Search results for "Complement"
showing 10 items of 2113 documents
Possible protective role for C-reactive protein in atherogenesis: complement activation by modified lipoproteins halts before detrimental terminal se…
2004
Background—Previous work indicated that enzymatically remodeled LDL (E-LDL) might activate complement in atherosclerotic lesions via a C-reactive protein (CRP)–dependent and CRP-independent pathway. We sought to substantiate this contention and determine whether both pathways drive the sequence to completion.Methods and Results—E-LDL was prepared by sequential treatment of LDL with a protease and cholesteryl esterase. Trypsin, proteinase K, cathepsin H, or plasmin was used with similar results. Functional tests were used to assess total complement hemolytic activity, and immunoassays were used to demonstrate C3 cleavage and to quantify C3a, C4a, C5a, and C5b-9. E-LDL preparations activated …
Activation of the first component of complement, C1: comparison of the effect of sixteen different enzymes on serum C1.
1983
In this study, the effect of sixteen different enzymes on serum C1 and its subcomponents was investigated. The sixteen enzymes could be divided into three groups. First, enzymes which activate native C1: trypsin (optimal concentration 2.4 x 10(-4) mM); alpha-chymotrypsin (2.3 x 10(3) mM); thrombin (1.0 x 10(-5) mM); plasmin (1.9 x 10(-5) mM); elastase (5.8 x 10(-5) mM); pronase (3.0 x 10(-6) mM). All these enzymes are serine esterase and activate native serum C1 bound to EAC4 at the given concentration within 10 min at 30 degrees C. Furthermore, native C1 inhibited by a pentosanpolysulfoester, Sp54, is unable to undergo the internal activation but can be externally activated by the serine e…
Prenylated Flavonoids from the Roots of Tephrosia rhodesica
2020
Five new compounds—rhodimer (1), rhodiflavan A (2), rhodiflavan B (3), rhodiflavan C (4), and rhodacarpin (5)—along with 16 known secondary metabolites, were isolated from the CH2Cl2–CH3OH (1:1) extract of the roots of Tephrosia rhodesica. They were identified by NMR spectroscopic, mass spectrometric, X-ray crystallographic, and ECD spectroscopic analyses. The crude extract and the isolated compounds 2–5, 9, 15, and 21 showed activity (100% at 10 μg and IC50 = 5–15 μM) against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum. peerReviewed
Hijacking the human complement inhibitor C4b-binding protein by the sporozoite stage of the Plasmodium falciparum parasite
2022
We thank Anna Blom for donating the C4bpα CCP1-2 expression plasmid (pET26-CCP1-2). The following reagent was obtained through BEI Resources, NIAID, NIH: Plasmid pDS56-32/RBSII-CS27IVC-6XHis, MRA-272, contributed by Photini Sinnis. The complement system is considered the first line of defense against pathogens. Hijacking complement regulators from blood is a common evasion tactic of pathogens to inhibit complement activation on their surfaces. Here, we report hijacking of the complement C4b-binding protein (C4bp), the regulator of the classical and lectin pathways of complement activation, by the sporozoite (SPZ) stage of the Plasmodium falciparum parasite. This was shown by direct binding …
El futuro de los plásticos o los plásticos del futuro
2020
espanolEn los ultimos tiempos politicos, activistas ambientales, periodistas y otros lideres de opinion han dirigido sus armas contra los plasticos. Este mal concepto nace como resultado de los cambios en el entorno como consecuencia de la utilizacion de nuevas fuentes de energia, tanto nuclear como la de combustibles fosiles y el desarrollo de la industria petroquimica en especial la de los plasticos que se da a partir del descubrimiento del petroleo. Sin embargo y a pesar de las consideraciones ambientales el plastico ha construido nuestro mundo hasta el punto en que hoy es dificil imaginar nuestra vida sin el. Muchos disenadores han sostenido desde mediados del siglo XX, que los articulo…
A critical role of plastidial glycolytic Glyceraldehyde-3-Phosphate Dehydrogenase in the control of plant metabolism and development
2009
3 páginas.
Mouse embryonic stem cells are hypersensitive to apoptosis triggered by the DNA damage O(6)-methylguanine due to high E2F1 regulated mismatch repair.
2007
Exposure of stem cells to genotoxins may lead to embryonic lethality or teratogenic effects. This can be prevented by efficient DNA repair or by eliminating genetically damaged cells. Using undifferentiated mouse embryonic stem (ES) cells as a pluripotent model system, we compared ES cells with differentiated cells, with regard to apoptosis induction by alkylating agents forming the highly mutagenic and killing DNA adduct O(6)-methylguanine. Upon treatment with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG), ES cells undergo apoptosis at much higher frequency than differentiated cells, although they express a high level of the repair protein O(6)-methylguanine-DNA methyltransferase (MGMT). Apo…
Stem cells, cancer stem-like cells, and natural products.
2012
Somatic stem cells can be found in many rapidly regenerating tissues, e.g., the skin, gastrointestinal mucosa, and hematopoietic system, but are also present at low numbers in non-regenerative organs such as the heart and brain. In these organs, somatic stem cells aid in normal tissue homeostasis and repair after injury as well as self-renewal and the generation of specific progenitor cells during differentiation. Cancer stem-like cells are a small subpopulation of self-renewing cells that are able to proliferate upon appropriate stimulation and differentiate into heterogeneous lineages in tumors. Modulation of the behavior of normal tissue stem cells and cancer stem-like cells is an emergi…
François Le Lionnais and the Oulipo. The Unexpected Role of Mathematics in Literature
2020
“The true spirit of delight, the exaltation, the sense of being more than Man, which is the touchstone of the highest excellence, is to be found in mathematics as surely as poetry” (Bertrand Russel, Mysticism and Logic, 1910). This sentence, quoted by François Le Lionnais in his work La Beauté en Mathématiques in [1], reflects his conception of a deep bond between mathematics and literature. He had a multifaceted education and was an erudite and founder of the Oulipo with Raymond Queneau. Even though he was neither a “professional” mathematician nor a “professional” man of letters but only an épicurien passionné as he defined himself [2],1 while alive, he channelled his interests in the the…
El diseño de packaging y su contribución al desarrollo de pequeños y medianos emprendimientos
2019
El presente trabajo refiere a la problemática del diseño de packaging orientado hacia pequeños y medianos emprendimientos de diseño que requieren de packaging innovadores, personalizados y de baja serie.El objetivo de este trabajo es dar a conocer los requerimientos generales que se deben considerar al emprender un proyecto de diseño de packaging de modo que presente mayores posibilidades de éxito. Para tal fin, se establecen una serie de pautas, identificando los puntos mas sensibles e influyentes para lograr que el Sistema PP (Packaging + producto) se convierta en un elemento estratégico en el punto de venta.En esta publicación se presenta además un marco metodológico para el análisis de …