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At least 757 records · Page 42Linked to original sources
PubMed1999

[Study on high performance liquid chromatography/indirect photometric detection of fosfomycin with acridine as detection reagent].

Fosfomycin is a broad-spectrum antibacterial agent which has strong polarity and weak UV absorption. In this work, a method using standard ODS column and conventional UV detector set at 254 nm to analyse fosfomycin was investigated. Firstly, several UV detection reagents were tested and acridine(A) was found to give the highest indirect detection response and proper modification on retention of fosfomycin. With acridine as the UV detection reagent, the mobile phase parameters which affect retention and detection response of solute are discussed, e.g. pH, concentration of organic solvent and concentration of acridine. The mechanism is interpreted for each case. After optimization, we adopted mobile phase as V(CH3OH):V(H2O) = 50:50, pH 3.18, [HAc] = 2 mmol/L, [A] = 1 x 10(-5) mol/L. A new chromatographic system monitored by indirect photometry for detection of fosfomycin was established. This method was used for quantitative analysis, the minimum detectable level was 10 mumol/L, the relative deviation was 4.51%.

Acridines↗
PubMed2002

Application of a laser flare-cell meter to examine blood-aqueous barrier function in a patient with retinitis punctata albescens.

A laser flare-cell meter was used to examine blood-aqueous barrier function in a 21-year-old male patient who had typical retinitis punctata albescens with white dots scattered throughout large areas of the fundus in both eyes. Fluorescein angiography showed multiple areas of hyperfluorescence over dot lesions and window defects. Electroretinogram demonstrated subnormal amplitude and electrooculogram showed a reduced light-peak/dark-trough ratio. Goldmann perimetry revealed constricted peripheral fields. Laser photometry showed an increased aqueous flare intensity in both eyes compared to results in 10 normal subjects. Quantitative measurement of the aqueous flare intensity by a laser flare-cell meter might indicate abnormalities in the blood-aqueous barrier in patients with retinitis punctata albescens.

Adult↗
PubMed1975

[Physicochemical study of platelet aggregation by 3 polylysines].

The action of polylysines of various molecular weight on platelet behaviour is studied with the help of 3 techniques: photometric test, screen filtration pressure on PRP and electrophoretic mobility. Polylysines, which are polybasic substances, produce a platelet aggregation studied by photometry after a short period of latency. Aggregation, depending on the doses of poly-lysine and chiefly on the optic density, shows a "plateau" with the dose of 100 gamma/ml for poly-lysine L, of molecular weight 17000. The screen filtration pressure increases continuously in the presence of the polylysines studies. Finally, the platelet charge decreases. The results depend on the concentration of poly-lysine, and the optimal concentration which involves the more marked alterations is inversely proportional to the molecular weight of the polylysine studied.

Blood Platelets↗
PubMed2004

[Hypomagnesemia in patients with chronic alcoholism in the course of alcohol withdrawal syndrome].

AIM: To ascertain hypomagnesemia (HM) rate in patients with chronic alcoholism (CA) with alcohol withdrawal syndrome (AWS); correlation between AWS severity and HM rate. MATERIAL AND METHODS: Mg in plasm was measured at photometry in 129 CA patients treated in Kaunas Mental Hospital. RESULTS: Plasma Mg in CA patients with AWS was reduced (< 0.749 mmol/l), normal (0.750-1.250 mmol/l) or high (> 1.251 mmol/l) in 28.7, 65.1 and 6.2% patients, respectively. HM was diagnosed in 42.3% with a severe, 19.1% with a moderate and 20.0% with weak AWS. CONCLUSION: HM in AWS was registered in 28.7% patients. It occurred significantly more frequently (p < 0.05) in patients with a severe AWS. Pathogenetic mechanisms of HM in AWS are described.

Adult↗
PubMedDate not supplied

[A morpho-photometric study of laryngeal epidermoid carcinoma].

At the moment the use of quantitative techniques in anatomopathology is more and more frequent. In this study the authors use for the first time the morpho-photometry approach in epidermoid carcinomas of the larynx coming from filed material. In this way they are checking if this method adds anything to conventional anatomopathology.

Carcinoma, Squamous Cell↗
PubMed2005

Blood-aqueous barrier function in a patient with combined hamartomas of the retina and retinal pigment epithelium.

Clinical data showing breakdown in the blood-aqueous barrier in patients with combined hamartomas of the retina and retinal pigment epithelium are very limited. We used a laser flare-cell meter to examine blood-aqueous barrier function in a 35-year-old male patient who had typical combined hamartomas of the retina and retinal pigment epithelium characterized by an ill-defined, slightly elevated, grey-white epipapillary lesion with overlying glial proliferation and surrounding vascular tortuosity. Fluorescein angiography showed early hypofluorescence corresponding to the pigmented area with speckled hyperfluorescence in the lesion. Prominent retinal vascular tortuosity and late dye leakage were noted in the late phase. Visual evoked potential demonstrated poor waveform. Laser photometry showed an increase in the aqueous flare intensity in the affected eye, as compared to the results in the unaffected eye and to data from normal subjects. The increase in the aqueous flare intensity in this patient suggests that the function of the blood-aqueous barrier may be affected in combined hamartomas of the retina and retinal pigment epithelium.

