Search

* Context.--Pemphigus is an autoimmune blister disease that causes blisters on the skin and mucosal surfaces. Direct immunofluorescence (DIF) testing is critical for the clinical diagnosis of pemphigus. However, it is limited to fresh tissue specimens and fluorescence microscopy. Objective.--To assess the value of C3d immunohistochemistry (IHC) on paraffin-embedded skin tissue for the diagnosis of pemphigus by comparing C3d-IHC results to DIF and enzyme-linked immunosorbent assay testing in pemphigus and other blister-related skin diseases. Design.--C3d-IHC assays were retrospectively performed on paraffin-embedded skin tissue sections from 115 patients (63 with pemphigus and 52 controls). Both the case group and the control group underwent the same protocol, and cases with C3d position in the peripheral spinous layer were considered as positive samples. Results.--C3d-IHC and DIF testing had similar performance for pemphigus diagnosis, with a sensitivity of 71.0% (95% CI, 51.8%-85.1 %) and 77.4% (95% CI, 58.5%-89.7%), specificity of 96.4% (95% CI, 79.8%-99.8%) and 100% (95% CI, 85.0%-100%), positive predictive value of 95.7% (95% CI, 76.0%-99.8%) and 100% (95% CI, 82.8%-100%), and a negative predictive value of 75.0% (95% CI, 57.5%-87.3%) and 80.0% (95% CI, 62.5%-90.9%), respectively. Conclusions.--Our study indicated that C3d-IHC results for paraffin-fixed tissues were not significantly different from DIF results for the diagnosis of pemphigus. The C3dIHC assay has the potential for routine diagnosis of pemphigus, especially in the absence of fresh-frozen tissue. (Arch Pathol Lab Med. 2024;148:1022-1027; doi: 10.5858/arpa.2023-0274-OA), Pemphigus is an autoimmune blister disease that causes blisters on the skin and mucosal surfaces (1) and is characterized by autoantibodies against desmoglein (Dsg)1 or Dsg3. (2-4) There are 2 [...]

BACKGROUND. Noninvasive assessment of metabolic processes that sustain regeneration of human retinal visual pigments (visual cycle) is essential to improve ophthalmic diagnostics and to accelerate development of new treatments to counter retinal diseases. Fluorescent vitamin A derivatives, which are the chemical intermediates of these processes, are highly sensitive to UV light; thus, safe analyses of these processes in humans are currently beyond the reach of even the most modern ocular imaging modalities. METHODS. We present a compact, 2-photon-excited fluorescence scanning laser ophthalmoscope and spectrally resolved images of the human retina based on 2-photon excitation (TPE) with near-infrared light. A custom Er:fiber laser with integrated pulse selection, along with intelligent postprocessing of data, enables excitation with low laser power and precise measurement of weak signals. RESULTS. We demonstrate spectrally resolved TPE fundus images of human subjects. Comparison of TPE data between human and mouse models of retinal diseases revealed similarity with mouse models that rapidly accumulate bisretinoid condensation products. Thus, visual cycle intermediates and toxic byproducts of this metabolic pathway can be measured and quantified by TPE imaging. CONCLUSION. Our work establishes a TPE instrument and measurement method for noninvasive metabolic assessment of the human retina. This approach opens the possibility for monitoring eye diseases in the earliest stages before structural damage to the retina occurs. FUNDING. NIH, Research to Prevent Blindness, Foundation for Polish Science, European Regional Development Fund, Polish National Agency for Academic Exchange, and Polish Ministry of Science and Higher Education., Introduction Ophthalmic imaging techniques are cornerstones in diagnosing retinal pathologies, disease management, and as a measure of surgical outcomes. In the last few decades, improvements in noninvasive imaging techniques have [...]

