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Aptamers in Bacterial, Viral, and Parasitic Diseases
Published in Rakesh N. Veedu, Aptamers, 2017
Henning Ulrich, Arquimedes Cheffer, Flávia M. Zimbres, Attila Tárnok, Carsten Wrenger
The rabies virus (RABV) causes a zoonotic disease named rabies, which is transmitted through contact with infected saliva during a bite or through direct contact with mucosal tissues. The viral infection leads to an acute fatal encephalitis, resulting in coma and death. Various warm-blooded mammals are affected by this infectious disease. To date, there is no available approved therapy against the clinical signs of the disease. As the infection is lethal in all the cases, the development of a cheap and effective drug has drawn attention. The aptamers represent, in this sense, a promising alternative. Indeed, aptamers have already been selected against RABV-infected cells by using the cell-SELEX technique [62]. These aptamers were posteriorly employed in viral titer assays, demonstrating that viral replication is inhibited in RABV-infected cells while no blockade of the canine distemper virus or canine parvovirus replication was observed, which confirms the specificity of the selected aptamers. Most importantly, the aptamers have been demonstrated to protect mice to some extent from RABV infection. Interestingly, the aptamers had a protective effect, since only circa 15% of the previously aptamer-treated animals died after inoculation with CVS-11. On the other hand, almost no mice survived when the aptamers were used for treatment [62].
Microscopy and related techniques
Published in C M Langton, C F Njeh, The Physical Measurement of Bone, 2016
Jean E Aaron, Patricia A Shore, Roger C Shore, Jennifer Kirkham
As a consequence of developments in microsampling and the observations of authors such as Ascenzi based upon the mechanical testing of individual trabeculae, separate osteons and lamellae, increasing attention is directed at the properties of bone at a microstructural and ultrastructural level. Technological advances have resulted in an expanding range of general and specialist microscopes and accessories, many of which are useful for bone. These include light microscopes (fluorescence, polarization, interference contrast, laser confocal which may be combined with absorption spectrometry), electron microscopes (e.g. transmission, scanning, high voltage), composition analysis systems (electron backscatter diffraction, X-ray microanalysis, i.e. EDX and XRF, energy filtering transmission electron microscopy (EFTEM), together with scanning probe microscopes (tunnelling, atomic force). These are used with histological, histochemical and immunohistochemical stains and tissue markers which differentiate or label (a) structural features (e.g. osteoid tissue, cell types, organelles), (b) specific enzymes (e.g. acid or alkaline phosphatase, proteinases such as collagenase), (c) specific structural proteins in the cells or extracellular matrix (e.g. collagenous and non-collagenous proteins), or (d) general and specific genomic activity in health and disease (e.g. the detection of messenger ribonucleic acid (mRNA) for natural cytokines such as growth factors and for pathogenic infection such as the canine distemper virus in pagetic bone). There are also markers for (e) inorganic ions (e.g. radioisotopes and calcium-sensitive fluorescent dyes such as tetracycline). These latter act as molecular probes to facilitate time-lapse investigation of cells in culture. They may be combined with laser confocal cellular three-dimensional morphology which enables interaction with the matrix to be observed in vitro (for an earlier alternative method see Aaron and Pautard [1] who viewed living bone cells under the optical microscope in situ possibly for the first time, and advocated the necessity of identifying ‘the right cell, in the right place, at the right time, using the right technique’). Added to stains for bone salt are (f) diverse special stains (e.g. to determine the matrix distribution of iron from ethnic cooking vessels (figure 7.1(a)), or excessive aluminium accumulation at the calcification front in the bone matrix after renal dialysis (figure 7.1(b)), where aluminium is used to chelate and control phosphate). Further afield in biology are (g) other stains with a more unusual skeletal application (e.g. to identify fungal spores and hyphae in palaeopathological specimens (figure 7.1(c)), crucial in separating the disturbances of putative past bone disease from post-interment changes [2]).
