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PubMed1977

Determination of serum bilirubin concentration during phototherapy of newborns and in vitro: results compared by the direct spectrometric method and the diazo method.

During direct illumination of a serum bilirubin solution the bilirubin concentration decreased markedly, both as determined by the direct spectrometric method and (even more so) by the diazo method. In contrast, I found the same values for serum bilirubin concentrations as determined by these two methods for serum from untreated, "single light", and "double light" treated full-term infants with neonatal hyperbilirubinemia without blood type immunization. The same was true for untreated and "single light" treated premature infants with this disease. Furthermore, no difference was found in the above-mentioned relationship between "single light" treated infants with the same disease, and untreated infants with neonatal hyperbilirubinemia without immunization, all born at term. This is important, because the direct spectrometric method is simpler and requires less serum than does the diazo method.

Azo Compounds↗
PubMed1975

A new assay method for hydrogenase based on an enzymic electrode reaction. The enzymic electric cell method.

A new assay method for hydrogenase [EC 1.12.2.1] based on the enzymic electrode reaction of H2-H+ equilibrium has been established. The method is based on the experimental fact that the short-circuit current of the electric cell composed of an electrode with hydrogenase and methylviologen as the mediator of H2-H+ equilibrium and a saturated calomel electrode as the counter electrode, is practically proportional to the amount of hydrogenase in the cell. The new method is referred to as the "enzymic electric cell method." This technique has applications not only to routine activity assay but also to the direct determination of the time course of enzyme denaturation, which has not previously been possible.

Cytochrome c Group↗
PubMed1978

Two immunofluorescent methods compared with a radial immunodiffusion method for measurement of serum immunoglobulins.

We found high correlations when the values for immunoglobulins G, A, and M, obtained from the analysis of a group of 50 or more human sera by a measured-time radial immunodiffusion method, were compared to values found by two new commercial immunofluorescent methods. The Fiax and the Immuno-Fluor systems make use of fluorescently labeled antibodies and solid-phase immunoadsorbents and offer simple, precise, and objective methods for immunoglobulin quantitation. The Fiax procedure is less time consuming than is the Immuno-Fluor and gives IgG and IgA concentrations that are in close agreement with those found by radial immunodiffusion and IgM values that are significantly lower than the radial immunodiffusion values. The IgG results determined by the Immuno-Fluor method compare well with the radial immunodiffusion results, uhile the IgA values are significantly higher and IgM values significantly lower than those obtained by radial immunodiffusion.

Evaluation Studies as Topic↗
PubMed1978

[Quantitative functional analysis of the left ventricle in coronary heart disease: an evaluation of current methods. I description of basic methods and definition of normal range (author's transl)].

The present work consists of an evaluation of quantitative laevocardiographic methods of analysis in coronary heart disease. An attempt has been made to find a correlation between the laevocardiographic results and the extent of coronary artery disease, heart size on a conventional chest X-ray with left ventricular end-diastolic pressure. In the first part, basic methods are described, particularly the laevocardiographic area-length-method of Dodge. The accuracy of the procedure and its statistical methods are discussed in detail.

Coronary Disease↗
PubMed1979

Comparison of an automated radioimmunoassay method and a competitive protein-binding method for evaluation of serum cortisol.

A competitive protein-binding method (CPB) for serum cortisol determination has been compared with a newly developed automated radioimmunoassay (RIA) technic with respect to reproducibility and correlation of patient results. The RIA method uses an immobilized anti-cortisol antibody covalently coupled to the inner surface of a plastic cartridge. A mixture of 3H-labeled and unlabeled cortisol is passed through the cartridge to achieve separation of free and bound cortisol. The bound cortisol is later eluted to regenerate the antibody for the next sample. The RIA procedure had a day-to-day coefficient of variation (CV) of 7% at three cortisol levels. The CPB method had a day-to-day CV of 10% at a concentration of 8 microgram/dl. A comparison of 67 patient samples showed no statistically significant difference between the methods. The regression equation was RIA = 0.96 CPB + 0.14 microgram/dl, with a correlation of 0.92.

Binding, Competitive↗
PubMed1979

Whole-body autoradiography of bumetanide-14C in dogs by round saw method.--A combined method of autoradiography and tissue radioassay--.

