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Query: UMLS:C0016382 (flushing)
 6,387 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The effect of evacuation of atmospheric air during transportation on recovery of anaerobic bacteria was investigated. Evacuation of atmospheric air from glass tubes by flushing with pure carbon dioxide lowered the content of oxygen to about 0.4 per cent. Three B. fragilis strains and one strain of Fusobacterium mortiferum and of Peptostreptococcus anaerobius were investigated. Bacterial recovery was determined one hour and 24 hours after evacuation of atmospheric air by pure carbon dioxide and pure nitrogen, was compared to bacterial recovery from samples transported with free access to atmospheric air. Evacuation by pure carbon dioxide significantly improved the recovery of one B. fragilis strain after 24 hours of transportation and significantly impaired the recovery of Peptostreptococcus anaerobius after one hour of transportation, while evacuation by pure nitrogen significantly improved the recovery of Peptostreptococcus anaerobius after 24 hours of transportation. In all other cases, however, no statistically significant effect on bacterial recovery was found.
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PMID:Survival of anaerobic bacteria during transportation. 1. Experimental investigations on the effect of evacuation of atmospheric air by flushing with carbon dioxide and nitrogen. 0 89

Spermatozoa were collected from the rete testis of conscious boars, from the cauda epididymidis by retro-flushing, and by ejaculation. Testicular spermatozoa showed no progressive motility, and that of ejaculated was greater than that of epididymal spermatozoa. Glycolysis and respiration of testicular spermatozoa, while lower than that of the more mature cells, were only slightly affected by the incubation conditions. Epididymal spermatozoa converted 83% of the glucose they utilized to CO2 or lactate, but testicular cells converted only 35% to these metabolites. Synthesis of lipid was greatest by testicular spermatozoa. With the more mature cells hyperosmolar conditions depressed CO2 production, but increased lactate production, and these changes were greater for ejaculated than for epididymal spermatozoa. Glycolysis plus respiration of these cells was related to their motility. These results were interpreted as showing increasing motility, glycolysis and respiration with maturation, but also decreased synthetic capacity and increased sensitivity to the environment.
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PMID:Effects of osmolality, bicarbonate and buffer on the metabolism and motility of testicular, epididymal and ejaculated spermatozoa of boars. 43 62

A rapid and reliable method of carboxyhemoglobin determination is described. Hemoglobin-bound carbon monoxide is released chemically into a continuous nitrogen stream and transported to an infrared gas analyser. The total amount of released CO is determined electronically. 100% CO Hb values are obtained in the same way from diluted blood samples after flushing with pure CO in special saturation vessels. The method described yields results with a standard deviation of +/- 2.5%.
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PMID:[A rapid carboxyhemoglobin determination by means of non-dispersive ultra-red gas analysis (author's transl)]. 103 9

The influence of common duct occlusion on susceptibility to infection with anaerobic gram-negative rods was investigated in rabbits. Intravenous inoculation was performed with three B. fragilis strains isolated from human infections and with a stock culture of Fusobacterium mortiferum. Liver tissue, gallbladder, bile, and blood were investigated. Anaerobic culture procedures were based on the use of a 'glove-box' with an oxygen-free atmosphere and pre-reduced, anaerobically sterilized media. Anaerobic transport was based on flushing of samples with oxygen-free carbon dioxide and transport-time less than 30 minutes. In regard to two B. fragilis strains (ss. fragilis) and in regard to Fusobacterium mortiferum, common duct occlusion significantly increased the number of infected animals compared to a control group of inoculated animals without common duct occlusion. Spontaneous infection did not arise in a control group of animals with common duct ligation. It is concluded that: 1) in biliary tract occlusion, anaerobic bacteria are able to invade the biliary tract from the blood stream, and 2) biliary tract occlusion produces sufficient anaerobic conditions for obligate anaerobic bacteria to multiply in the bile.
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PMID:Susceptibility of the liver and biliary tract to anaerobic infection in extrahepatic biliary tract obstruction. Bacteriological investigations - an experimental study in rabbits. 118 11

