The effects of large doses of fentanyl and fentanyl with nitrous oxide on renal function in the dog

Renal effects of large doses of fentanyl (1 mg/kg) were determined in 14 mongrel dogs before and after addition of 50 per cent nitrous oxide. Fentanyl significantly increased urine osmolarity and decreased urine output and free water clearance but did not change inulin or PAH clearances. The arterial blood pressure and cardiac output were significantly decreased after 0.1 mg/kg fentanyl and these changes were then maintained during the remainder of the study period. Addition of nitrous oxide produced no further changes in cardiac output and arterial blood pressure but did increase urine output, PAH, inulin and free water clearances and decreased urine osmolarity. These data demonstrate that high doses of fentanyl have significant antidiuretic properties in the dog and these probably are related to the release of antidiuretic hormone. Our results also indicate that addition of nitrous oxide reverses fentanyl induced antidiuresis.     

Effect of anaesthesia with nitrous oxide in oxygen and fentanyl on renal function in the artificially ventilated dog

The effect on renal function of a large dose (25 micrograms kg-1) of fentanyl was investigated in 10 labrador dogs. The animals were anaesthetized with nitrous oxide in oxygen and a small supplement of fentanyl 0.4 microgram min-1 throughout the experiment, and muscular relaxation was provided by alcuronium, pulmonary ventilation being controlled. In the initial phase of each experiment, estimated renal plasma flow, glomerular filtration rate, urine volume, mean arterial pressure and renal vascular resistance were measured at 30-min intervals, three sets of samples being taken. Then the large dose of fentanyl was given over a 10-min period and the measurements were repeated at 30-min intervals for 90 min. Changes in renal function lasted for about 90 min; there was a significant decrease in estimated renal plasma flow (P less than 0.01), glomerular filtration rate (P less than 0.001), urine volume (P less than 0.01) and mean arterial pressure (P less than 0.001) together with an increase in renal vascular resistance (0.05 greater than P greater than 0.02). These changes were accompanied by bradycardia, but were still present when atropine was given.     

The relationship between mRNA half-life and gene function in the yeast Saccharomyces cerevisiae

Saccharomyces cerevisiae (Sc) mRNAs have been described as falling into two major classes with respect to mRNA half-life [Santiago et al., Nucleic Acids Res. 14 (1986) 8347-8360]. We have used DNA sequence analysis to address the functional roles of eleven of the thirteen cDNAs upon which Santiago et al. based their conclusions. Eight had been described as copies of short half-life and five as copies of long-half-life mRNAs. We show here that five members of the short-half-life class encode known Sc cytosolic ribosomal proteins (rp). One further short-half-life cDNA appears to encode a new Sc rp related to higher eukaryotic rp S12. Among the long-half-life cDNAs, one encodes the glucose-inducible glycolytic enzyme enolase, while another is related to the mouse housekeeping gene MER5.     

The relationship between glucose production and plasma glucose concentration in children with falciparum malaria

The pathophysiology of hypoglycaemia in children with acute falciparum malaria, a frequent and serious complication, is unknown due to absence of data on glucose kinetics. We investigated the correlation between basal glucose production and plasma glucose concentration in 20 children (8 girls) with acute, uncomplicated falciparum malaria by infusion of [6,6-2H2]glucose. Median plasma glucose concentration was 4.5 (range 2.1-6.5) mmol/L and the median glucose production 5.0 (range 4.1-8.4) mg/kg/min. There was a positive correlation between basal glucose production and plasma glucose concentration (r = 0.53, P = 0.016). There was no correlation between the rate of glucose production and the plasma concentrations of alanine, lactate, counter-regulatory hormones or cytokines. It was concluded that, in children with acute uncomplicated falciparum malaria, endogenous glucose production is an important determinant of plasma glucose concentration, contrary to previous findings in adults with malaria, in whom peripheral uptake seems to be more important than glucose production in determining plasma glucose concentration.     

The relationship between primary care and psychiatry: an opportunity for change

The past two decades have seen the development of a symbiotic relationship between primary care and psychiatric services. The changes which have taken place, however, have been piecemeal and variable in their extent. With some exceptions, they have followed an empirical route, and have come about largely because individual practitioners intuitively felt that they yielded positive results or attractive patterns of working. For the most part, they have not followed the elaboration of a specific theory and although a great deal of subsequent research has been carried out in order to analyse their benefits and limitations, routine practice has been slow to change. The recent reorganization of the health service has yet to exert an appreciable effect on the relationship between the two disciplines. Owing to the newly developing structures and patterns of care, future change is inevitable and brings with it both opportunities and dangers. This paper sets out some of the arguments in favour of a new contract between psychiatry and primary care based on an equal partnership.     

