Abstract Advanced renal disease is a formal contraindication to heart transplantation, and heart failure may make a patient ineligible for kidney transplantation. The International Society of Heart ...and Lung Transplantation has reported 336 simultaneous heart and kidney transplantations with a 70% rate of 5 year survival. Herein we have presented the first case of simultaneous heart plus kidney transplantation in Chile. The patient is a 62-year-old man with diabetes mellitus and arterial hypertension who in 1997 had a myocardial infarction with cardiogenic shock and acute renal failure. He underwent a coronary bypass but developed progressive heart failure, with an ejection fraction less than 20% and moderate mitral regurgitation. He required chronic hemodialysis and survived a cardiac arrest, receiving an implantable cardioverter defibrillator. Transplantation was performed in 2004 in 2 phases: initially a heart, followed by a kidney transplantation. Immunosuppression included Daclizumab, cyclosporine, mycophenolate mofetil (MMF) and steroids. He developed acute renal failure but did not receive dialysis. He left the hospital at 25 days posttransplantation. Two years following double transplantation, he has not shown acute rejection episodes of either the cardiac or the kidney graft. Both cardiac and renal functions are normal. In conclusion, simultaneous heart plus kidney transplantations offer a good alternative treatment for patients with advanced disease of both organs.
More than a hundred conotoxins are known today and from them, only seven conopeptides have been identified to target voltage-gated potassium channels (Kv). Conotoxin sr11a belongs to the I
...2-superfamily which is characterized by four disulfide bridges and provokes muscle stiffness when injected intracranially in mice. The aim of this work was to test the biological activity of sr11a on recombinant voltage-gated Kv1 potassium channels expressed in
Xenopus laevis oocytes. Peptide sr11a was purified by high-performance liquid chromatography from the venom of the vermivorous
Conus spurius. We found that peptide sr11a inhibits the delayed rectifiers Kv1.2 and Kv1.6 but had not effect on the slowly inactivating Kv1.3 channel. The functional dyad composed of a basic Lys and a hydrophobic amino acid residue is a crucial structural element, regarding the binding properties and blocking activities of more than a hundred K
+ channel toxins. Peptide sr11a does not contain Lys residues and then, it lacks the functional dyad. Molecular modeling of peptide sr11a reveals the presence of exposed basic residues of Arg and suggests that Arg17 and Arg29 are important on its biological activity.
FMRFamide and related peptides in the phylum mollusca López-Vera, Estuardo; Aguilar, Manuel B.; Heimer de la Cotera, Edgar P.
Peptides (New York, N.Y. : 1980),
02/2008, Letnik:
29, Številka:
2
Journal Article, Conference Proceeding
Recenzirano
FMRFamide is one of the well-known peptides studied within the phylum Mollusca. It was first isolated from the clam
Macrocallista nimbosa during the end of the 1960s. Since then, a number of reports ...related to FMRFamide have been published from different experimental approaches, revealing that it and its related peptides (FaRPs) are implicated in a variety of physiological processes. As this year is the 30th anniversary since its discovery, this review focuses on diverse findings related to both FMRFamide and FaRPs in the phylum Mollusca.
The SpitzerIRAC observations (Stolovy et al., these proceedings) of the central 265 pc × 210 pc provide an opportunity to study the relationships between massive stars, gas, and dust in the Galactic ...Center at unprecedented resolution. The observations are inclusive of the three known extremely dense clusters of massive hot young stars which ionize the unusual thermal filaments seen at both radio wavelengths and in PAH emission in the IRAC images. Here we explore the effects of the massive stars, particularly in regions including the Quintuplet and Arches clusters, on the nearby diffuse ISM emission (see also Simpson et al. these proceedings). We discuss the diagnostics available using the IRAC colors, and what these show us in regards to known massive stars. Finally, we discuss the 1-8 μm SEDs which are currently under construction, and the preliminary results using a novel SED fitting program to determine the stellar type and extinction to all available point sources in the survey region.
We have studied the correlation between 2357 Chandra X-ray point sources identified by Muno et al. (2003) in a 40 × 40 parsec field and ∼20,000 infrared sources we observed in the corresponding ...subset of our 2 × 1.5 degree Spitzer/IRAC Galactic Center Survey at 3.6-8.0 μm (see Stolovy et al.; this conference), using various spatial and brightness thresholds. The correlation was determined for source separations of less than 0.5, 1.0 or 2.0 arcsec. No significant correlation was found between the X-ray and infrared point sources on these scales. Only one compact infrared source, IRS 13, can be identiffed with any of the dozen prominent X-ray emission features in the 3 × 3 parsec region centered on Sgr A*, and the diffuse X-ray and infrared emission around Sgr A* seems to be anti-correlated on a few-arcsecond scale. We compare our results with previous identifications of near infrared companions to Chandra X-ray sources.
A major peptide, de13a from the crude venom of Conus delessertii collected in the Yucatan Channel, Mexico, was purified. The peptide had a high content of posttranslationally modified amino acids, ...including 6-bromotryptophan and a nonstandard amino acid that proved to be 5-hydroxylysine. This is the first report of 5-hydroxylysine residues in conotoxins. The sequence analysis, together with cDNA cloning and a mass determination (monoisotopic mass of 3486.76 Da), established that the mature toxin has the sequence DCOTSCOTTCANGWECCKGYOCVNKACSGCTH*, where O is 4-hydroxyproline, W 6-bromotryptophan, and K 5-hydroxylysine, the asterisk represents the amidated C-terminus, and the calculated monoisotopic mass is 3487.09 Da. The eight Cys residues are arranged in a pattern (C-C-C-CC-C-C-C) not described previously in conotoxins. This arrangement, for which we propose the designation of framework #13 or XIII, differs from the ones (C-C-CC-CC-C-C and C-C-C-C-CC-C-C) present in other conotoxins which also contain eight Cys residues. This peptide thus defines a novel class of conotoxins, with a new posttranslational modification not previously found in other Conus peptide families.
cDNA was prepared from the venom duct of a single
Conus spurius specimen collected near the coast of Campeche, Mexico. From it, PCR products were generated, sequenced, and predicted to encode eight ...distinct precursors of T-1-conotoxins. These precursors contain five different mature toxins, of which four are novel and one (sr5a) has been previously purified and characterized from the venom of this species. Three of the novel toxins are very similar to sr5a: two have one amino acid substitution at position 8, whereas the other is predicted to have one additional residue at the C-terminus; the fourth toxin has five amino acid substitutions and is predicted to have two additional residues at the C-terminus. In general, the precursors include a 22-residue signal peptide, a 24-residue “pro” region, and a 13- to 16-residue mature toxin region; however, the C-termini of two mature toxin regions are predicted to be altered by post-translational processing. Three precursors lack, in the same positions, 15 amino acid residues included in the “pre” (one residue) and “pro” (14 residues) regions, which suggests the existence of an exon encoding the last signal peptide residue and the first 14 residues of the “pro” region. Phylogenetic analysis indicates that the T-1-conotoxin precursors and mature toxins of
C. spurius are more similar to certain precursors and toxins from molluscivorous
Conus species than to any precursors and toxins from vermivorous cones. The results reported here will be useful for synthesizing the novel toxins in order to identify their molecular targets.
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