PubMed Health⌕ Search
Home/Archive/PubMed

PubMed · 9564923

Allograft heart valve viability and valve-processing variables.

K L Gall·S E Smith·C A Willmette·M F O'Brien
View original source ↗Export metadata ↓

Abstract

BACKGROUND: The impact of allograft valve viability on valve durability remains controversial. Analyses of our clinical results have demonstrated the superiority of the cryopreserved valve viable at the time of implantation over the 4 degrees C stored valve nonviable at the time of implantation. In this study, we quantitatively assessed the effects on viability of current and past valve-processing protocols at The Prince Charles Hospital. METHODS: The viability of pulmonary valves was quantitatively analyzed by thin-layer autoradiography to assess the effects of donor type, antibiotics, and valve storage. RESULTS: Control valve segments obtained from beating-heart donor valves had a higher initial viability (0.92+/-0.02) than nonbeating-heart donor valves (0.66+/-0.03). Cryopreservation after low-dose antibiotic sterilization significantly reduced viability to 50% to 60% of the control, and in the presence of amphotericin B, viability dropped further to 10% to 36% of the control. After 7 days' storage at 4 degrees C, viability was reduced to 2% of control and to 0% viability after 21 days. CONCLUSIONS: For maximal preimplantation viability, valves should be procured as soon as possible after cessation of heart beat and should be cryopreserved if they are not to be clinically implanted within 1 to 2 days. Amphotericin B should not be used in conjunction with cryopreservation if viability is to be maximized.

Explore related subjects

Amphotericin BAnalysis of VarianceAnti-Bacterial AgentsAntifungal AgentsAutoradiographyCell CountColoring AgentsCryopreservationCryoprotective AgentsDimethyl SulfoxideFibroblastsGraft SurvivalHumansOrgan PreservationPulmonary ValveSterilizationTissue DonorsTissue SurvivalTissue and Organ ProcurementTransplantation, HomologousJournal ArticleResearch Support, Non-U.S. Gov't

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

K L Gall, S E Smith, C A Willmette, M F O'Brien. 1998. Allograft heart valve viability and valve-processing variables.. https://doi.org/10.1016/s0003-4975(98)00085-x

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2025

Multi-Omics Analysis of Experimentally Evolved Candida auris Isolates Reveals Modulation of Sterols, Sphingolipids, and Oxidative Stress in Acquired Amphotericin B Resistance.

Clinical isolates of Candida auris show a high prevalence of resistance to Amphotericin B (AmB)-an uncommon trait in most Candida species. Alterations in ergosterol biosynthesis can contribute to acquired AmB resistance in C. auris laboratory strains but are rarely seen in clinical isolates. In this study, we experimentally evolved two drug-susceptible Clade II isolates of C. auris to develop AmB resistance. The evolved strains displayed a four to eight fold increase in MIC50 compared to the parental cells. We analyzed changes in their karyotype, genome, lipidome, and transcriptome associated with this acquired resistance. In one lineage, AOX2 was upregulated, and its deletion reversed the AmB resistance phenotype. The aox2Δ mutant also failed to evolve AmB resistance under experimental conditions. In the same lineage, restoring the UPC2 S332R and RTG3 S101T mutations to the wild-type allele restored AmB susceptibility. In another lineage, the ergosterol and sphingolipid pathways were observed to play a critical role, and upregulation of the ERG genes elevated the total sterol content, while significant downregulation of HSX11 (glucosylceramide synthase) resulted in lower levels of glucosylceramides. To our knowledge, this study is the first to show that AmB resistance in C. auris can be acquired through mechanisms both dependent on or independent of sterol content modulation, highlighting Aox2 and Upc2 as key regulators of amphotericin resistance.

Amphotericin B↗
PubMed2007

Correlation of Neo-Sensitabs tablet diffusion assay results on three different agar media with CLSI broth microdilution M27-A2 and disk diffusion M44-A results for testing susceptibilities of Candida spp. and Cryptococcus neoformans to amphotericin B, caspofungin, fluconazole, itraconazole, and voriconazole.

We compared the Neo-Sensitabs tablet assay to both reference M27-A2 broth microdilution and M44-A disk diffusion methods for testing susceptibilities of 110 isolates of Candida spp. and Cryptococcus neoformans to amphotericin B, caspofungin, fluconazole, itraconazole, and voriconazole. Neo-Sensitabs assay inhibition zone diameters in millimeters on three agars (Mueller-Hinton agar supplemented with 2% dextrose and 0.5 microg/ml methylene blue [MGM], Shadomy [SHA], and RPMI 1640 [RPMI, 2% dextrose]) were obtained at 24 to 72 h. The correlation coefficient of Neo-Sensitabs results with MICs was similar to that of the disk method for most of the five agents on MGM (R, 0.80 to 0.89 versus 0.76 to 0.89, respectively). Overall, superior correlation was observed at 24 h for most agents. The exception was amphotericin B (R values of 0.68 and 0.5 for disk and tablet, respectively, at 48 h versus 0.68 and 0.48, respectively, at 24 h). In general, Neo-Sensitabs results were less consistent on SHA and RPMI agars. Although agreement by breakpoint category of Neo-Sensitabs and disk results with CLSI method M27-A2 was also similar on MGM (92.7 to 98.2% versus 95.5 to 100%, respectively), the Neo-Sensitabs method failed to identify two of the six isolates with high amphotericin B MICs. These data suggest the potential value of the Neo-Sensitabs assay for testing at least four of the five agents against yeasts evaluated in the clinical laboratory.

Amphotericin B↗