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Journal of Indian Prosthodontic Society 2023The intraoral scanners are digital devices used to digitise the oral tissues. The accuracy of the intraoral scanners has been studied under different environmental... (Clinical Trial)
Clinical Trial
Comparative analysis on efficiency and accuracy of parallel confocal microscopy and three-dimensional in motion video with triangulation technology-based intraoral scanner under influence of moisture and mouth opening - A crossover clinical trial.
AIM
The intraoral scanners are digital devices used to digitise the oral tissues. The accuracy of the intraoral scanners has been studied under different environmental conditions, but there might be differences that occur in the actual oral environment, which is still in question. The aim of the study was to evaluate the accuracy and efficiency of Parallel Confocal Microscopy and 3D in motion video with triangulation technology-based intraoral scanners under the influence of moisture and mouth opening.
SETTINGS AND DESIGN
This was an Cross over clinical controlled study.
MATERIALS AND METHODS
The controlled in vivo study included healthy subjects who were in need of CBCT for the purpose of locating the position of unerupted third molars before going abroad for a job. The subjects were exposed to scans in the upper and lower jaws with two intraoral scanners based on 3D motion video technology with triangulation (Medit) and parallel confocal microscopy (Trios) under the influence of two oral conditions, which were moisture (presence and absence of moisture) and mouth opening (30 mm and 50 mm, respectively). A total of 96 scans were obtained and superimposed individually over the reference CBCT scans to find the deviations in the Geomagic Rapidform (version 2020, USA) software. The efficiency of the scanners was calculated by recording the time taken and the number of images obtained after each scan.
STATISTICAL ANALYSIS USED
The significance was calculated by using the independent and paired sample t test in SPSS software (IBM, version 23).
RESULTS
Based on the surface analysis, the trueness of the intra-oral scanners had statistically significant differences when compared between 3D in motion video technology with Triangulation and Parallel Confocal Microscopy (P < 0.05) whereas no statistical significance was observed in precision. There was a significant difference observed in the efficiency of the intra-oral scanners (P < 0.05).
CONCLUSION
There is a significant difference in the accuracy and efficiency of the intraoral scanners under the influence of oral conditions, such as different moisture levels and mouth opening conditions. 3D in motion video technology with Triangulation showed better results with the least deviation than Parallel Confocal Microscopy.
Topics: Humans; Computer-Aided Design; Dental Impression Technique; Imaging, Three-Dimensional; Microscopy, Confocal; Technology; Cross-Over Studies
PubMed: 37929362
DOI: 10.4103/jips.jips_65_23 -
BioRxiv : the Preprint Server For... Oct 2023HIV-1 budding as well as many other cellular processes require the Endosomal Sorting Complex Required for Transport (ESCRT) machinery. Understanding the architecture of...
HIV-1 budding as well as many other cellular processes require the Endosomal Sorting Complex Required for Transport (ESCRT) machinery. Understanding the architecture of the native ESCRT-III complex at HIV-1 budding sites is limited due to spatial resolution and transient ESCRT-III recruitment. Here, we developed a drug-inducible transient HIV-1 budding inhibitory tool to enhance the ESCRT-III lifetime at budding sites. We generated auto-cleavable CHMP2A, CHMP3, and CHMP4B fusion proteins with the hepatitis C virus NS3 protease. We characterized the CHMP-NS3 fusion proteins in the absence and presence of protease inhibitor Glecaprevir with regard to expression, stability, localization and HIV-1 Gag VLP budding. Immunoblotting experiments revealed rapid and stable accumulation of CHMP-NS3 fusion proteins with variable modification of Gag VLP budding upon drug administration. Notably, CHMP2A-NS3 and CHMP4B-NS3 fusion proteins substantially decrease VLP release while CHMP3-NS3 exerted a minor effect and synergized with CHMP2A-NS3. Localization studies demonstrated the re-localization of CHMP-NS3 fusion proteins to the plasma membrane, endosomes, and Gag VLP budding sites. Through the combined use of transmission electron microscopy and video-microscopy, we unveiled drug-dependent accumulation of CHMP2A-NS3 and CHMP4B-NS3, causing a delay in HIV-1 Gag-VLP release. Our findings provide novel insight into the functional consequences of inhibiting ESCRT-III during HIV-1 budding and establish new tools to decipher the role of ESCRT-III at HIV-1 budding sites and other ESCRT-catalyzed cellular processes.
