Male reproductive tract CD52 (mrtCD52) is an antigen recognized by a complement-dependent sperm-immobilizing monoclonal antibody (SI-Abs) derived in an infertile patient. The molecule has been shown ...to contain a unique N-linked carbohydrate that does not cross-react with other tissues. In this study, we have investigated whether O-linked carbohydrate as well as N-linked carbohydrate is present in mrtCD52 using specific lectins and anti-CD52 core peptide antiserum. The lectin PNA, which recognizes O-linked carbohydrate Galβ1−3GalNAc, reacted with mrtCD52 and showed a similar polymorphic reaction pattern to that of the anti-peptide antiserum in western blotting analysis on two-dimensional SDS–PAGE. The PNA-reactive spots disappeared after removal of O-linked carbohydrate, but not after removal of N-linked carbohydrate. These results suggest that O-linked carbohydrate is present in mrtCD52. The moiety may possibly contribute to a specific antigenic epitope of mrtCD52.
We perform two-dimensional numerical simulations on the core collapse of a massive star with strong magnetic fields and differential rotations using the numerical code ZEUS-2D. Changing field ...configurations and laws of differential rotation parametrically, we compute 14 models and investigate the effects of these parameters on the dynamics. In our models we do not solve the neutrino transport but instead employ a phenomenological parametric EOS that takes into account the neutrino emissions. As a result of the calculations, we find that the field configuration plays a significant role in the dynamics of the core if the initial magnetic field is large enough. Models with initially concentrated fields produce more energetic explosions and more prolate shock waves than the uniform field. Quadrupole-like fields produce a remarkably collimated and fast jet, which might be important for gamma-ray bursts (GRBs). The Lorentz forces exerted in the region where the plasma b is less than unity are responsible for these dynamics. The pure toroidal field, on the other hand, does not lead to any explosion or matter ejection. This suggests that the presupernova models, in which toroidal fields are predominant are disadvantageous for the magnetorotation-induced supernova considered here. Models with initially weak magnetic fields do not lead to explosion or matter ejection, either. In these models magnetic fields play no role, as they do not grow on the timescale considered in this paper and the magnetic pressure could be comparable to the matter pressure. This is because the exponential field growth as expected in MRI is not seen in our models. The magnetic field is amplified mainly by field compression and field wrapping in our simulations.
We describe a real-world application for a next generation airline network using a novel Small-World (SW) network architecture. An emergent method that creates a new type of Small-World network with ...less average path-length than that obtained with conventional small-world networks is presented. This method is inspired from an Ant-Colony Optimization (ACO) algorithm. The resultant network architecture becomes a multi-star network, which yields a large clustering coefficient and the shortest average path-length among the conventional complex networks such as the Watts-Strogatz and Barabási-Albert models etc., from both a theoretical and an experimental analysis of the properties of those networks. Given the advantageous properties of the multi-star network in real-world applications, it could be used to design a new generation global airline network superseding in terms of efficiency and convienience the current, conventional airline network owing to fewer transits and a shorter cruising distance on average from any starting point to any destination on Earth. This will be beneficial not only both to travelers and airline companies, but will also contribute to the reduction of greenhouse gases such as carbon dioxide (CO 2 ) in the near future, while enhancing communications and transportation worldwide.
Human monoclonal antibody, MAb H6‐3C4, possesses strong sperm immobilizing activity. MAb H6‐3C4 has been suggested by several research groups to react with a carbohydrate moiety of male reproductive ...tract CD52 (mrtCD52). In the present study, we analysed the epitope on mrtCD52 for MAb H6‐3C4 and found that it was polymorphic in Western blot analysis and disappeared after enzymatic removal of the N‐linked carbohydrate moiety. Two other monoclonal antibodies (1G12, campath‐1) with sperm‐immobilizing activity recognized mrtCD52 in a polymorphic manner similar to MAb H6‐3C4. Further analysis showed that 1G12 recognized a structure formed by the peptide and/or a glycosylphosphatidylinositol (GPI) anchor portion as does campath‐1. Results of a lectin binding assay suggested the presence of O‐linked carbohydrates on mrtCD52. Our results also indicated that the peptide portion of CD52 could serve as an epitope for sperm‐immobilizing antibodies. It was concluded that the epitope of MAb H6‐3C4 is similar to, but distinct from, those of 1G12 and campath‐1, and that mrtCD52 contains different antigenic epitopes.
Cytoglobin (Cgb), a newly discovered member of the vertebrate globin family, binds O2 reversibly via its heme, as is the case for other mammalian globins (hemoglobin (Hb), myoglobin (Mb) and ...neuroglobin (Ngb)). While Cgb is expressed in various tissues, its physiological role is not clearly understood. Here, the X-ray crystal structure of wild type human Cgb in the ferric state at 2.4Å resolution is reported. In the crystal structure, ferric Cgb is dimerized through two intermolecular disulfide bonds between Cys38(B2) and Cys83(E9), and the dimerization interface is similar to that of lamprey Hb and Ngb. The overall backbone structure of the Cgb monomer exhibits a traditional globin fold with a three-over-three α-helical sandwich, in which the arrangement of helices is basically the same among all globins studied to date. A detailed comparison reveals that the backbone structure of the CD corner to D helix region, the N terminus of the E-helix and the F-helix of Cgb resembles more closely those of pentacoordinated globins (Mb, lamprey Hb), rather than hexacoordinated globins (Ngb, rice Hb). However, the His81(E7) imidazole group coordinates directly to the heme iron as a sixth axial ligand to form a hexcoordinated heme, like Ngb and rice Hb. The position and orientation of the highly conserved residues in the heme pocket (Phe(CD1), Val(E11), distal His(E7) and proximal His(F8)) are similar to those of other globin proteins. Two alternative conformations of the Arg84(E10) guanidium group were observed, suggesting that it participates in ligand binding to Cgb, as is the case for Arg(E10) of Aplysia Mb and Lys(E10) of Ngb. The structural diversities and similarities among globin proteins are discussed with relevance to molecular evolutionary relationships.
