scholarly journals Effect of contrast media on radioimmunoassay of beta-endorphin in cerebrospinal fluid.

1984 ◽  
Vol 30 (2) ◽  
pp. 311-314 ◽  
Author(s):  
V S Fang ◽  
R G Fessler ◽  
J R Rachlin ◽  
F D Brown

Abstract An effect of metrizamide, a contrast medium, on results of beta-endorphin radioimmunoassay was examined. We found that 1, 5, and 10 microL of the medium added to 100 microL of standard containing 0 to 500 pg of beta-endorphin shifted the standard curve to the left in proportion to the metrizamide concentration. Three other contrast media showed a similar effect at low concentrations of beta-endorphin. This effect of contrast media artificially increased results in radioimmunoassay of beta-endorphin in cerebrospinal fluid, the mean overestimate being 121.9% (range, 0 to 435%). For plasma samples, this effect of contrast media resulted in an average 11.7% overestimate of beta-endorphin (range, -16% to 41%). These observations bring into question the validity of a previous suggestion that an increase in beta-endorphin in cerebrospinal fluid after intracerebral electrical stimulation is the mechanism for stimulation-produced analgesia.

1987 ◽  
Vol 33 (8) ◽  
pp. 1450-1452 ◽  
Author(s):  
D R Luke ◽  
G R Matzke ◽  
J T Clarkson ◽  
W M Awni

Abstract This is an assay for labetalol in plasma by "high-performance" liquid chromatography, with 5-(2-[4-(4-chlorophenyl)ethyl]) salicylamide hemihydrate as the internal standard. Plasma samples (500 microL) are extracted with acetonitrile, evaporated under nitrogen, reconstituted in the mobile phase, and injected onto a PRP-1 (Hamilton) column packed with particles of poly(styrene-divinylbenzene) copolymer. Fluorescence, enhanced by post-column introduction of NH4OH, was measured in the effluent (excitation wavelength 340 nm, emission wavelength 418 nm). Retention times for labetalol and the internal standard were 1.99 and 3.32 min, respectively. Inter- and intraday CVs for high and low concentrations of the drug were less than 7.5%. The assay standard curve is linear from 1 to 250 micrograms/L. Some commonly co-administered drugs were tested and did not interfere.


1995 ◽  
Vol 36 (2) ◽  
pp. 198-203 ◽  
Author(s):  
J. Karstoft ◽  
L. Bååth ◽  
I. Jansen ◽  
L. Edvinsson

Angiographic contrast media (CM) may cause both vasodilatation and vasoconstriction. This study evaluates a contrast medium-induced vasoconstriction that occurs when isolated arteries are exposed directly to a CM. Segments of rabbit coronary arteries were mounted in tissue baths containing buffer solution. During the experiments the buffer solution was exchanged with iohexol iso-osmolar with plasma, which caused a temporary vasoconstriction of the vessel segments. The constriction did not depend on the degree of oxygenation of iohexol. The endothelium was not involved in the vasoconstriction. Prazosin slightly decreased the vasoconstriction and a small part of the constriction might thus depend on liberation of norepinephrine by iohexol. The constriction was totally inhibited by the calcium antagonist nifedipine, while it was augmented by addition of low concentrations of KCl to ihoexol. It is concluded that the otherwise safe CM iohexol causes vasoconstriction in vitro by depolarizing the smooth muscle cells and the nerve terminals in the vessel wall.


2007 ◽  
Vol 53 (8) ◽  
pp. 1541-1544 ◽  
Author(s):  
Hiroyuki Ebinuma ◽  
Takashi Miida ◽  
Toshimasa Yamauchi ◽  
Yusuke Hada ◽  
Kazuo Hara ◽  
...  

