19 research outputs found
Should ACE2 be given a chance in COVID-19 therapeutics: a semi-systematic review of strategies enhancing ACE2
No full textThe severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) has resulted in almost 28 million cases of COVID-19 (Corona virus disease-2019) and more than 900000 deaths worldwide since December 2019. In the absence of effective antiviral therapy and vaccine, treatment of COVID-19 is largely symptomatic. By making use of its spike (S) protein, the virus binds to its primary human cell receptor, angiotensin converting enzyme 2 (ACE2) which is present in the pulmonary epithelial cells as well as other organs. SARS-CoV-2 may cause a downregulation of ACE2. ACE2 plays a protective role in the pulmonary system through its Mas-receptor and alamandine-MrgD-TGR7 pathways. Loss of this protective effect could be a major component of COVID-19 pathogenesis. An attractive strategy in SARS-CoV-2 therapeutics would be to augment ACE2 either directly by supplementation or indirectly through drugs which increase its levels or stimulate its downstream players. In this semi-systematic review, we have analysed the pathophysiological interplay between ACE and ACE2 in the cardiopulmonary system, the modulation of these two proteins by SARS-CoV-2, and potential therapeutic avenues targeting ACE-Ang II and ACE2-Ang (1-7) axes, that can be utilized against COVID-19 disease progression
Subacute Sclerosing Panencephalitis in a 63-Year-Old Woman Presenting as Generalized Choreoathetosis
No full text20.500.12530/87912The persistence of measles virus infection in childhood and early adolescence can rarely lead to a fatal progressive neurodegenerative disorder known as subacute sclerosing panencephalitis (SSPE), characterized by behavioral disturbances and intellectual disability followed by myoclonic jerks and occasional negative myoclonus. Movement disorders are rarely presenting manifestations in SSPE. We herein report a 63-year-old woman with generalized choreoathetosis as the presenting manifestation of stage-I SSPE. Our case was atypical for the patient's age and clinical presentation with generalized choreoathetosis and bilateral putaminal and caudate nucleus signal hyperintensity. Though highly uncommon, neurologists should keep SSPE as a differential diagnosis among patients with movement disorders. Measles-endemic countries should be more vigilant to the atypical and rare presentations of SSPE, such as generalized choreoathetosis
Norovirus-associated neurological manifestations: summarizing the evidence
No full textNorovirus, a positive-stranded RNA virus, is one of the leading causes of acute gastroenteritis among all age groups worldwide. The neurological manifestations of norovirus are underrecognized, but several wide-spectrum neurological manifestations have been reported among infected individuals in the last few years. Our objective was to summarize the features of norovirus-associated neurological disorders based on the available literature. We used the existing PRISMA consensus statement. Data were collected from PubMed, EMBASE, Web of Science, and Scopus databases up to Jan 30, 2023, using pre‐specified searching strategies. Twenty-one articles were selected for the qualitative synthesis. Among these, seven hundred and seventy-four patients with norovirus-associated neurological manifestations were reported. Most cases were seizure episodes, infection-induced encephalopathy, and immune-driven disorders. However, only a few studies have addressed the pathogenesis of norovirus-related neurological complications. The pathogenesis of these manifestations may be mediated by either neurotropism or aberrant immune-mediated injury, or both, depending on the affected system. Our review could help clinicians to recognize these neurological manifestations better and earlier while deepening the understanding of the pathogenesis of this viral infection.Depto. de MedicinaFac. de MedicinaTRUEpubAPC financiada por la UC
Atypical chest pain with non-specific ST changes: an incidental finding of myocardial bridge without flow limiting coronary lesion
No full textMyocardial bridging is a developmental anomaly characterized by intramural course of a short segment of epicardial coronary artery which mostly remains silent in the initial few decades of life. A 42 years old male non diabetic, hypertensive on single regime therapy presented with atypical chest pain for the last two hours. Serial 12 lead ECGs on an interval of half-hour showing nonspecific dynamic ST changes in lead II, III and aVF suggesting of inferior wall changes with negative bio markers like troponin-T and troponin-I. Coronary angiography reveals myocardial bridge in mid segment of left anterior descending artery (LAD). Considering superficial type of bridging in this case, a conservative management strategy was planned accordingly. Physicians should be more vigilant on possibilities of underlying myocardial bridging as a major differential in emergency scenarios with low suspicion of atherosclerosis but with a picture equivalent to acute coronary syndrome (ACS). Myocardial bridge carries a wide array of complications depending on variabilities like depth of tunnelling, collapsibility, loss of wall sheer stress and vasospastic changes. Hence it needs to be promptly diagnosed with immediate treatment
