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1.
Methods Mol Biol ; 2852: 33-46, 2025.
Article in English | MEDLINE | ID: mdl-39235735

ABSTRACT

Foodborne pathogens are responsible for foodborne diseases and food poisoning and thus pose a great threat to food safety. These microorganisms can adhere to surface and form a biofilm composed of an extracellular matrix. This matrix protects bacterial cells from industrial environmental stress factors such as cleaning and disinfection operations. Moreover, during these environmental stresses, many bacterial species can be entered in a viable but nonculturable (VBNC) state. VBNC cells are characterized by an active metabolism and a loss of cultivability on conventional bacteriological agar. This leads to an underestimation of total viable cells in environmental samples and thus may pose a risk for public health. In this chapter, we present a method to detect viable population of foodborne pathogens in industrial environmental samples using a molecular method combining propidium monoazide (PMA) and quantitative PCR (qPCR) and a fluorescence microscopic method associated with the LIVE/DEAD BacLight™ viability stain.


Subject(s)
Azides , Food Microbiology , Microbial Viability , Propidium , Real-Time Polymerase Chain Reaction , Food Microbiology/methods , Azides/chemistry , Propidium/analogs & derivatives , Real-Time Polymerase Chain Reaction/methods , Bacteria/genetics , Bacteria/isolation & purification , Foodborne Diseases/microbiology , Microscopy, Fluorescence/methods , Humans
2.
Methods Mol Biol ; 2852: 159-170, 2025.
Article in English | MEDLINE | ID: mdl-39235743

ABSTRACT

The functional properties of biofilms are intimately related to their spatial architecture. Structural data are therefore of prime importance to dissect the complex social and survival strategies of biofilms and ultimately to improve their control. Confocal laser scanning microscopy (CLSM) is the most widespread microscopic tool to decipher biofilm structure, enabling noninvasive three-dimensional investigation of their dynamics down to the single-cell scale. The emergence of fully automated high content screening (HCS) systems, associated with large-scale image analysis, has radically amplified the flow of available biofilm structural data. In this contribution, we present a HCS-CLSM protocol used to analyze biofilm four-dimensional structural dynamics at high throughput. Meta-analysis of the quantitative variables extracted from HCS-CLSM will contribute to a better biological understanding of biofilm traits.


Subject(s)
Biofilms , Microscopy, Confocal , Biofilms/growth & development , Microscopy, Confocal/methods , Food Microbiology/methods , Imaging, Three-Dimensional/methods , Foodborne Diseases/microbiology , High-Throughput Screening Assays/methods , Image Processing, Computer-Assisted/methods
3.
Methods Mol Biol ; 2852: 171-179, 2025.
Article in English | MEDLINE | ID: mdl-39235744

ABSTRACT

Studying host-pathogen interactions is essential for understanding infectious diseases and developing possible treatments, especially for priority pathogens with increased virulence and antibiotic resistance, such as Klebsiella pneumoniae. Over time, this subject has been approached from different perspectives, often using mammal host models and invasive endpoint measurements (e.g., sacrifice and organ extraction). However, taking advantage of technological advances, it is now possible to follow the infective process by noninvasive visualization in real time, using optically amenable surrogate hosts. In this line, this chapter describes a live-cell imaging approach to monitor the interaction of K. pneumoniae and potentially other bacterial pathogens with zebrafish larvae in vivo. This methodology is based on the microinjection of fluorescent bacteria into the otic vesicle, followed by time-lapse observation by automated fluorescence microscopy with environmental control, monitoring the dynamics of immune cell recruitment, bacterial load, and larvae survival.


