Search results for "intermediate"
showing 10 items of 440 documents
Conformational dynamics of active site loops 5, 6 and 7 of enzyme Triosephosphate Isomerase: A molecular dynamics study
2018
AbstractTriosephosphate Isomerase is a glycolytic enzyme catalyzing the interconversion of Dihydroxyacetone phosphate to Glyceraldehyde-3-phosphate. The active site is comprised of three distinct loops loop-6, loop-7 and loop-8. Based on loop-6 and loop-7 conformation we describe the enzyme as Open TIM and Closed TIM. Various NMR, X-ray crystallography and QM/MM simulation techniques have provided glimpses of individual events of what is essentially a dynamic process. We studied the conformational changes of two distinct loops (loop-6 and loop-7) enveloping the active site, in the presence of natural substrate, reaction intermediates and inhibitor molecules, by means of microsecond atomisti…
Tension causes structural unfolding of intracellular intermediate filaments
2020
AbstractIntermediate filament (IF) proteins are a class of proteins that constitute different filamentous structures in mammalian cells. As such, IF proteins are part of the load-bearing cytoskeleton and support the nuclear envelope. Molecular dynamics simulations have shown that IF proteins undergo secondary structural changes to compensate mechanical loads, which has been confirmed by experimental in vitro studies on IF hydrogels. However, the structural response of intracellular IF to mechanical load has yet to be elucidated in cellulo. Here, we use in situ nonlinear Raman imaging combined with multivariate data analysis to quantify the intracellular secondary structure of the IF cytoske…
Spatial distribution of various types of bulbar respiratory neurons in the rabbit
1977
In anesthetized rabbits, the burst activity of 277 single respiratory neurons was recorded extracellularly. The neurons were classified according to their spike incidence distribution within the respiratory cycle and to their response to lung distension or collapse (alpha or beta type). About one third of the neurons found in all animals were located at the level of the caudal end of the promontorium gliosum, widely scattered over the bulbar cross-section. More rostrally the units were located within a dorsal area neighbouring the tractus solitarius, more caudally within a ventral field surrounding the nucleus ambiguus. Most of the inspiratory neurons (the most frequently encountered type) …
First Record of the Nematode Physaloptera squamatae in the Helminth Community of the Introduced Anole Anolis grahami (Polychrotidae) on Bermuda
2021
The gastrointestinal helminth communities of five populations of Anolis grahami, an introduced anole on Bermuda, were surveyed to determine the prevalence, abundance, and species diversity of parasites in these reptiles. Only three nematode species were found, Atractis scelopori, Parapharyngodon cubensis, and Physaloptera squamatae. This species, P. squamatae, is recorded for the first time in Anolis grahami on Bermuda, probably introduced through its arthropod intermediate host. The role of the host A. grahami as a “spillover” agent for these parasites is discussed.
Defective carbohydrate metabolism in multiple sclerosis
2015
La esclerosis múltiple (EM) es una enfermedad crónica del sistema nervioso central (SNC) en el que episodios repetidos de inflamación (bortes), dan lugar a inflamación que conduce a la interrupción de la vaina de mielina por daños producidos en la misma. Junto a este fenómeno de inflación focal, existe una inflamación difusa en el SNC, que unida a la anterior, dará lugar a que aparezca un proceso de neurodegeneración, que será el responsable último de la afectación axonal y neuronal difusa que es la que va a condicionar la discapacidad en los pacientes afectos de EM. La enfermedad es una causa importante de discapacidad neurológica y de disfunción neurológica en adultos jóvenes que afecta a…
Ecological divergence of closely related Diplostomum (Trematoda) parasites.
2006
Parasite life-cycles present intriguing model systems to study divergence in resource use and ecology between parasite taxa. In ecologically similar taxa, consistent selective forces may lead to convergence of life-history traits, but resource overlap and similarity of life-cycles may also promote divergence between the taxa in (1) use of host species or (2) specific niche within a host. We studied the life-history characteristics of 2 sympatric species of Diplostomum parasites, D. spathaceum and D. gasterostei, concentrating particularly on differences in intermediate host use and characteristics of the infective stages between the species. This group of trematodes is a notoriously difficu…
Benzo-Fused Periacenes or Double Helicenes? Different Cyclodehydrogenation Pathways on Surface and in Solution
2019
Controlling the regioselectivity of C-H activation in unimolecular reactions is of great significance for the rational synthesis of functional graphene nanostructures, which are called nanographenes. Here, we demonstrate that the adsorption of tetranaphthyl- p-terphenyl precursors on metal surfaces can completely change the cyclodehydrogenation route and lead to obtaining planar benzo-fused perihexacenes rather than double [7]helicenes during solution synthesis. The course of the on-surface planarization reactions is monitored using scanning probe microscopy, which unambiguously reveals the formation of dibenzoperihexacenes and the structures of reaction intermediates. The regioselective pl…
Localization of the giant axonal neuropathy gene to chromosome 16q24
1998
Giant axonal neuropathy (GAN) is a degenerative disorder of the peripheral nerves that is inherited as an autosomal recessive trait, presenting in early childhood and progressing to death, usually by late adolescence. Diagnosis is made by peripheral nerve biopsy, in which a striking pathological finding is seen--fibers distorted by giant axonal swellings filled with densely packed bundles of neurofilaments (the primary intermediate filament in neurons), with segregation of other axoplasmic organelles. In addition to disorganized neurofilaments in nerve, disorganization of other members of the intermediate filament family of proteins is seen in other tissues; this implies that the underlying…
Neurofilament light chain levels reflect outcome in a patient with glutamic acid decarboxylase 65 antibody–positive autoimmune encephalitis under imm…
2020
Neurological immune-mediated side effects are rare but often severe complications of immune checkpoint inhibitor (ICI) treatment. This report describes a severe case of nivolumab/ipilimumab-associated glutamic acid decarboxylase 65-positive autoimmune encephalitis. It proposes neurofilament light chain levels, a biomarker indicating axonal damage, in the cerebrospinal fluid and serum as a putative novel biomarker for this diagnostically and therapeutically challenging entity with an often unfavorable outcome. Additionally, we provide an overview of previous reports of patients developing autoimmune encephalitis under ICI treatment.
Partial wave analysis of ψ(2S)→ppˉη
2013
Using a sample of 1.06 x 10(8) psi(2) events collected with the BESIII detector at BEPCII, the decay psi(2S) -> p (p) over bar eta is studied. A partial wave analysis determines that the intermediate state N(1535) with a mass of 1524 +/- 5(-4)(+10) MeV/c(2) and a width of 130(-24-10)(+27+57) MeV/c(2) is dominant in the decay; the product branching fraction is determined to be B(psi(2S) -> N(1535)(p) over bar x B(N(1535) -> p eta + c.c. = 5.2 +/- 0.3(-1.2)(+3.2)) x 10(-5). Furthermore, the branching fraction of psi(2S) -> p (p) over bar eta is measured to be (6.4 +/- 0.2 +/- 0.6) x 10(-5). Here, the first error is statistical and the second is systematic.