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

Published procedures for experimentation under anoxic conditions generally involve specialized apparatus that hinders the easy manipulation of experimental samples. We describe here some procedures that rapidly remove oxygen from experimental solutions, maintain anoxia with simple equipment for long periods of time, and do not interfere with normal sample addition and removal, spectrometric measurements, chromatographic manipulations, and the like. Anoxia can be achieved and maintained by the use of an enzyme system (glucose oxidase, glucose, catalase), or an inorganic oxygen-reducing system (ferrous pyrophosphate), or dithionite. Physical isolation of experimental samples from atmospheric oxygen can be maintained by continuous flushing with treated argon gas and/or by an overlay of heavy mineral oil.
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PMID:Biochemistry without oxygen. 357 95

The high levels of delta-aminolevulinate synthetase (ALA-S) in Rhodopseudomonas palustris cells grown anaerobically in the light (Ph) decrease to those found in cells grown aerobically in the dark (A), when the former cultures were vigorously oxygenated; simultaneously bacteriochlorophyll (Bchl) synthesis abruptly halted leading to diminished steady-state specific Bchl content. When flushing oxygen was interrupted, enzymic activity increased, whether chloramphenicol was present or not in the medium; if the protein synthesis inhibitor was added when oxygenation started, ALA-S declined in the same fashion as in its absence, but thereafter reactivation of the enzyme was lower than before. Succinyl-CoA-synthetase and ALA-dehydratase activities were also measured under the conditions described, and no changes at all have been observed. The existence of different forms of ALA-S in R. palustris depending on growth conditions is postulated along with the formation of low molecular weight factors which can modulate ALA-S activity by binding to the enzyme; a widespread mechanism in the adaptation of micro-organisms to changes in environment. It is also proposed that this particular regulatory phenomenon, could be referred to as a switch off/on mechanism controlling ALA-S activity in R. palustris.
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PMID:Porphyrin biosynthesis in Rhodopseudomonas palustris--XII. delta-Aminolevulinate synthetase switch-off/on regulation. 359 86

Conditions for tracheal intubation at 90 seconds, time to onset of maximum block and duration of clinical relaxation after five different doses of atracurium, which ranged from 0.4 to 1.0 mg/kg were studied in 200 adult patients who were anaesthetized with nitrous oxide, oxygen and halothane or fentanyl. The conditions for intubation improved significantly with increasing doses, and were acceptable in 55% patients with a 0.4 mg/kg dose and in about 90% of those who received the two higher doses. The time to onset of complete block was 257 seconds with 0.4 mg/kg and decreased progressively to 124 seconds with 1.0 mg/kg. The duration of clinical relaxation under fentanyl anaesthesia averaged 29 minutes with 0.4 mg/kg and increased in a dose-related manner to 57 minutes with 1.0 mg/kg: halothane anaesthesia produced only a marginal increase. There was no evidence of cumulation with up to six repeat doses of 0.125 mg/kg. The only side effect noticed was cutaneous flushing observed in 42% of patients. This was again dose dependent, being 18% with 0.4 mg/kg and increasing to 73% after 1.0 mg/kg. There was associated hypotension and bronchospasm in one patient.
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PMID:Atracurium in clinical anaesthesia: effect of dosage on onset, duration and conditions for tracheal intubation. 383 80

A 32 year old female developed a severe hepatitis (serum bilirubin 544 mumol/l) one week after a halothane anaesthetic. Six months later a general anaesthetic was administered via a halothane free circuit without incident. A year later a further non halothane anaesthetic was administered this time utilising the routine circuit after briefly flushing the rubber tubing with oxygen. That evening she became febrile and the following day abnormal liver function tests were documented. She remained asymptomatic.
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PMID:Halothane hepatitis: toxicity or hypersensitivity? 386 77

