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Fluorescence in Histochemical Reactions
Published in Victoria Vladimirovna Roshchina, Fluorescence of Living Plant Cells for Phytomedicine Preparations, 2020
Victoria Vladimirovna Roshchina
Among fluorescent histochemical methods, there are only a few real dyes for lipids that have been applied to plant tissues. Among these is auramine O, used for cut sections of leaves from medicinal Agave spp. as well as for Dianthus and Brassica spp. (Gahan 1984). The samples are stained in a 0.01% solution of the dye for10 min, after which unsaturated acidic waxes fluoresce in greenish-yellow under blue light excitation in a fluorescence microscope. In some cases, many fluorescent flavonoids and coumarins, contained in secretory cells enriched oils, serve as markers for lipids and lipophilic compounds in thin-layer chromatography (Wagner and Bladt 1996).
Pharyngitis
Published in John C Watkinson, Raymond W Clarke, Terry M Jones, Vinidh Paleri, Nicholas White, Tim Woolford, Head & Neck Surgery Plastic Surgery, 2018
The diagnosis is usually clear because of the association with pulmonary disease, both clinically and radiologically, although pharyngeal squamous cell carcinoma with pulmonary metastases is the obvious differential. Microscopic examination of stained smears for acid-fast bacilli is still one of the most useful tests for the initial diagnosis of TB. Although less sensitive and specific than culture, the sensitivity can be greatly improved by using phenol auramine stain as compared with the older Ziehl–Neelsen technique. Semi-automated and continuous monitoring systems developed specifically for the isolation of mycobacteria include enzyme-linked immunosorbent assay (ELISA) tests to detect antigens and PCR to detect genetic elements.
An Outbreak of Cryptosporidium sp. Associated with a Public Swimming Pool
Published in Meera Chand, John Holton, Case Studies in Infection Control, 2018
Christina J. Atchison, Rachel M. Chalmers
A questionnaire was completed and stool samples were collected from the 11 children. In addition, other cases were sought by requesting local GPs, paediatricians, walk-in centres, and hospital microbiologists to report to GMHPU suspected cases of diarrhoea, vomiting, or both, that were potentially linked to the swimming pool, and to obtain a stool specimen if appropriate. Initial review of the questionnaires suggested that illness was linked to attendance at a training session at the pool on September 13. By September 28, three cases had submitted stool samples to the local microbiology laboratory and they tested positive for Cryptosporidium. The tests detected oocysts using fluorescent microscopy with auramine-phenol stain. These specimens were typed as Cryptosporidium hominis by real-time polymerase chain reaction (PCR) at the National Cryptosporidium Reference Unit, Public Health Wales, Swansea. An outbreak was declared and an Outbreak Control Team (OCT) was convened with representatives from GMHPU, the City Council Environmental Health Department, regional epidemiology and microbiology services, the national Cryptosporidium Reference Unit, and local Public Health. An outbreak investigation followed.
Lack of reactivation of tuberculosis in patients with psoriasis treated with secukinumab in a real-world setting of latent tuberculosis infection
Published in Journal of Dermatological Treatment, 2022
Matteo Megna, Cataldo Patruno, Maria Rita Bongiorno, Alessio Gambardella, Claudio Guarneri, Caterina Foti, Serena Lembo, Francesco Loconsole, Gabriella Fabbrocini
In our study, there were no cases of active TBC or TBC reactivation among 59 psoriasis patients with latent TBC treated with secukinumab for a mean time of 84 weeks of therapy. Of note, the sample also included 10 (17%) patients who did not undergo TBC prophylaxis prior to secukinumab treatment. Hence, our real-life data further supports data from phase III clinical trials, which showed no cases of TBC reactivation with secukinumab (15,18,21). Secukinumab is not likely to induce TB reactivation probably because, unlike TNF-α, IL-17 is not involved in the pathogenesis of M. tuberculosis infection reactivation. Indeed, it appears that, as the target of IL-17A antibody treatments, such as secukinumab, is downstream of the immune pathway, reactivation of latent TBC or other opportunistic infections is minimized (16,28,31). These data are also all supported by an in vitro study of Kammuller et al. (33), who examined the effect of the anti-TNF-α monoclonal antibody, adalimumab, and secukinumab on dormant M. tuberculosis H37Rv in a novel human three-dimensional microgranuloma model. In particular, they showed that secukinumab was comparable to control treatment, indicating a lack of effect on M. tuberculosis dormancy. In contrast, adalimumab showed increased staining for Auramine-O, decreased Nile red staining and decreased rifampicin resistance, indicative of mycobacterial reactivation (33).
Chapter 3: Diagnosis of tuberculosis disease and drug-resistant tuberculosis
Published in Canadian Journal of Respiratory, Critical Care, and Sleep Medicine, 2022
Marcel A. Behr, Simon Grandjean Lapierre, Dennis Y. Kunimoto, Robyn S. Lee, Richard Long, Inna Sekirov, Hafid Soualhine, Christine Y. Turenne
Sputum smear microscopy is the most widely used test for TB disease.26 Two stains are widely used: 1) the traditional Ziehl-Neelsen or Kinyoun staining, which requires a light or bright field microscopy and 2) the auramine-rhodamine stain, which requires fluorescence microscopy (see Appendix 1). In most high-income countries (including Canada), fluorescence microscopy is standard practice because it can be read at a lower magnification than the classic Ziehl-Neelsen or Kinyoun stain, thus allowing slides to be read more quickly.28 The sensitivity of all staining methods, however, is inferior to that of culture. The threshold of detection of AFB in concentrated specimens using a fluorochrome stain is 5,000-10,00045,46 bacteria/mL of sputum and is 100,000 bacteria/mL using the Ziehl-Neelsen stain. The threshold of detection in unconcentrated smears is 10-fold higher, resulting in much lower sensitivity. This is important to remember, since often “stat” smears are unconcentrated. In contrast, as few as 10 viable bacteria can be detected by culture.
New therapies versus first-generation biologic drugs in psoriasis: a review of adverse events and their management
Published in Expert Review of Clinical Immunology, 2018
J. M. Carrascosa, E. Del-Alcazar
No cases of acute TB or reactivation of LTBI have been reported in the clinical trials of secukinumab and ixekizumab [41,43], and in the case of secukinumab, no cases of TB were reported in the 12 months after treatment [63]. This low risk of TB reactivation during and after treatment with secukinumab in patients with a history of TB or treated LTBI is also supported by experimental in vitro studies. The effects of adalimumab and secukinumab on latent M. tuberculosis have been investigated in a novel human three-dimensional microgranuloma model. In vitro, adalimumab treatment showed increased staining for Auramine-O, decreased Nile red staining, and decreased rifampicin resistance, all signs indicative of mycobacterial reactivation. The results of treatment with secukinumab, by contrast, were comparable to the controls, indicating a lack of effect on the latency of M. tuberculosis [63]. Finally, no cases of TB reactivation or active TB have been reported in phase III trials of guselkumab [16,17], tildrakizumab [18], or brodalumab [20,21], or in phase II trials of risankizumab [19]. However, the impact of the new anti-IL-17A and anti-p19 agents on TB infection will only become clear in the coming years.