Long-term relationship between weight and aerobic-fitness change in children.

The relationship between changes in relative weight and fitness was assessed 5 years after children began treatment for obesity. Multivariate regression analysis showed that two factors were independently related to fitness change: (a) maintenance of weight loss from the end of 6 months of treatment to the 5-year follow-up and (b) initial fitness level. Children who showed the largest long-term changes in relative weight and the lowest initial fitness showed the largest improvements in fitness. Short-term weight loss was not related to long-term fitness change. These results show that weight loss and fitness are related over 5 years. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Oxygen contamination of the nitrous oxide pipeline supply

Venlafaxine, a structurally novel antidepressant that combines mechanisms of action of both the cyclic antidepressants and SSRIs, may be effective in the treatment of panic disorder. Thirteen patients with DSM-IV panic disorder with or without agoraphobia participated in an open-label, fixed-flexible dose treatment study with venlafaxine. All patients who completed the 10-week trial exhibited statistically significant decreases in scores on anxiety symptoms as well as complete cessation of panic attacks at an effective mean daily dose of 47 mg per day. Venlafaxine was well tolerated in all completers. Venlafaxine may be an effective antipanic agent, even at lower than typical antidepressant dosages.     

The reduction of nitrous oxide to dinitrogen by Escherichia coli

Escherichia coli K12 reduces nitrous oxide stoichiometrically to molecular nitrogen with rates of 1.9 mumol/h x mg protein. The activity is induced by anaerobiosis and nitrate. N2-formation from N2O is inhibited by C2H2 (Ki approximately 0.03 mM in the medium) and nitrite (Ki = 0.3 mM) but not by azide. A mutant defective in FNR synthesis is unable to reduce N2O to N2. The reaction in the wild type could routinely be followed by gas chromatography and alternatively by mass spectrometry measuring the formation of 15N2 from 15N2O. The enzyme catalyzing N2O-reduction in E. coli could not be identified; it is probably neither nitrate reductase nor nitrogenase. E. coli does not grow with N2O as sole respiratory electron acceptor. N2O-reduction might not have a physiological role in E. coli, and the enzyme involved might catalyze something else in nature, as it has a low affinity for the substrate N2O (apparent Km approximately 3.0 mM). The capability for N2O-reduction to N2 is not restricted to E. coli but is also demonstrable in Yersinia kristensenii and Buttiauxella agrestis of the Enterobacteriaceae. E. coli is able to produce NO and N2O from nitrite by nitrate reductase, depending on the assay conditions. In such experiments NO2- is not reduced to N2 because of the high demand for N2O of N2O-reduction and the inhibitory effect of NO2- on this reaction.     

The relationship between serum concentration and therapeutic effect of haloperidol in patients with acute schizophrenia

Haloperidol is the most commonly used antipsychotic drug in the therapy of acute schizophrenia. Clinicians have been using therapeutic drug monitoring in an attempt to improve clinical application of this drug. The scale of interest in this area is emphasised by the large number of studies (about 50) concerning the serum concentration-therapeutic effect relationship (SCTER) of haloperidol, including 35 studies on patients with acute schizophrenia. However, conflicting results concerning the existence and position of a therapeutic window have emerged. This article aims to provide a comprehensive review of the study design of studies in patients with acute schizophrenia before the study data are used for decision-making. For this purpose, a reproducible system for the evaluation of studies in this special area, a so-called total study score (TSS), was developed on an empirical basis. Thus, insufficient study design was found to be a reason for negative results. On the other hand, in spite of a great variability, the majority of studies with good design provided evidence for a significant SCTER: a bisigmoidal dependence of clinical effect on haloperidol serum concentration. The therapeutic effects of haloperidol increase at low concentrations, and the concentration has a maximum effect at about 10 micrograms/L and again decreasing at higher concentrations. The data of 552 patients also fit to this model in a single scatter plot (pseudo-r2 = 0.076, p < 0.001). The position of the therapeutic window was determined at about 5.6 to 16.9 micrograms/L. Patients treated with serum concentrations within this optimal range had a significantly better response compared with outside this range (p < 0.001, Student t-test). Therefore, a quantitative synthesis of all available data by means of effect-size analysis provides a mean effect-size (g) = 0.499 +/- 0.182 (standard deviation) for the comparison of haloperidol-treatment with serum concentrations within versus outside the therapeutic window. Thus, because of this moderate positive effect, serum concentration assay of haloperidol is recommended for patients with acute schizophrenia in a therapeutic drug monitoring programme. The modalities of haloperidol therapeutic drug monitoring in clinical practice are discussed, e.g. patient selection, method and time for serum concentration measurement, influence of premedication and comedication, interpretation of results and dose adjustment. Clinical investigations into this subject should focus on covariates which are responsible for the variability of the SCTER. Serum concentration assay is advised for investigations of nonresponse to exclude patients with pseudo-drug resistance.     