Cryptosporidiosis in Cats, Dogs, Ferrets, Raccoons, Opossums, Rabbits, and Non-Human Primates
Published in J. P. Dubey, C. A. Speer, R. Fayer, Cryptosporidiosis of Man and Animals, 2018
Most reports of intestinal cryptosporidiosis in the domestic dog have involved the young or immunosuppressed. The initial report was in a 1-week-old Pomeranian puppy.892 The pup was presented for acute diarrhea after litter mates died from undetermined causes. Histologic examination was limited to the small intestine of the diarrheic pup. Numerous Cryptosporidia were observed in the epithelium of villous tips and crypts. Villi were mildly blunted and the lamina propria had a mild increase in mononuclear cells. Concurrent infections could not be excluded. In another report, cryptosporidiosis was diagnosed in a 6-month-old Siberian husky with canine distemper virus infection.805 The pup had diarrhea and seizures. An immunodeficient state secondary to distemper virus infection was indicated by (1) neutropenia and bone marrow myeloid hypoplasia, (2) IgG hypoglobulinemia, (3) subnormal lymphocyte mitogenic responses, and (4) lymphoid depletion in thymus, spleen, and lymph nodes. The dog had also been treated with corticosteroids (dexamethasone and prednisone) at 19 weeks of age. Trichomonas, Giardia, and Cryptosporidium were identified in feces. Cryptosporidia were seen in small intestinal villous epithelial cells but lesions were not observed. Due to concurrent infections, the role of Cryptosporidium infection in the diarrhea could not be determined. In six cases of cryptosporidiosis in puppies, the infection was not associated with vomition or diarrhea.186,254,738 The first case was in a 6-week-old mixed breed pup presented in a semicomatose condition.738 The pup subsequently died, but the cause of death could not be determined. Cryptosporidia were observed within villous and crypt epithelial cells in the ileum. Ultrastructurally there was microvillar effacement in parasitized enterocytes, but other intestinal lesions were not observed. The second case was in a 6-week-old mixed breed pup presented for seizures.738 The clinical signs and subsequent death were attributed to toxaphene intoxication. Sections of small and large intestine contained cellular debris in scattered crypts and increased numbers of neutrophils and mononuclear cells in the lamina propria. A few Cryptosporidia were observed in ileal enterocytes. Parvovirus infection was excluded. The third subclinical case of cryptosporidiosis was reported in a 3-month-old Cockapoo with canine distemper virus infection.254 Cryptosporidia were observed in villous and crypt epithelium of the jejunum. Ultrastructurally, microvilli surrounding developmental stages were blunted. No other intestinal lesions were described and the infection was considered an incidental finding. In three 8-week-old puppies which were inoculated orally with Cryptosporidium oocysts from feces of an AIDS patient, the prepatent and patent periods were 5 and 7 d, respectively.186 Clinical signs were not observed. In puppies inoculated orally with oocysts from calves, the prepatent and patent periods were 2 to 14 d and 3 to 33 d, respectively.61
In vitro antiviral effect of Mexican and Brazilian propolis and phenolic compounds against human coronavirus 229E
Published in International Journal of Environmental Health Research, 2022
Norma Patricia Silva-Beltrán, Juan Carlos Galvéz-Ruíz, Luisa A. Ikner, Marcelo Andrés Umsza-Guez, Thiago Luiz de Paula Castro, Charles P. Gerba
On the other hand, it was demonstrated that of the three phenolic compounds, one phenolic acid (caffeic acid), and two flavonoids (rutin and quercetin) (Figure 5), quercetin was the most effective individual component to reduce the cytopathogenic activity of HCoV-229E. Previous studies on propolis from Mexico have evaluated the antiviral effects of quercetin and have reported a significant reduction in canine distemper virus (González-Búrquez et al. 2018). Likewise, Wu et al. (2015) found that quercetin inhibited influenza infection across a broad spectrum of strains including A/Puerto Rico/8/34 (H1N1), A/FM-1/47/1 (H1N1), and A/Aichi/2/68 (H3N2). In addition, in vitro and in vivo studies (rat model) performed by Shimizu et al. (2008) verified that ethanolic extracts of Brazilian propolis collected by Africanized bees Apis mellifera exhibited antiviral activity against influenza A (H1N1) at the concentration of 25 µg/mL. In this study, approximately 50 µg/mL of quercetin was needed to achieve a reduction greater than 90% of HCoV-229E cytopathology.