| 1. |
- Berglund, L, et al.
(författare)
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Heme oxygenase inhibitors transiently increase serum ferritin concentrations without altering other acute-phase reactants in man
- 1999
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Ingår i: Pharmacology. - : S. Karger AG. - 0031-7012 .- 1423-0313. ; 59:1, s. 51-56
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Tidskriftsartikel (refereegranskat)abstract
- Sn protoporphyrin (SnPP) and Sn mesoporphyrin (SnMP), potent inhibitors of heme oxygenase (HO), significantly suppress bilirubin production, lower serum and biliary bilirubin levels and increase biliary heme output in animals and man. In this study, 20 healthy volunteers, 7 patients with primary biliary cirrhosis and 4 patients with idiopathic hemochromatosis were treated with SnPP and 4 healthy volunteers with SnMP. In all cases, serum ferritin levels increased substantially but transiently after administration of these HO inhibitors. Values returned to baseline within a few days. Infusion of hematin in 4 healthy volunteers did not significantly affect ferritin levels. No increases occurred in 7 other acute-phase reactants. The observation that these HO inhibitors transiently increase serum ferritin levels implies a link between ferritin, iron metabolism and HO activity which may be usefully explored in disorders of iron metabolism.
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| 2. |
- Drummond, IA, et al.
(författare)
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Early development of the zebrafish pronephros and analysis of mutations affecting pronephric function
- 1998
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Ingår i: Development (Cambridge, England). - : The Company of Biologists. - 0950-1991 .- 1477-9129. ; 125:23, s. 4655-4667
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Tidskriftsartikel (refereegranskat)abstract
- The zebrafish pronephric kidney provides a simplified model of nephron development and epithelial cell differentiation which is amenable to genetic analysis. The pronephros consists of two nephrons with fused glomeruli and paired pronephric tubules and ducts. Nephron formation occurs after the differentiation of the pronephric duct with both the glomeruli and tubules being derived from a nephron primordium. Fluorescent dextran injection experiments demonstrate that vascularization of the zebrafish pronephros and the onset of glomerular filtration occurs between 40 and 48 hpf. We isolated fifteen recessive mutations that affect development of the pronephros. All have visible cysts in place of the pronephric tubule at 2–2.5 days of development. Mutants were grouped in three classes: (1) a group of twelve mutants with defects in body axis curvature and manifesting the most rapid and severe cyst formation involving the glomerulus, tubule and duct, (2) the fleer mutation with distended glomerular capillary loops and cystic tubules, and (3) the mutation pao pao tang with a normal glomerulus and cysts limited to the pronephric tubules. double bubble was analyzed as a representative of mutations that perturb the entire length of the pronephros and body axis curvature. Cyst formation begins in the glomerulus at 40 hpf at the time when glomerular filtration is established suggesting a defect associated with the onset of pronephric function. Basolateral membrane protein targeting in the pronephric duct epithelial cells is also severely affected, suggesting a failure in terminal epithelial cell differentiation and alterations in electrolyte transport. These studies reveal the similarity of normal pronephric development to kidney organogenesis in all vertebrates and allow for a genetic dissection of genes needed to establish the earliest renal function.
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| 3. |
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| 4. |
- Malomed, B. A., et al.
(författare)
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Spatiotemporal solitons in multidimensional optical media with a quadratic nonlinearity
- 1997
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Ingår i: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics. - 1063-651X .- 1095-3787. ; 56:4, s. 4725-4735
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Tidskriftsartikel (refereegranskat)abstract
- We consider solutions to the second-harmonic generation equations in two- and three-dimensional dispersive media in the form of solitons localized in space and time. As is known, collapse does not take place in these models, which is why the solitons may be stable. The general solution is obtained in an approximate analytical form by means of a variational approach, which also allows the stability of the solutions to be predicted. Then, we directly simulate the two-dimensional case, taking the initial configuration as suggested by the variational approximation. We thus demonstrate that spatiotemporal solitons indeed exist and are stable. Furthermore, they are not, in the general case, equivalent to the previously known cylindrical spatial solitons. Direct simulations generate solitons with some internal oscillations. However, these oscillations neither grow nor do they exhibit any significant radiative damping. Numerical solutions of the stationary version of the equations produce the same solitons in their unperturbed form, i.e., without internal oscillations. Strictly stable solitons exist only if the system has anomalous dispersion at both the fundamental harmonic and second harmonic (SH), including the case of zero dispersion at SH. Quasistationary solitons, decaying extremely slowly into radiation, are found in the presence of weak normal dispersion at the second-harmonic frequency
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