SG_Mutual_Beam_Pump_Power.mp4
No full textThe video displays the evolution of a mutual beam comprised of signal and idler as a function of incident pump power in an MgO-doped PPLN based optical parametric generation experiment. Here, the pump is an 400 femtosecond ultrashort pulse being incident on the MgO-doped PPLN crystal at a repetition rate of1 MHz and spatial beam waist of 220 micron.</p
Moyamoya disease presenting with transient nonfocal neurological attacks in an Indian woman carrying a previously unreported RNF213 missense variant (p.Thr554Ile)
No full textMoyamoya disease is a rare cerebrovascular disorder characterized by progressive internal carotid artery stenosis and compensatory collateral vessel formation, producing a characteristic “puff of smoke” angiographic appearance. Genetic predisposition, particularly involving the RNF213 gene, plays a central role. We report a 48-year‐old Indian woman with type 2 diabetes, arterial hypertension, and a prior transient ischemic attack who presented with intermittent bilateral upper limb paresthesia. Imaging revealed bilateral supraclinoid internal carotid artery stenosis (Suzuki stage III). Genetic testing identified a heterozygous RNF213 missense variant (Thr554Ile, rs766831703), which is extremely rare in global databases and predicted to be deleterious by multiple in silico tools. This variant has not been previously described in association with Moyamoya disease. The patient underwent bilateral superficial temporal artery to middle cerebral artery bypass, achieving sustained clinical improvement without recurrent events over two years.Depto. de MedicinaFac. de MedicinaTRUEpu
Geometric representation of adiabatic distributed-Bragg-reflectors and broadening the photonic bandgap
No full textAdiabatic following has been an widely-employed technique for achieving near-complete population transfer in a `two-level' quantum mechanical system. The theoretical basis, however, could be generalized to a broad class of systems exhibiting SU(2) symmetry. In the present work, we present an analogy of population transfer dynamics of two level atomic system with that of light propagation in a classical `one-dimensional' photonic crystal, commonly known as distributed-Bragg-reflector (DBR). This formalism facilitates in adapting the idea of adiabatic following, more precisely the rapid adiabatic passage (RAP) which is usually encountered in a broad class of quantum-mechanical systems. We present a chirped DBR configuration in which the adiabatic constraints are satisfied by virtue of optimally chirping the DBR. The reflection spectrum of the configuration exhibit broadening of photonic bandgap (PBG) in addition to a varying degree of suppression of sharp reflection peaks in the transmission band. The intermodal coupling between counter-propagating modes as well as their phase-mismatch, for the DBR configuration, exhibits a longitudinal variation which is usually observed in `Allen-Eberly' scheme of adiabatic population transfer in two-level atomic systems
Supplementary document for Infrared rainbow trapping via optical Tamm modes in one-dimensional dielectric chirped photonic crystals - 5401888.pdf
No full textSupplementary document S
Diverse immunopathological manifestations and immunogenomic predispositions in COVID-19: summarizing the evidence
No full textThe COVID-19 pandemic has caused immense damage to most nations of the world, both in terms of loss of human lives, as well as, socio-economic attributes. The immunopathogenesis of the responsible pathogen, SARS-CoV-2, has been a focal point and researchers have succeeded in deciphering the multi-organ tropism of the virus along with its different routes of infection. The hallmark feature of the SARS-CoV-2 disease pathogenesis is the high rates of transmission and the susceptibility of a vulnerable group with systemic co-morbidities. Also, genetic components of the host, as well as mutant variants of the virus have further complicated the development of appropriate treatment strategies and preventive measures. The virus is aptly able to modulate the host immune system and mediate immune-dysregulation in terms of cytokine or chemokine production leading to a heightened inflammatory response. In the current review, we have summarized the present research on SARS-CoV-2 from the angles of host genetic polymorphism, genetic variants of the virus, and how these affect the high transmission, disease susceptibility, and tissue tropism in multiple organs of the human body