Four novel fluorescence sensors bearing a quinolylbenzothiazole platform were synthesized and characterized. The sensors displayed excellent selectivity and highly sensitive fluorescence response to [Fe.sup.3+] ion in [H.sub.2]O/DMSO buffer solution (1:4 volume ratio; Tris-HCl, 0.01 mol/L; pH = 7.40) at 500 nm originating from quinolylbenzothiazole fluorophore group. Other cations, namely Li (+], Na (+], K (+], Mg (2+], [Ca.sup.2+], [Co.sup.2+], [Ni.sup.2+], Cd (2+], [Cu.sup.2+], [Zn.sup.2+], Mn (2+], [Ba.sup.2+], Pb (2+], Hg (2+], Al (3+], and E[u.sup.3+], showed no appreciable change in fluorescence spectrum. The binding stoichiometry between sensors L1, L2, L3, or L4 and [Fe.sup.3+] was observed to be 1:1 based on fluorescence titration and Jobs plot analysis. The detection limits of L1, L2, L3, and L4 for [Fe.sup.3+]were found to be 0.155, 0.362, 0.249, and 0.517 [micro]mol/L, respectively. Furthermore, possible utilization of sensors to detect [Fe.sup.3+] in living HeLa cells was also investigated by confocal fluorescence microscopy. Key words: fluorescence sensor, quinolylbenzothiazole, [Fe.sup.3+] detection, fluorescence imaging. Nous avons synthetise et caracterise quatre nouveaux capteurs de fluorescence portant une plateforme de quinolylbenzothiazole. Ces capteurs ont presente une excellente selectivite et sensibilite elevee de la reponse en fluorescence aux ions [Fe.sup.3+] dans une solution tampon faite d'un melange de [H.sub.2]O/DMSO (rapport volumique de 1:4, Tris-HCl a 0,01 mol/L, pH = 7,40) a 500 nm. L'emission a cette longueur d'onde provient du groupe fluorophore quinolylbenzothiazole. Aucun changement appreciable n'a ete note dans le spectre de fluorescence d'autres cations, soit les ions Li (+], Na (+], K (+], Mg (2+], [Ca.sup.2+], [Co.sup.2+], [Ni.sup.2+], Cd (2+], [Cu.sup.2+], [Zn.sup.2+], Mn (2+], [Ba.sup.2+], Pb (2+], Hg (2+], Al (3+] et E[u.sup.3+]. En nous fondant sur le titrage fluorimetrique et l'analyse la courbe de Job, nous avons observe que la stoechiometrie de liaison entre les capteurs L1, L2, L3 ou L4 et le [Fe.sup.3+] etait de 1:1. Les capteurs L1, L2, L3 ou L4 ont revele des limites de detections des ions [Fe.sup.3+] de 0,155, 0,362, 0,249 et 0,517 [micro]mol/L, respectivement. De plus, nous avons egalement etudie la possibilite d'utiliser ces capteurs en bio-imagerie par fluorescence pour la detection d'ions [Fe.sup.3+] dans des cellules HeLa vivantes par microscopie de fluorescence confocale. [Traduit par la Redaction] Mots-cles: capteur de fluorescence, quinolylbenzothiazole, detection de [Fe.sup.3+], imagerie par fluorescence., Introduction Molecular sensors are highly valuable tools for the selective recognition of chemical and biological species. A fluorescent sensor commonly contains at least two parts, receptor unit and fluorophore unit. [...]

Techniques that render tissues as clear as glass and swell them to several times their original size are giving unprecedented access to the inner workings of biological systems.Techniques that render tissues as clear as glass and swell them to several times their original size are giving unprecedented access to the inner workings of biological systems., Author(s): Michael EisensteinAuthor Affiliations:Transparent tissues bring cells into focus for microscopy 3D image of peripheral nerves (green) in a tissue-cleared 8-week-old human embryo. [see PDF for image]Credit: Alain Chédotal/Morgane Belle3D [...]

Abstract: Autofluorescence of aldehyde-fixed tissues greatly hinders fluorescence microscopy. In particular, lipofuscin, an autofluorescent component of aged brain tissue, complicates fluorescence imaging of tissue in neurodegenerative diseases. Background and lipofuscin [...]

Abstract. In light sheet microscopy, optical sectioning by selective fluorescence excitation with a sheet of light is combined with fast full-frame acquisition. This illumination scheme provides minimal photobleaching and phototoxicity. [...]

Vibrational signals from molecules can provide contrast in bioimaging techniques, but are difficult to detect. Light in a 'squeezed' quantum state has been used to reveal molecular vibrational signals previously obscured by noise. Background noise reduced in a bioimaging method., Author(s): Eric O. Potma Author Affiliations: Squeezed light improves sensitivity of microscopy technique Much like fluorescence microscopy, stimulated Raman scattering (SRS) gain microscopy is an optical imaging method capable of [...]