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At least 667 records · Page 37Linked to original sources
PubMed1998

Increased concentration of circulating acid glycosaminoglycans in chronic lymphocytic leukaemia and essential thrombocythaemia.

To verify whether the increase in the number of circulating blood cells that synthesize glycosaminoglycans, B-lymphocytes or platelets, in proliferative disorders, may be associated with changes in the circulation of acid glycosaminoglycans, the serum and plasma concentrations of these polysaccharides have been measured in terms of their sugar components, following isolation and purification by chromatographic methods, in patients with chronic lymphocytic leukaemia or with essential thrombocythaemia and in healthy controls. In the patients, the concentrations of total circulating glycosaminoglycans and of both glucosamine-containing and galactosamine-containing serum glycosaminoglycans were significantly higher than in controls. These concentrations did not significantly correlate with the number of lymphocytes in patients with chronic lymphocytic leukaemia and of platelets in patients with essential thrombocythaemia. Analytical data suggest that excess glycosaminoglycans are mainly composed of chondroitin sulphate molecules and contain heparan sulphate structures.

Adult↗
PubMed1999

Health care system and laboratory medicine in Austria: present status and future perspectives.

In the recent past, the role of laboratory medicine has changed from merely supplier of analytical data to supplier of results together with clinical interpretation. In addition, the role of medical laboratories as important partners of health care management by providing data for management functions and decisions is rapidly growing. The article has the purpose of giving an overview of Austria's population, the governmental system and Austrian health politics in context with European health care. The existing health care system with its historical development, to-date status and recent changes due to socio-economic pressure are outlined. Special emphasis is given to the present situation of medical laboratories in Austria. Furthermore, hospital management strategies and some adjustment processes in the authors' clinical-medical laboratory to alleviate the ongoing economic pressure are described. As far as possible, an attempt of forecasting future scenarios is made.

Austria↗
PubMed1983

Real time control procedures for monitoring SMAC analytical performance.

A system has been developed in our Hospital Clinical Chemistry Laboratory with the aid of a minicomputer on line with SMAC. The programs are in Basic and comprise management of patient samples and of reference sera, on-line acquisition of analytical data, checks of error reporting and of abnormal result values, real time processing of quality control parameters and data transfer on floppy disk. An efficient and easy monitoring of the chemical procedures and result reliability is achieved together with instrument performance optimization.

Autoanalysis↗
PubMed2001

Synthesis and pharmacological activity of 1,2,4-triazolo[4,3-a]quinolines.

The synthesis of a series of 1,2,4-triazolo[4,3-a]quinoline derivatives is described; their structures were assigned by 1H NMR and analytical data. The new compounds were tested in vivo for their antiinflammatory and analgesic activities, as well as for their ulcerogenic action. Some of the tested triazoles showed an analgesic activity in the acetic acid writhing test and antiinflammatory properties on carrageenan paw edema assay.

Analgesics↗
PubMed2000

Trace analysis of ten chlorinated benzenes in water by headspace solid-phase microextraction.

Headspace solid-phase microextraction (SPME), as a simple, solvent-free method, has been applied to the analysis of 10 chlorinated benzenes (CBs) present at trace levels in water samples. An SPME fibre coated with 100-microm thick poly(dimethylsiloxane) was used for extraction. The analytical data exhibited a relative standard deviation (RSD) range of 1.19% (for pentachlorobenzene) to 8.19% (for hexachlorobenzene) for the 10 CBs; the RSD of most compounds was under 6%. The sensitivity of the method was enhanced with agitation and with addition of salt to the sample solutions. With mass spectrometric detection, the limit of detection was below 0.006 microg/l for all 10 CBs after a 30-min sampling time. The linearity range was 0.02-20 microg/l for the compounds studied. Water samples collected from a reservoir, and from the tap in a laboratory were analysed using the optimised conditions.

Chlorobenzenes↗
PubMed2000

Application of solid-phase extraction to the analysis of the isomers generated in biodesulfurization against methylated dibenzothiophenes.