Several metabolic fluxes were analyzed during gradual transitions from aerobic to oxygen-limited conditions in chemostat cultures of Pseudomonas mendocina growing in synthetic medium at a dilution rate of 0.25 h-1. P. mendocina growth was glucose limited at high oxygen partial pressures (70 and 20% pO2) and exhibited an oxidative type of metabolism characterized by respiratory quotient (RQ) values of 1.0. A similar RQ value was obtained at low pO2 (2%), and detectable levels of acetic, formic, and lactic acids were determined in the extracellular medium. RQs of 0.9 +/- 0.12 were found at 70% pO2 for growth rates ranging from 0.025 to 0.5 h-1. At high pO2, the control coefficients of oxygen on catabolic fluxes were 0.19 and 0.22 for O2 uptake and CO2 production, respectively. At low pO2 (2%), the catabolic and anabolic fluxes were highly controlled by oxygen. P. mendocina showed a mixed-type fermentative metabolism when nitrogen was flushed into chemostat cultures. Ethanol and acetic, lactic, and formic acids were excreted and represented 7.5% of the total carbon recovered. Approximately 50% of the carbon was found as uronic acids in the extracellular medium. Physiological studies were performed under microaerophilic conditions (nitrogen flushing) in continuous cultures for a wide range of growth rates (0.03 to 0.5 h-1). A cell population, able to exhibit a near-maximum theoretical yield of ATP (YmaxATP = 25 g/mol) with a number of ATP molecules formed during the transfer of an electron towards oxygen along the respiration chain (P/O ratio) of 3, appears to have adapted to microaerophilic conditions.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Metabolic and energetic control of Pseudomonas mendocina growth during transitions from aerobic to oxygen-limited conditions in chemostat cultures. 144 29

All methods for growth of anaerobic bacteria on solid media depend on the elimination of atmospheric O2 through use of a palladium catalyst (Deoxo-Catalyst), active in presence of at least 5% H2 with resultant formation of water. Anaerobic chambers and jars are the two conventional methods employed. Both are based on the elimination of air by means of a pump and its replacement with gas from a cylinder (evacuation-replacement technique). An alternative chemical technique for use in anaerobic jars consists of adding internal gas-generating sachets. The former techniques are more efficient but the trend, particularly in the clinical laboratories, is to use the simpler chemical system that has two inconveniences: a slow establishment of anaerobiosis, and a high cost. We propose a new system that does not require a vacuum pump and consists in flushing anaerobic jars with a convenient gas mixture (H2, CO2, N2: 4.5; 5; 90.5 v/v) by means of an automaton regulating both time and gas flow. Gas-liquid chromatography analysis of the gas inside the jar shows a rapid elimination of gaseous O2, whose residual concentration is low enough to permit growth of all anaerobes of clinical interest, including those which are more O2-sensitive. Comparative qualitative and quantitative data obtained with all available techniques demonstrate the advantages of the new system.
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PMID:[An automatic gas scanning device, technical improvement for obtaining a favourable atmosphere for in vitro culture of anaerobic bacteria]. 145 2

During mechanical ventilation the apparatus dead space can be eliminated by insufflating through one lumen of a tracheal double-lumen tube and allowing expiration through the other. In six intravenously anesthetized pigs, this technique resulted in an 18% (1 kPa) decrease in PaCO2 compared with insufflating through both lumens (32 ml rebreathing volume). Oxygenation, airway pressures, and tidal volumes were unchanged. Flushing the trachea with fresh gas during the expiratory phase did not improve the efficiency of ventilation. It is concluded that elimination of apparatus dead space improves CO2 removal without increasing airway pressures and tidal volumes, and it is suggested that minimization of apparatus dead space should be tried before more advanced ventilatory modes are considered.
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PMID:Elimination of apparatus dead space--a simple method for improving CO2 removal without increasing airway pressure. 146 17

The ventilator support utilized in acute respiratory failure can exacerbate an underlying lung injury. Various ventilation techniques have been introduced to prevent such damage by limiting tidal volume and inflation pressure, ensuring uniform expansion of the lung, and stabilizing lung volume during expiration. Acceptance of such methods has been limited. Intermittent-flow expiratory ventilation (IFEV) is the latest development in limited-excursion pulmonary ventilation. The method involves the delivery of fresh gas to the respiratory tree during expiration, thereby flushing out the anatomic deadspace and ensuring that the gas initially delivered to the alveolus with the succeeding inspiration is able to participate in gas exchange. By eliminating end-tidal gas in the conducting air passages, series deadspace is functionally reduced, permitting lowering of tidal volume and airway pressures without a corresponding reduction in CO2 removal. This effect may benefit patients who have acute lung injury by permitting ventilator settings with lower tidal volumes and peak airway pressures. The technique of IFEV delivery, a successful clinical application, and possible ways to improve IFEV efficiency are discussed.
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PMID:Intermittent-flow expiratory ventilation (IFEV): delivery technique and principles of action--a preliminary communication. 177 67