Subject(s)
Host-Pathogen Interactions , Klebsiella Infections , Klebsiella pneumoniae , Larva , Microinjections , Microscopy, Fluorescence , Zebrafish , Animals , Zebrafish/microbiology , Klebsiella pneumoniae/immunology , Microinjections/methods , Larva/microbiology , Larva/immunology , Microscopy, Fluorescence/methods , Host-Pathogen Interactions/immunology , Klebsiella Infections/microbiology , Klebsiella Infections/immunology , Disease Models, Animal
4.
Article in English | MEDLINE | ID: mdl-39328351

ABSTRACT

The definitive diagnosis of patients with indeterminate biliary strictures remains challenging. Probe-based confocal laser endomicroscopy (pCLE) provides real-time histological assessment of bile duct tissues. Since no previous studies have evaluated the efficacy of pCLE under direct cholangioscopic visualization for biliary strictures that cannot be definitively diagnosed through endoscopic retrograde cholangiopancreatography using fluoroscopy, we prospectively assessed the feasibility and safety of this procedure in three cases. pCLE findings were obtained in three cases, providing accurate diagnoses. Additionally, no adverse event was reported. pCLE under direct cholangioscopic visualization for indeterminate biliary strictures might be feasible and safe, even though these strictures were not previously diagnosed using endoscopic retrograde cholangiopancreatography. Further studies with more cases are warranted to clarify the effectiveness of pCLE under direct cholangioscopic visualization.

5.
J Environ Sci (China) ; 148: 602-613, 2025 Feb.
Article in English | MEDLINE | ID: mdl-39095193

ABSTRACT

Airborne microplastics (MPs) are important pollutants that have been present in the environment for many years and are characterized by their universality, persistence, and potential toxicity. This study investigated the effects of terrestrial and marine transport of MPs in the atmosphere of a coastal city and compared the difference between daytime and nighttime. Laser direct infrared imaging (LDIR) and polarized light microscopy were used to characterize the physical and chemical properties of MPs, including number concentration, chemical types, shape, and size. Backward trajectories were used to distinguish the air masses from marine and terrestrial transport. Twenty chemical types were detected by LDIR, with rubber (16.7%) and phenol-formaldehyde resin (PFR; 14.8%) being major components. Three main morphological types of MPs were identified, and fragments (78.1%) are the dominant type. MPs in the atmosphere were concentrated in the small particle size segment (20-50 µm). The concentration of MPs in the air mass from marine transport was 14.7 items/m3 - lower than that from terrestrial transport (32.0 items/m3). The number concentration of airborne MPs was negatively correlated with relative humidity. MPs from terrestrial transport were mainly rubber (20.2%), while those from marine transport were mainly PFR (18%). MPs in the marine transport air mass were more aged and had a lower number concentration than those in the terrestrial transport air mass. The number concentration of airborne MPs is higher during the day than at night. These findings could contribute to the development of targeted control measures and methods to reduce MP pollution.


Subject(s)
Air Pollutants , Environmental Monitoring , Microplastics , China , Microplastics/analysis , Air Pollutants/analysis , Cities , Atmosphere/chemistry , Particle Size
6.
Methods Mol Biol ; 2854: 177-188, 2025.
Article in English | MEDLINE | ID: mdl-39192129

ABSTRACT

Cryo-electron microscopy is a powerful methodology in structural biology and has been broadly used in high-resolution structure determination for challenging samples, which are not readily available for traditional techniques. In particular, the strength of super macro-complexes and the lack of a need for crystals for cryo-EM make this technique feasible for the structural study of complexes involved in antiviral innate immunity. This chapter presents detailed information and experimental procedures of Cryo-EM for determining the structures of the complexes using STING as an example. The procedures included a sample quality check, high-resolution data acquisition, and image processing for Cryo-EM 3D structure determination.


Subject(s)
Cryoelectron Microscopy , Immunity, Innate , Cryoelectron Microscopy/methods , Humans , Membrane Proteins/immunology , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods
7.
Food Chem ; 462: 140925, 2025 Jan 01.
Article in English | MEDLINE | ID: mdl-39190981

