| 11. |
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| 12. |
- Kimberling, William J., et al.
(author)
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Localization of Usher syndrome type II to chromosome 1q
- 1990
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In: Genomics. - : Elsevier BV. - 0888-7543 .- 1089-8646. ; 7:2, s. 245-249
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Journal article (peer-reviewed)abstract
- Usher syndrome is characterized by congenital hearing loss, progressive visual impairment due to retinitis pigmentosa, and variable vestibular problems. The two subtypes of Usher syndrome, types I and II, can be distinguished by the degree of hearing loss and by the presence or absence of vestibular dysfunction. Type I is characterized by a profound hearing loss and totally absent vestibular responses, while type II has a milder hearing loss and normal vestibular function. Fifty-five members of eight type II Usher syndrome families were typed for three DNA markers in the distal region of chromosome 1q: D1S65 (pEKH7.4), REN (pHRnES1.9), and D1S81 (pTHH33). Statistically significant linkage was observed for Usher syndrome type II with a maximum multipoint lod score of 6.37 at the position of the marker THH33, thus localizing the Usher type II (USH2) gene to 1q. Nine families with type I Usher syndrome failed to show linkage to the same three markers. The statistical test for heterogeneity of linkage between Usher syndrome types I and II was highly significant, thus demonstrating that they are due to mutations at different genetic loci.
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| 13. |
- Starczewski, Tomas, et al.
(author)
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Time-resolved Harmonic-generation In An Ionizing Gas
- 1994
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In: Journal of Physics B: Atomic, Molecular and Optical Physics. - : IOP Publishing. - 0953-4075 .- 1361-6455. ; 27:14, s. 3291-3301
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Journal article (peer-reviewed)abstract
- We report on a time-resolved study of the fifth harmonic generated in xenon by 140 ps pulses from a Nd:YAG laser in the 10(13) W cm-2 intensity regime. Absolute timing between the driving laser pulse and the harmonic pulse could be determined by means of reference harmonics generated in non-linear crystals and a single common streak camera. Above a certain laser intensity the centre of the observed harmonic pulse was shifted earlier in time relative to the laser pulse. We found the intensity dependence of this shift to be approximately linear within the intensity range used which is consistent with the results of numerical simulations taking the ionization and dispersion of the xenon gas into account.
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| 14. |
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| 15. |
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| 16. |
- Degerman, Eva, et al.
(author)
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Single-step affinity purification, partial structure and properties of human platelet cGMP inhibited cAMP phosphodiesterase
- 1994
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In: Biochimica et Biophysica Acta. - 0006-3002. ; 1205:2, s. 189-198
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Journal article (peer-reviewed)abstract
- The human platelet cilostamide- and cGMP-inhibited cAMP phosphodiesterase (cGI-PDE) was rapidly purified approximately 19,000-fold to apparent homogeneity using single step affinity chromatography on the isothiocyanate derivative of cilostamide coupled to aminoethyl agarose. Within 24 h, 30 micrograms of enzyme protein was obtained from 20 ml of packed platelets. Vmax for cAMP and cGMP was 6.1 and 0.9 mumol/min per mg protein, respectively. Several polypeptides (110/105, 79, 62, 55/53 kDa) were identified after SDS-PAGE, all of which were immunologically related to cGI-PDE and represented approx. 5, 20, 50 and 20% of the total protein, respectively. Limited proteolysis of the cGI-PDE with chymotrypsin produced a major fragment of approximately 47 kDa (and at least two smaller peptides) with catalytic activity and sensitivity to cGMP and OPC 3911 similar to controls. Phosphorylation of the cGI-PDE by cAMP-dependent protein kinase (A-kinase) resulted in maximal incorporation of 0.6-1.8 mol of 32P/mol 110/105 and 79 kDa polypeptides; much lower and variable amounts of phosphate were incorporated into the 62 and 55/53 kDa polypeptides. After digestion of cGI-PDE with several proteinases a number of peptides were isolated and sequenced. Most of the peptide sequences obtained could be aligned within the carboxy terminal domain of the deduced sequence of the human cardiac cGI-PDE. These and other results suggest that the subunit size of the intact platelet cGI-PDE is 110 kDa and that proteolytic fragments of 79, 62 and 55/53 kDa are produced during purification. The smaller fragments (62 and 55/53 kDa) contain the catalytic domain; the larger fragments (110 and 79 kDa) also contain the regulatory domain with phosphorylation sites for A-kinase.