The distribution of a new potent diuretic, Bumetanide, in dogs was studied by means of a combined method of whole-body autoradiography and tissue radioassay, after oral administration of Bumetanide-14C to five young beagle dogs (ca. 1.2 kg). A round saw method developed by Kalberer was applied to obtain frozen slices of dog whole-body with a thickness of 3 mm. After exposure to X-ray films from both sides of the slices at -60 degrees C, frozen samples of the main tissues as well as the blood, urine, bile and intestinal contents were obtained to be assayed for radioactivity and to be analyzed for metabolites by TLC. The advantages of the round saw method (thick slices) in larger animals as dogs and monkeys as compared to the conventional microtome method (thin sections) were pointed out and discussed.

Administration, Oral↗
PubMed1978

[Comparison of two methods of antibiotic sensitivity test: gel diffusion and automatic method using ABAC apparatus. II. Study on 399 strains isolated in hospital (author's transl)].

The authors compared for routine use, the results obtained on 399 strains of Gram negative bacilli by two technics of antibiotic sensitivity: the technic of gel diffusion with imprenated discs and an automatic method (ABAC apparatus). Among the antibiotics used as a routine in our laboratory by the diffusion method and the 16 studied with the ABAC apparatus, 11 are common to both methods and were compared. The concordance of the results was greater than 90% for colistine (94.5%), oxolinic acid (93.5%), tobramycin (91.7%). It lies between 80 and 90% in the case of carbenicillin (89.1%), nalidixic acid (87.5%), kanamycin (87.2%). It is less in the case of gentamicin (77.9%), ampicillin (77.3%, chloramphenicol (76%), streptomycin (70.3%), minocycline with 55.9% gave the lowest results. The percentage of uninterpretable responses by ABAC was 0.7% for all 11 antibiotics. The correlations were good for the Enterobacteriaceae: Serratia (75.4%), Eschericia coli (87.5%). They are less in the case of Pseudomonas aeruginosa (71.6%). The ABAC makes sensitivity test automatic and appears a reliable method.

Anti-Bacterial Agents↗
PubMedDate not supplied

[Simple and rapid heterologous method of radioimmunochemical determination of luteinizing hormone in the blood serum of rats. 1. Basic principles of the method].

Possibilities of creation of a radioimmunochemical method (RICM) of determination of the luteinising hormone (LH) were studied. The method is based on the application in the binding system of a water-insoluble immunosorbent obtained by copolymerization of antisera with isobutyl ester of chlorocarbonic acid. The antisera were obtained by immunization of rabbits with a highly-purified LH isolated from sheep hypophyses. The method is rapid and precise, and is carried out in a single stage. Significant results of RICM in the LH determination can be obtained with the minimal two-hour incubation time. Using different amounts of the immunosorbent in the reaction mixture with the same indicator dose of I125-LH it is possible to vary the method sensitivity (from 0.05 to 5 ng/test).

Animals↗
PubMed1978

[Measurement of cerebral blood flow with hydrogen clearance method: technique and a comparative study with the venous out flow method (author's transl)].

Local cerebral blood flow was measured with hydrogen clearance method in fifteen dogs and compared to direct measurement obtained by Michenfelder's venous out flow method. The sagittal sinus was exposed by a midline frontooccipital incision and extensive craniectomy. A tappered catheter was passed in to the superior sagittal. sinus. For measuring hydrogen clearance, platinum wire electrodes with a red tip of 0.5 mm in length and 0.3 mm in diameter were introduced into the parietal and occipital cortex. About ten percent hydrogen gas was given directly into the endotracheal tube for three to five minutes and the obtained clearance curves were transferred to semilog graph papers. Total cerebral blood flow was caliculated by bicompartmental analysis and compared to the two minutes initial slop index. The results are as follows. 1) A linear regression analysis of flows caliculated from the initial slope and bicompartmental analysis shows a high correlation coefficient. 2) There is a high correlation between flows caliculated from electrodes used at the same experiments. 3) Cerebral blood flow from the initial slope measured by hydrogen clearance method shows a high correlation wit flows caliculated from Michenfelder's venous out flow method.

Animals↗
PubMed1979

Charcoal column/thin layer chromatographic method for high fructose corn sirup and spectrophotometric method for hydroxymethylfurfural in honey: collaborative studies.

