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PubMedDate not supplied

[Colorimetric method of sequential determination of several dehydrogenases in a smear of human leukocytes].

Activity of several dehydrogenases was estimated by means of sequential incubation of a smear of human leukocytes in various media containing specific substrates for each enzyme and p-nitrotetrazolium violet as an acceptor of electrons. Photometry of the coloured products of redox reactions was carried out in the photoelectrocolorimeter, which was used for registration of steady state kinetics of all the reactions studied under usual conditions. Relative activity of succinate-alpha-glycerophosphate dehydrogenases and NADH/alpha-glycerophosphate dehydrogenases was estimated with an error of 2-4% in individual donors, while deviations of these values in leukocytes of the donors constituted +/- 15% as compared with their middle level calculated in 32 donors.

Colorimetry↗

PubMed1986

[Sodium and potassium content of some fresh, frozen and canned vegetables].

Sodium and potassium content was determined in fresh, frozen and canned green peas, corn and green beans, as well as in fresh and canned tomatoes. Flame photometry was the method used for this analysis, as the AOAC recommends. Among the fresh products tested, green beans yielded the lowest sodium and potassium contents, with 2.2 and 150.2 mg/100 g, respectively. The highest sodium content was found in green peas, with 31.8 mg/100 g, and the highest potassium values were determined in tomatoes and green peas, with 271.7 and 271.3 mg/100 g, values which are not statistically different. In regard to frozen products, green beans also presented the lowest values of these cations, with 3.0 mg/100 g sodium, and 111.0 mg/100 g potassium. The highest averages were detected in green peas, with a sodium content of 149.4 mg/100 g, and 145.1 mg/100 g potassium. In general, all canned products tested showed higher sodium and lower potassium values than those found in fresh or frozen products. The highest sodium content (317.3 mg/100 g) was found in canned green peas, and the lowest (127.4 mg/100 g), in canned tomatoes. With respect to potassium, the highest values corresponded to canned tomatoes, with 168.8 mg/100 g, and the lowest to corn, with 7.6 mg/100 g.

Fabaceae↗

PubMedDate not supplied

Homogeneity of potassium chloride in small volume intravenous containers.

The purpose of this investigation was to determine whether potassium chloride as an additive is distributed homogeneously throughout small volume parenteral solutions and whether the pattern of electrolyte distribution is identical for two types of delivery systems. The effect of purposeful mixing after addition of potassium chloride was also studied. Thirty-one registered nurses prepared two supplementary intravenous solutions consisting of 10mEq potassium chloride in 50ml of 5% dextrose solution. One solution was prepared in a soft polyvinyl chloride minibag (Viaflex, Baxter-Travenol), the other in a semirigid plastic burette (Buretrol, Baxter-Travenol). The solutions were discharged through a volumetric pump (IMED) and four aliquots were taken at regular intervals. Samples were chemically analyzed by flame photometry to determine the potassium concentration in each solution layer of the container. For each container type, there were significant differences in the potassium concentrations among the layers of solution. The pattern of distribution also differed significantly between the two containers. The strata in the minibag showed smaller variations in potassium concentration than did corresponding layers in the burette. Some single sample concentrations from burettes exceeded the expected concentration of 200mEq/L by 105mEq. Nurses manipulated the two types of containers differently. Thirty of 31 minibags were mechanically mixed, but only 11 of 31 burettes were treated in this way. When the effect of mixing was considered, solutions in mixed containers were essentially no different from those not agitated after addition of the electrolyte.

Drug Packaging↗

PubMedDate not supplied

[Effectiveness of the cryoprotective effect of glycerol and polyethylene glycol on plasma membranes].

The barrier properties of erythrocyte membranes were studied under freezing-thawing in cryopreservatives based on glycerol or polyethylene glycol Mm 1500 Da (PEG-1500) (at cryoprotectant concentrations from 0.5 to 30%). The state of the membrane barrier function in reconstituted and native erythrocytes subjected to rapid (200-400 degrees C per min) freezing has been registered by spectrophotometry, flame photometry, and radiolabel analysis as judged by labeled compound release (hemoglobin, K+, [14C]sucrose, 86Rb+). It is demonstrated that the effective cryoprotection of erythrocyte membranes in reconstituted erythrocytes is attained at cryoprotectant concentrations in the medium of 0.5-1% or in erythrocytes of 8-30%.

Blood Preservation↗

PubMedDate not supplied

[Change in sodium and potassium concentration in human seminal plasma infected experimentally with Ureaplasma urealyticum].

