Comet Tail Research Articles

Cross-Sectional Descriptive Study of the Utility of Dermoscopy in Assessing the Activity and Stability of Vitiligo

Introduction: Dermoscopy is an important noninvasive tool that helps to determine the stability and activity of vitiligo. Various dermoscopic findings help classify the disease as stable or unstable. This is important for the management of the disease, as surgical management requires disease stability. Objectives: We aimed to describe the dermoscopic findings in vitiligo and to assess the frequency of various dermoscopic findings in stable and unstable vitiligo. Methods: This was a hospital-based, cross-sectional, descriptive study of 100 vitiligo patients and various dermoscopic findings. Results are expressed as percentages. Results: The most common dermoscopic findings in stable vitiligo patches were sharp border, marginal and perifollicular pigmentation, and reticulate pigment network. Findings such as polka dot appearance, starburst appearance, comet tail, and satellite lesions were seen in unstable vitiligo patches. Conclusions: Dermoscopy is extremely helpful in determining the stability of vitiligo patches.

Simulating overtaking interactions of dust-acoustic N-shock waves in oppositely charged dusty plasmas with Q-distributed electrons

Simulating overtaking interactions (OIs) of dust-acoustic N-shock waves (DANSWs) in dust plasmas with opposite polarities and q-distributed electrons and Boltzmann distributed ions are examined in this work. Reductive perturbation theory is used to obtain a Burgers’ equation (BE), and dust-acoustic N-shock wave solutions are derived using the Cole-Hopf transformation and exponential function. Numerical simulations show that the evolution and OIs of DANSWs and their electric fields are modified by the effects of negative/positive dust fluid kinematic viscosity, the ratio of negative dust to positive dust mass, and the nonextensive q-distribution of electrons. This work may help explain the properties of dust-acoustic shock waves in cometary tails and Jupiter's magnetosphere that support the propagation of nonlinear waves.

A comparative study of the blue comets C/1908 R1 (Morehouse) and C/2016 R2 (Pan-STARRS)

The long-period comet C/1908 R1 (Morehouse) is distinguished by its early spectroscopic tail photography, which uncovered notably intense emission bands of N2+ and CO+ similar to the unusual characteristics of the atypical blue comet C/2016 R2 (Pan-STARRS). To probe potential parallels with C/2016 R2 further, we revisited the historical spectroscopic plates of C/1908 R1 while leveraging the New Astrometric Reduction of Old Observations (NAROO) project's advanced sub-micrometric scanner. We first reviewed the intensity ratio method, followed by a comprehensive spectroscopic analysis of the original historical plates to determine the comet's composition. Our analysis also encompassed an evaluation of C/1908 R1's dynamic trajectory using an N-body integrator and a detailed examination of tail morphology records. Our findings suggest that C/1908 R1 experienced no significant close encounters as it crossed the inner Solar System, anchoring its origins directly in the Oort Cloud and allowing us to ascertain that this was its inaugural voyage near the Sun. We determined a N2+ CO+ ratio of $ along with a dust-poor composition, particularities it shares with C/2016 R2. Moreover, by synthesizing observations of the tail's structure over the three-month period of visibility, we uncovered a link between tail dislocation events and aurora borealis sightings on Earth. This association underscores the comet tail’s heightened sensitivity to solar wind fluctuations due to its volatile makeup. The comet C/1908 R1 (Morehouse) emerges as one of the most unaltered relics of our Solar System's formation, offering another instance of a C/2016 R2-analogous comet. This underscores the importance of preserving and reexamining historical astronomical datasets, not only for historical significance but as a critical resource for contemporary scientific advancement.

Effect of CAT gene polymorphism on sensitivity of human lymphocytes to genotoxic effect of organochlorine pesticide in vitro