A solid-phase extraction (SPE) technique was applied to analyze and characterize the biodesulfurization reactions against asymmetrically methylated dibenzothiophenes (mDBTs) such as 1-, 2-, 3- and 4-methyldibenzothiophenes present in fossil fuels. Recently, we found that these mDBTs are efficiently degraded by the bacterial strain, Rhodococcus erythropolis KA2-5-1. Separation and concentration of the microbial desulfurization products from each of the mDBTs could be carried out with high efficiency and reproducibility by the SPE procedure. These desulfurization products were identified using the SPE technique combined with GC, GC-atomic emission detection, GC-MS and 1H nuclear magnetic resonance spectroscopy. The analytical data obtained suggested that the desulfurization reactions against mDBTs by this bacterial strain may occur through specific carbon-sulfur bond-targeted cleavages that can be affected by the positions of methyl groups.

Chromatography, Gas↗
PubMed1976

High-resolution liquid chromatographic analysis of methylated purine and pyrimidine bases in transfer RNA.

Methylated and major purine and pyrimidine bases were separated and quantified by high-resolution liquid chromatography after hydrolyzing transfer ribonucleic acids (tRNAs). Separation was accomplished by eluting the hydrolyzed samples from an anion-exchange column with a concentration gradient of ammonium acetate at pH 9.2. Isolated sample of tRNA were hydrolyzed to the free bases with a trifluoroacetic acid-formic acid mixture of 200 degrees. Detection limits of 100-200 ng/ml were measured for the methylated bases; analytical data are reported for ten methylated bases plus the four major bases of calf liver and rat liver tRNA.

Adenine↗
PubMed2001

Separation and identification of enzymatic sucrose hydrolysis products by high-performance anion-exchange chromatography with pulsed amperometric detection.

An accurate carbohydrate analysis method, namely high-performance anion-exchange chromatography with pulsed amperometric detection was successfully applied to the study of sucrose hydrolysis under enzymatic (baker's yeast invertase) conditions. The hydrolysis was monitored by determining sucrose degradation and the corresponding formation of D-glucose, D-fructose and five intermediate fructans using a CarboPac PA-100 (Dionex) analytical anion-exchange column. Highly reproducible results were obtained. The unknown fructans were collected from a semi-preparative CarboPac PA-100 (Dionex) column, neutralized and then desalted on a column containing mixed bed resin AG 501-X8 (D) before identification of the chemical structure. This procedure permitted us to obtain about 20 microg of pure product which is not enough for NMR analysis. Detailed GC-MS analytical data of the methylated compounds indicated that these oligosaccharides were beta-D-Fru-(2 --> 1)-beta-D-Fru-(2 --> 1)-alpha-D-glucopyranoside (1-kestose), beta-D-Fru-(2 --> 6)-alpha-D-glucopyranoside (6-beta fructofuranosylglucose), beta-D-Fru-(2 --> 1)-beta-D-fructofuranoside (inulobiose), beta-D-Fru-(2 --> 6)-beta-D-Fru-(2 --> 1)-alpha-D-glucopyranoside (6-kestose) and beta-D-Fru-(2 --> 6)-alpha-D-Glc-(1 --> 2)-beta-D-fructofuranoside (neokestose) coeluating with a disaccharide.

Chromatography, High Pressure Liquid↗
PubMed2001

Application of static liquid-phase microextraction to the analysis of organochlorine pesticides in water.

Static liquid-phase microextraction, with subsequent analysis by gas chromatography-electron-capture detection, has been applied to extract eight organochlorine pesticides from water. A conventional microsyringe was used to extract analytes from water samples over a concentration range of 0.05-100 microg/l. Factors relevant to the extraction process were investigated. The sensitivity of the method was enhanced with agitation, and increasing the extraction temperature, of the sample solution. Concentration factors of >50-fold were easily achieved within 25 min of extraction. The analytical data exhibited a relative standard deviation (RSD) range of 3.2% (lindane) to 10.7% (methoxychlor) for the eight pesticides; most RSD values were under 7%. Water samples collected from a reservoir, and from tap water in a chemical laboratory were analyzed using the procedure.

Chromatography, Liquid↗
PubMed1987

High-performance liquid chromatographic method for determining the enantiomeric purity of a benzindene prostaglandin by a diastereomeric separation.