The concentration of sodium and potassium ions was measured by flame photometry in human seminal plasma and human sperm cells as well as in a sperm cell suspension infected experimentally with Ureaplasma urealyticum during incubation as long as 22 hours. The sodium concentration is 86.2 +/- 21.97 mmol/l cells in sperm cells and 120.8 +/- 15.87 mM in seminal plasma. The potassium concentration is 33.2 +/- 16.35 mmol/l cells in sperm cells and 26.7 +/- 4.92 mM in seminal plasma. The sodium concentration decreased considerably in the suspension medium of sperm cells during the first hour of incubation and increased again subsequently. The potassium concentration in the suspension medium changed only little. The sodium concentration in the infected sperm cell suspension was insignificantly increased compared with the mycoplasma-free controls. The potassium concentration was slightly higher in the infected specimens than in the controls. There was no mycoplasma-induced effect on the concentration of sodium and potassium in the sperm suspension after experimental infection.

Humans↗

PubMed1986

[Cytophotometric studies of urinary bladder tumors of various degrees of differentiation].

With the help of the scanning microscope photometry DNA content and size of Feulgen-stained cytoblasts may be measured. On smears of 28 tumours of the urinary bladder of all degrees of differentiation in each case 200 nuclei were investigated, the DNA and surface values were applied in histograms and these were compared one with another. With increasing dedifferentiation the mean nucleus-DNA content and the spreading of DNA and surface values significantly increased. The mean size of the nuclei did not increase. Increasingly ploidy deviations appeared--clinically significant for the recidivation. With the help of the proportion of non-diploid nuclei the histo-pathological graduation could be repeatedly performed and statements could be made as to the proliferative behaviour of tumours of the same classification. The "chromatin density" of non-diploid nuclei allowed the exact separation of the papillomas (Gx2) from the carcinoma preparations. The results are discussed on the basis of the literature.

Aged↗

PubMedDate not supplied

A theoretical approach to the spectrophotometry of nucleic acids on paper disks.

A linear approximated model is presented that takes into account a local anisotropic distribution of scattered light within a turbid medium. Light intensity depends upon the distance from the boundary surface of the scattering centers, so that the probability of photon-chromophore interaction is a function of the distance. For the sake of simplicity it is assumed that there are only two main zones, corresponding to two probabilities of photon-chromophore interaction. In this form, the Kubelka-Munk theory fits the experimental data supplied by bichromatic photometry of nucleic acids on paper disks.

Chromatography, Paper↗

PubMed1979

[Theoretical grounds for free osteoplasty in suppurative infection].

From the materials of extensive experimental studies and clinical observations the theoretical grounds for the free bone plasty under the conditions of purulent infection were devised. The methods of investigation of the microcirculatory vascular bed, luminescent microscopy with a tetracycline mark, photometry, planimetry and other specific tests were applied. Findings obtained in earlier experiments on 2000 animals (rabbits and dogs) and data of supplementary special studies on 185 rabbits were used. It was found, that from the point of view of the condition of the microcirculatory bed and osteogenetic potentiatlities of the mother bone, the free bone plasty is quite grounded theoretically. The authors' theoretical postulates are supported by successful treatment of 47 patients with hematogenic spine osteomyelities, subjected to bone plasty of the defects formed after the removal of purulent inflammatory foci.

Animals↗

PubMed1986

A microcomputer system for video image analysis and diagnostic microdensitometry.

A system for microdensitometry based on a microcomputer, video digitizer and solid-state camera has been developed. Image analysis and densitometry are achieved with convenient control over image editing and calibration. The linear photometric properties of the imaging device enable measurements of high accuracy. The system has proven to give rapid and repeatable performance for determining DNA content distribution from measurements of Feulgen-stained cell nuclei. The results show that a practical image analysis microdensitometer can be designed using a readily available microcomputer. The low cost and simple operation are of benefit for diagnostic applications in which flow cytometry is not possible, the time required for microscope photometry is too great or an automated image analyzer and support staff are not available.

Animals↗

PubMed1986

[DNA content and prognosis in atypical cervix epithelium].

At 76 patients an atypical epithelium of the uterine cervix was verified colposcopically, cytologically and by biopsy. The mean content and the distribution of DNA was measured by single cell-photometry of Feulgen-stained smears. These findings were compared with the spontaneous follow up of these cases. No correlation could be registered between DNA-characteristics and the fate of atypical epithelium, which was suitable for a clinical therapeutic resolution.

Carcinoma in Situ↗

PubMed1987

[Study of infant milk formulas present on the Spanish market and its adaptation to the recommendations of the European Society of Gastroenterology and Pediatric Nutrition].