The carbon monoxide complex of ascorbate-reduced dopamine beta-hydroxylase has been prepared and characterized by Fourier transform infrared, fluorescence, and x-ray absorption spectroscopies. CO has previously been shown to be a competitive inhibitor with respect to O2, and binds to only one of the two copper atoms/active site (Blackburn, N. J., Pettingill, T. M., Seagraves, K. S., and Shigeta, R. T. (1990) J. Biol. Chem. 265, 15383-15386). Thus, it acts as an excellent probe of the O2-binding site. A single C-O infrared absorption band is observed at 2089 cm-1, shifting by 46 cm-1 to lower energy on substitution with either 13C16O or 12C18O. The 13C isotope shift is reversed to the position expected for 12CO upon vacuum flushing with 12CO gas, indicating that formation of the CO adduct is a fully reversible process. Binding of the substrate tyramine does not eliminate the infrared peak but causes a 3-cm-1 shift to lower energy. On the other hand, binding of a bifunctional inhibitor which cross-links the substrate and O2-binding site does eliminate the CO peak. These data, in conjunction with the competitive nature of CO binding with respect to O2, identify the CO-binding site as the O2-binding site, and place it in close proximity to the substrate-binding site. CO-dopamine beta-hydroxylase exhibits no luminescence in the visible region, suggesting a structure different from carbonmonoxy hemocyanin, and in all probability mononuclear. Analysis of extended x-ray absorption spectroscopy data is most consistent with an average coordination per Cu of 2-3 histidines, 0.5 CO, and 0.5 S atoms as ligands, and absorption edge comparisons indicates pseudo-4 coordination as the most likely geometry at each Cu(I) center. The results can be interpreted by a model involving inequivalent 4-coordination at each Cu(I) center in the CO adduct with CuAHis3S...CuBHis2CO-X as the coordination most consistent with all of the data.
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PMID:Carbonmonoxy dopamine beta-hydroxylase. Structural characterization by Fourier transform infrared, fluorescence, and x-ray absorption spectroscopy. 189 98

The major use of N-acetylcysteine in clinical toxicology is in the treatment of acetaminophen (paracetamol) overdosage. The hepatorenal toxicity of acetaminophen is mediated by a reactive metabolite normally detoxified by reduced glutathione. If glutathione is depleted, covalent binding to macromolecules and/or oxidation of thiol enzymes can lead to cell death. Oral or intravenous N-acetylcysteine or oral D,L-methionine mitigates acetaminophen-induced hepatorenal damage if given within 10 hours, but becomes less effective thereafter. In vivo, N-acetylcysteine forms L-cysteine, cystine, L-methionine, glutathione, and mixed disulfides; L-methionine also forms cysteine, thus giving rise to glutathione and other products. Oral therapy with N-acetylcysteine or methionine for acetaminophen poisoning is contraindicated in the presence of coma or vomiting, or if activated charcoal has been given by mouth. Nausea, vomiting, and diarrhea may also occur as a result of oral N-acetylcysteine administration. Anaphylactoid reactions including angioedema, bronchospasm, flushing, hypotension, nausea/vomiting, rash, tachycardia, and respiratory distress may occur 15-60 minutes into N-acetylcysteine infusion (20 hours intravenous regimen) in up to 10% of patients. Following accidental intravenous overdosage, the adverse reactions of N-acetylcysteine are similar but more severe; fatalities have occurred. A reduction in the loading dose of N-acetylcysteine may reduce the risk of adverse reactions while maintaining efficacy. Administration of N-acetylcysteine for a longer period might provide enhanced protection for patients in whom acetaminophen absorption or elimination is delayed. N-acetylcysteine may also have a role in the treatment of toxicity from carbon tetrachloride, chloroform, 1,2-dichloropropane, and other compounds. The possible use of N-acetylcysteine and other agents in the prevention of the neuropsychiatric sequelae of acute carbon monoxide poisoning is an important area for future research.
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PMID:Use of N-acetylcysteine in clinical toxicology. 192 4


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