Closed system with agent-specific vaporizers and nitrous oxide

Through judicious use of nitrous oxide the closed system can be quite effectively used with currently available equipment including both agent-specific direct-reading percentage vaporizers and suitable devices for the measurement of end-tidal concentrations of oxygen, carbon dioxide and anaesthetic agents. It is only necessary to think in terms of required volumes of fresh gases and vapours added to the system as well as the appropriate concentrations of oxygen and anaesthetic in the respired mixture. When used as described the inspired concentration of nitrous oxide in the closed system should never exceed 50% (usually about 40%). Therefore nitrous oxide will not pose the threat of hypoxaemia unless misused. Experience in teaching this method during the previous decade supports a belief that learning the use of a truly closed circle absorption anaesthesia system is fundamentally important to the development of clinical skills and also facilitates understanding of basic concepts related to respiratory physiology and the uptake and distribution of inhalation anaesthetics. It follows that students and residents should be introduced to this method in the early weeks of their learning experience.     

The relationship between concentration of growth hormone in serum and microangiopathy in patients with diabetes mellitus

OBJECTIVE: To study the relationship between growth hormone (GH) and microangiopathy in patients with diabetes mellitus in order to elucidate pathogenesis on microangiopathy in diabetics. METHODS: GH and insulin (INS) were detected by rdioimmunoassay, and blood sugar (BS) was detected by oxydase method. RESULTS: 138 NIDDM diabetics were examined. The concentration of serum GH in diabetics without microangiopathy (2.3 +/- 1.2 micrograms/L) was higher than in normal people (1.0 +/- 1.2 micrograms/L) and GH in diabetics with microangiopathy (5.74 +/- 1.94 micrograms/L) was higher than in diabetics without microangiopathy. The differences were significant (P < 0.01). As the history of diabetes went on, the level of GH in serum increased, and the incidence of microangiopathy increased too. The correlation of GH in serum with BS was parallel. The correlation of GH in serum with INS was not apparent. 27 ID-DM diabetics were examined, their level of GH in serum (6.8 +/- 3.4 micrograms/L) was higher than that of NIDDM diabetics (4.6 +/- 1.8 micrograms/L). They were all patients with microangiopathy. CONCLUSION: The rise of GH in serum may be an important pathogeny that causes microangiopathy in diabetics.     

Correction method for end-tidal xenon concentration in CBF measurements with xenon-enhanced CT

PURPOSE: The goal of this work is to show how variations in respiratory rate and tidal volume affect calculated cerebral blood flow (CBF) values on xenon-enhanced CT. In xenon-enhanced CT examination, the patient often takes shallow and rapid breaths. Thus, it is less likely that end-tidal xenon concentration reflects arterial xenon concentration, and appropriate correction measures should be taken for the end-distal respiratory data to obtain reliable CBF values. METHOD: Preliminary breathing tests were performed using a lung phantom to determine the influence of respiratory volume and rate on end-tidal xenon concentration. Two xenon-enhanced CT studies were conducted of a healthy person with completely different respiratory manners between two studies. One was deep and slow respiration. The other was shallow and rapid respiration. RESULTS: The lung phantom results prove that deep and slow respiration is essential for the end-tidal method. The results of xenon-enhanced CT studies of the same person show that the direct use of end-tidal data for shallow and rapid respiration leads to CBF values much lower than the actual values. CONCLUSION: Differences in respiratory rate and tidal volume during xenon inhalation can significantly affect calculated CBF values on xenon-enhanced CT. With use of the correction methods described herein, these effects can be minimized. We have derived the end-tidal correction method on the assumption that a person's CBF values should be kept unchanged regardless of different respiratory manners.     