The aim of this study was to investigate energy as well as the protein and mineral composition of milk formulas available on the Spanish market. We studied 20 milk formulas, 14 of which were adapted milk formulas intended for feeding newborns during the first 4-6 months of life and the other 6 ones were follow-up milk formulas. Determinations of energy, total protein, osmolality, sodium, potassium, chloride, phosphorus and calcium were performed by adiabatic calorimetry, cryoscopy, flame photometry, photocolorimetry and flame atomic absorption spectrophotometry respectively. Experimental energy in all formulas was higher than that determined by nutrient contents and conversion factors. Three of the adapted formulas presented higher values of protein than those recommended by ESPGAN and some of them also high levels for sodium total electrolytes. However, the estimated renal solute load for each of the formulas was lower than the minimum renal concentration ability. All formulas, except one, showed normal values for calcium and the contents of phosphorus, were within normalcy. All the follow-up formulas agreed with the ESPGAN recommendations related with protein and mineral composition.

Energy Intake↗

PubMed1985

Ion-selective electrode technology: an overview.

Diluting a sample before analysis, as is required by both flame photometry and indirect reading ISE analysers, gives less relevant analytical results than measuring an undiluted sample directly. This is because dilution masks the impact that protein and lipids exert on the true activity of an ion in a clinical sample. Measuring a sample directly without dilution enables only those ions which are not bound to other materials, e.g. other ions or proteins, to be detected. The levels of these free ions are more likely to reflect true physiological status than analysis of both free and bound ions. Measuring a sample of whole blood directly without dilution can only be performed accurately if the ISE analyser reference junction is unaffected by changes in haematocrit. Calibrant compositions should be of an ionic strength similar to that of physiological samples. Residual liquid junction potentials between calibrants and samples should be minimised by careful design of the reference electrode.

Autoanalysis↗

PubMed1985

[Foreign substances as indicators of liver function].

The need to use xenobiotics to quantify liver function is based on the fact that the serum levels of endogenous tracers (such as transaminases, alkaline phosphatase, bilirubin and bile acids) cannot be interpreted in pharmacokinetic terms, since information is lacking on volume of distribution and on rate of synthesis and of disposition. Methods are now available which allow practically non-invasive estimation of (minimal) hepatic perfusion by indocyanine green fractional clearance, of portosystemic shunt flow by finger pulse photometry following nitroglycerin administration, of microsomal capacity by the aminopyrine breath test (ABT) or caffeine clearance, and of cytosolic function by galactose elimination capacity (GEC). Assessment of inherited hydroxylation deficiency of the debrisoquine type is best performed with dextromethorphan, and of the acetylator phenotype with sulfadimidine. Recently, caffeine clearance in saliva has been studied extensively in this laboratory, and, on the basis of a constant relationship between caffeine concentrations in serum and saliva, overnight clearance measurements (requiring a saliva sample at bedtime and upon arising following a single oral dose of caffeine) have been shown to be closely related to ABT or GEC. This approach, which has been successfully used in children, may represent the first simple and innocuous test for quantifying of hepatic function in the pediatric age group. The clinical utility of these clearance tests is to assess severity of disease (or genetically determined impairment of function), thus yielding important clues to prognosis.

Aminopyrine↗

PubMed1985

Distribution of laminin within rat and mouse renal, splenic, intestinal, and hepatic basement membranes identified after the intravenous injection of heterologous antilaminin IgG.

To determine the fate of circulating antibodies against the basement membrane glycoprotein laminin, affinity-purified sheep antilaminin IgG (S alpha L) was radioiodinated and intravenously injected into rats. Twenty-four hours later, approximately 60% of the bound S alpha L was present in the kidneys, spleen, small intestine, and liver and less than 1% was present within the lungs and heart. S alpha L bound rapidly to the glomerular basement membrane and reached maximal levels 75 minutes after injection. Fifteen days later, 65% of maximal levels remained within the glomerular basement membrane as shown by immunofluorescent photometry. Injected S alpha L, S alpha L that had been further purified against a pepsin-resistant subfragment of laminin (S alpha P1), and rabbit alpha L (Rb alpha L) bound in identical patterns with various basement membranes in both the rat and mouse as shown by immunofluorescent microscopy. In addition, injected conjugates of S alpha L and horseradish peroxidase (S alpha L-HRP), S alpha P1-HRP, and Rb alpha L-HRP had the same ultrastructural distribution in both rats and mice. In the kidneys, HRP reaction product was present throughout the full thickness of the glomerular basement membrane, on the base of the epithelial foot processes, and throughout the tubular basement membrane. In the spleen, alpha L was within basement membrane-like material at the periphery of the white pulp, in cords of the red pulp, and surrounding the venous sinuses. Intestinal alpha L was visualized throughout the subendothelial, crypt, and villous epithelial basement membranes and on the basal surface of the epithelium. In the liver, alpha L was present throughout the basement membranes of the portal and central veins and bile duct epithelium and on basement membrane-like structures in the space of Disse of hepatic sinusoids. Sheep, rabbits, and rats immunized against laminin did not develop antibasement membrane disease. Autoantibodies (IgG) were not detected in their basement membranes and rat alpha L injected into rats did not bind to the glomerular basement membrane. We conclude that the intravenous injection of heterologous alpha L results in the rapid deposition of alpha L within basement membranes of organs with fenestrated endothelia, laminin is present throughout basement membranes and on the surface of the epithelia adjoining basement membranes, and animals generally do not produce alpha L that binds to autologous or homologous basement membranes.