ABSTRACT

Grape pomace (GP) and pecan shell (PS) are two by-products rich in phenolic compounds (PC), and dietary fiber (DF) that may be considered for the development of functional baked foods. In this study, four formulations with different GP:PS ratios (F1(8%:5%), F2(5%:5%), F3(5%:2%), F4(0%:5%), and control bread (CB)) were elaborated and characterized (physiochemical and phytochemical content). Also, their inner structure (SEM), changes in their FTIR functional group's vibrations, and the bioaccessibility of PC and sugars, including an in vitro glycemic index, were analyzed. Results showed that all GP:PS formulations had higher mineral, protein, DF (total, soluble, and insoluble), and PC content than CB. Additionally, PC and non-starch polysaccharides affected gluten and starch absorbance and pores distribution. In vitro digestion model showed a reduction in the glycemic index for all formulations, compared to CB. These findings highlight the possible health benefits of by-products and their interactions in baked goods.


Subject(s)
Bread , Dietary Fiber , Glycemic Index , Phenols , Vitis , Dietary Fiber/analysis , Dietary Fiber/metabolism , Bread/analysis , Vitis/chemistry , Phenols/chemistry , Phenols/metabolism , Humans , Digestion , Food, Fortified/analysis , Waste Products/analysis
8.
J Biomed Opt ; 29(Suppl 2): S22702, 2025 Dec.
Article in English | MEDLINE | ID: mdl-38434231

ABSTRACT

Significance: Advancements in label-free microscopy could provide real-time, non-invasive imaging with unique sources of contrast and automated standardized analysis to characterize heterogeneous and dynamic biological processes. These tools would overcome challenges with widely used methods that are destructive (e.g., histology, flow cytometry) or lack cellular resolution (e.g., plate-based assays, whole animal bioluminescence imaging). Aim: This perspective aims to (1) justify the need for label-free microscopy to track heterogeneous cellular functions over time and space within unperturbed systems and (2) recommend improvements regarding instrumentation, image analysis, and image interpretation to address these needs. Approach: Three key research areas (cancer research, autoimmune disease, and tissue and cell engineering) are considered to support the need for label-free microscopy to characterize heterogeneity and dynamics within biological systems. Based on the strengths (e.g., multiple sources of molecular contrast, non-invasive monitoring) and weaknesses (e.g., imaging depth, image interpretation) of several label-free microscopy modalities, improvements for future imaging systems are recommended. Conclusion: Improvements in instrumentation including strategies that increase resolution and imaging speed, standardization and centralization of image analysis tools, and robust data validation and interpretation will expand the applications of label-free microscopy to study heterogeneous and dynamic biological systems.


Subject(s)
Histological Techniques , Microscopy , Animals , Flow Cytometry , Image Processing, Computer-Assisted
9.
J Nanobiotechnology ; 22(1): 589, 2024 Sep 28.
Article in English | MEDLINE | ID: mdl-39342336

ABSTRACT

BACKGROUND: Patients with HER2-positive breast cancer can significantly benefit from HER2-directed therapy - such as the monoclonal antibody trastuzumab. However, some patients can develop therapy resistance or change HER2 status. Thus, we urgently need new, noninvasive strategies to monitor patients frequently. Extracellular vesicles (EVs) secreted from tumor cells are emerging as potential biomarker candidates. These membrane-delimited nanoparticles harbor molecular signatures of their origin cells; report rapidly on changes to cellular status; and can be frequently sampled from accessible biofluids. RESULTS: Using Single Extracellular VEsicle Nanoscopy (SEVEN) platform that combines affinity isolation of EVs with super-resolution microscopy, here we provide multiparametric characterization of EVs with ~ 8 nm precision and molecular sensitivity. We first interrogated cell culture EVs affinity-enriched in tetraspanins CD9, CD63, and CD81; these transmembrane proteins are commonly found on EV membranes. SEVEN robustly provided critical parameters of individual, tetraspanin-enriched EVs: concentration, size, shape, molecular cargo content, and heterogeneity. Trastuzumab-resistant cells (vs. trastuzumab-sensitive) secreted more EVs. Additionally, EVs from trastuzumab-resistant cells had lower tetraspanin density and higher HER2 density. We also evaluated EVs affinity-enriched in HER2; we found that these EVs (vs. tetraspanin-enriched) were larger and more elongated. We further optimized analytical sample processing to assess a rare population of HER2-enriched EVs from patient plasma. In breast cancer patients with elevated HER2 protein expression (vs. controls), HER2-enriched EVs had distinct characteristics including typically increased number of tetraspanin molecules and larger size. Importantly, these EVs were on average 25-fold more abundant compared to no cancer controls. CONCLUSIONS: SEVEN revealed unique characteristics of HER2-enriched EVs in cultured cells and complex biological fluid. In combination with current clinical approaches, this method is well poised to support precise therapeutic decisions.