The relationship between cardiac function and neuropsychological status among heart transplant candidates

Psychological dependence was induced in rats by a 1-year intermittent exposure to intoxicating doses of ethanol, and recorded by the rat's ability to later take the same dose of ethanol independent of the offered concentration. Citalopram (10 or 40 mg/kg/day) was given for 3 weeks with ethanol available only the first and the last day; 10 mg/kg had no effect. On the first treatment day 40 mg/kg decreased ethanol intake. On the last treatment day 40 mg/kg had no effect. The following week the ethanol intake was higher than before the treatment in the 40 mg/kg group. During the four posttreatment weeks the ethanol intake of the 40 mg/kg group dropped significantly. Citalopram was retested 18 weeks after the first treatment during 1 week, with continuous access to ethanol; 10 mg/kg had no effect and 40 mg/kg decreased ethanol intake at day 1, reaching a minimum in day 3. A tolerance to this effect was seen at the end of the week. Thus, in this model an acute dose of citalopram can decrease ethanol intake, but tolerance to this effect develops when citalopram is given both with and without access to ethanol.     

Dose-response relationship between plasma epinephrine concentration and alveolar liquid clearance in dogs

Previously, alveolar liquid clearance (ALC) was observed to increase in a canine model of neurogenic pulmonary edema (NPE) by adrenal epinephrine (S. M. Lane, K. C. Maender, N. E. Awender, and M. B. Maron. Am. J. Respir. Crit. Care Med. 158: 760-768, 1998). In this study the dose-response relationship between plasma epinephrine concentration and ALC was determined in anesthetized dogs by infusing epinephrine to produce plasma concentrations of 256 +/- 37, 1,387 +/- 51, 15,737 +/- 2,161, and 363,997 +/- 66,984 (SE) pg/ml (n = 6 for each concentration) for 4 h and measuring the resultant ALC. The latter was determined by mass balance after instillation of autologous plasma into a lower lung lobe. These plasma concentrations produced ALCs of 14.3 +/- 1.2, 20.5 +/- 1.9, 30.1 +/- 1.5, and 37.9 +/- 2.7% of the instilled volume, respectively. ALC after the lowest infusion rate was not different from that previously observed under baseline conditions (14.1 +/- 2.1%), whereas in a previous study of NPE, plasma epinephrine concentration increased to 7,683 +/- 687 pg/ml and ALC was 30.4 +/- 1.6%. These data indicate that, during recovery from canine NPE, ALC is not maximally stimulated and suggest that it might be possible to pharmacologically produce further increases in the rate of resolution of this form of edema.     

Relationship between respiratory muscle function and quality of life in sarcoidosis

In sarcoidosis, pulmonary and general symptoms often do not correlate with radiographic stage and routinely performed lung function tests. Asymptomatic muscle involvement in sarcoidosis is common, but little is known about respiratory muscle involvement. The aim of this study was to investigate any relationships between persistent complaints and/or quality of life and respiratory muscle strength and endurance, respectively. Measurements of maximal inspiratory and expiratory mouth pressures (PI,max and PE,max), respiratory muscle endurance and routine lung function were made in 18 patients with sarcoidosis. To assess health status and quality of life, patients completed the Sickness Impact Profile (SIP). Respiratory muscle strength and endurance time were lower in the patient group than in a group of healthy controls (p=0.05). Compared to a general population, the patients with sarcoidosis were found to be limited in physical and psychosocial functioning. The respiratory muscle endurance time correlated with the SIP subscales "mobility" (r=-0.56; p<0.01), and "body care and movement" (r=-0.79; p<0.001). The total lung capacity (TLC), inspiratory vital capacity (IVC) and forced expiratory volume in one second (FEV1) were normal in all subjects. In conclusion, patients with sarcoidosis and normal lung function showed reduced respiratory muscle strength and endurance time. Correlations were found between these indices and both symptoms and certain Sickness Impact Profile domains. Therefore, we suggest inclusion of measurements of respiratory muscle strength in the assessment and follow-up of patients with sarcoidosis.     

The relationship between judgments of a communicator's position and extent of opinion change.

3 groups of Ss, college students, were formed: 2 exposed to a communication on juvenile delinquency and a control group that was not. One group read an appeal for the adoption of a punitive policy toward delinquents; the other group read the same basic communication with the addition of a few introductory statements. Both groups then responded to a modification of Form A of the Wang-Thurstone scale of attitude toward the treatment of the criminal. Judgment of the communicator's position was not found to be related to own opinion on the treatment of delinquents. (PsycINFO Database Record (c) 2010 APA, all rights reserved)