Introduction. Over recent decades, toxicogenetic studies have focused on the issues of genome instability under the action of genotoxicants, taking into account biomarkers of sensitivity. The question about the genotoxic potential of chlorpyrifos remains open, since both positive and negative effects have been revealed in various tests. The aim of the study is the investigation of sensitivity of donor peripheral blood lymphocytes to chlorpyrifos in vitro and evaluation of the contribution of polymorphism of antioxidant defense system genes (CAT (rs1001179), SOD2 (rs4880)) to the response of human cells to the action of genotoxicant. Materials and methods. The DNA damaging effect of chlorpyrifos was assessed on lymphocytes from fifty two donors using DNA-comet assay with metabolic activation (+S9) and without it (–S9). The study of cytotoxic effects of chlorpyrifos on human lymphocytes was carried out using an automatic fluorescent cell analyzer ADAMII LS. Results. Chlorpyrifos had a pronounced cytotoxic effect on lymphocytes in most donors in the absence of metabolic activation system. With increasing concentration of the pesticide in the medium and time of cultivation, the viability of lymphocytes decreased, and the proportion of cells in late apoptosis and necrosis increased. Positive genotoxic effects were found on the cells of 33 donors (-S9). In the presence of the S9, mild but statistically significant effects were detected only on cells from 2 donors. % DNA values in the comet tail after exposure to the pesticide varied for cells from different donors. In the absence of metabolic activation, a statistically significant increase in the level of DNA damage was found in cells of individuals with genotype AA (homozygote for the minor allele) for the CAT G262A catalase gene (rs1001179), compared with homozygote for the dominant GG allele. Limitations. The genotoxicity of chlorpyryfos was studied in vitro. Conclusion. The results of the study shown cytotoxic and genotoxic effects of chlorpyrifos. The sensitivity of lymphocytes from different donors to the pesticide was found to be significantly different. The association of the level of DNA damage under exposure of chlorpyrifos in vitro with the G262A polymorphism of the catalase gene was found. The research also confirms the possibility of using a model test-system with peripheral blood lymphocytes to assess the potential genetic risk for humans and to study the contribution of gene polymorphism to individual sensitivity to the action of genotoxicants.

Hidden comet tails of marine snow impede ocean-based carbon sequestration.

Gravity-driven sinking of "marine snow" sequesters carbon in the ocean, constituting a key biological pump that regulates Earth's climate. A mechanistic understanding of this phenomenon is obscured by the biological richness of these aggregates and a lack of direct observation of their sedimentation physics. Utilizing a scale-free vertical tracking microscopy in a field setting, we present microhydrodynamic measurements of freshly collected marine snow aggregates from sediment traps. Our observations reveal hitherto-unknown comet-like morphology arising from fluid-structure interactions of transparent exopolymer halos around sinking aggregates. These invisible comet tails slow down individual particles, greatly increasing their residence time. Based on these findings, we constructed a reduced-order model for the Stokesian sedimentation of these mucus-embedded two-phase particles, paving the way toward a predictive understanding of marine snow.

Citizen Scientists Discover “Asteroid in a Cometary Orbit” 2010 MK43 has a Comet Tail

We present the discovery of a short, diffuse tail on minor planet 2010 MK43 (alternate designation 2010 RA78)—an object previously identified as an asteroid in a cometary orbit—by volunteers of our Citizen Science program Active Asteroids. Our follow-up investigation revealed eight Dark Energy Camera images showing 2010 MK43 with a tail spanning UT 2024 February 12–UT 2024 February 18 when the object was outbound from perihelion. We now classify 2010 MK43 as a Jupiter-family comet based on its Tisserand parameter with respect to Jupiter T J = 2.888, though our dynamical simulations reveal that, due to frequent close encounters with Jupiter, 2010 MK43 was likely a quasi-Hilda within the last 10 kyr.

Myosin-I synergizes with Arp2/3 complex to enhance the pushing forces of branched actin networks.

Class I myosins (myosin-Is) colocalize with Arp2/3 complex-nucleated actin networks at sites of membrane protrusion and invagination, but the mechanisms by which myosin-I motor activity coordinates with branched actin assembly to generate force are unknown. We mimicked the interplay of these proteins using the "comet tail" bead motility assay, where branched actin networks are nucleated by the Arp2/3 complex on the surface of beads coated with myosin-I and nucleation-promoting factor. We observed that myosin-I increased bead movement efficiency by thinning actin networks without affecting growth rates. Myosin-I triggered symmetry breaking and comet tail formation in dense networks resistant to spontaneous fracturing. Even with arrested actin assembly, myosin-I alone could break the network. Computational modeling recapitulated these observations, suggesting myosin-I acts as a repulsive force shaping the network's architecture and boosting its force-generating capacity. We propose that myosin-I leverages its power stroke to amplify the forces generated by Arp2/3 complex-nucleated actin networks.

Teaching NeuroImage: Imaging in VAC14-Associated Neurodegeneration With Brain Iron Accumulation Resembles a Comet Tail.

Teaching NeuroImage: Imaging in VAC14-Associated Neurodegeneration With Brain Iron Accumulation Resembles a Comet Tail.

Process Parameters Optimization and Numerical Simulation of AlCoCrFeNi High-Entropy Alloy Coating via Laser Cladding.