Subject(s)
Breast Neoplasms , Extracellular Vesicles , Receptor, ErbB-2 , Humans , Extracellular Vesicles/metabolism , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Female , Receptor, ErbB-2/metabolism , Cell Line, Tumor , Trastuzumab/pharmacology , Biomarkers, Tumor/metabolism , Drug Resistance, Neoplasm , Tetraspanins/metabolism , Tetraspanin 29/metabolism
10.
Eur J Ophthalmol ; : 11206721241286252, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39295314

ABSTRACT

PURPOSE: To describe features in silicone oil keratopathy using multimodal imaging and histopathological examination. METHODS: Case report. RESULT: A 21-year-old male developed right corneal decompensation in the heavy SO (HSO)-filled eye. The patient underwent an initial lensectomy, pars plana vitrectomy (PPV) and HSO tamponade due open-globe injury with corneal wound, lens damage and in two retained intravitreal glass foreign bodies, followed by a revisional PPV with HSO tamponade due to tractional detachment associated with proliferative vitreoretinopathy and epiretinal membrane. One month after the removal of HSO, ophthalmic examination of the right eye showed corneal decompensation. The AS-OCT showed corneal thickening, intrastromal scattered hyperreflective dots and large rounded/oval hyporeflective space; the latter were suggestive of emulsified HSO microbubbles and larger bubbles, respectively. In vivo confocal microscopy showed multiple presumed SO-related corneal changes, including hyper-reflective fibrotic changes in the basal epithelium, reduced density ans altered morphology of keratocytes cell population, increased pleomorphism and polymegathism of the endothelium with reduced endothelial cell, and presence of inflammatory cells. The patient underwent a penetrating keratoplasty, pupilloplasty and retropupillary iris-claw IOL implantation. The histopathological examination of the host corneal button showed Descemet's membrane irregularity and thickened corneal stroma with focal intrastromal silicone oil vacuoles, surrounded by macrophages. CONCLUSION: We described for the first time intrastromal hyperreflective dots as a sign associated with SO-related keratopathy. Moreover, this case report supports the ability of emulsified SO to penetrate the cornea inducing a local low-grade chronic inflammation.

11.
Article in English | MEDLINE | ID: mdl-39295551

ABSTRACT

Functional and abundant substrate materials are relevant for applying all sophisticated semiconductor-based device components such as nanowire arrays. In the case of GaN nanowires grown by metalorganic vapor phase epitaxy, Si(111) substrates are widely used, together with an AlN interlayer to suppress the well-known Ga-based melt-back-etching. However, the AlN interlayer can degrade the interfacial conductivity of the Si(111) substrate. To reveal the possible impact of this interlayer on the overall electrical performance, an advanced analysis of the electrical behavior with suitable spatial resolution is essential. For the electrical investigation of the nanowire-to-substrate junction, we used a four-point probe measurement setup with sufficiently high spatial resolution. The charge separation behavior of the junction is also demonstrated by an electron beam-induced current mode, while the n-GaN nanowire (NW) core exhibits good electrical conductivity. The charge carrier-selective transport at the NW-to-substrate junction can be attributed to different, local material compositions by two main effects: the reduction of Ga adatoms by shadowing of the lower part of the NW structure by the top part during growth, i.e. the protection of the pedestal footprint from Ga adsorption. Our combination of investigation methods provides direct insight into the nanowire-to-substrate junction and leads to a model of the conductivity channels at the nanowire base. This knowledge is crucial for all future GaN bottom-up grown nanowire structure devices on conductive Si(111) substrates.