A new spectrophotometric method is described for determining hydroxymethylfurfural in honey in which interfering background absorption of honey is corrected for by use of a bisulfite-treated sample as blank. Two procedures for detecting high-fructose corn sirup (HFCS) in honey were also tested. In one, charcoal column pretreatment is used to concentrate trace oligosaccharides, followed by thin layer chromatography to differentiate those of HFCS from those of honey. The other method depends on measurement of the isomaltose/maltose ratio by gas-liquid chromatography. The charcoal/thin layer chromatographic method for HFCS has been adopted official first action. The bisulfite method for hydroxymethylfurfural has been adopted interim first action.

Charcoal↗
PubMed1978

Specific method for serum creatinine determination based on ion exchange chromatography and an automated alkaline picrate reaction -- a proposed reference method.

A proposed reference method for serum creatinine has been developed under the auspices of the Committee on Reference Methods and Reference Materials of the Canadian Society of Clinical Chemists. A serum ultrafiltrate at pH 2.0 is applied through a closed sample loop injection system to a short column containing cationic resin of high resolving power. Elution with sodium citrate buffer by means of minipump at constant rate passes the eluate into alkaline picrate reagents in a continuous flow system (Technicon AAIII pump, AAII colorimeter 50 mm x 1.5 mm flow cell, narrow band width filter). The colour reaction peak is monitored visually to verify specificity and the area is calculated electronically. Specificity has been demonstrated by use of Jaffé-reactive substances such as glucose, sodium acetoacetate, L-ascorbic acid, pyruvic acid, L-dopa and glycocyamidine and also by use of an alternate colour reaction, sodium 3,5-dinitrobenzoate in place of alkaline picrate in the analysis of serum pools. Routine methods in common use, i.e., manual and automated alkaline picrate procedures, demonstrated a statistically significant high bias in interlaboratory studies in which this procedure was used for reference.

Autoanalysis↗
PubMed1979

[Isotope methods in the diagnosis of venous disease. I. Methods of radionuclide venography (author's transl)].

The method of radionuclide venography is best determined by the localisation and type of suspected venous abnormality. The authors describe four methods using 99mTc microspheres and 99mTc-pertechnetate. Correlation of the isotope and angiographic findings in 150 patients indicated an accuracy of 90% for the isotope methods. The risks of radionuclide venography are discussed. Isotope venography is recommended as a simple, non-invasive technique.

Arm↗
PubMed1976

[Comparison between the official indirect method and the direct method of control of vaccines against sheep enterotoxemia].

The official methods of control of vaccines against sheep enterotoxemia are indirect in two ways : on the one hand they are carried out on animals for which the vaccine is not intended, and on the other hand they test only an immunological serum reaction. Another method consisting of direct testing by intravenous injection of toxin has been carried out on mice previously vaccinated with different doses. It has been shown that it is possible to obtain a certain level of protection giving a good dose-effect relation. However, immunity provided by this direct method is weak although the vaccine utilized is considered very efficacious with regard to the official norms of the direct test. These results, which are both encouraging and disappointing, will be the subject of a more intensive study of the different parameters in question.

Animals↗
PubMed1979

Application of a high-performance liquid chromatographic fluorescence method for the rapid determination of alpha-tocopherol in the plasma of cattle and pigs and its comparison with direct fluorescence and high-performance liquid chromatography-ultraviolet detection methods.

High-performance liquid chromatography is used to develop a sensitive method for the determination of tocopherol levels in the plasma of cattle and pigs. This method is compared with a similar method using UV detection and one using direct fluorescence determination of tocopherol. Finally a double injection technique used in conjunction with fluorescence detection is shown to enhance the rate of analysis of the tocopherol levels in bovine plasma extracts.

Animals↗
PubMed1976

V. a new method for the assessment of skeletal maturity- the mat- method (mean appearance time of bone stages).

By means of probit analysis of the age at the appearance of the various bone stages according to Tanner-Whitehouse and using a logarithmic time concept (logarithmic conceptional age), a new approach to the evaluation of skeletal maturity has been elaborated. The maturity score of each bone stage corresponds to th4 mean maturity level of the observation of being within each stage. The individual maturity level is calculated by averaging the maturity scores of the stages of the various bones and is then evaluated is standard deviation scores by comparing with teh Gaussian fitted distribution of averages maturity scores of the age of the child examined. Special conditions apply for the scoring of a first and a last bone stage in a sequence, which will introduce less bias in the estimation of individual skeletal maturity with the MAT-method than with the TW-method. Ossification during early infancy can be evaluated and sequence polymorphism be detected by using the bone stage chart of the MAT-method.