The use of laser cladding technology to prepare coatings of AlCoCrFeNi high-entropy alloy holds enormous potential for application. However, the cladding quality will have a considerable effect on the properties of the coatings. In this study, considering the complex coupling relationship between cladding quality and the process parameters, an orthogonal experimental design was employed, with laser power, scanning speed, and powder feed rate as correlation factor variables, and microhardness, dilution rate, and aspect ratio as characteristic variables. The experimental data underwent gray correlation analysis to determine the effect of various process parameters on the quality of cladding. Then, the NSGA-II algorithm was used to establish a multi-objective optimization model of process parameters. Finally, the ANSYS Workbench simulation model was employed to conduct numerical simulations on a group of optimized process parameters and analyze the change rule of the temperature field. The results demonstrate that the laser cladding coating of AlCoCrFeNi high-entropy alloy with the single pass is of high quality within the determined orthogonal experimental parameters. The powder feed rate exerts the most significant influence on microhardness, while laser power has the greatest impact on dilution rate, and scanning speed predominantly affects aspect ratio. The designed third-order polynomial nonlinear regression model exhibits a high fitting accuracy, and the NSGA-II algorithm can be used for multi-objective optimization to obtain the Pareto front solution set. The numerical simulation results demonstrate that the temperature field of AlCoCrFeNi high-entropy alloy laser cladding exhibits a "comet tail" phenomenon, where the highest temperature of the molten pool is close to 3000 °C. The temperature variations in the molten pool align with the features of laser cladding technology. This study lays the groundwork for the widespread application of laser cladding AlCoCrFeNi high-entropy alloy in surface engineering, additive manufacturing, and remanufacturing. Researchers and engineering practitioners can utilize the findings from this research to judiciously manage processing parameters based on the results of gray correlation analysis. Furthermore, the outcomes of multi-objective optimization can assist in the selection of appropriate process parameters aligned with specific application requirements. Additionally, the methodological approach adopted in this study offers valuable insights applicable to the exploration of various materials and diverse additive manufacturing techniques.

On the generation of force required for actin-based motility

The fundamental question of how forces are generated in a motile cell, a lamellipodium, and a comet tail is the subject of this note. It is now well established that cellular motility results from the polymerization of actin, the most abundant protein in eukaryotic cells, into an interconnected set of filaments. We portray this process in a continuum mechanics framework, claiming that polymerization promotes a mechanical swelling in a narrow zone around the nucleation loci, which ultimately results in cellular or bacterial motility. To this aim, a new paradigm in continuum multi-physics has been designed, departing from the well-known theory of Larché–Cahn chemo-transport-mechanics. In this note, we set up the theory of network growth and compare the outcomes of numerical simulations with experimental evidence.

Abstract Mo036: DNA Damage and Repair in Patients Undergoing Myocardial Perfusion Single-Photon Emission Computed Tomography

Background: As medical imaging has continuously grown, patient exposure to ionizing radiation and the risks associated with it are important issues. Myocardial perfusion single-photon emission computed tomography (MP-SPECT) is one of the most frequently performed noninvasive cardiac imaging tests, generating concern about the potentially excessive radiation exposure for patients, including the cumulative doses of lifetime radiation. even though the individual levels of radiation exposure are considered low. Aim: To evaluate DNA damage and DNA repair markers after MP-SPECT. Methods: Thirty-two patients undergoing Tc-99m sestamibi MP-SPECT (mean injected Tc-99m sestamibi dose: 15.1 mCi) were studied. Peripheral blood was collected before radiotracer injection at rest and 60-90 minutes after injection. The comet assay (single-cell gel electrophoresis) was performed with blood lymphocytes to detect DNA strand breaks, which appear as DNA fragmentation (the comet tail; Figure1). Images of fluorescence microscopy were analyzed using the Comet Assay Software Project Lab (CASPLab 1.2.3 beta 2). Three parameters were evaluated: the percentage of DNA in the comet tail, tail length, and tail moment (the measure of migratory DNA and number of fragments). Quantitative PCR (qPCR) was performed to evaluate the expression of five genes related to signaling pathways in response to DNA damage and repair (ATM, ATR, BRCA1, CDKN1A, XPC). Data are expressed as medians, and Wilcoxon or Mann-Whitney tests were employed for statistical analysis. A p-value <0.05 was considered statistically significant. Results: Figure 2 shows pre- and post- radiation exposure comet assay parameters. After radiotracer injection, there was a 10.7% increase of the DNA percentage in the tail (pre-exposure median 2.185 vs post-exposure median 2.418, p<0.0065). Tail length increased 6.7% (15.0 pre-exposure vs 16.0 post-exposure, p<0.0034). Tail moment increased 27.5% (0.3177 pre-exposure vs 0.4050 post-exposure, p<0.0001). qPCR did not reveal increased expression of any gene after radiation exposure. Conclusion: An increase in DNA damage was detected after a single radiotracer injection for MP-SPECT, yet unaccompanied by activation of repair genes. This may suggest that DNA damage is not large enough to trigger intense repair responses and might not result in biologically significant DNA damage.