12.
Planta ; 260(4): 97, 2024 Sep 15.
Article in English | MEDLINE | ID: mdl-39278990

ABSTRACT

MAIN CONCLUSION: Microscopic analyses and chemical profiling demonstrate that the white rind phenotype in melon fruit is associated with the accumulation of n-alkanes, fatty alcohols, aldehydes and wax esters. Serving as an indicator of quality, the rind (or external) color of fruit directly affects consumer choice. A fruit's color is influenced by factors such as the levels of pigments and deposited epicuticular waxes. The latter produces a white-grayish coating often referred to as "wax bloom". Previous reports have suggested that some melon (Cucumis melo L.) accessions may produce wax blooms, where a dominant white rind color trait was genetically mapped to a major locus on chromosome 7 and suggested to be inherited as a single gene named Wi. We here provide the first direct evidence of the contribution of epicuticular waxes to the dominant white rind trait in melon fruit. Our light and electron microscopy and gas chromatography-mass spectrometry (GC-MS) comparative analysis of melon accessions with white or green rinds reveals that the rind of melon fruit is rich in epicuticular waxes. These waxes are composed of various biochemical classes, including fatty acids, fatty alcohols, aldehydes, fatty amides, n-alkanes, tocopherols, triterpenoids, and wax esters. We show that the dominant white rind phenotype in melon fruit is associated with increased accumulation of n-alkanes, fatty alcohols, aldehydes and wax esters, which are linked with the deposition of crystal-like wax platelets on their surfaces. Together, this study broadens the understanding of natural variation in an important quality trait of melon fruit and promotes the future identification of the causative gene for the dominant white rind trait.


Subject(s)
Fruit , Waxes , Color , Cucumis melo/genetics , Cucumis melo/metabolism , Cucurbitaceae/genetics , Cucurbitaceae/metabolism , Fruit/genetics , Fruit/metabolism , Gas Chromatography-Mass Spectrometry , Phenotype , Pigmentation/genetics , Waxes/metabolism , Waxes/chemistry
13.
BMC Ophthalmol ; 24(1): 408, 2024 Sep 19.
Article in English | MEDLINE | ID: mdl-39300374

ABSTRACT

BACKGROUND: Implantable Collamer Lense (ICL) presents a viable alternative to conventional refractive surgeries, but their impact on corneal microstructure remains unclear. By employing in vivo confocal microscopy (IVCM), we examined changes in stromal and endothelial cells following the insertion of V4c ICLs, with the goal of enhancing post-surgical care and outcomes. METHODS: In this longitudinal investigation, we conducted detailed preoperative assessments on 103 eyes from 53 participants. Follow-up evaluations were carried out after surgery at set intervals: one day, one week, one month, three months, six months, and twelve months. We used IVCM to analyze changes in stromal and endothelial cells. To assess differences between pre- and post-surgery variables and to investigate correlations with age, axial length (AL), and spherical equivalent refraction (SER), we applied a repeated measures mixed-effects model, with statistical significance set at P < 0.05. RESULTS: No vision-threatening complications were reported post-surgery. Significant reductions in stromal cell density (SCD) were observed postoperatively, with anterior and mid- SCD reaching their lowest values at 3 months and posterior SCD at 1 month, remaining below baseline at 12 months. endothelial cell density (ECD) and percentage of hexagonal cells (PHC) decreased initially, recovering by 12 months. Conversely, endothelial cellular area (ECA) and coefficient of variation of cell size (CoV) increased postoperatively, with the most significant change at 1 week. Endothelial deposits were detected in 49 of 101 eyes on postoperative day 1, half of them were absorbed within 3 months post-surgery. Changes in posterior SCD were negatively related to AL, while AL, SER, lens thickness showed associated with endothelium changes. CONCLUSION: Our findings elucidate the corneal microstructural changes following V4c ICL implantation, particularly the significant early reductions in stromal and endothelial cell densities. We recommend careful management of viscoelastics during surgery to minimize endothelial deposits that may harm the endothelium. Enhanced early postoperative monitoring and these surgical adjustments can lead to improved surgical and post-surgical care, ultimately supporting better patient recovery.


