Search results for "Type I"
showing 10 items of 966 documents
Photochemical reactivity of 6α-hydroxy, 7-keto neoclerodane diterpenoids
2006
Abstract The photochemical reactivity, in methanol at λ = 254 nm, of two 6α-hydroxy-7-keto neoclerodane, isoeriocephalin ( 1 ) and teucrolivin B ( 2 ) was evaluated. From the first compound, two new products were obtained: the 6β-hydroxy epimer ( 3 ) and the ɛ-lactone ( 4 ). The second one yielded exclusively the new spiro γ-lactone ( 5 ). The formation of these new products can be explained by the well-known radical mechanism Norrish type I.
WRN protects against topo I but not topo II inhibitors by preventing DNA break formation
2008
The Werner syndrome helicase/3′-exonuclease (WRN) is a major component of the DNA repair and replication machinery. To analyze whether WRN is involved in the repair of topoisomerase-induced DNA damage we utilized U2-OS cells, in which WRN is stably down-regulated (wrn-kd), and the corresponding wild-type cells (wrn-wt). We show that cells not expressing WRN are hypersensitive to the toxic effect of the topoisomerase I inhibitor topotecan, but not to the topoisomerase II inhibitor etoposide. This was shown by mass survival assays, colony formation and induction of apoptosis. Upon topotecan treatment WRN deficient cells showed enhanced DNA replication inhibition and S-phase arrest, whereas af…
219 Incidence Testing of Hunter Syndrome in A Population at Risk - First Results of A Binational Screening Programme
2012
Background Hunter syndrome (Mucopolysaccharidosis type II; X-linked inheritance; prevalence rate in Europe approximately 1:77000 male newborns) is a rare, progressive, multisystemic disease, caused by deficiency of the lysosomal enzyme Iduronate-2-sulfatase. Due to the very heterogeneous phenotype Hunter syndrome is often not diagnosed before pre-school age. This is unfortunate, because patients would significantly benefit from the earliest possible start of treatment containing enzyme replacement therapy. Early screening methods are possible, but due to the rarity of this disease they are too expensive to be performed in all newborns. An at-risk patient population screening provides opport…
Learning Curve in Surgical Treatment of Odontoid Fixation for a Series of Type II C2 Fractures
2019
The craniovertebral junction (CVJ) is a complex anatomical area upon which most of the motion of the upper cervical spine depends [1]. Because of its unique range of motion, the CVJ is subject to several types of traumatic injury; it has been shown that odontoid fractures are the most common ones in the general population and are the most common isolated spinal fractures [2]. Accounting for up to 18% of all cervical fractures, odontoid fractures are the most common ones in elderly patients [3], in whom they account for up to 60% of spinal cord injuries [4].
Type II keratin cDNAs from the rainbow trout: implications for keratin evolution.
2002
From a teleost fish, the rainbow trout Oncorhynchus mykiss, we have cloned and sequenced cDNAs encoding five different type II keratins. The corresponding protein spots, as separated by 2D-PAGE of trout cytoskeletal preparations, have been identified by peptide mass mapping using MALDI mass spectrometry. Three of the sequenced keratins are expressed in the epidermis (subtype IIe), and two in simple epithelia and mesenchymal cells (subtype IIs). The IIs keratins are both orthologs of human K8. This leaves unsequenced only the trace component S3 of the biochemically established trout keratin catalog. A phylogenetic tree has been constructed from a multiple alignment of the rod domains of the …
A mutation in the second intracellular loop of the pituitary adenylate cyclase activating polypeptide type I receptor confers constitutive receptor a…
2000
AbstractThe pituitary adenylate cyclase activating polypeptide (PACAP) type I receptor belongs to the glucagon/secretin/vasoactive intestinal polypeptide (VIP) receptor family. We mutated and deleted an amino acid residue (E261) which is located within the second intracellular loop of the rat PACAP type I receptor and which is highly conserved among the receptor family. The wild-type receptor and the mutant receptors were efficiently expressed at the surface of COS-7 cells at nearly the same level and revealed the same high affinity for the agonist PACAP-27. The cAMP contents of COS cells transfected with the E261A, E261Q, and the deletion mutant receptor were 4.6-, 5.7-, and 6.7-fold highe…
Poincaré Type Inequalities for Vector Functions with Zero Mean Normal Traces on the Boundary and Applications to Interpolation Methods
2019
We consider inequalities of the Poincaré–Steklov type for subspaces of H1 -functions defined in a bounded domain Ω∈Rd with Lipschitz boundary ∂Ω . For scalar valued functions, the subspaces are defined by zero mean condition on ∂Ω or on a part of ∂Ω having positive d−1 measure. For vector valued functions, zero mean conditions are applied to normal components on plane faces of ∂Ω (or to averaged normal components on curvilinear faces). We find explicit and simply computable bounds of constants in the respective Poincaré type inequalities for domains typically used in finite element methods (triangles, quadrilaterals, tetrahedrons, prisms, pyramids, and domains composed of them). The second …
Effect of the Time Dependent Loading of Type IV Cylinders using a Multiscale Model
2019
International audience; The current requirements for composite cylinders are still based on an arbitrary approach derived from the behaviour of metal structures, that the designed burst pressure should be at least 2.5 times the maximum in-service pressure [1]. This could lead to an over-designed composite cylinder for which the weight saving would be less than optimum. Moreover, predicting the lifetime of composite cylinders is a challenging task due to their anisotropic characteristics. A federal research institute in Germany (BAM) has proposed a minimum load-cycle requirement that mitigates this issue by using a Monte-Carlo analysis of the burst test results [2-3]. To enrich this study, m…
Integrin-mediated Cell Adhesion to Type I Collagen Fibrils
2004
In the integrin family, the collagen receptors form a structurally and functionally distinct subgroup. Two members of this subgroup, α1β1 and α2β1 integrins, are known to bind to monomeric form of type I collagen. However, in tissues type I collagen monomers are organized into large fibrils immediately after they are released from cells. Here, we studied collagen fibril recognition by integrins. By an immunoelectron microscopy method we showed that integrin α2I domain is able to bind to classical D-banded type I collagen fibrils. However, according to the solid phase binding assay, the collagen fibril formation appeared to reduce integrin α1I and α2I domain avidity to collagen and to lower …
On Descriptive Characterizations of an Integral Recovering a Function from Its $$L^r$$-Derivative
2022
The notion of Lr-variational measure generated by a function F ∈ Lr[a, b] is introduced and, in terms of absolute continuity of this measure, a descriptive characterization of the HKr -integral recovering a function from its Lr-derivative is given. It is shown that the class of functions generating absolutely continuous Lr-variational measure coincides with the class of ACGr -functions which was introduced earlier, and that both classes coincide with the class of the indefinite HKr-integrals under the assumption of Lr-differentiability almost everywhere of the functions consisting these classes