Potentiometric analysis for sodium and potassium in biological fluids.

1982 ◽  
Vol 28 (1) ◽  
pp. 170-172 ◽  
Author(s):  
E Langhoff ◽  
I Steiness

Abstract Results obtained with a potentiometric analyzer, NOVA 1, specific for sodium and potassium, were compared with those by flame photometry. Both instruments showed linearity within a physiological range of sodium and potassium concentrations and had similar precisions. Volume displacements from addition of albumin or Intralipid to aqueous samples yielded the predicted lower flame-photometric results because of the relative decrease in sample water. There may be a small interaction between sodium and albumin. Physiological measurements on plasma from uremic patients showed no change after dialysis that could be ascribed to a decrease in interaction of these ions with creatinine and urea. Potentiometric values for sodium and potassium did not differ significantly, whether measured in cerebrospinal fluid or in the corresponding plasma. Results for urine were the same potentiometrically and by flame photometry.

1953 ◽  
Vol 30 (1) ◽  
pp. 1-17
Author(s):  
J. A. RAMSAY ◽  
R. H. J. BROWN ◽  
S. W. H. W. FALLOON

1. A method of flame photometry is described, by which the amount of sodium and potassium in biological fluids can be determined simultaneously, using samples of the order of 10-3 cu.mm. 2. When the method is tested with quantities near the lower limits of detection (of the order 4 x 10-8 mg. sodium, 6 x 10-8 mg. potassium) the reproducibility, measured as standard deviation, is ±7 x 10-9 mg. sodium and ± 17 x 10-9 mg. potassium. 3. When larger quantities (up to certain limits) are used, the standard deviation is approximately ± 3 % of the quantity in the sample, both for sodium and for potassium. 4. As is usual in flame photometry serious errors can be caused by the presence of other substances in the sample. In the case studied for purposes of illustration it is shown that these interference errors can be reduced to the order of ± 6 % by the addition of excess ammonium phosphate.


Author(s):  
С.Н. Шатохина ◽  
Н.А. Кузнецова ◽  
В.Н. Шабалин

Цель проведённого исследования состояла в оценке эффективности визуального анализа твёрдофазных структур спинномозговой жидкости для диагностики ранних форм нейросифилиса. Методы. Использован метод краевой дегидратации биологических жидкостей, входящий в состав авторской диагностической технологии «Литос-система». Диагностика раннего асимптомного нейросифилиса заключается в выявлении деструктивных образований в форме овалов в морфологической картине твёрдой фазы спинномозговой жидкости. Результаты. Проведён сравнительный анализ результатов исследования спинномозговой жидкости у 19 больных с подтверждённым диагнозом «ранний асимптомный нейросифилис», полученных традиционными лабораторными методами и методом краевой дегидратации. Выявлено, что локализация овалов внутри сферолитов указывает на длительность заболевания нейросифилисом менее трёх лет, а вне сферолитов - от трех до пяти лет. Заключение. Метод краевой дегидратации позволяет диагностировать ранний асимптомный нейросифилис по наличию деструктивных образований в форме овалов в морфологической картине твёрдой фазы спинномозговой жидкости. The aim of this study was to evaluate effectiveness of visual analysis of solid-phase structures in cerebrospinal fluid to diagnose early forms of neurosyphilis. Methods. We used a method of marginal dehydration of biological fluids as a part of the author’s diagnostic technology, Litos-System. Early asymptomatic neurosyphilis is diagnosed based on detection of destructive, oval-shaped formations in the morphological picture of cerebrospinal fluid solid phase. Results. Data from analyses of cerebrospinal fluid performed with traditional laboratory methods and the method of marginal dehydration were compared for 19 patients with documented diagnosis of early asymptomatic neurosyphilis. A localization of ovals within spherulites indicated a less than a three-year duration of neurosyphilis while a localization outside spherulites indicated a duration of three to five years. Conclusion. The method of marginal dehydration allows detecting early asymptomatic neurosyphilis based on the presence of destructive, oval-shaped formations in the morphological picture of cerebrospinal fluid solid phase.


1993 ◽  
Vol 39 (2) ◽  
pp. 309-312 ◽  
Author(s):  
O Gaillard ◽  
D Meillet ◽  
M C Diemert ◽  
L Musset ◽  
J Delattre ◽  
...  

