Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0848332 (Spots)
 453 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

At 24 hr following orthotopic transplantation, rat liver grafts were perfused in situ for 7 min with trypan blue, a vital dye that provides information on hepatic microcirculation and stains nuclei of nonviable cells. Spotty and uneven dye distribution was observed indicating that hepatic microcirculation was disturbed 24 hr following transplantation surgery. Under these conditions, 15-20% of the hepatocytes were nonviable as assessed from trypan blue staining and frank necrosis. In contrast, perfusion of livers from untransplanted rats or liver explants exposed to cold ischemia for 60 min were judged normal by the criteria of uniform distribution of dye in the organ and absence of necrosis and nuclear dye uptake. Thus the observed damage was associated with reintroduction of blood and can therefore be classified as a reperfusion injury. The altered microcirculation and cell death following the operation was reduced markedly by perfusion of the cold, ischemic explant with nitrogen-saturated but not with oxygen-saturated buffer for 5 min prior to the implantation operation. Protection was even greater if the perfusion medium contained verapamil (20 micrograms/ml), a Ca++ channel blocker. We conclude that reperfusion of the stored liver causes an oxygen-dependent alteration in hepatic microcirculation that leads to hypoxia and scattered hepatocellular necrosis in the implanted graft. Brief perfusion of the hypoxic implant under anaerobic conditions may remove substrates involved in oxygen radical generation and prevent reperfusion injury upon introduction of oxygen into the graft via the blood. Taken together, these results suggest that removal of Euro-Collins' solution under anaerobic conditions may be beneficial clinically in preventing injury of surgical explants.
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PMID:Hepatic reperfusion injury following orthotopic liver transplantation in the rat. 305 56

We present a combinatorial approach for development of materials for use in optical gas sensors, with oxygen being used as an exemplary target gas. Combinatorial chemistry is shown to be a promising tool for speeding up the search for new sensor materials. The method is based on the use of various polymers, solvents, indicators, plasticizers, and other additives. Solutions of the respective materials are prepared in appropriate organic solvents, and a robotic station is programmed to mix the components. Spots of the sensing materials are deposited in the wells of glass substrates resembling microtiterplates. After drying off the solvent, the sensor spots are automatically analyzed in a test stand, where they are exposed to a carrier gas containing oxygen in various concentrations. Changes in the decay time of fluorescence of the indicator probes are measured and used (along with sensor response time) as a main criterion for sensor assessment. It is shown that the combinatorial approach can reduce the time and effort needed to establish libraries of sensor materials by a factor of at least 1000. We describe in detail the device for preparation of sensor libraries and for testing the respective materials. The potential of the system is demonstrated for the characterization of optical oxygen sensors.
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PMID:A combinatorial approach for development of materials for optical sensing of gases. 1513 91

Objective quantification of epidermal melanin concentration (EMC) should be useful in laser dermatology to determine the individual maximum safe radiant exposure (IMSRE). We propose a single-wavelength remittance measurement at 390 nm as an alternative optical method to determine EMC and IMSRE. Remittance spectra (360 to 740 nm), melanin index (MI) measurements and the transient radiometric temperature increase, DeltaT(t), upon skin irradiation with an Alexandrite laser (755 nm, 3-ms pulse duration, 6 Jcm(2)) were measured on 749 skin spots (arm and calf) on 23 volunteers (skin phototypes I to IV). Due to the shallow penetration depth and independence of blood oxygen saturation (isosbestic point), remittance at 390 nm appears to provide better estimates for EMC and IMSRE than MI.
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PMID:Remittance at a single wavelength of 390 nm to quantify epidermal melanin concentration. 1925 93

Erythropoietin (Epo) is produced primarily in the kidneys upon low blood oxygen availability and stimulates erythropoiesis in the bone marrow. Recombinant human Epo (rHuEpo), a drug developed to increase arterial oxygen content in patients, is also illicitly used by athletes to improve their endurance performance. Therefore, a robust and sensitive test to detect its abuse is needed. The aim of the present study was to investigate potential human serum biomarkers of Epo abuse employing a proteomic approach. Eight healthy male subjects were injected subcutaneously with rHuEpo (5,000 IU) every second day for a 16-day period. Serum was collected before starting the treatment regime and again at days 8 and 16 during the treatment period. Samples were homogenized and proteins separated by two-dimensional gel electrophoresis (2DE). Spots that changed significantly in response to rHuEpo treatment were identified by mass spectrometry. Both the number of reticulocytes and erythrocytes increased throughout the study, leading to a significant increase in hematocrit and hemoglobin content. In addition, transferrin levels increased but the percentage of iron bound to transferrin and ferritin levels decreased. Out of 97 serum proteins, seven were found to decrease significantly at day 16 compared with pre-Epo administration, and were identified as four isoforms of haptoglobin, two isoforms of transferrin, and a mixture of hemopexin and albumin. In support, total serum haptoglobin levels were found to be significantly decreased at both days 8 and 16. Thus a 2DE proteomic approach for discovery of novel markers of Epo action appears feasible.
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PMID:Novel serum biomarkers for erythropoietin use in humans: a proteomic approach. 2096 91

Pericellular oxygen concentration represents an important factor in the regulation of cell functions, including cell differentiation, growth and mitochondrial energy metabolism. Hypoxia in adipose tissue has been associated with altered adipokine secretion profile and suggested as a possible factor in the development of type 2 diabetes. In vitro experiments provide an indispensable tool in metabolic research, however, physical laws of gas diffusion make prolonged exposure of adherent cells to desired pericellular O2 concentrations questionable. The aim of this study was to investigate the direct effect of various O2 levels (1%, 4% and 20% O2) on the proteomic profile and triglyceride accumulation in 3T3-L1 differentiated preadipocytes using gas-permeable cultureware. Following differentiation of cells under desired pericellular O2 concentrations, cell lysates were subjected to two-dimensional gel electrophoresis and protein visualization using Coomassie blue staining. Spots showing differential expression under hypoxia were analyzed using matrix-assisted laser desorption/ionization mass spectrometry. All identified proteins were subjected to pathway analysis. We observed that protein expression of 26 spots was reproducibly affected by 4% and 1% O2 (17 upregulated and 9 downregulated). Pathway analysis showed that mitochondrial energy metabolism and triglyceride synthesis were significantly upregulated by hypoxia. In conclusion, this study demonstrated the direct effects of pericellular O2 levels on adipocyte energy metabolism and triglyceride synthesis, probably mediated through the reversed tricarboxylic acid cycle flux.
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PMID:The Effect of Pericellular Oxygen Levels on Proteomic Profile and Lipogenesis in 3T3-L1 Differentiated Preadipocytes Cultured on Gas-Permeable Cultureware. 2702 42