Abstract Background: Human serum adiponectin exists in 3 multimer forms: high molecular weight (HMW), middle molecular weight, and low molecular weight (LMW), with some of the latter bound to albumin (Alb)-LMW. Some studies have suggested that adiponectin crosses the blood–brain barrier and plays a central role in energy homeostasis. Methods: To determine cerebrospinal fluid (CSF) adiponectin at extremely low concentrations, we modified the protocol of the ELISA system used to assay serum adiponectin. The 3 multimers of adiponectin were measured separately by pretreating CSF with 2 proteases. We measured the CSF adiponectin concentrations in anonymous human samples (n = 19). The molecular sizes of adiponectin in CSF pretreated with proteases or untreated were determined by use of native PAGE and immunoblotting. Results: The ELISA system measured adiponectin in the range of 1.0–167 μg/L. The between-assay imprecision estimates (CVs) were 6%–17% for the 3 forms. The mean total CSF adiponectin concentration (7.2 μg/L) was ∼1/1000 of the mean concentration in serum. Unlike serum adiponectin, the LMW and Alb-LMW forms predominated in all of the CSF samples. Immunoblotting analysis revealed that most LMW forms were bound to Alb, although the HMW form was detected in some samples. Conclusions: The modified ELISA system measures the 3 multimers separately and is sufficiently sensitive to measure adiponectin in CSF.


1984 ◽  
Vol 25 (6) ◽  
pp. 517-522 ◽  
Author(s):  
S. E. Ekholm ◽  
M. Foley ◽  
D. K. Kido ◽  
T. W. Morris

Neurotoxicity from subarachnoid contrast media is probably related to their specific pharmacologic effects and to their penetration into the central nervous system. The lack of a barrier between the cerebrospinal fluid and the extracellular fluid of the brain and cord allows water-soluble contrast media to diffuse into the neural tissue. The aim of this investigation was to develop a method that allows one to quantify the neural tissue penetration for a given contrast medium in relation to the cerebrospinal fluid concentration and contact time and apply this to the use of metrizamide. The result shows a good correlation between iodine concentration in the lumbar cerebrospinal fluid and that in the lumbar cord suggestive of a simple diffusion. When time of sacrifice (contact time) is added as a covariant there is also some indication of retention of metrizamide in the neural tissue. The investigation also demonstrates that the resorption of the contrast medium in the rabbit in this experimental model is mainly in the lumbo-sacral region.


1974 ◽  
Vol 76 (2) ◽  
pp. 377-387 ◽  
Author(s):  
Ø. Andresen

ABSTRACT A radioimmunoassay (RIA) for 5α-androst-16-en-3-one (5α-androstenone) in peripheral plasma from pigs has been developed. Antibodies against 5α-androstenone conjugated through C-3 to bovine serum albumin (BSA) were produced in rabbits. The antiplasma used in this study show a cross-reaction of 100% with 4,16-androstadien-3-one (androstadienone), 5.3 % with 5α-androst-16-en-3β-ol (an-β), 3.3 % with 5α-androst-16-en-3α-ol (an-α), 2.6 % with 4-androstene-3,17-dione (androstenedione) and 1.4% with 5,16-androstadien-3β-ol (andien-β). The standard curve plotted as log picogram (pg) unlabelled 5α-androstenone against counts per minute (cpm) bound radioactive steroid was almost linear from 50 to 800 pg 5α-androstenone. Regression analysis of the data from the accuracy study gave the curve y = 0.99 x+ 203. The precision and sensitivity of the method were satisfactory. In plasma samples from sows and castrated male pigs the mean 5α-androstenone found was 1.1 ng/ml. In plasma samples from boars from 1.2 to 54.1 ng/ml was found.


Author(s):  
V J C Willson ◽  
J G Graham ◽  
I N F McQueen ◽  
R J Thompson

Nervous-system specific aldolase C has been detected in human cerebrospinal fluid (CSF) by radioimmunoassay. Measurement of 138 samples of CSF showed a mean level of 92 ± 28 ng/ml. There was no correlation between the level of CSF aldolase C and the CSF total protein, albumin, IgG, or IgA levels. Aldolase C immunoreactivity present in concentrated CSF diluted out in parallel with the standard curve in the assay and showed an elution profile on ion-exchange and gel filtration chromatography similar to that of aldolase present in whole human brain extracts. Addition of known quantities of purified aldolase C4 to CSF gave quantitative recovery on subsequent radioimmunoassay. Measurement of aldolase C in the CSF of 66 patients with neurological disorders showed several patients with levels considerably in excess of 120 ng/ml, but there was no statistically significant difference in the mean levels between groups of patients with different diseases.