Adult↗
PubMed1991

[The current possibilities for optimizing the diagnosis of acute cholecystitis].

Based on an analysis of the material of clinical observations of 1523 patients with acute cholecystitis the authors make a conclusion that findings of repeated echosonography with photometry and endoscopic intraduodenal electrothermometry of the duodenal mucosa allow reliable diagnosis of acute cholecystitis, estimation of the character of morphological alterations of the gallbladder wall, determination of the morphofunctional state of the liver. These methods allow to reliably control the course of the inflammatory process in acute cholecystitis and to timely change the curative tactics.

Acute Disease↗
PubMed1991

[Tissue typing using a Soviet automated luminescent microscope-photometer].

Automated fluorescent microscope developed by the authors permits photometry of microquantities of cellular suspensions in scanning standard 60-well plates with a flat bottom. Automated and semiautomated modes of operation are possible. Fluorescent stains and schemes of staining the examined cells that yield stable results in the lymphocytotoxic test have been selected. Comparative analysis of the efficacies of histocompatibility antigens detection by the routine and the fluorescent technique has shown a number of advantages of the fluorescent method. Specific features of fluorescent stains used for staining live cells are described.

Histocompatibility Testing↗
PubMed1992

Interocular differences in macular pigment density.

Interocular differences in the optical density of macular pigment were examined. Foveal and parafoveal sensitivities to lights of 460 and 530 nm were measured by heterochromatic flicker photometry for both eyes of ten subjects. These two wavelengths represent the maximum and minimum absorbance for macular pigment. Taking the difference in log sensitivity to the 460 nm light for the fovea and parafovea, after normalizing with respect to 530 nm, yields a measurement of the optical density of the macular pigment. Consistent interocular differences in macular pigment density were found for only two subjects, and these differences were less than 0.1. Other subjects frequently showed significant interocular differences on a given day but showed no consistent differences over the course of many days. In general, the amount of macular pigment measured for one eye was found to be essentially the same as that for the other eye. When measurements were averaged for the two eyes of each subject, significant differences in macular pigment density among subjects were found.

Adult↗
PubMed1977

[Spectrophotometric determination of rifampicin S in the presence of rifampicin O].

The limits of the use of the methods of direct photometric and differential spectrophotometric determination of rifamycin S containing rifamycin O as an admixture were discussed. The method of direct photometry did not provide determination of rifamycin S in the presence of rifamycin O since instability of the latter under the analysis conditions. A possibility of using the differential-spectrophotometric method for determination of rifamycin S in the presence of not more than 5 per cent of rifamycin O was shown.

Buffers↗
PubMed1991

Visualisation and measurement of the calcium message in guard cells.

We have applied several novel technologies to investigate the role of cytosolic free calcium [Ca2+]i in signal transduction in guard cells of Commelina communis L. Fluorescence ratio imaging and photometry together with the fluorescent Ca2+ indicator Indo-1 were used to directly visualise and measure dynamic spatial and temporal changes in [Ca2+]i in response to various exogenous stimuli. More subtle manipulation of the Ca2+ signal transduction pathway was achieved through the use of photoactivateable, caged Ca2+ and caged inositol-1,4,5-triphosphate (InsP3) released directly into the cytoplasm of the guard cell after microinjection. In these experiments, changes in [Ca2+]i were simultaneously monitored with the fluorescent Ca2+ indicator, Fluo-3. Resting levels of [Ca2+]i (100-200 nM) increased in response to elevated [Ca2+]e, lowering [K+]e, application of the ionophore A-23187 or cytosolic release of either Ca2+ or InsP3 from their caged forms. Stomatal closure was triggered if [Ca2+]i increased above a threshold of about 600 nM. Abscisic acid (ABA) had little effect on [Ca2+]i in the majority of cells studied, being elevated in only a minority of cells investigated. However, stomatal closure occurred in all cases after ABA application. This suggests that ABA acts through both Ca(2+)-independent and Ca(2+)-dependent pathways. The imaging data revealed a substantial heterogeneity in [Ca2+]i within the guard cell. Cytoplasmic regions, particularly near the nucleus, often showed marked elevations and sometimes oscillations. The origin and kinetics of the Ca2+ fluxes leading to the dynamic spatial patterns is discussed along with several new approaches directed towards identification of the source of the Ca2+. These methods include optical sectioning and 3-D reconstruction of both the endomembrane system and [Ca2+]i in living guard cells using confocal microscopy. Overall, our data is consistent with multiple sources for [Ca2+]i, including uptake across the plasma membrane and InsP3- or Ca(2+)-induced Ca2+ release from internal stores.

