology: A Method for High-resolution Optical Imaging of Clinical Tissue Samples
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2023
In this video, we describe a method called expansion pathology, a variant of expansion microscopy, wherein the clinical tissue specimens are chemically expanded using a polymer network for microscopic examination of nanoscale structures.
09:42
Analysis of Thermal Expansion via Dilatometry
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2023
Source: J. Jacob Chavez, Ryan T. Davis, and Taylor D. Sparks, Department of Materials Science and Engineering, The University of Utah, Salt Lake City, UT Thermal expansion is extremely important when considering which materials will be used in systems that experience fluctuations in temperature. A high or low thermal expansion in a material may or may not be desirable, depending on the application. For instance, in a common liquid thermometer, a material with a high thermal expansion would be...
08:29
Symmetric Bihemispheric Postmortem Brain Cutting to Study Healthy and Pathological Brain Conditions in Humans
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Cited by 7 •
2016
Organized brain cutting procedures are necessary to correlate specific neuropsychiatric phenomena with definitive neuropathologic diagnoses. Brain cuttings are performed differently based on various clinico-academic contingencies. This protocol describes a symmetric bihemispheric brain cutting procedure to investigate hemispheric differences in human brain pathologies and to maximize current and future biomolecular/neuroimaging techniques.
01:24
Evaluating the Effect of a Synbiotic Formulation on Alzheimer’s Disease Pathology in Drosophila
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2025
Take a transgenic Drosophila.The brain of the Drosophila expresses the human amyloid peptide protein or APP and a cleaving enzyme.The enzyme cleaves APP, enabling the formation of beta-amyloid plaque, which leads toAlzheimer's disease or AD pathology in Drosophila.Feed the Drosophila AD model a diet containing a synbiotic formulation.The formulation contains a combination of three bioactive probiotic bacteria and a prebiotic.Inside the fly's gut, the prebiotic supports the growth and survival...
01:24
Heat and Free Expansion
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2023
The work done by a thermodynamic system depends not only on the initial and final states but also on the intermediate states—that is, on the path. Like work, when heat is added to a thermodynamic system, it undergoes a change of state, and the state attained depends on the path from the initial state to the final state. Consider an ideal gas cylinder fitted with a piston. When the cylinder is heated at a constant temperature, the gas molecules absorb energy and expand slowly in a controlled...
FAQs
During replication or repair, unstable tandem repeats can gain additional units, and an expansion becomes disease-associated when it crosses a relevant threshold. The resulting change may interfere with gene expression, alter RNA processing, or create a toxic protein. This explains why the same underlying DNA instability can produce different molecular effects across inherited disorders.
The clinical consequence depends on how the expanded sequence affects the gene or its RNA and protein products. Some disorders primarily reflect reduced or abnormal gene expression, whereas others involve disrupted RNA processing or toxic proteins. These mechanisms help connect a repeat expansion to disease manifestations without assuming that all expansion disorders operate through the same pathway.
Genetic anticipation means that repeat length may increase across generations. In clinical families, this pattern can help explain why disease appears at a younger age or with greater severity in later generations, although the observed phenotype remains variable. Recognizing anticipation supports family risk assessment and interpretation of apparently changing disease patterns.
Repeat-primed PCR is useful for detecting a repeat expansion, while long-read sequencing can characterize expanded regions that standard sequencing may miss. These approaches address a limitation of conventional sequence analysis: repetitive DNA can be difficult to evaluate directly. Choosing an appropriate test therefore improves molecular diagnosis in suspected expansion-related disease.
Consider expansion-focused evaluation when an inherited neurological, muscular, or multisystem disorder remains unexplained and the suspected change lies in repetitive DNA. Standard sequencing may fail to identify such expansions, so repeat-primed PCR or long-read sequencing can provide complementary evidence. The result may clarify diagnosis and guide assessment of familial risk.
Expansion pathology has clinical value beyond confirming a molecular diagnosis. Identifying the repeat change can help clinicians assess familial risk and interpret why affected individuals differ in age of onset or disease severity. This is especially relevant when evaluating neurological, muscular, or multisystem genetic disease, where variable presentation can complicate recognition.