A high throughput screen for neutral, magnesium-dependent sphingomyelinase (SMase) was performed. One inhibitor discovered
in the screen, GW4869, functioned as a noncompetitive inhibitor of the ...enzyme in vitro with an IC 50 of 1 μ m . It did not inhibit acid SMase at up to at least 150 μ m . The compound was then evaluated for its ability to inhibit tumor necrosis factor (TNF)-induced activation of neutral SMase
(N-SMase) in MCF7 cells. GW4869 (10 μ m ) partially inhibited TNF-induced sphingomyelin (SM) hydrolysis, and 20 μ m of the compound was protected completely from the loss of SM. The addition of 10â20 μ m GW4869 completely inhibited the initial accumulation of ceramide, whereas this effect was partially lost at later time points
(24 h). These data therefore support the inhibitory action of GW4869 on N-SMase not only in vitro but also in a cellular model. The addition of GW4869 at both 10 and 20 μ m did not modify cellular glutathione levels in response to TNF, suggesting that the action of GW4869 occurred downstream of
the drop in glutathione, which was shown previously to occur upstream of the activation of N-SMase. Further, whereas TNF treatment
also caused a 75% increase of de novo synthesized ceramide after 20 h of incubation, GW4869, at either 10 or 20 μ m , had no effect on this pathway of ceramide generation. In addition, GW4869 did not significantly impair TNF-induced NF-κB
translocation to nuclei. Therefore, GW4869 does not interfere with other key TNF-mediated signaling effects. GW4869 was able,
in a dose-dependent manner, to significantly protect from cell death as measured by nuclear condensation, caspase activation,
PARP degradation, and trypan blue uptake. These protective effects were accompanied by significant inhibition of cytochrome
c release from mitochondria and caspase 9 activation, therefore localizing N-SMase activation upstream of mitochondrial dysfunction.
In conclusion, our results indicate that N-SMase activation is a necessary step for the full development of the cytotoxic
program induced by TNF.
Assessment of a novel method of retinal stimulation, known as suprachoroidal-transretinal stimulation (STS), which was designed to minimize insult to the retina by implantation of stimulating ...electrodes for artificial vision.
In 17 normal hooded rats and 12 Royal College of Surgeons (RCS) rats, a small area of the retina was focally stimulated with electric currents through an anode placed on the fenestrated sclera and a cathode inserted into the vitreous chamber. Evoked potentials (EPs) in response to STS were recorded from the surface of the superior colliculus (SC) with a silver-ball electrode, and their physiological properties and localization were studied.
In both normal and RCS rats, STS elicited triphasic EPs that were vastly diminished by changing polarity of stimulating electrodes and abolished by transecting the optic nerve. The threshold intensity (C) of the EP response to STS was approximately 7.2 +/- 2.8 nC in normal and 12.9 +/- 7.7 nC in RCS rats. The responses to minimal STS were localized in an area on the SC surface measuring 0.12 +/- 0.07 mm(2) in normal rats and 0.24 +/- 0.12 mm(2) in RCS rats. The responsive area corresponded retinotopically to the retinal region immediately beneath the anodic stimulating electrode.
STS is less invasive in the retina than stimulation through epiretinal or subretinal implants. STS can generate focal excitation in retinal ganglion cells in normal animals and in those with degenerated photoreceptors, which suggests that this method of retinal stimulation is suitable for artificial vision.
Decauridylate containing exclusively a 2'-5' phospho-diester bond (2'-5'U₁₀) served as a template for the synthesis of oligoadenylates oligo(A)s from the 5'-phosphorimidazolide of 2'-5' diadenylate ...(ImpA-2'p5'A). Joining of 2'-5'U₁₀ and ImpA2'p5'A also took place in substantial amounts to yield long-chain oligoribonucleotides in the template-directed reaction. An unusual CD spectrum ascribed to helix formation between 2'-5'U₁₀ and 2'-5'(pA)₂ was observed under the same conditions as that of the template-directed reaction. The 3'-5' linked decauridylate (3'-5'U₁₀) also promoted the template-directed synthesis of oligo(A)s from ImpA2'p5'A, but more slowly compared with 2'-5'U₁₀. The results indicate that short-chain RNA oligomers with a 2'-5' phosphodiester bond could lead to longer oligoribonucleotides by template-directed chain elongation.
We propose a new mechanism for pulsar kicks, which is magnetohydrodynamically-induced kick. We carry out two-dimensional numerical simulations on the core-collapse of a massive star with differential ...rotation and initially large magnetic fields which have equatorially asymmetric dipole-like configuration. As a result of the computations, we get transient large kick velocities which are up to 500 km/s. However, these large velocities are soon damped since surrounding matter prevent proto-neutron-stars from moving away and finally no substantial kicks are produced. This may be a crucial problem for all pulsar kick computations.
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