Sectioning Angles Using Hyperbolic Curves

In this paper, we construct a single hyperbola G that, along with a straight edge and compass, allow for the trisection of any angle. Descartes constructed a parabola with this property in his original treatment of analytic geometry. Unlike Descartes\u27s proof, the proof that all angles can be trisected with the hyperbola G is a geometric rather than an algebraic argument

Changes in intra-axonal calcium distribution following nerve crush

We used the oxalate-pyroantimonate method to demonstrate the ultrastructural distribution of calcium within rat sciatic nerve 4 h after a crush injury. In normal nerve there are discrete gradients of axoplasmic calcium precipitate with the amount of precipitate decreasing in the axoplasm beneath the Schmidt Lantermann clefts and in the paranodal regions at the node of Ranvier. Near the crush site a marked increase in endoneurial and intra-axonal calcium precipitate correlated with morphologic evidence of axonal degeneration. More distant from the crush site, both in the distal segment destined to degenerate and in the proximal segment destined to regenerate, the most prominent finding was a loss of the normal gradient of precipitate beneath the Schmidt Lantermann clefts. The calcium influx at the crush site corresponds to the known role of calcium in triggering degeneration. The alterations in the distal axon may be an early stage leading to degeneration. Alteration in calcium distribution in the proximal nerve stump may play a role in the regulation of the response to injury.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50077/1/480170508_ftp.pd

Cytochemical localization of Ca2+-ATPase activity in peripheral nerve

We used an electron microscopic cytochemical method to determine the localization of Ca2+-ATPase in rat peripheral nerve. We found that reaction product occurred along most cytoplasmic membranes in the dorsal root ganglia (DRG). Unmyelinated axons demonstrated reaction product on the axolemma diffusely along their length. Myelinated fibers, in contrast, had reaction product limited to the axolema in the paranodal region. Internodal axolemma never showed reaction product and nodal axolemma was only occasionally stained, usually in sections reacted for the maximum times. Schwann cell plasma membranes uniformly showed reaction product. The restricted localization of Ca2+-ATPase to the paranodal region of myelinated fibers suggests that calcium efflux may occur principally at those sites.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/27368/1/0000394.pd

Altered Cytokine Response of Human Brain Endothelial Cells after Stimulation with Malaria Patient Plasma

Infections with the deadliest malaria parasite, Plasmodium falciparum, are accompanied by a strong immunological response of the human host. To date, more than 30 cytokines have been detected in elevated levels in plasma of malaria patients compared to healthy controls. Endothelial cells (ECs) are a potential source of these cytokines, but so far it is not known if their cytokine secretion depends on the direct contact of the P. falciparum-infected erythrocytes (IEs) with ECs in terms of cytoadhesion. Culturing ECs with plasma from malaria patients (27 returning travellers) resulted in significantly increased secretion of IL-11, CXCL5, CXCL8, CXCL10, vascular endothelial growth factor (VEGF) and angiopoietin-like protein 4 (ANGPTL4) if compared to matching controls (22 healthy individuals). The accompanying transcriptome study of the ECs identified 43 genes that were significantly increased in expression (≥1.7 fold) after co-incubation with malaria patient plasma, including cxcl5 and angptl4. Further bioinformatic analyses revealed that biological processes such as cell migration, cell proliferation and tube development were particularly affected in these ECs. It can thus be postulated that not only the cytoadhesion of IEs, but also molecules in the plasma of malaria patients exerts an influence on ECs, and that not only the immunological response but also other processes, such as angiogenesis, are altered

Remodelling of human atrial K+ currents but not ion channel expression by chronic β-blockade

Chronic β-adrenoceptor antagonist (β-blocker) treatment in patients is associated with a potentially anti-arrhythmic prolongation of the atrial action potential duration (APD), which may involve remodelling of repolarising K+ currents. The aim of this study was to investigate the effects of chronic β-blockade on transient outward, sustained and inward rectifier K+ currents (ITO, IKSUS and IK1) in human atrial myocytes and on the expression of underlying ion channel subunits. Ion currents were recorded from human right atrial isolated myocytes using the whole-cell-patch clamp technique. Tissue mRNA and protein levels were measured using real time RT-PCR and Western blotting. Chronic β-blockade was associated with a 41% reduction in ITO density: 9.3 ± 0.8 (30 myocytes, 15 patients) vs 15.7 ± 1.1 pA/pF (32, 14), p < 0.05; without affecting its voltage-, time- or rate dependence. IK1 was reduced by 34% at −120 mV (p < 0.05). Neither IKSUS, nor its increase by acute β-stimulation with isoprenaline, was affected by chronic β-blockade. Mathematical modelling suggested that the combination of ITO- and IK1-decrease could result in a 28% increase in APD90. Chronic β-blockade did not alter mRNA or protein expression of the ITO pore-forming subunit, Kv4.3, or mRNA expression of the accessory subunits KChIP2, KChAP, Kvβ1, Kvβ2 or frequenin. There was no reduction in mRNA expression of Kir2.1 or TWIK to account for the reduction in IK1. A reduction in atrial ITO and IK1 associated with chronic β-blocker treatment in patients may contribute to the associated action potential prolongation, and this cannot be explained by a reduction in expression of associated ion channel subunits

Genomics of Loa loa, a Wolbachia-free filarial parasite of humans

Loa loa, the African eyeworm, is a major filarial pathogen of humans. Unlike most filariae, Loa loa does not contain the obligate intracellular Wolbachia endosymbiont. We describe the 91.4 Mb genome of Loa loa, and the genome of the related filarial parasite Wuchereria bancrofti, and predict 14,907 Loa loa genes based on microfilarial RNA sequencing. By comparing these genomes to that of another filarial parasite, Brugia malayi, and to several other nematode genomes, we demonstrate synteny among filariae but not with non-parasitic nematodes. The Loa loa genome encodes many immunologically relevant genes, as well as protein kinases targeted by drugs currently approved for humans. Despite lacking Wolbachia, Loa loa shows no new metabolic synthesis or transport capabilities compared to other filariae. These results suggest that the role played by Wolbachia in filarial biology is more subtle than previously thought and reveal marked differences between parasitic and non-parasitic nematodes