Calcium↗
PubMed1977

[Daily periods of aldosterone, sodium, and potassium excretion in the urine of newborns, infants, and children: influence of long-term steroid treatment and of the blockage of adrenergic beta-receptors (author's transl)].

Aldosterone, sodium, and potassium excretion in the urine of six newborns (5, 6, and 9 days), seven infants (2, 3, 4, and 6 months) and eight children (4, 5, 6, 12, and 15 years) was determined at 3-hour intervals during a 24-hour period via gas chromatography and/or flame photometry. The circadian rhythmn of aldosterone excretion could already be ascertained in the 5-day-old newborns. All babies and children examined showed a distinct increase in aldosterone excretion between 3 and 6 am or 6 and 9 am. On the overage, 41% of the total daily amount was excreted between 3 and 9 am. Excretion of sodium and potassium was very low for the newborns and infants. Only in small children and in school children did sodium excretion and the molecular relationship Na/k in urine have a statistically significant negative correlation with the excretion of aldosterone. After long-term prednisone therapy, the maximum amount of aldosterone was excreted in the afternoon. The findings after treatment with propranolol and administration of dexamethasone over a three-day period were similar.

Adolescent↗
PubMedDate not supplied

[Determination of perchlorate in drug preparations].

For quantitative analysis of perchlorate in capsules and solutions it has been proposed acidometric determination of perchloric acid in eluate after the use of cation exchangers. The comparison was made with colorimetric method of perchlorate determination after ion pairing with methylen blue which is extracted with chlorophorm and shows the maximum absorption at 655 nm. As an alternative method it has been used flame photometry of cations of these salts. The worked-out method with ion exchangers is recommended as a very suitable due to speed and simplicity of work and accurate and reproducible results.

Capsules↗
PubMed1990

Centrifugal ion-selective electrode system for potassium in whole blood.

We describe a novel ion-selective electrode (ISE) system that can be used in the Abbott Vision analyzer. A reusable sensor pack and a disposable test pack have been miniaturized to approximately the size and weight of a conventional Vision test pack, thus eliminating the need for a separate ISE module. The sensor pack contains a fluid path, battery-powered electronics, and screw-in electrodes. The test pack contains separate chambers and fluid channels for a blood specimen and two aqueous calibrators. During a run, plasma is separated from blood cells and is moved sequentially, along with the two calibrators, into and out of the sensor pack by centrifugal force. Each run includes checks for electromechanical integrity, fluid contamination, calibration slope and intercept, and specimen hemolysis. The system operates with CVs of less than 2% and gives results that correlate well with those by flame photometry and direct ISE methods. Either skin-puncture or venipuncture whole blood can be assayed, as well as serum or plasma.

Centrifugation↗
PubMed1990

[Photometric determination of xanthates in the air of work areas].

The article contains a description of a photometric technique for xanthate detecting in the air in the working zone area. The detection technique is based on the xanthates' interaction with the nickel salts, with the formation of yellow--coloured nickel xanthates and subsequent photometry of the 20 mn thick solution in dishes at 440 nm wave.

Air Pollutants, Occupational↗
PubMed1989

Flow injection analysis of inorganic cationic species in serum and urine.

This paper describes three flow injection analysis (FIA) systems for the automatic determination of sodium, potassium, lithium, calcium, magnesium, zinc, copper and iron in certain biological fluids and compares the results obtained to those of flame photometry and atomic absorption spectrometry. The set-ups were designed to allow the samples to be prepared in the same manner as that used for batch procedures with the same analytical instrument. For determinations requiring a high sample dilution, it was found of definite advantage to split the stream and pass large amounts of liquid through the detection systems. The comparison of the results obtained by FIA and conventional methods yielded correlation coefficients in the range 0.990 to 0.999. The proposed methodology show good precision, with variation coefficients between 0.5% to 5%.

Calcium↗
PubMed1989

[Photometric determination of butyl "aeroflot" flotation agent (sodium dibutyl dithiophosphate) in the air of work zone and skin washings].

Photometric procedure of butyl "aeroflot" identification in the work zone air and in wash-out from workers' integument was developed, The procedure was based on the formation of yellow- and orange-dyed copper dibutyl dithiophosphate under butyl "aeroflot" interaction with copper sulphate with the subsequent photometry of dyed solutions for the wavelength of 420 nm in the 10-mm cell. Buffer solution with pH-9.2 was used as an absorbing solution for the workplace air sampling and integument wash-out.

Air Pollutants, Occupational↗
PubMed1989

[Dynamics of albumin transport across the venule walls of the rat mesentery].

FITC-Albumin was injected into the circulation for estimating transport possibilities of blood microvessels and then investigating its maintenance near vessel wall with the help of the photometry. Velocity of albumin entrance into the interstitium and its top concentration near the wall of consecutive links of venules (20-60 mm) raised. Our data show that it may be caused by enhancing vessel surface and increasing its permeability for this protein.

Albumins↗