PubMed: 37905063
DOI: 10.1101/2023.10.16.562494 -
BioRxiv : the Preprint Server For... Feb 2024In curative-intent cancer surgery, intraoperative fluorescence imaging of both diseased and healthy tissue can help to ensure successful removal of all gross and...
In curative-intent cancer surgery, intraoperative fluorescence imaging of both diseased and healthy tissue can help to ensure successful removal of all gross and microscopic disease with minimal damage to neighboring critical structures, such as nerves. Current fluorescence-guided surgery (FGS) systems, however, rely on bulky and rigid optics that incur performance-limiting trade-offs between sensitivity and maneuverability. Moreover, many FGS systems are incapable of multiplexed imaging. As a result, clinical FGS is currently limited to millimeter-scale detection of a single fluorescent target. Here we present a scalable, lens-less fluorescence imaging chip, VISION, capable of sensitive and multiplexed detection within a compact form factor. Central to VISION is a novel optical frontend design combining a low-numerical-aperture fiber optic plate (LNA-FOP) and a multi-bandpass interference filter, which is affixed to a custom CMOS image sensor. The LNA-FOP acts as a planar collimator to improve resolution and compensate for the angle-sensitivity of the interference filter, enabling high-resolution and multiplexed fluorescence imaging without lenses. We show VISION is capable of detecting tumor foci of less than 100 cells at near video framerates and, as proof of principle, can simultaneously visualize both tumor and nerves in prostate tissue.
PubMed: 37904924
DOI: 10.1101/2023.10.16.562247 -
Cell Communication and Signaling : CCS Oct 2023Bladder cells face a challenging biophysical environment: mechanical cues originating from urine flow and regular contraction to enable the filling voiding of the organ....
Bladder cells face a challenging biophysical environment: mechanical cues originating from urine flow and regular contraction to enable the filling voiding of the organ. To ensure functional adaption, bladder cells rely on high biomechanical compliance, nevertheless aging or chronic pathological conditions can modify this plasticity. Obviously the cytoskeletal network plays an essential role, however the contribution of other, closely entangled, intracellular organelles is currently underappreciated. The endoplasmic reticulum (ER) lies at a crucial crossroads, connected to both nucleus and cytoskeleton. Yet, its role in the maintenance of cell mechanical stability is less investigated. To start exploring these aspects, T24 bladder cancer cells were treated with the ER stress inducers brefeldin A (10-40nM BFA, 24 h) and thapsigargin (0.1-100nM TG, 24 h). Without impairment of cell motility and viability, BFA and TG triggered a significant subcellular redistribution of the ER; this was associated with a rearrangement of actin cytoskeleton. Additional inhibition of actin polymerization with cytochalasin D (100nM CytD) contributed to the spread of the ER toward cell periphery, and was accompanied by an increase of cellular stiffness (Young´s modulus) in the cytoplasmic compartment. Shrinking of the ER toward the nucleus (100nM TG, 2 h) was related to an increased stiffness in the nuclear and perinuclear areas. A similar short-term response profile was observed also in normal human primary bladder fibroblasts. In sum, the ER and its subcellular rearrangement seem to contribute to the mechanical properties of bladder cells opening new perspectives in the study of the related stress signaling cascades. Video Abstract.
Topics: Humans; Urinary Bladder; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Cytoskeleton; Thapsigargin
PubMed: 37904178
DOI: 10.1186/s12964-023-01295-x -
Life (Basel, Switzerland) Oct 2023Multiple primary melanoma (MPM) is a diagnostic challenge even with ancillary imaging technologies available to dermatologists. In selected patients' phenotypes, the use...
BACKGROUND
Multiple primary melanoma (MPM) is a diagnostic challenge even with ancillary imaging technologies available to dermatologists. In selected patients' phenotypes, the use of imaging approaches can help better understand lesion characteristics, and aid in early diagnosis and management.