Age Determination by Skeleton↗
PubMed1979

Clinical applications of the enzyme labeled antibody method. Immunoperoxidase methods in diagnostic histopathology.

Histological criteria for the definition of disease entities have largely been established with light microscopy of conventionally stained and routinely processed tissue sections. More or less specific histochemical staining procedures and more recently enzyme-histochemical and quantitative histo- and cytochemical techniques in some cases provided additional criteria. In the last decade, however, the introduction of immunofluorescence and more recently the different immunoperoxidase methods have significantly influenced the scope of contemporary histopathology. Especially, the possibility to use immunoperoxidase methods on routinely processed tissue specimens has offered new dimensions in diagnostic pathology. These methods proved of particular importance for: 1) The development of new criteria for diagnosis, prognosis and treatment (e.g. immunological classification of lymphoma; plasmacell typing in intestinal inflammatory conditions; human chorionic gonadotropin and alpha-fetoprotein in germ cell tumors of the testis). 2) The possibility of etiological diagnosis (e.g. the recognition of hepatitis B viral antigens in liver biopsy specimens; histological typing of causative micro-organisms in inflammatory conditions). 3) The recognition of disease entities that were hitherto unrecognized (e.g. hyperplasia of parafolicular C-cells in the thyroid in multiple endocrine neoplasia syndromes; gastric G-cell hyperplasia as a variant of Zollinger-Ellisons syndrome). 4) Functional analysis of tissue components (e.g. hormone content of pituitary and pancreatic adenomas; cytoplasmic differentiation produces in "undifferentiated" tumors). It can be expected that immunoenzymehistochemistry will soon play a major role in routine diagnostic histopathology.

Antigen-Antibody Reactions↗
PubMed1979

An intercomparison between two methods of obtaining percentage depth doses for irregular shaped fields and comparison of each method with experimental data for 60Co and 10 MV X rays.

Measurements of central ray tissue-air ratio (TAR) for 60Co for a large number of irregularly shaped fields typically encountered in the cancer clinic were compared with TAR values either calculated by the Clarkson method using scatter air ratios or obtained from tables of square field data using the area/perimeter approach. Irregular field shapes included the "L", pentagonal, rectangular, upper and lower mantle and split fields. Agreement between both calculational methods and direct measurement is within +/- 2% if careful attention is given to central ray position as affected by the proper use of off-centre ratios in air. In the case of 10 MV X-rays, eight randomly chosen irregular fields again yielded an average agreement between both methods of calculation and experimental data of less than 1% and an agreement of less than 0.5% between the A/P and Clarkson calculations.

Cobalt Radioisotopes↗
PubMed1977

Evaluation of the dual-precipitation method by comparison with the ultracentrifugation method for measurement of lipoproteins in serum.

We evaluated the dual-precipitation method for quantitative measurement of lipoproteins as described by Wilson and Spiger [J. Lab. Clin. Med. 82, 473 (1973)] for normo- and hyperlipemic sera, by comparison with the results obtained with ultracentrifugation. If serum with an above-normal triglyceride concentration is analyzed, the very-low-density lipoprotein cholesterol value obtained with the precipitation method is usually too low. For measurement of high-density lipoprotein cholesterol the ultracentrifugation and precipitation procedures give comparable results, but the latter method is preferred because sinking pre-beta-lipoproteins present in the high-density lipoprotein fraction isolated by means of the ultracentrifuge may result in falsely high values for cholesterol in that fraction. Therefore, at least for the determination of very-low-density lipoprotein cholesterol in hyperlipemic serum, the use of an ultracentrifuge remains necessary. Because few laboratories have an ultracentrifuge at their disposal, it seemed important to look at the stability of sera in view of the forwarding of samples. Also, a way of increasing the efficiency of the ultracentrifuge was studied. Sera can be stored for a week at 4 degrees C or for 54 h at room temperature without noticeable effect on lipoprotein values. Moreover, reliable values can be obtained with an ultracentrifugation time of 8 h (0.8 X 10(8) g-min).

Chemical Precipitation↗