Subject(s)
Endothelium, Corneal , Microscopy, Confocal , Myopia , Phakic Intraocular Lenses , Humans , Male , Female , Adult , Endothelium, Corneal/pathology , Myopia/surgery , Cell Count , Lens Implantation, Intraocular , Young Adult , Middle Aged , Corneal Stroma/pathology , Corneal Stroma/surgery , Corneal Stroma/diagnostic imaging , Refraction, Ocular/physiology , Visual Acuity/physiology , Follow-Up Studies , Prospective Studies
14.
Neurosci Lett ; 841: 137959, 2024 Oct 15.
Article in English | MEDLINE | ID: mdl-39218293

ABSTRACT

Understanding the sequence of cellular responses and their contributions to pathomorphogical changes in spinal white matter injuries is a prerequisite for developing efficient therapeutic strategies for spinal cord injury (SCI) as well as neurodegenerative and inflammatory diseases of the spinal cord such as amyotrophic lateral sclerosis and multiple sclerosis. We have developed several types of surgical procedures suitable for acute one-time and chronic recurrent in vivo multiphoton microscopy of spinal white matter [1]. Sophisticated surgical procedures were combined with transgenic mouse technology to image spinal tissue labeled with up to four fluorescent proteins (FPs) in axons, astrocytes, microglia, and blood vessels. To clearly separate the simultaneously excited FPs, spectral unmixing including iterative procedures was performed after imaging the diversely labeled spinal white matter with a custom-made 4-channel two-photon laser-scanning microscope. In our longitudinal multicellular studies of injured spinal white matter, we imaged axonal dynamics and invasion of microglia and astrocytes for a time course of over 200 days after SCI. Our methods offer ideal platforms for investigating acute and chronic cellular dynamics, cell-cell interactions, and metabolite fluctuations in health and disease as well as pharmacological manipulations in vivo.


Subject(s)
Axons , Mice, Transgenic , Spinal Cord Injuries , White Matter , Animals , White Matter/pathology , White Matter/metabolism , White Matter/diagnostic imaging , Spinal Cord Injuries/pathology , Spinal Cord Injuries/metabolism , Spinal Cord Injuries/diagnostic imaging , Axons/pathology , Axons/metabolism , Neuroglia/metabolism , Neuroglia/pathology , Mice , Microscopy, Fluorescence, Multiphoton/methods , Spinal Cord/pathology , Spinal Cord/metabolism , Microglia/metabolism , Microglia/pathology , Astrocytes/metabolism , Astrocytes/pathology
15.
Sci Rep ; 14(1): 21997, 2024 09 23.
Article in English | MEDLINE | ID: mdl-39313528

ABSTRACT

This is the primary study at Matrouh Governorate to unveil antibiotic resistance, biofilm formation, silver nanoparticles (Ag-NPs) effect using electron microscopy, and REP-PCR analysis of Staphylococcus aureus strains isolated from COVID-19 patients, contaminated food, and Morel's diseased sheep and goats. A total of 15 S. aureus strains were isolated; five from each of the COVID-19 patients, Morel's diseased sheep and goats, and contaminated food. All strains were considered multidrug-resistant (MDR). All strains showed the presence of biofilm. Morphological changes in the cell surface of the bacterium were evidenced, and penetration with the rupture of some bacterial cells. Based on REP-PCR analysis, 4 clusters (C1-C4) with dissimilarity between clusters C1 and C2 8% and between C3 and C4 15%. Cluster I included 3 strains from contaminated food with a similarity of 97%, and Cluster II included 2 strains from contaminated food and 2 from COVID-19-infected patients with a similarity of 96% (confirming the zoonotic nature of this pathogen). Cluster III contained 4 strains isolated from Morel's diseased sheep & goats with a similarity ratio of 99% in comparison the 4th cluster contained 3 strains isolated from COVID-patients and one from Morel's diseased sheep & goats with a similarity ratio of 92%.