2012 ◽  
Vol 5 (1) ◽  
pp. 37-43
Author(s):  
ABMM Alam ◽  
M Moniruzzaman ◽  
MB Alam ◽  
N Islam ◽  
F Khatoon ◽  
...  

Background: CIN has gained increased attention in the clinical setting, particularly during cardiac intervention but also in many other radiological procedures in which iodinated contrast media are used. There is at present good clinical evidence from well-controlled randomized studies that CIN is a common cause of acute renal dysfunction.Methodology: This was a prospective study conducted among the patients who underwent coronary angiography and percutaneous coronary intervention in the Department of Cardiology, Dhaka Medical College Hospital during January 2010 to December 2010. A total of 111 patients age range from 25 to 75 years were included in the study. Serum creatinine level at baseline and at the end of 48 hours was done in all these patients. Study population was divided into two groups according to development of acute kidney injury (AKI). Group-I = AKI, Group II = Not developed AKI. Results: AKI developed 11.7% of the study patient. DM and Preexisting renal insufficiency were significantly higher in group I patients. HTN was (61.5% Vs 44.9%) higher in group I but not significantly. History of ACE inhibitor/ARB, NSAID intake and LVEF <40% were significantly higher in group I patients. The mean±SD volume of CM (Contrast Media) were 156.9±44.8 ml and 115.4±30.0 ml in group I and group II respectively, which was significant. The mean±SD of serum creatinine after 48-72 hours of CAG/PCI was 1.4±0.37 mg/dl and 1.1±0.2 mg/dl in group I and group II respectively. The serum creatinine level increased significantly (p<0.05) after 48-72 hours of CAG/PCI in group I. In group II, S. creatinine level increased but not significant (p>0.05). Impaired renal function was found 76.9% and 2.0% in group I and group II respectively. DM, HTN, preexisting renal insufficiency, ACE inhibitor/ARB, NSAIDs, contrast volume (>150 ml), eGFR (<60 ml/min/ 1.73m2) and LVEF (<40%) are significantly (p0.05) associated for CIN development.Conclusion: CIN is an iatrogenic but preventable disorder results from the administration of contract media. Although rare in the general population, CIN occurs frequently in patients with underlying renal dysfunction and diabetes. In patients with pre angiographic normal renal function, the prevalence is low but in pre-existing renal impairment it may pose a serious threat. Thus risk factors are synergistic in their ability to predispose to the development of CIN. A careful risk-benefit analysis must always be performed prior to the administration of contrast media to patients at risk for CIN. DOI: http://dx.doi.org/10.3329/cardio.v5i1.12227 Cardiovasc. j. 2012; 5(1): 37-43


Reproduction ◽  
2000 ◽  
pp. 331-336 ◽  
Author(s):  
L Holm ◽  
H Ekwall ◽  
GJ Wishart ◽  
Y Ridderstrale

Sperm storage tubules from the utero-vaginal junction of chickens, quails and turkeys were analysed for calcium and zinc using X-ray microanalysis of ultra-rapidly frozen tissue in a scanning electron microscope. This technique enabled the tubular fluid surrounding the stored spermatozoa and the intracellular content of the cells of the sperm storage tubules to be analysed separately and, by using standards with known concentrations, their elemental concentrations were estimated. The mean (+/- SEM) concentration of calcium in the tubular fluid from chickens, quails and turkeys was 17 +/- 3, 19 +/- 3 and 17 +/- 4 mmol kg(-1) wet weight, respectively. The intracellular calcium concentration of the cells of the tubules did not differ significantly from these values and was also similar in the mucosal epithelial cells of the utero-vaginal junction. Zinc was localized in the cells of turkey sperm storage tubules and tubular fluid, but at low concentrations. No zinc could be detected in corresponding structures from chickens and quails. The concentration of calcium in the tubular fluid is within the range known to inhibit the motility of spermatozoa, supporting this function for calcium during storage. Zinc is known to depress turkey sperm metabolism and it may also be involved in inducing quiescence of spermatozoa during storage in this species.


1988 ◽  
Vol 29 (6) ◽  
pp. 741-743 ◽  
Author(s):  
P. P. Harnish ◽  
J. Zuniga ◽  
F. K. Northington ◽  
P. A. Melrose ◽  
S. A. Joseph ◽  
...  

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