Numerical simulations of exocomet transits: Insights from β Pic and KIC 3542116

In recent years, the topic of existence and exploration of exocomets has been gaining increasing attention. The asymmetrical decrease in the star’s brightness due to the passage of a comet-like object in front of the star was successfully predicted. It was subsequently confirmed on the basis of the light curves of stars observed by Kepler and TESS orbital telescopes. Since then, there have been successful attempts to fit the asymmetrical dips observed in the stars’ light curves utilizing a simple 1D model of an exponentially decaying optically thin dust tail. In this work, we propose fitting the photometric profiles of some known exocomet transits based on a Monte Carlo approach to build up the distribution of dust particles in a cometary tail. As the exocomet prototypes, we used the physical properties of certain Solar System comets belonging to the different dynamical groups and moving at heliocentric distances of 0.6 au, 1.0 au, 5.0 au, and 5.5 au. We obtained a good agreement between the observed and modeled transit light curves. We also show that the physical characteristics of dust particles, such as the particle size range, the power index of dust size distribution, the particle terminal velocity, and distance to the host star affect the shape of the transit light curve, while the dust productivity of the comet nucleus and the impact parameter influence its depth and duration. The estimated dust production rates of the transiting exocomets are at the level of the most active Solar System comets.

Exocomet Models in Transit: Light Curve Morphology in the Optical—Near Infrared Wavelength Range

Following the widespread practice of exoplanetary transit simulations, various presumed components of an extrasolar system can be examined in numerically simulated transits, including exomoons, rings around planets, and the deformation of exoplanets. Template signals can then be used to efficiently search for light curve features that mark specific phenomena in the data, and they also provide a basis for feasibility studies of instruments and search programs. In this paper, we present a method for exocomet transit light curve calculations using arbitrary dust distributions in transit. The calculations, spanning four distinct materials (carbon, graphite, pyroxene, and olivine), and multiple dust grain sizes (100–300 nm, 300–1000 nm, and 1000–3000 nm) encompass light curves in VRJHKL bands. We also investigated the behavior of scattering colors. We show that multicolor photometric observations are highly effective tools in the detection and characterization of exocomet transits. They provide information on the dust distribution of the comet (encoded in the light curve shape), while the color information itself can reveal the particle size change and material composition of the transiting material, in relation to the surrounding environment. We also show that the typical cometary tail can result in the wavelength dependence of the transit timing. We demonstrate that multi-wavelength observations can yield compelling evidence for the presence of exocomets in real observations.

Solar Wind Interactions with Comet C/2021 A1 Using STEREO HI and a Data-assimilative Solar Wind Model

Cometary tails display dynamic behavior attributed to interactions with solar wind structures. Consequently, comet-tail observations can serve as in situ solar wind monitors. During 2021 December, Comet Leonard (C/2021 A1) was observed by the STEREO-A heliospheric imager. The comet tail exhibited various signatures of interactions with the solar wind including bending, kink formation, and finally complete disconnection. In this study, we compare the timing of these events with solar wind structures predicted by the Heliospheric Upwind eXtrapolation model with a time-dependency (or HUXt) solar wind model using new solar wind data assimilation (DA) techniques. This serves both to provide the most accurate solar wind context to interpret the cometary processes, but also as a test of the DA and an example of how comet observations can be used in model validation studies. Coronal mass ejections, stream interaction regions (SIRs), and heliospheric current sheet (HCS) crossings were all considered as potential causes of the tail disconnection. The results suggest the tail disconnection at Comet Leonard was the result of it crossing the HCS and into an SIR. The timing of these features agree better with the DA model results than the non-DA model, showing the value of this approach. Case studies such as this expand our understanding of comet–solar wind interactions, and in demonstrating the utility of DA for solar wind modeling. We note that this could lead to comets acting as additional in situ measures for solar wind conditions for regions where no in situ spacecraft are available, potentially improving solar wind DA in the future.

