PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Photometry”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1977

Use of a wedge cuvette in thin layer photometry and its application to oximetry.

A wedge cuvette was constructed by fixing 2 glass plates at a known angle with a spacer at one end. This resulted in a thin layer with thickness varying from 0 to 250 micrometer. By measuring the intensity of a beam of light through the thin layer as a function of distance along the wedge (and thus layer thickness), the absorption coefficient at the light wavelength used could be obtained without a separate measurement of I0, the reference light intensity. In addition, the difficult problem of determining accurate layer thickness as encoutered in conventional thin layer photometry has been avoided. Tests of the wedge cuvette method with Evans Blue and Malachite Green serial dilutions as well as with haemoglobin solutions at several oxygen saturations demonstrate that accuracy of the order of 1% can be obtained. Application of the wedge cuvette in experiments on oxygen uptake by layers of haemoglobin solution are discussed.

Hemoglobins↗
PubMed1979

Multiangle light scattering flow photometry of cultured human fibroblasts: comparison of normal cells with a mutant line containing cytoplasmic inclusions.

Multi-angle light scattering flow photometry was used to study the light scattering properties of normal cultured fibroblasts and a mutant fibroblast line containing cytoplasmic lysosomal inclusions. The effect of glutaraldehyde fixation on the light scattering properties of the cells was also examined and correlated with their ultrastructure. Normal fibroblasts showed uniform organelle distribution with few vacuoles or dense bodies in the cytoplasm while the mutant line showed abnormal cytoplasmic inclusions of varying morphology, density and lucency. As predicted by light scattering theory, the mutant cells containing the cytoplasmic inclusions scattered more light at large angles (greater than theta = 1.85 degrees) than did the normal cells. Glutaraldehyde fixation decreased light scattering at small angles (less than theta = 1.85 degrees), increased light scattering at larger angles (greater than theta = 1.85 degrees) in both normal and mutant cells and enhanced resolution of the light scattering signatures. The mutant line scattered 2-3 times more light at a wide angle (greater than theta = 12.74 degrees) than did the normal cells. These data suggest that abnormal lysosomal storage inclusion bodies in the cytoplasm of the cells can be detected by differential light scattering methods.

Cell Line↗
PubMed1979

[Comparison of ion-selective electrodes and flame photometry for the determination of serum Na+ and K+ for clinical purposes (author's transl)].

The ORION SPACE-STAT (SS-30) and the TECHNICON STAT/ION were used to investigate quality control of Na+- and K+-determinations in test sera (n=8) and in the plasma of 100 patients. The flame photometer IL 543 was used as a reference apparatus. The ion-selective electrode instruments, SS-30 and STAT/ION, gave results very similar to those of flame photometry. The values from the SS-30 were higher by an average of 3% to 5% compared with the values from the other instruments. An explanation for this bias may be the fact that the SS-30 (unlike the STAT/ION and the IL 543) measures electrolyte activities or concentrations in undiluted plasma water. On the basis of these results the routine use of ion-selective electrodes for Na+- and K+-determination can be recommended for clinical laboratories.

Electrodes↗
PubMed1979

[Optimal measurement technic for the vasoconstrictor effect of corticosteroids. Comparative studies with reflection photometry and flow measurement].

In 20 healthy male test subjects, a non-specific ointment base was applied to the back of the hand over 16 hours. Two days later, the same ointment base with 0.25% triamcinolone acetonide was once more applied to the back of the hand over 16 hours. The light reflection of the skin was measured by reflection photometry and the heat transport coefficient was measured fluvographically under the condition of the tourniquet test. The results show that the vasoconstrictor effect of triamcinolone acetonide is best detected by the reflection photometric measurements. In fluvographic measurement, the heat transport coefficient is most affected in maximal reactive hyperemia when the tourniquet has been removed. Application of the base led to a reduction of the blood flow and the water content of the skin after 16 hours, whereas the water content of the skin was unaffected in the presence of triamcinolone acetonide.