Subject(s)
COVID-19 , Goats , Metal Nanoparticles , Silver , Staphylococcal Infections , Staphylococcus aureus , Staphylococcus aureus/genetics , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/drug effects , Silver/pharmacology , Animals , Humans , Sheep , COVID-19/virology , COVID-19/microbiology , COVID-19/veterinary , Staphylococcal Infections/microbiology , Staphylococcal Infections/veterinary , Biofilms/drug effects , Biofilms/growth & development , Polymerase Chain Reaction/methods , Food Microbiology , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Microbial Sensitivity Tests
16.
Discov Nano ; 19(1): 154, 2024 Sep 23.
Article in English | MEDLINE | ID: mdl-39313578

ABSTRACT

Acinetobacter baumannii, an opportunistic pathogen has shown an upsurge in its multi-drug resistant isolates. OmpA of A. baumannii induces incomplete autophagy and apoptosis in host cells. Various therapeutic alternatives are under investigation against A. baumannii. Here, the major emphasis has been laid on comparing the efficacy of AgNP with different capping agents. OmpA targeted lead, Ivermectin capped AgNP (IVM-AgNP) has been compared with the antibacterial polyvinylpyrrolidone capped AgNP (PVP-AgNP) for their role in the modulations of host autophagy. Upregulation of p62 and LC3B confirmed by real-time PCR analysis indicated an increased autophagic flux upon the treatment with AgNPs. The elongation and closure of autophagic vacuoles was also supported by upregulated Atg genes (Atg4, Atg3, Atg5) in A. baumannii infected cells after treatment with AgNP. Autophagic flux increased on treatment with PVP-AgNP as suggested by the rise in mcherryLC3B fluorescence in A549 cells treated with PVP-AgNP as compared to the GFP-LC3B of IVM-AgNP. This suggests that PVP-AgNP treatment more effectively promotes the elongation and maturation stages of autophagy by increasing autophagic flux. These results indicate that capped AgNPs have the efficiency to revert the incomplete autophagy induced by A. baumannii back to normal autophagic levels.

17.
Mater Today Bio ; 28: 101238, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39318377

ABSTRACT

This study introduces the time-gated analysis of room-temperature phosphorescence (RTP) for the in-situ analysis of the visible and spectral information of photons. Time-gated analysis is performed using a microscopic system consisting of a spectrometer, which is advantageous for in-situ analysis since it facilitates the real-time measurement of luminescence signal changes. An RTP material hybridized with a DNA aptamer that targets a specific protein enhances the intensity and lifetime of phosphorescence after selective recognition with the target protein. In addition, time-gated analysis allows for the millisecond-scale imaging of phosphorescence signals, excluding autofluorescence, and improves the signal-to-background ratio (SBR) through the accumulation of signals. While collecting the time-gated images and spectra of RTP and autofluorescent materials simultaneously, we develop a method for obtaining phosphorescence signals by means of selective exclusion of autofluorescence signals in simulated or real cell conditions. It is confirmed that the accumulated time-gated analysis can provide ample information about luminescence signals for bioimaging and biosensing applications.

