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ABSTRACT: Opioids have inhibitory effects on gastric motility, but the mechanism is far from clear. Electrical slow waves in the stomach determine the frequency and the peristaltic nature of gastric contractions. The primary aim of this study was to investigate the effects of the opioid fentanyl on gastric myoelectric activity. As there were large variations between the subjects, we investigated whether the variation was correlated to single nucleotide polymorphisms (SNP) of the mu-opioid receptor (MOR) gene.
We used cutaneous multichannel electrogastrography (EGG) to study myoelectrical activity in 20 patients scheduled for elective surgery. Fasting EGG was recorded for 30 min, followed by intravenous administration of fentanyl 1 microg/kg and subsequent EGG recording for 30 min. Spectral analysis of the two recording periods was performed and the variables assessed were dominant frequency (DF) of the EGG and its power (DP). Genetic analysis of the SNP A118G and G691C of the MOR gene was performed with the polymerase chain reaction technique.
There was a significant reduction in DF and DP after intravenous fentanyl. However, there was a large variation between the patients. In eight subjects EGG was unaffected, five subjects had a slower DF (bradygastria) and in six subjects the slow waves disappeared. We found no correlation between the EGG outcome and the presence of A118G or G691C in the MOR gene.
Fentanyl inhibited gastric myoelectrical activity in about half of the subjects. The variation could not be explained by SNP in the MOR gene. Because of small sample size, the results must be regarded as preliminary observations.
Acta Anaesthesiologica Scandinavica 06/2008; 52(5):708-15. · 2.19 Impact Factor
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ABSTRACT: The aim of the present study was to examine the level of unconsciousness measured with bispectral index (BIS) at different minimal alveolar concentration (MAC) levels of sevoflurane, and to study the hemodynamic and BIS reactions during noxious stimulation with transcutaneous electrical nerve stimulation (TENS) and an ice water pain test (IWP).
This study was approved by the Ethics Committee and was performed on 10 healthy, young volunteers (six males and four females), ASA physical status I. Anesthesia was induced and maintained with sevoflurane in an oxygen/air mixture. The volunteers were spontaneously breathing, but if necessary, ventilation was mechanically supported. TENS and IWP were performed at 1.0, 1.5 and 2.0 MAC of sevoflurane.
At 1.0 MAC, there was a significant increase in BIS during pain stimulation both with IWP (P<0.03) and with TENS (P<0.005), but at 1.5 MAC there were no changes. A marked variation in BIS was seen at 2.0 MAC, with periods of burst suppression and periods of high BIS values despite clinical signs of deep anesthesia. These marked variations in BIS were seen before, during and after pain stimulation. One volunteer (# 8) had a short episode of convulsions at 2.0 MAC.
BIS, heart rate and blood pressure increased during pain stimulation at 1.0 MAC but not at 1.5 MAC of sevoflurane. There was a remarkable variation in BIS at 2.0 MAC of sevoflurane, with BIS values indicating wakefulness despite clinical signs of deep anesthesia. This BIS variation is probably caused by epileptogenic activity due to sevoflurane.
Acta Anaesthesiologica Scandinavica 03/2008; 52(3):420-6. · 2.19 Impact Factor
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ABSTRACT: The uptake of octyl ethanolamine (C8EA) by Pseudomonas pseudoalcaligenes was determined at pH 7.1-10.0. At pH 9.1 the total uptake was nearly three times higher and at pH 10.0 four times higher than at pH 7.1. Also the initial rate of uptake was lowest at pH 7.1. At pH 7.1 five to ten times higher concentrations of C8EA were needed than at pH 9.1 to achieve the same degree of leakage of cytoplasmic constituents. The results support the hypothesis that penetration of the bacterial cytoplasmic membrane by C8EA in its uncharged form is favoured. This takes place particularly with high pH in the suspending medium. In the cytoplasm, the pH is lower, and C8EA becomes more protonated. This will prevent back diffusion, promote accumulation and enhance membrane interaction and toxicity at high pH.
FEMS Microbiology Letters 04/1992; 70(2):147-51. · 2.04 Impact Factor
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ABSTRACT: The antimicrobial effects of diethanolamine, dimethylamino-methyl-propanol, and butylethanolamine are greatly enhanced at high pH. Their antimicrobial activities are closely correlated with their uncharged forms, indicating that diffusion through cell membrane(s) is rate limiting for the antimicrobial action. Since these compounds are selectively toxic at high pH, they are appropriate antimicrobial agents for use in alkaline metalworking fluids.
Antimicrobial Agents and Chemotherapy 04/1990; 34(3):491-3. · 4.84 Impact Factor
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ABSTRACT: The dynamics of microbial growth in metal-working fluids (MWF) and the effect of the addition of biocides were studied in large fluid systems, in this case, one central tank which holds 150 m3. In this system, populations of Pseudomonas pseudoalcaligenes (greater than 10(8) CFU/ml) were sustained for a year, although large quantities of biocides were added. Quantitation of 3-OH lauric acid, a marker for many Pseudomonas spp., by gas chromatography indicated that the bacterial biomass exceeded the viable counts by approximately 15 times. Fungi were grown on several occasions, the dominating genera being Fusarium and Candida. Soon after the old MWF was removed and the tank was provided with fresh MWF, which consisted of an emulsion of mineral oil in water, there was a massive growth of P. pseudoalcaligenes that reached levels of greater than 10(8) bacteria per ml. Initially, only low concentrations of other species were found for some weeks. After this period, different enterobacteria and other gram-negative rods often appeared at high concentrations (10(7) and 10(8) bacteria per ml, respectively). Bacteria identified as P. pseudoalcaligenes showed great variation with respect to colony morphology and a certain heterogeneity with respect to biochemical characteristics. Certain bacterial species grew as microcolonies on metal strips immersed in the circulating MWF, but P. pseudoalcaligenes was not recovered from this habitat. The total bacterial count in the air surrounding the machines in the metal-working shop showed an inverse relation to increasing distance from the machine. The concentration of bacteria in the air varied because of the number of machines in use, temperature, and humidity.(ABSTRACT TRUNCATED AT 250 WORDS)
Applied and Environmental Microbiology 11/1989; 55(10):2681-9. · 3.83 Impact Factor
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ABSTRACT: Large neocortical injuries can interfere with the initial performance of many previously learned behaviors. This dysfunction, however, may not be attributable to the loss of the memories of learned behaviors but to a failure to access memories that are spared. The results of this experiment support this hypothesis by demonstrating that the calcium entry blocker nimodipine, which prevents trauma-induced retrograde amnesia in a 1-trial passive learning situation, will also facilitate the recovery of pre-operatively learned brightness discrimination in rats with visual neocortical injuries.
Behavioral Neuroscience 07/1989; 103(3):561-5. · 2.62 Impact Factor
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ABSTRACT: Impairments of recent memory are a common complaint associated with aging and especially with respect to certain neural pathological conditions that may accompany aging. While this is well recognized, there is little clear evidence for a viable therapeutic treatment. Recently, however, certain investigations have suggested that blocking neuronal calcium channels may be an effective treatment for the memory impairments that are associated with brain injury as well as the memory failures that may occur during aging. The present research supports this suggestion by demonstrating that the dihydropyridine calcium channel blocker, nimodipine, will significantly improve the stabilized performance of 28-29-year-old rhesus monkeys when they are tested on a delayed-response task which depends upon trial-specific, or recent, memory.
Neurobiology of Aging 11(5):573-5. · 6.19 Impact Factor