Genotoxic effects in blood cells of sturger (Acipenseridae) grown in conditions of cage farming of the Volga delta, Russia

The purpose of this work was to assess the degree of genotoxic influence of the habitat on individuals of Russian sturgeon and sterlet raised in cage farming conditions in the Volga delta, using micronucleus and DNA comet tests.The blood of the individual Russian sturgeon and sterlet was shaved off during their lifetime. A comet DNA test was performed using the alkaline method. The number of erythrocytes with micronuclei was determined microscopically. To assess the physiological state of sturgeons, conventional hematological and biochemical methods were used.In the samples of fish blood smears studied, the average proportion of erythrocytes with micronuclei was 3.20 ± 1.24 ‰ in Russian sturgeon and 5.25 ± 1.18 ‰ in sterlet. The proportion of DNA in the comet tail in erythrocytes of Russian sturgeon was 3,99 %, and in sterlet 6, 48 %. The values of tail moment and Olivet moment were also lower in Russian sturgeon. Among sterlet erythrocytes, a more heterogeneous pattern of DNA damage can be noted. The length of the comet tail in starlet individuals turned out to be lower than in Russian sturgeon: apparently, larger fragments of these molecules were formed when the DNA of starlet erythrocytes was damaged. The physiological state of sterlet individuals can be characterised as normal, and that of the Russian sturgeon as satisfactory, due to the deviations identified in the values of some hematological and biochemical blood parameters.Having studied the influence of the environment on individual sturgeon kept in cage aquaculture conditions in the Volga delta using micronuclear and DNA comet tests, we can conclude that there was no acute genotoxic effect at the time of the study.

The role of upper airway ultrasonography in tracheal necrosis diagnosis: a case report

BackgroundTracheal necrosis post endotracheal intubation is a rare life-threatening disease that can compromise airway patency. We demonstrated a novel usage of upper airway ultrasonography (USG) to diagnose tracheal necrosis.Case presentationA middle-aged smoking male presented with productive cough, noisy breathing and exertional dyspnea for 2 weeks. He was intubated one month prior due to a traumatic brain injury. Upper airway USG findings showed irregular air-mucosal interface (AMI) and comet tail artefacts over the 1st and 2nd tracheal ring. A direct laryngoscopy in the operating room showed thick mucopus inferior to the vocal cords, with necrotic tracheal cartilages and debris obstructing the airway. He was successfully treated with parenteral antibiotics, wound debridement and tracheostomy.ConclusionOur case highlights the first documented USG findings of tracheal necrosis. Upper airway USG serves as a potential diagnostic modality in managing the condition.

Ultrasound Sonography Features of the Thyroid Papillary Carcinoma in West Azerbaijan Province, Iran

Objectives: The most frequent form of thyroid cancer (TC) is papillary thyroid carcinoma (PTC), which has been significantly increasing worldwide. This study aimed to determine the relative frequency of various sonographic PTC findings in the West Azerbaijan Province, Iran. Methods: In this retrospective study, the ultrasonic features of 67 patients with proven PTC, confirmed by pathology, were analyzed. The sonographic features were categorized into low-risk (hyperechoic echogenicity, macrocalcification, peripheral vascularity, puff appearance, spongy form nodule, comet tail shadowing) and high-risk (irregular margin, hypoechoic echogenicity, microcalcification, central vascularity, taller-than-wide shape, twinkling, two-lobe nodule, neck lymphadenopathy) PTC features. Results: The frequency of hypoechoic echogenicity was higher in both genders (81.8% in males and 72.5% in females) and among three groups of ages (P=0.55). Microcalcification had a higher frequency in both genders (65.4 in males and 65.5 in females) and in two age groups of 20-45 and more than 45 years (68.3% and 66.7%, respectively) (P=0.4 and P=0.99, respectively). Central vascularity was more frequent in men (61.5%), and peripheral vascularity was more frequent among females (57.1%) and in two age groups of 20-45 and more than 45 years (68.3% and 66.7%, respectively) (P=0.41). Also, taller-than-wide shape had a high frequency in males (20%). Sponginess, puff appearance, and comet tail had the same frequency among the three age groups. In the age group under 20 years, peripheral incomplete halo had a high frequency (17.8%). Discussion: The appearance of high-risk papillary carcinoma sonographic features is typical in PTC patients. Moreover, low-risk sonographic PTC features occur more often than expected in our patients. We can infer that the frequency of PTC ultrasonography features in the West Azerbaijan Province of Iran can be due to iodine deficiency due to being far from the sea and the lack of easy access to seafood.