METHODS
Under a 5-year prospective single-center follow-up, 58 s primary melanomas (SPMs) were diagnosed in two first-degree relatives, with fair skin color, red hair, green eyes, and personal history of one previous melanoma each. Patients' behavior and descriptive demographic data were collected from medical records. The information on the first two primary melanomas (PMs) were retrieved from pathology reports. The characteristics of 60 melanomas were collected from medical records, video dermoscopy software, and pathology reports. Reflectance confocal microscopy (RCM) was performed prior to excision of 22 randomly selected melanomas.
RESULTS
From February 2018 to May 2023, two patients underwent a pooled total of 214 excisional biopsies of suspect lesions, resulting in a combined benign versus malignant treatment ratio (NNT) of 2.0:1.0. The number of moles excised for each melanoma diagnosed (NNE) was 1.7:1.0 and 6.9:1.0 for the female and male patient respectively. The in-situ melanoma/invasive melanoma ratio (IIR) demonstrated a higher proportion of in-situ melanomas for both patients. From June 2018 to May 2023, a total of 58 SPMs were detected by the combination of total body skin exam (TBSE), total body skin photography (TBSP), digital dermoscopy (DD), and sequential digital dermoscopy imaging (SDDI) via comparative approach. The younger patient had her PM one month prior to the second and third cutaneous melanomas (CMs), characterizing a case of synchronous primary CM. The male older relative had a total of 7 nonsynchronous melanomas.
CONCLUSIONS
This CM cohort is composed of 83.3% in-situ melanoma and 16.7% invasive melanoma. Both patients had a higher percentage of SPM with clinical nevus-like morphology (84.5%), global dermoscopic pattern of asymmetric multiple component (60.3%) and located on the lower limbs (46.6%). When RCM was performed prior to excision, 81% of SPM had features suggestive of malignancy. As well, invasive melanomas were more frequent in the lower limbs (40%). In the multivariate model, for the two high-risk patients studied, the chance of a not associated with nevus ("de novo") invasive SPM diagnosis is 25 times greater than the chance of a diagnosis of a nevus-associated invasive SPM.
PubMed: 37895483
DOI: 10.3390/life13102102 -
Nature Communications Oct 2023Antigen cognate dendritic cell (DC)-T cell synaptic interactions drive activation of T cells and instruct DCs. Upon receiving CD4 T cell help, post-synaptic DCs (psDCs)...
Antigen cognate dendritic cell (DC)-T cell synaptic interactions drive activation of T cells and instruct DCs. Upon receiving CD4 T cell help, post-synaptic DCs (psDCs) are licensed to generate CD8 T cell responses. However, the cellular and molecular mechanisms that enable psDCs licensing remain unclear. Here, we describe that antigen presentation induces an upregulation of MHC-I protein molecules and increased lipid peroxidation on psDCs in vitro and in vivo. We also show that these events mediate DC licensing. In addition, psDC adoptive transfer enhances pathogen-specific CD8 T responses and protects mice from infection in a CD8 T cell-dependent manner. Conversely, depletion of psDCs in vivo abrogates antigen-specific CD8 T cell responses during immunization. Together, our data show that psDCs enable CD8 T cell responses in vivo during vaccination and reveal crucial molecular events underlying psDC licensing.
Topics: Mice; Animals; CD8-Positive T-Lymphocytes; CD4-Positive T-Lymphocytes; Up-Regulation; Lipid Peroxidation; Antigen Presentation; Antigens; Histocompatibility Antigens Class I; Dendritic Cells; Synapses; Mice, Inbred C57BL
PubMed: 37880206
DOI: 10.1038/s41467-023-42480-3 -
Epilepsia Dec 2023Sudden unexpected death in epilepsy (SUDEP) is a leading cause of death for patients with epilepsy; however, the pathophysiology remains unclear. Focal-to-bilateral...