Adrenal Cortex Hormones↗
PubMed1976

Measurement of plasma levels of tricylic psychoactive drugs and their metabolites by UV reflectance photometry of thin layer chromatograms.

A method has been developed for the determination of perazine, clozapine, imipramine and amitriptyline and their demethylated metabolites in plasma. Other metabolites measured were perazine sulfoxide and the N-oxides of clozapine and perazine, the latter two following their reduction to the parent drugs with ascorbic acid. 10-Hydroxynortriptyline was identified as an amitriptyline metabolite in plasma. The general procedure included extraction of alkalinized plasma samples (3 - 6 g) with benzene or toluene and thin layer chromatography of the extracts, followed by reflectance photometry of the plates at appropriate wave lengths in ultraviolet light. Spots of questionable identity were further characterized by two-dimensional chromatography and by colour reactions. Therecoveries of compounds added in therapeutic concentrations were between 70 and 98 %. The limits of detectability were 5 - 10 ng/g plasma.

Amitriptyline↗
PubMed1979

[Determination of Fe, Cu and Zn by a mechanised micro-method of flame photometry (author's transl)].

By sample application in measured quantities ("injection method") the quality of serum required for the determination of trace elements can be considerably decreased with essentially no loss in sensitivity. The volume of solution, 50 or 100 microliters, required for a single measurement is added to the nebulizer of the AAS apparatus manually with a bulb pipette, or automatically by a suitable sample changing system. A total of 500 microliters serum is sufficient for the determination of traces of Fe, Cu, and Zn. It was shown that under suitable conditions a total volume of 25 microliters serum is sufficient for the determination of Cu and Zn by flame atomic absorption-atomic emission photometry.

Copper↗
PubMed1977

[Determination of urinary alpha-keto-gamma-methylthiobutyric acid in hypermethionemia by use of gas chromatography and flame photometry (author's transl)].

In this paper we describe the determination of urinary alpha-keto-gamma-methylthiobutyric acid (ACMTB) by the use of gas chromatography of its quinoxalinol derivative and specific detection of sulphur with a flame photometric detector. Using these techniques, it was possible to study the urinary elimination of this secondary metabolite of methionine in normal children, homocystinurics and in one case of hypermethioninemia. The excretion of ACMTB is normally very weak and is strongly increased when the principal pathway of methionine is blocked.

Amino Acid Metabolism, Inborn Errors↗
PubMed1976

[Flow fluorescence-photometry in ovarian carcinomas with and without effusion].

By flow microfluorometry the DNA distribution curve of the cell nuclei of 39 adnex tumors, mainly ovarian carcinomas, was measured. 47% of the malignant tumor cell populations were diploid, the other ones were heteroploid (i.e. polyploid, tetraploid, aneuploid stem lines). Heteroploid tumors had the worse prognosis. In 8 cases effusions were analysed (7 ascites, 1 pleura). It is possible to diagnose a malignant tumor from effussion fluid by impulse cytophotometry. But in one case a great difference was found between the primary tumor and the ascites fluid, which only shows the DNA distribution of an irritative effusion. The value of impulse cytophotometry for clinical purposes is discussed.

Ascites↗
PubMed1979

[Determination of Li, Na, K, Mg and Ca with a mechanised flame photometric micro-method. Mechanised micro-method ("injection method") of flame photometry (atomic absorption--atomic emission) for the determination of serum electrolytes and trace elements (Fe, Cu, Zn); Part I. (author's transl)].

By introduction of the analysis solution in measured quantities in atomic absorption and atomic emission spectrometry, the quantity sensitivity of these methods can be increased by an order of magnitude, while the concentration sensitivity remains unchanged. The required volume of sample (serum) is thereby considerably reduced. Using this method, the serum electrolytes and certain trace elements can be determined simply and quickly in only a few microlitres of serum. The automation of this micro-sample application ("injection method") largely abolishes individual errors, and markedly shortens the time for the analysis of large series of samples. The first part of this paper describes the determination of serum electrolytes and lithium, using only 5--20 microliters of serum.

Calcium↗