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Non-Organic Vision Loss
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
Ashwini Kini, Mangayarkarasi Thandampallayam Ajjeya, Padmaja Sudhakar
In a patient displaying unilateral profound vision loss to extent of NLP, an absent RAPD in the presence of normal ophthalmic exam should raise suspicion for NOVL. This would be difficult to assess when the complaint is bilateral or unilateral and with subtle/hemianopic loss. Absence of RAPD may need to be verified using neutral density filters as subtle RAPD can be missed. Absence of RAPD would essentially mean in simple terms either no R, no A, no P or no D. No R means one would not expect to see a RAPD in bilateral and symmetric disease and hence would not be useful in a patient reporting bilateral deficit. No A means the defect is not in the afferent pathway, for example, if the patient complains of diplopia, which is an efferent pathway defect there would not be an RAPD. Similarly no RAPD is seen in cases of media opacities like corneal opacity or cataract. No P, means there is no defect in the pupillary pathway, i.e., the issue is either in front of the pupil pathway like refractive error, amblyopia, media opacity or beyond the pupillary pathway, i.e., cortical pathology. Lastly no D, means that no defect detectable either because of anatomic pupillary abnormality or patient is one eyed.
Medicinal Plants: Future Thrust Areas and Research Directions
Published in Amit Baran Sharangi, K. V. Peter, Medicinal Plants, 2023
Different types of markers like restriction fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD), inter simple sequence repeats (ISSR), simple sequence repeats (SSR) and amplified fragment length polymorphism (AFLP) markers are used for validation purpose in MAPs. DNA barcodes using second internal transcribed spacer (ITS2) region are used for discriminating medicinal plant species (Pang and Chen, 2014). RAPD analysis was used for evaluation of genetic relationships in several medicinal plant species. ISSR markers were used to evaluate the genetic diversity in many of the medicinal plants. Molecular markers can be employed to characterize any phenotypic trait, biochemical, and/or physiological mechanisms. The direct measurement of such traits can be simultaneously mapped. The number of loci controlling genetic variation of any important agronomic trait(s) in segregating population can be estimated, and the map positions of these loci in the genome be determined by means of molecular linkage genetic maps and QTL mapping technology.
Distribution, Biology, and Bio-Diversity of Fenugreek
Published in Dilip Ghosh, Prasad Thakurdesai, Fenugreek, 2022
Choudhary et al. (2013) evaluated the genetic variability in 17 Indian fenugreek varieties through morphological and molecular markers. Fifteen Random Amplified Polymorphic DNA (RAPD) markers were used and showed a 57.66% polymorphism. Further, based on the results all the varieties were classified into two major clusters, cluster-I and cluster-II, cluster-I irrespective of their geographical distribution.
Immune Checkpoint Inhibitors and Optic Neuropathy: A Systematic Review
Published in Seminars in Ophthalmology, 2023
James Pietris, Sanjana Santhosh, Gianni Ferdinando Cirocco, Antoinette Lam, Stephen Bacchi, Yiran Tan, Aashray K. Gupta, Joshua G. Kovoor, WengOnn Chan
Clinical presentation also varied considerably among cases of optic neuropathy. A painless reduction in visual acuity was reported in all four included studies that documented presenting symptoms.20,21,25,27 Other presenting symptoms included impaired colour vision and ocular pain.19 On examination, optic disc swelling was the most common finding, reported by three of the included studies.20,21,27 RAPD was reported in one study.21 Brain MRI findings were documented in three of the included studies. Two studies found an unaffected optic nerve, while one study found hyperintensities of the affected optic nerve.21,25,27 OCT showed optic nerve head oedema in one case, and HVF visual field defect was variable.21 It is noteworthy that while ICI-associated optic neuropathy may include typical optic neuritis, other phenotypes may occur including painless vision loss, without optic disc swelling, or MRI signal changes. This clinical heterogeneity highlights the need to maintain a high index of suspicion for optic neuropathy in patients receiving ICI.
Selected Ophthalmological Features in Children with Septo-Optic Dysplasia and Optic Nerve Hypoplasia
Published in Neuro-Ophthalmology, 2022
Michael S. Salman, Shakhawat Hossain, Elizabeth Carson, Chelsea A. Ruth, Ian H. Clark
An RAPD is more likely to be present: 1) in cases in which there is more severe BCVA impairment in the worse eye; 2) on the side of the hypoplastic optic disc; and 3) in cases with asymmetrical or unilateral BCVA impairment, specifically on the side with the greater visual impairment. Such findings have been described in patients with acquired unilateral or asymmetrical optic neuropathy from many causes but only in few studies on patients with SOD/ONH.26,27 The absence of an RAPD in cases with asymmetrical or unilaterally impaired BCVA may have been due to technical difficulties in eliciting the sign for example, due to poor cooperation of the child, the presence of nystagmus, or the presence of strabismus. Alternatively, the absence of RAPD in cases with asymmetrical or unilateral BCVA may point to the presence of amblyopia, which is not typically associated with RAPD. Therefore, such patients should be assessed carefully for amblyopia.
Evaluation of the genetic structure of Bromus inermis populations from chemically and radioactively polluted areas using microsatellite markers from closely related species
Published in International Journal of Radiation Biology, 2022
Elena V. Antonova, Marion S. Röder
Bromus inermis Less. is one from species of Poaceae family extensively utilized as a model organism in the field of phylogeny and evolution (Williams et al. 2011), cytology and karyology (Tuna et al. 2001; 2004; Nizam et al. 2020), ecology (Ishikawa et al. 1995; Antonova et al. 2020; Grant et al. 2020; Saeidnia et al. 2020), radiation biology (Antonova et al. 2014, 2015, 2019, 2020), breeding (Osipova 1982), population genetics (Diaby and Casler 2003; Sutkowska and Mitka 2008; Zhang et al. 2011; Cheng et al. 2014; Antonova et al. 2019) and genomics (Pillay 1993). The genetic parameters are widely studied on the representatives of the genus Bromus. Thus, the variability of RAPD and AFLP markers has been investigated in B. inermis (Zhang et al. 2011; Cheng et al. 2014; Antonova et al. 2019), Bromus catharticus (Puecher et al. 2001), Bromus sterilis (Green et al. 2000), and Bromus tectorum (Ramakrishnan et al. 2002, 2006; Kindiger and Conley 2009; Leger et al. 2009). ISSR markers have been studied in Bromus ircutensis (Yu et al. 2011), and isozyme markers have been studied in compact brome, red brome, rip gut brome, sterile brome, and cheatgrass (Oja 1998), as well as field brome and soft brome (Oja 2005). The similarity of the polyploids of the genus Bromus to the diploid B. sterilis (Oja 1998) has been shown, which may indicate the contribution of the sterile brome genome to the origin of these species.