DNA damage and repair in patients undergoing myocardial perfusion single-photon emission computed tomography

As patient exposure to ionizing radiation from medical imaging and its risks are continuing issues, this study aimed to evaluate DNA damage and repair markers after myocardial perfusion single-photon emission computed tomography (MPS). Thirty-two patients undergoing Tc-99m sestamibi MPS were studied. Peripheral blood was collected before radiotracer injection at rest and 60–90 min after injection. The comet assay (single-cell gel electrophoresis) was performed with peripheral blood cells to detect DNA strand breaks. Three descriptors were evaluated: the percentage of DNA in the comet tail, tail length, and tail moment (the product of DNA tail percentage and tail length). Quantitative PCR (qPCR) was performed to evaluate the expression of five genes related to signaling pathways in response to DNA damage and repair (ATM, ATR, BRCA1, CDKN1A, and XPC). Mann–Whitney’s test was employed for statistical analysis; p < 0.05 was considered significant. Mean Tc-99m sestamibi dose was 15.1 mCi. After radiotracer injection, comparing post-exposure to pre-exposure samples of each of the 32 patients, no statistically significant differences of the DNA percentage in the tail, tail length or tail moment were found. qPCR revealed increased expression of BRCA1 and XPC, without any significant difference regarding the other genes. No significant increase in DNA strand breaks was detected after a single radiotracer injection for MPS. There was activation of only two repair genes, which may indicate that, in the current patient sample, the effects of ionizing radiation on the DNA were not large enough to trigger intense repair responses, suggesting the absence of significant DNA damage.

Coma and tail of Comet 67P/Churyumov–Gerasimenko during the 2021–2022 apparition

ABSTRACT We present results on the global activity of comet 67P/Churyumov–Gerasimenko (67P), the ROSETTA target, during its first perihelion passage after the mission and after an encounter with planet Jupiter. 67P was observed by broad-band filter imaging at 33 epochs during 2021 May 21 to 2022 June 1. The mean radial flux profiles suggest that ‘equilibrium’ conditions for the dust flow in the coma existed from around perihelion until about 100 d thereafter. We propose a scenario for the smaller and larger radial exponents, measured before and after the ‘equilibrium’ phase. Four coma fans with possible source regions at +40°, –10°, –50°, and –70° latitude on the nucleus are identified. The three fans at southern latitudes may be identical with fan sources seen during post-perihelion in 2015–2016. The rotation axis of 67P may not have changed at all or at least not much (&amp;lt;5°) from the orientation measured during the Rosetta mission at the comet. The dust streamers in the coma originated from observed coma fans, containing mostly dust emitted within days to weeks before observation. Two dust streamers, a long- and a short-lasting one, contained heavy dust grains from emission periods hundreds of days before perihelion. Similar emission periods are obtained for the dust seen in the tail region of the comet. Similarities and differences in the dust activity during the recent apparition with that of the Rosetta mission at the comet are found.

Cosmic Whirl: Navigating the Comet Trail in DNA: H2AX Phosphorylation and the Enigma of Uncertain Significance Variants.

Pathogenic variations in the BRCA2 gene have been detected with the development of next-generation sequencing (NGS)-based hereditary cancer panel testing technology. It also reveals an increasing number of variants of uncertain significance (VUSs). Well-established functional tests are crucial to accurately reclassifying VUSs for effective diagnosis and treatment. We retrospectively analyzed the multi-gene cancer panel results of 922 individuals and performed in silico analysis following ClinVar classification. Then, we selected five breast cancer-diagnosed patients' missense BRCA2 VUSs (T1011R, T1104P/M1168K, R2027K, G2044A, and D2819) for reclassification. The effects of VUSs on BRCA2 function were analyzed using comet and H2AX phosphorylation (γH2AX) assays before and after the treatment of peripheral blood mononuclear cells (PBMCs) of subjects with the double-strand break (DSB) agent doxorubicin (Dox). Before and after Dox-induction, the amount of DNA in the comet tails was similar in VUS carriers; however, notable variations in γH2AX were observed, and according to combined computational and functional analyses, we reclassified T1001R as VUS-intermediate, T1104P/M1168K and D2819V as VUS (+), and R2027K and G2044A as likely benign. These findings highlight the importance of the variability of VUSs in response to DNA damage before and after Dox-induction and suggest that further investigation is needed to understand the underlying mechanisms.