A roll tube technique (Hungate method) was employed in an attempt to cultivate a maximal portion of the organisms in the gingival crevice area of man. This technique achieves an anaerobic state by flushing the local environment with oxygen-free gas. Once collected, the crevicular debris was immediately placed into sterile oxygen-free test tubes which were flushed out by the oxygen-free gas. In this manner, the samples were weighed, dispersed, diluted, and cultured in roll tubes and plates. The medium for control (Brewer Jar technique) and Hungate techniques was Heart Infusion Agar fortified with 10% defibrinated horse blood. When the Hungate technique was used, the recovery of viable bacteria, as a percentage of the direct microscopic count, was significantly greater than plates incubated aerobically or utilizing the Brewer Anaerobic technique. Cultural counts by using the Hungate method averaged 41.3% for six samples when 90% nitrogen and 10% hydrogen were used, 70.4% for eight samples when 85% nitrogen, 10% hydrogen, and 5% carbon dioxide were used, and 63.4% for eight samples when 100% carbon dioxide was the gaseous atmosphere. At no time were cultural counts, by using anaerobic plates (Brewer Jar), more than 24% of the direct microscopic count. This suggests that exclusion of oxygen and the presence of carbon dioxide maximized recovery of gingival crevice bacteria.
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PMID:Improved isolation of anaerobic bacteria from the gingival crevice area of man. 493 91

Previous workers from this laboratory observed considerable variation in the proportions of acetic and lactic acids produced in pure broth culture as compared to consistently high proportions of acetic acid produced in the sourdough and flour suspension systems. In the latter the proportion of acetic acid was always in the range of 20 to 35% of the total, whereas in pure broth culture frequently less than 5% acetic acid was produced. In the natural environment, the sourdough bacteria, tentatively identified as lactobacilli, coexist with a yeast, Saccharomyces exiguus, and this study was undertaken to determine whether this yeast or flour ingredients including glucose or other factors were involved in this variable production of acetic acid. The proportion of acetic acid produced in broth culture on maltose, the preferred carbohydrate source, was found to depend almost entirely on the degree of aeration. Essentially anaerobic conditions, as obtained by thorough evacuation and flushing with CO(2) or N(2), resulted in very low (5% or less) proportions of acetic acid. Aerobic conditions, achieved by continuous shaking in cotton-plugged flasks, yielded high levels (23 to 39% of the total) of acetic acid. Similar effects of aeration were observed with glucose as the substrate, although growth was considerably slower, or in nonsterile flour suspension systems. It is theorized that, under aerobic conditions, the reduced pyridine nucleotides generated in the dissimilation of carbohydrate are oxidized directly by molecular oxygen, thereby becoming unavailable for the reduction of the acetyl phosphate intermediate to ethyl alcohol, the usual product of anaerobic dissimilation of glucose by heterofermentative lactic acid bacteria. Comparative studies with known strains of homo- and heterofermentative lactobacilli showed similar effects of aeration only on the heterofermentative strains, lending additional support to the tentative grouping by previous workers from this laboratory of the sourdough bacteria with the heterofermentative lactobacilli.
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PMID:Factors affecting organic acid production by sourdough (San Francisco) bacteria. 504 65

The present studies were designed to achieve a good maintenance of energy metabolism as a means of improving the quality of liver preservation in rats. For this purpose, investigation were made whether initial warm ischemia may affect energy metabolism during preservation and oxygen supply during initial cold flushing process may protect energy metabolism. The following are the results. Compared with non-oxygenated groups, the oxygenated groups during the initial cooling process proved to be effective in, 1) reducing the precipitous fall in the ATP level of the liver during the initial cooling process, 2) maintaining the higher ATP level for 8 hours of hypothermic immersion storage, 3) maintaining energy production for 24 hours in intermittent perfusion storage, 4) obtaining a more rapid recovery of energy production in rewarming and reperfusion after 8 or 16 hours of hypothermic immersion storage, 5) obtaining the higher ATP level by high flow rate of flushing. It may be concluded that maintenance of energy metabolism in the preserved liver is related to the degree of interference with energy metabolism during the initial cold flushing and this interference can be prevented by flushing with the oxygenated perfusate of high flow rate.
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PMID:[Experimental study on maintenance of energy metabolism of the preserved liver]. 661 23