Abstract Complement components have a role in various neurological disorders. Complement C3 can be measured by immunochemical methods, but only radioimmunoassays and electroimmunodiffusion assays (EIDs) are sufficiently sensitive to be applied to biological fluids in which the C3 concentration is low, especially cerebrospinal fluid (CSF). We report a sandwich-type time-resolved immunofluorometric assay (TR-IFMA) for C3 in CSF. The linearity (0.7-3650 micrograms/L) and intra- (CV < 4.8%) and inter-assay (CV < 10.9%) precision were satisfactory and the results agreed with those of EID. The assay is extremely sensitive (< 1 microgram/L) and its analytical range is large and well suited to clinical applications. This simple TR-IFMA is thus a nonisotopic alternative to radioimmunoassay for the quantification of complement C3 in CSF.


1990 ◽  
Vol 265 (2) ◽  
pp. 471-477 ◽  
Author(s):  
M J Watts ◽  
J R Dankert ◽  
B P Morgan

We have previously reported the isolation of a membrane-attack-complex-inhibiting protein (MIP) from human erythrocyte membranes [Watts, Patel & Morgan (1987) Complement 4, 236] and the production of polyclonal antibodies to this protein. Here we report the identification in plasma, urine, saliva and cerebrospinal fluid of a protein immunochemically identical with the membrane-derived MIP. The protein has been isolated from plasma by immunoaffinity chromatography on an anti-(erythrocyte MIP)-Sepharose column and shown by SDS/polyacrylamide-gel electrophoresis to be of similar molecular mass to the erythrocyte protein (55 kDa non-reduced and 65 kDa under reducing conditions). Monoclonal antibodies have been raised against plasma MIP and used to establish a two-site enzyme-linked immunoadsorbent assay, enabling quantification of MIP in plasma, urine and cerebrospinal fluid. Plasma MIP, though not able to incorporate spontaneously into membranes, was deposited on heterologous and homologous erythrocyte membranes during complement activation in a C8-dependent manner. Depletion of MIP from plasma resulted in enhancement of the lytic capacity of the plasma on heterologous erythrocytes.


2020 ◽  
Vol 51 (2) ◽  
pp. 129-138
Author(s):  
Ksenija Šandor ◽  
Svjetlana Terzić ◽  
Anja Vujnović ◽  
Eleonora Perak Junaković ◽  
Irena Žarković ◽  
...  

A study of florfenicol (FF) and its metabo- lite florfenicol amine (FFA) in pig cerebrospinal fluid was conducted following repeated intramuscular administration of the original (reference) and a generic veterinary medicinal product (VMP) under the same experimental conditions (20 mg FF/kg body weight, 48-hour interval). Both VMPs are solutions for injection containing FF as an active substance in the concentration of 300 mg/mL and have been authorized in Croatia for use in cattle and pigs. In this study, clinically healthy pigs were randomly divided into three groups. The first group was treated with the reference VMP, the second with the generic VMP, while the third served as the control group. Animals were sacrificed at 216, 288 and 384 hours after the first drug administration. Cerebrospinal fluid samples were analysed by the optimized and validated high-performance liquid chromatography-diode array detector method (HPLC-DAD). The solid-phase extraction (SPE) technique was chosen for sample preparation. The HPLC-DAD method provides good linearity over the concentration range of 0.05 to 5.00 μg/mL for FF and FFA. Limits of detection were 0.0023 μg/mL for FF and 0.0100 μg/mL for FFA. Extraction recoveries of FF were from 86.6% to 111.8%, and of FFA from 91.7% to 98.8%. The SPE-HPLC-DAD method has been demonstrated to be a selective, sensitive and suitable analytical method for the determination of FF and FFA in cerebrospinal fluid. The present study was based on a preliminary study that quantified FF in pig plasma at 216 hours after the first application of reference or generic VMP. However, FF and FFA were not detected in any of the cerebrospinal fluid samples during the experimental period. According to the nature of biological fluids, the SPE-HPLC-DAD method can be suitable for further pharmacokinetic studies of FF in pig plasma and serum after intramuscular administration of VMPs.


1970 ◽  
Vol 16 (6) ◽  
pp. 472-476 ◽  
Author(s):  
Elizabeth B Solow ◽  
L W Freeman

Abstract Sensitive or simple methods for the rapid determination of cholesterol in biological fluids have been developed during the past 10 years. Sensitivity has been increased by fluorimetry of the Lieberman—Burchard reaction for cholesterol. Measurement of the reaction of cholesterol with ferric chloride is simpler. Still, there are great differences between the results when different methods are used to measure the microquantities of cholesterol present in small volumes of serum or cerebrospinal fluid. In the proposed method, the simpler ferric chloride technique has been made highly sensitive by use of fluorometry. As little as 100 µl of cerebrospinal fluid, containing less than 1 µg of cholesterol, may be used, and the reaction is stable for as long as 1 h. Interference was negligible from pigments (such as bilirubin and hemoglobin), certain drugs, and ionic substances that might be expected to affect fluorescence.


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