Animals↗

PubMed1985

Microcomputers and neurobiology: a short review.

A brief history of the application of computing techniques emphasizes the two-part development with expensive minicomputers available in a few laboratories being added to by inexpensive microcomputers ubiquitously available. Computers are used for microscope control and plotting, serial section reconstruction, morphometric measurement, stereology, video image analysis, photometry and fluorescence microscopy. Basic principles are exemplified by considering nerve cell reconstruction. General principles of computerized electrical measurement including filtering, averaging and stimulus generation are discussed. Computerized waveform selection as used for spike discrimination, when considered along with computer control of electrode position and the growing availability of multichannel recording arrays, suggests a possible advance in automatic analyses. With the ability to process more complex waveforms successfully, electrophysiological data such as compound extracellular potentials may usefully replace the cleaner, but more limited intracellular data. Success with multichannel feedback controlled stimulators making paraplegics stand and walk point to a developing application with much potential.

Microcomputers↗

PubMed1985

Molar absorptivity and the blank correction factor.

In photometry, where both the product formed and one or several reactants absorb light at the same wavelength, the absorbance of the "blank" of the sample at the end of the reaction may be less than that measured at the beginning of the reaction, because of consumption of reactant(s). The blank correction factor for the determined result with one light-absorbing reagent is epsilon P / (epsilon P - epsilon R), where epsilon R and epsilon P are the molar absorptivities of the reagent and the product, respectively. We derived a factor for the case when more than one reagent absorbs light at the same wavelength as the measured product. This factor is independent of the concentration of reagent(s) and can correct the determined result or absorbance for the consumption of light-absorbing reagent(s) during the reaction.

Biuret Reaction↗

PubMed1985

[Addition of muscle relaxants to intravenous regional anesthesia].

Nine volunteers received two intravenous regional anaesthetics in the right arm. The first anaesthetic was performed with plain 0.25% lignocaine (dose 1 ml/kg body weight), the second with the same volume of lignocaine, with the addition of 0.5 mg pancuronium-Bromide. Latency for onset of the following was measured in both groups: 1. analgesia, 2. cold sensation, 3. warm sensation, 4. touch, 5. motor blockade. As expected, the addition of pancuronium had no influence on sensory blockade, however, motor block was significantly stronger, faster in onset, and longer in duration. Significant systemic side effects after pancuronium were not observed. No pancuronium was found in flame photometry plasma studies. On the basis of these investigations, one can recommend, for I.V.R.A., a relatively large volume of dilute local anaesthetic solution and, to achieve better muscle relaxation, the addition of 0.5 mg of pancuronium.

Adult↗

PubMed1985

[The ISE 2020 electrolyte analyzer: results of a multicenter evaluation].

The ISE 2020 electrolyte analyzer has been investigated within the framework of a multicentre evaluation in 5 laboratories. The users quickly learnt how to operate the instrument, and changes of personnel in the course of the trial had no influence upon the quality of the results. Regardless of the sample material (blood, serum, plasma) and the manner of introduction of the sample (manual or with the sampler), the in-series precision averaged 0.8% for sodium and 1.0% for potassium. The day-to-day precision was only slightly worse, at 1% (Na) and 2% (K). The recover, referred to the nominal values of control sera, averaged 100.3%. Investigations of linearity for potassium in the range from 0 to 12 mmol/l and for sodium in the range from 80 to 180 mmol/l confirmed a linear course of the measurements in the range of electrolyte concentrations of diagnostic interest. In extensive investigations by the testers with serum and plasma samples, the results showed good comparability with those from flame emission photometry. The mean values obtained by the two methods differed from one another only minimally in the case of sodium and potassium. The results with whole blood and with plasma prepared from it were in very close agreement. The ISE 2020 is regarded as highly suitable for routine work and emergency investigations in the central laboratory as well as for wards and operating rooms.

Anticoagulants↗