OBJECTIVES
Sudden unexpected death in epilepsy (SUDEP) is a leading cause of death for patients with epilepsy; however, the pathophysiology remains unclear. Focal-to-bilateral tonic-clonic seizures (FBTCS) are a major risk factor, and centrally-mediated respiratory depression may increase the risk further. Here, we determined the volume and microstructure of the amygdala, a key structure that can trigger apnea in people with focal epilepsy, stratified by the presence or absence of FBTCS, ictal central apnea (ICA), and post-convulsive central apnea (PCCA).
METHODS
Seventy-three patients with focal impaired awareness seizures without FBTC seizures (FBTCneg group) and 30 with FBTCS (FBTCpos group) recorded during video electroencephalography (VEEG) with respiratory monitoring were recruited prospectively during presurgical investigations. We acquired high-resolution T1-weighted anatomic and multi-shell diffusion images, and computed neurite orientation dispersion and density imaging (NODDI) metrics in all patients with epilepsy and 69 healthy controls. Amygdala volumetric and microstructure alterations were compared between three groups: healthy subjects, FBTCneg and FBTCpos groups. The FBTCpos group was further subdivided by the presence of ICA and PCCA, verified by VEEG.
RESULTS
Bilateral amygdala volumes were significantly increased in the FBTCpos cohort compared to healthy controls and the FBTCneg group. Patients with recorded PCCA had the highest increase in bilateral amygdala volume of the FBTCpos cohort. Amygdala neurite density index (NDI) values were decreased significantly in both the FBTCneg and FBTCpos groups relative to healthy controls, with values in the FBTCpos group being the lowest of the two. The presence of PCCA was associated with significantly lower NDI values vs the non-apnea FBTCpos group (p = 0.004).
SIGNIFICANCE
Individuals with FBTCpos and PCCA show significantly increased amygdala volumes and disrupted architecture bilaterally, with greater changes on the left side. The structural alterations reflected by NODDI and volume differences may be associated with inappropriate cardiorespiratory patterns mediated by the amygdala, particularly after FBTCS. Determination of amygdala volumetric and architectural changes may assist identification of individuals at risk.
Topics: Humans; Sleep Apnea, Central; Seizures; Epilepsies, Partial; Epilepsy; Electroencephalography; Amygdala; Apnea; Epilepsy, Tonic-Clonic
PubMed: 37857465
DOI: 10.1111/epi.17804 -
PNAS Nexus Oct 2023Time-resolved techniques have been widely used in time-gated and luminescence lifetime imaging. However, traditional time-resolved systems require expensive lab...
Time-resolved techniques have been widely used in time-gated and luminescence lifetime imaging. However, traditional time-resolved systems require expensive lab equipment such as high-speed excitation sources and detectors or complicated mechanical choppers to achieve high repetition rates. Here, we present a cost-effective and miniaturized smartphone lifetime imaging system integrated with a pulsed ultraviolet (UV) light-emitting diode (LED) for 2D luminescence lifetime imaging using a videoscopy-based virtual chopper (V-chopper) mechanism combined with machine learning. The V-chopper method generates a series of time-delayed images between excitation pulses and smartphone gating so that the luminescence lifetime can be measured at each pixel using a relatively low acquisition frame rate (e.g. 30 frames per second [fps]) without the need for excitation synchronization. Europium (Eu) complex dyes with different luminescent lifetimes ranging from microseconds to seconds were used to demonstrate and evaluate the principle of V-chopper on a 3D-printed smartphone microscopy platform. A convolutional neural network (CNN) model was developed to automatically distinguish the gated images in different decay cycles with an accuracy of >99.5%. The current smartphone V-chopper system can detect lifetime down to ∼75 µs utilizing the default phase shift between the smartphone video rate and excitation pulses and in principle can detect much shorter lifetimes by accurately programming the time delay. This V-chopper methodology has eliminated the need for the expensive and complicated instruments used in traditional time-resolved detection and can greatly expand the applications of time-resolved lifetime technologies.
PubMed: 37829844
DOI: 10.1093/pnasnexus/pgad313 -
Cell Communication and Signaling : CCS Oct 2023Specific interactions between G protein-coupled receptors (GPCRs) and G proteins play a key role in mediating signaling events. While there is little doubt regarding...