18.
Iran J Parasitol ; 19(3): 370-375, 2024.
Article in English | MEDLINE | ID: mdl-39318817

ABSTRACT

Trypanosomes are the extraerythrocytic haemoflagellate protozoan parasites of domestic and wild animals including dogs. A male Rottweiler dog was presented with the history of anorexia, cloudy eyes and vomiting for a week. The dog was examined both physically and clinically. Blood was collected and subjected to haematological and biochemical analysis. Echocardiography of the thoracic cavity and ultrasonography of the abdominal cavity were performed. Molecular confirmation of parasite was carried out by PCR and DNA was sequenced to identify strain variations. Upon clinical examination, the dog revealed emaciation with high fever, unilateral corneal opacity, anemia, enlarged lymph nodes and distended abdomen. Echocardiography of the thoracic cavity showed ventricular hypertrophy and cardiomyopathy. Ultrasonography of the abdominal cavity showed splenomegaly and renomegaly. Haematological findings revealed decreased haemoglobin and erythrocyte count and biochemical findings revealed increased BUN and creatinine, hypoglycemia and hypoalbuminemia. Wet film and blood smear examination revealed actively motile trypanosomes and massive infection of trypanosomes, respectively. Molecular confirmation of species was carried out by amplification of 227 bp partial VSG gene of Trypanososma evansi, subsequently sequenced and phylogenitically analysed. The infected dog was treated intramuscularly with diminazene aceturate @ 3.5 mg/kg b.wt along with the supportive therapy. The study described the occurrence and diagnosis of trypanosomosis in dog. Early diagnosis and timely treatment is the most reliable way to safeguard the companion animals. It is the first report on trypanosomosis in dog from Cauvery delta region of Tamil Nadu, India.

19.
Toxicol Res (Camb) ; 13(5): tfae150, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39319343

ABSTRACT

Paclitaxel (PCTX) is one of the most prevalently used chemotherapeutic agents. However, its use is currently beset with a host of problems: solubility issue, microplastic leaching, and drug resistance. Since drug discovery is challenging, we decided to focus on repurposing the drug itself by remedying its drawbacks and making it more effective. In this study, we have harnessed the aqueous solubility of sugars, and the high affinity of cancer cells for them, to entrap the hydrophobic PCTX within the hydrophilic shell of the carbohydrate ß-cyclodextrin. We have characterized this novel drug formulation by testing its various physical and chemical parameters. Importantly, in all our in vitro assays, the conjugate performed better than the drug alone. We find that the conjugate is internalized by the cancer cells (A549) via caveolin 1-mediated endocytosis. Thereafter, it triggers apoptosis by inducing the formation of reactive oxygen species. Based on experiments on zebrafish larvae, the formulation displays lower toxicity compared to PCTX alone. Thus, our "Trojan Horse" approach, relying on minimal components and relatively faster formulation, enhances the anti-tumor potential of PCTX, while simultaneously making it more innocuous toward non-cancerous cells. The findings of this study have implications in the quest for the most cost-effective chemotherapeutic molecule.

20.
Proc Natl Acad Sci U S A ; 121(40): e2402556121, 2024 Oct.
Article in English | MEDLINE | ID: mdl-39320920

ABSTRACT

Fluorescence lifetime imaging microscopy (FLIM) is a powerful imaging technique that enables the visualization of biological samples at the molecular level by measuring the fluorescence decay rate of fluorescent probes. This provides critical information about molecular interactions, environmental changes, and localization within biological systems. However, creating high-resolution lifetime maps using conventional FLIM systems can be challenging, as it often requires extensive scanning that can significantly lengthen acquisition times. This issue is further compounded in three-dimensional (3D) imaging because it demands additional scanning along the depth axis. To tackle this challenge, we developed a computational imaging technique called light-field tomographic FLIM (LIFT-FLIM). Our approach allows for the acquisition of volumetric fluorescence lifetime images in a highly data-efficient manner, significantly reducing the number of scanning steps required compared to conventional point-scanning or line-scanning FLIM imagers. Moreover, LIFT-FLIM enables the measurement of high-dimensional data using low-dimensional detectors, which are typically low cost and feature a higher temporal bandwidth. We demonstrated LIFT-FLIM using a linear single-photon avalanche diode array on various biological systems, showcasing unparalleled single-photon detection sensitivity. Additionally, we expanded the functionality of our method to spectral FLIM and demonstrated its application in high-content multiplexed imaging of lung organoids. LIFT-FLIM has the potential to open up broad avenues in both basic and translational biomedical research.


Subject(s)
Microscopy, Fluorescence , Microscopy, Fluorescence/methods , Animals , Humans , Imaging, Three-Dimensional/methods , Mice , Fluorescent Dyes/chemistry , Tomography/methods
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