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| 17. |
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| 18. |
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| 19. |
- Lindvall, O., et al.
(author)
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Differential regulation of mRNAs for nerve growth factor, brain-derived neurotrophic factor, and neurotrophin 3 in the adult rat brain following cerebral ischemia and hypoglycemic coma
- 1992
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In: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 89:2, s. 648-652
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Journal article (peer-reviewed)abstract
- In situ hybridization was used to study expression of mRNAs for members of the nerve growth factor (NGF) family in the rat brain after 2 and 10 min of forebrain ischemia and 1 and 30 min of insulin-induced hypoglycemic coma. Two hours after the ischemic insults, the level of brain-derived neurotrophic factor (BDNF) mRNA was markedly increased in the granule cells of the dentate gyrus, and at 24 h it was still significantly elevated. NGF mRNA showed a pronounced increase 4 h after 2 min of ischemia but had returned to a control level at 24 h. Both 2 and 10 min of ischemia caused a clear reduction of the level of mRNA for neurotrophin 3 (NT-3) in the dentate granule cells and in regions CA2 and medial CA1 of the hippocampus 2 and 4 h after the insults. The increase of BDNF mRNA could be partially blocked by the α-amino-3- hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor antagonist NBQX but was not influenced by the N-methyl-D-aspartate (NMDA) receptor antagonist MK-801. Both NBQX and MK-801 attenuated the decrease of NT-3 mRNA after ischemia. One and 30 min of hypoglycemic coma also induced marked increases in BDNF and NGF mRNA in dentate granule cells with maximal levels at 2 h. If the changes of mRNA expression lead to alterations in the relative availability of neurotrophic factors, this could influence functional outcome and neuronal necrosis following ischemic and hypoglycemic insults.
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| 20. |
- Lundgren, Johan, et al.
(author)
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Acidosis-induced ischemic brain damage: are free radicals involved?
- 1991
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In: Journal of Cerebral Blood Flow and Metabolism. - 1559-7016. ; 11:4, s. 587-596
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Journal article (peer-reviewed)abstract
- Substantial evidence exists that reactive oxygen species participate in the pathogenesis of brain damage following both sustained and transient cerebral ischemia, adversely affecting the vascular endothelium and contributing to the formation of edema. One likely triggering event for free radical damage is delocalization of protein-bound iron. The binding capacity for some iron-binding proteins is highly pH sensitive and, consequently, the release of iron is enhanced by acidosis. In this study, we explored whether enhanced acidosis during ischemia triggers the production of reactive oxygen species. To that end, enhanced acidosis was produced by inducing ischemia in hyperglycemic rats, with normoglycemic ones serving as controls. Production of H2O2, estimated from the decrease in catalase activity after 3-amino-1,2,4-triazole (AT) administration, was measured in the cerebral cortex, caudoputamen, hippocampus, and substantia nigra (SN) after 15 min of ischemia followed by 5, 15, and 45 min of recovery, respectively (in substantia nigra after 45 min of recovery only). Free iron in cerebrospinal fluid (CSF) was measured after ischemia and 45 min of recovery. Levels of total glutathione (GSH + GSSH) in cortex and hippocampus, and levels of alpha-tocopherol in cortex, were also measured after 15 min of ischemia followed by 5, 15, and 45 min of recovery. The results confirm previous findings that brief ischemia in normoglycemic animals does not measurably increase H2O2 production in AT-injected animals. Ischemia under hyperglycemic conditions likewise failed to induce increased H2O2 production. No difference in free iron in CSF was observed between animals subjected to ischemia under hyper- and normoglycemic conditions. The moderate decrease in total glutathione or alpha-tocopherol levels did not differ between normo- and hyperglycemic animals in any brain region or at any recovery time. Thus, the results failed to give positive evidence for free radical damage following brief periods of ischemia complicated by excessive acidosis. However, it is possible that free radical production is localized to a small subcellular compartment within the tissue, thereby escaping detection. Also, the results do not exclude the possibility that free radicals are pathogenetically important after ischemia of longer duration.
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