BACKGROUND
Specific interactions between G protein-coupled receptors (GPCRs) and G proteins play a key role in mediating signaling events. While there is little doubt regarding receptor preference for Gα subunits, the preferences for specific Gβ and Gγ subunits and the effects of different Gβγ dimer compositions on GPCR signaling are poorly understood. In this study, we aimed to investigate the subcellular localization and functional response of Gαi-based heterotrimers with different combinations of Gβ and Gγ subunits.
METHODS
Live-cell imaging microscopy and colocalization analysis were used to investigate the subcellular localization of Gαi in combination with Gβ or Gβ heterotrimers, along with representative Gγ subunits. Furthermore, fluorescence lifetime imaging microscopy (FLIM-FRET) was used to investigate the nanoscale distribution of Gαi-based heterotrimers in the plasma membrane, specifically with the dopamine D receptor (DR). In addition, the functional response of the system was assessed by monitoring intracellular cAMP levels and conducting bioinformatics analysis to further characterize the heterotrimer complexes.
RESULTS
Our results show that Gαi heterotrimers mainly localize to the plasma membrane, although the degree of colocalization is influenced by the accompanying Gβ and Gγ subunits. Heterotrimers containing Gβ showed slightly lower membrane localization compared to those containing Gβ, but certain combinations, such as Gαiβγ and Gαiβγ, deviated from this trend. Examination of the spatial arrangement of Gαi in relation to DR and of changes in intracellular cAMP level showed that the strongest functional response is observed for those trimers for which the distance between the receptor and the Gα subunit is smallest, i.e. complexes containing Gβ and Gγ or Gγ subunit. Deprivation of Gαi lipid modifications resulted in a significant decrease in the amount of protein present in the cell membrane, but did not always affect intracellular cAMP levels.
CONCLUSION
Our studies show that the composition of G protein heterotrimers has a significant impact on the strength and specificity of GPCR-mediated signaling. Different heterotrimers may exhibit different conformations, which further affects the interactions of heterotrimers and GPCRs, as well as their interactions with membrane lipids. This study contributes to the understanding of the complex signaling mechanisms underlying GPCR-G-protein interactions and highlights the importance of the diversity of Gβ and Gγ subunits in G-protein signaling pathways. Video Abstract.
Topics: GTP-Binding Protein alpha Subunits; GTP-Binding Protein gamma Subunits; GTP-Binding Proteins; Signal Transduction; Carrier Proteins; Receptors, G-Protein-Coupled
PubMed: 37817242
DOI: 10.1186/s12964-023-01307-w -
BioRxiv : the Preprint Server For... Sep 2023Understanding cancer cell mechanics allows for the identification of novel disease mechanisms, diagnostic biomarkers, and targeted therapies. In this study, we utilized...
Understanding cancer cell mechanics allows for the identification of novel disease mechanisms, diagnostic biomarkers, and targeted therapies. In this study, we utilized our previously established fluid shear stress assay to investigate and compare the viscoelastic properties of normal immortalized human astrocytes (IHAs) and invasive human glioblastoma (GBM) cells when subjected to physiological levels of shear stress that are present in the brain microenvironment. We used a parallel-flow microfluidic shear system and a camera-coupled optical microscope to expose single cells to fluid shear stress and monitor the resulting deformation in real-time, respectively. From the video-rate imaging, we fed cell deformation information from digital image correlation into a three-parameter generalized Maxwell model to quantify the nuclear and cytoplasmic viscoelastic properties of single cells. We further quantified actin cytoskeleton density and alignment in IHAs and GBM cells via immunofluorescence microscopy and image analysis techniques. Results from our study show that contrary to the behavior of many extracranial cells, normal and cancerous brain cells do not exhibit significant differences in their viscoelastic behavior. Moreover, we also found that the viscoelastic properties of the nucleus and cytoplasm as well as the actin cytoskeletal densities of both brain cell types are similar. Our work suggests that malignant GBM cells exhibit unique mechanical behaviors not seen in other cancer cell types. These results warrant future study to elucidate the distinct biophysical characteristics of the brain and reveal novel mechanical attributes of GBM and other primary brain tumors.
PubMed: 37808779
DOI: 10.1101/2023.09.23.559055