Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020672 (hypothermia)
 17,327 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Four groups of young adult male Brown-Norway rats (strain: BN/RijHsd) were either exposed whole-body (WB) to filtered air (negative control) or to respirable aerosols of monomeric diphenylmethane-4,4'-diisocyanate (MDI) at actual breathing zone concentrations of 9.2 +/- 1.5 and 118 +/- 8.6 mg/m3. One additional group was exposed to 11,0 +/- 14.4 mg/m3 MDI using a nose-only (NO) mode. Exposure was 1 h/day, one exposure per week on 3 consecutive weeks. MDI aerosols were generated using either a condensation (WB) or a dispersion-condensation (NO) principle with resultant MMADs of 2.4-3.1 microm and 1.2 microm (GSD approximately l.5), respectively. Humidity ranged from approximately 40% (WB) to approximately 5% (NO). Positive controls received cyclophosphamide and colcemid. Micronuclei in polychromatic erythrocytes (MN-PCE) were counted in bone marrow smears prepared after the final exposure on post-exposure days 1, 2 and 7 and stained with acridine orange or Wright-Giemsa. Both the WB-exposure regimen and the 7-day sampling time point were based upon a previous study in which a significant increase in MN-PCE was reported to occur. Rats exposed to 118 (WB) and 110 mg/m3 MDI (NO) exhibited signs of respiratory distress, including hypothermia, and increased lung weights when compared to WB-exposed rats. The intensity of changes appeared to be slightly more pronounced in NO-exposed rats. At no time point did this study provide any evidence of an MDI-induced effect on the frequency of MN-PCE. No differences in outcome existed following staining with acridine orange or Wright-Giemsa. There was an absence of any effect on the frequency of mast cells and their frequency was low enough not to interfere with the outcome of study. Positive control groups exhibited significant increases in MN-PCE. In summary, monomeric MDI aerosol did not induce cytogenetic damage in Brown-Norway rats when investigated according to current testing guidelines.
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PMID:Bone marrow micronucleus assay in Brown-Norway rats exposed to diphenyl-methane-4,4'-diisocyanate. 1148 22

The acute effects of ultraprofound hypothermia and blood substitution (UHBS) on neuronal cell viability were examined in adult rat hippocampus, a brain region particularly vulnerable to ischemic cell death. UHBS was performed using either artificial cerebrospinal fluid (ACSF) or Hypothermosol, an "intracellular-type" hypothermic preservation solution. After the procedure, the hippocampus was sliced and tested for cellular viability using a combination of cellular fluorochromes that are markers for live cells (acridine orange) and dead cells (propidium iodide). UHBS with ACSF resulted in a variable degree of neuronal death within the hippocampal subfields CA1/CA3, and dentate granular layer and hilus (CA4). In contrast, UHBS with Hypothermosol consistently resulted in hippocampal slices with only mild neuronal death. Our results of preserved hippocampal neuronal viability with use of UHBS and Hypothermosol support the demonstrated central nervous system (CNS) protective effects of UHBS and Hypothermosol when used during prolonged cardiac arrest. The results of this study also suggest that UHBS and Hypothermosol may be useful in the preparation and maintenance of viable hippocampal tissue for physiological studies, especially those involving aged animals, which are particularly vulnerable to hypoxic-ischemic cellular injury
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PMID:Ultraprofound cerebral hypothermia and blood substitution with an acellular synthetic solution maintains neuronal viability in rat hippocampus. 1178 40

Hypothermic machine perfusion (HMP) provides better protection against cold ischemic injury than cold storage in marginal donor kidneys. Also, in liver transplantation a switch from static cold storage to HMP could be beneficial as it would allow longer preservation times and the use of marginal donors. A critical question concerning application of HMP in liver preservation is the crucial balance between perfusion pressure and occurrence of endothelial injury. Rat livers were cold-perfused for 24 hours to study perfusion pressures for both hepatic artery and portal vein. Cold storage served as control and was compared to HMP-preserved livers using a mean arterial perfusion pressure of 25 mm Hg and a portal perfusion pressure of 4 mm Hg (25% of normothermic liver circulation) and to HMP at 50 mm Hg and 8 mm Hg perfusion, respectively (50% of normothermic liver circulation). UW solution was enriched with 14.9 micromol/L propidium iodide (PI) to stain for dead cells and with an additional 13.5 micromol/L acridine orange to stain for viable hepatocytes. A low PI-positive cell count was found using HMP at 25% of normal circulation compared to cold storage. The PI count was high for the HMP group perfused at just 50% of normal circulation compared to HMP at 25% and compared to cold storage. In summary, for liver HMP, perfusion at 25% showed complete perfusion with minimal cellular injury. HMP using perfusion pressures of 25 mm Hg for the hepatic artery and 4 mm Hg for the portal vein is feasible without induction of endothelial injury.
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PMID:Hypothermic machine perfusion of the liver and the critical balance between perfusion pressures and endothelial injury. 1580 34

Hypothermic machine perfusion (HMP) provides better protection against ischemic damage of the kidney compared to cold-storage. The required perfusion pressures needed for optimal HMP of the liver are, however, unknown. Rat livers were preserved in University of Wisconsin organ preservation solution enriched with acridine orange (AO) to stain viable cells and propidium iodide (PI) to detect dead cells. Perfusion pressures of 12.5%, 25% or 50% of physiologic perfusion pressures were compared. Intravital fluorescence microscopy was used to assess liver perfusion by measuring the percentage of AO staining. After 1-h, the perfusion pressure of 12.5% revealed 72% +/- 3% perfusion of mainly the acinary zones one and two. The perfusion pressure of 25% and 50% showed complete perfusion. Furthermore, 12.5% showed 14.7 +/- 3.6, 25% showed 3.7 +/- 0.9, and 50% showed 11.2 +/- 1.4 PI positive cells. One hour was followed by another series of experiments comprising 24-h preservation. In comparison with 24-h cold-storage, HMP at 25% showed less PI positive cells and HMP at 50% showed more PI positive cells. In summary, perfusion at 25% showed complete perfusion, demonstrated by AO staining, with minimal cellular injury, shown with PI. This study indicates that fine-tuning of the perfusion pressure is crucial to balance (in)complete perfusion and endothelial injury.
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PMID:Determination of an adequate perfusion pressure for continuous dual vessel hypothermic machine perfusion of the rat liver. 1732 75