Atracurium has been reported to have minimal haemodynamic effects in healthy patients. The purpose of this study was to determine its effects in patients with coronary artery disease. Sixteen patients scheduled for elective coronary artery surgery were studied in two equal groups. Group 1 received a bolus injection of atracurium 0.3 mgkg-1 and group 2 0.4 mgkg-1. Under local anaesthesia, radial artery, pulmonary artery thermodilution and central venous catheters were placed and the appropriate vascular pressures continuously monitored, as were leads II and V5 of the electrocardiogram. Sleep was induced with lorazepam and fentanyl while the patients were breathing nitrous oxide in oxygen (50:50). Control measurements of arterial pressure (AP) (mean, systolic, diastolic), CO (thermodilution), CVP, PA, PCW and HR were obtained. Atracurium was administered as a bolus and measurements repeated at 2, 5, and 10 min. In group 1 mean and diastolic arterial pressure decreased significantly at 2 min (73 +/- 2 to 66 +/- 3 mm Hg, P less than 0.05; 58 +/- 3 to 51 +/- 2 mm Hg, P less than 0.05). The changes were not significant at 5 or 10 min. There were no significant changes in CO or SVR. One patient in this group exhibited a typical histamine response with vasodilatation and flushing. In this patient mean arterial pressure decreased from 70 to 55 mm Hg and CO increased from 4.90 to 7.24 litre min-1. Excluding this patient from group 1 eliminated the significance of the haemodynamic changes for the rest of the group (MAP = 73 +/- 2 to 68 +/- 2 mm Hg, n.s.; mean diastolic AP = 58 +/- 3 to 53 +/- 2 mm Hg, n.s.). In group 2 none of the haemodynamic parameters measured showed significant changes. These results demonstrate minimal haemodynamic effects with 0.3- or 0.4-mgkg-1 bolus injections of atracurium in 15 patients with coronary artery disease, but in one patient doses of 0.3 mgkg-1 produced a typical histamine response with marked cardiovascular changes.
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PMID:Haemodynamic effects of bolus injections of atracurium in patients with coronary artery disease. 668 8

Phenomena associated with a deformation of short-time occurrence and noticed on concentration curves of tidal O2 and CO2 were examined in adult hens sitting quietly in a cage or suspended in prone position. During the episode of deformation, a decrease in arterial oxygen-gas tension was apparent. It was associated with a slight increase in arterial carbon-dioxide-gas tension and a slight acidic shift of arterial blood pH. The episode was associated with increases in intrapressure of the interclavicular and bilateral abdominal air sacs. The tracheal expiratory-gas flow changed in pattern. Hypoventilation due to reduction in tidal volume or respiratory rate could not be detected during the episode. The episode was suddenly terminated at the hen's body movement induced spontaneously or by pinching the comb, at coughlike activity or at no obvious change in behavior in a quietly resting position. Deformation similar to the spontaneous one could be induced by 3 ml-water flushing into the trachea or 0.1% methacholine aerosol inhalation. The mechanism responsible for the genesis of deformation was discussed. It was presumed to be based upon some mechanism, such as mucous accumulation in the lung, rather than upon the pulmonary smooth-muscle contraction.
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PMID:An analysis on the mechanism responsible for genesis of deformation of expiratory-gas-concentration curves in chickens. 680 76

The performance of five of the most commonly used halothane vaporizers and three enflurane vaporizers was tested under conditions encountered in low-flow and closed-circuit anesthesia. Anesthetic gas concentrations were measured continuously with a mass spectrometer connected to a circle system. The results indicated that all of the units tested, except the Fluotec Mark II, may be adapted for use in low-flow or closed-circuit anesthesia to provide accurate amounts of potent inhalation anesthetics. One should be aware, however, that the concentration of nitrous oxide affects vaporizer output, that changes in output occur during positive-pressure ventilation, and that the output of some of the vaporizers may increase when a change from high flow to low flow is made. It is also strongly recommended that upstream oxygen flushing be abandoned in the practice of low-flow or closed-circuit anesthesia.
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PMID:Assessment of vaporizer performance in low-flow and closed-circuit anesthesia. 698 90


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