An isocratic high-performance liquid chromatographic (HPLC) method was developed to determine the enantiomeric purity of a benzindene prostaglandin (U-62,840) which is currently being evaluated for pharmaceutical applications. The enantiomers were converted to diastereomeric amide derivatives using optically pure S-(--)-1-phenylethylamine (greater than 99.9%). Separation of the diastereomers was demonstrated on achiral silica-based stationary phases using a hexane-dioxane-water mobile phase and UV detection at 214 nm. Due to the use of an optical derivatizing agent, method validation addressed the issues of optical purity of the reagent and comparative rates of reaction of each enantiomer. Analytical data is reported that demonstrates quantitative derivation, linearity, accuracy, precision, and ruggedness of the optimized assay conditions. Limit of quantitation for the enantiomeric impurity was determined to be 1.1% (signal-to-noise ratio 13). A brief description of the results of a parallel study of an enantiomeric separation using various chiral HPLC columns is included.

Chromatography, High Pressure Liquid↗
PubMed1985

Automated gas chromatographic method for the determination of residual solvents in bulk pharmaceuticals.

A generalized gas chromatographic method is described for the determination of a wide variety of residual solvents and other volatile impurities in bulk pharmaceuticals. The method employs a highly selective graphitized carbon-black stationary phase, which is demonstrated to retain compounds on the basis of a linear combination of their boiling points and molecular volumes (i.e., molecular weight divided by density). An autosampler is utilized to optimize injection precision and to provide for high sample throughput. Analytical data from replicate determinations of seven representative compounds are reported, and it is shown that calibration of the chromatographic systems against external standards produces comparable results to those obtained by standard addition techniques.

Autoanalysis↗
PubMed2002

Application of static and dynamic liquid-phase microextraction in the determination of polycyclic aromatic hydrocarbons.

Two modes of liquid-phase microextraction (LPME), static and semi-automated dynamic, have been developed for the HPLC analysis of polycyclic aromatic hydrocarbons. In static LPME, a small drop (3 microl) of organic solvent was held at the tip of a microsyringe needle and exposed to the sample containing the analytes, permitting extraction to occur. In semi-automated dynamic LPME, a syringe pump was used to automate the repetitive procedure of filling a microsyringe barrel that functioned as a microseparatory funnel, with fresh aliquots of sample, and expelling them after extraction. The factors influential to both techniques such as the type of organic solvent, extraction time, sampling volume, number of samplings, salt concentration and temperature were investigated. Static LPME provided high enrichment (60- to 180-fold) and simplicity. The analytical data exhibited a relative standard deviation range of 4.7-9.0%. Dynamic LPME provided higher (>280-fold) enrichment within nearly the same extraction time (approximately 20 min) and better precision (< or = 6.0%). Both methods allow the detection of polycyclic aromatic hydrocarbons at microg/l levels in water by HPLC. Water samples collected from two rivers were analyzed using the methods, respectively. The results demonstrated that both modes of LPME were fast, simple and accurate.

Chromatography, High Pressure Liquid↗
PubMed1997

Simple and rapid chromatographic method for the separation of major classes of ribosomal ribomononucleotides.

We have described a simple and rapid chromatographic method for the analytical and preparative separation of major types of ribosomal ribomononucleotides with Dowex 1-X10 (HCOO-, 37-74 microns) and Dowex 2-X10 (HCOO-, 37-74 microns) columns, by desorption with formiate solutions in 1-2 h. The separation has been achieved for Cp, Ap, Up and Gp, while a mixture of 2'-, and 3'-nucleoside phosphates desorbs as a single peak; with both resins, a successful separation was achieved with a load from 25 micrograms to 1 mg of ribomononucleotide mixture per ml of packed resin. A complete separation was achieved with Dowex 1, while the separation with Dowex 2 resin was even better. The resins cannot separate unusual nucleosides; therefore, our method is suitable for studies of ribonucleic acids with a low content of unusual nucleosides. Our method has been applied for the quantitative determination of the ribomononucleotide composition of 18S and 28S rRNAs, isolated from mammalian tissues: rat liver, mouse kidney and Ehrlich ascites cells. Dowex 1 and Dowex 2 resins afforded similar or identical ribomononucleotide compositions in all cases; analytical data were in agreement with the literature data. Our method is competitive, in several respects, with modern HPLC techniques for the separation of ribomononucleotides.

Animals↗
PubMed1998

Analysis of water from the Space Shuttle and Mir Space Station by ion chromatography and capillary electrophoresis.

Drinking water and condensate samples collected from the US Space Shuttle and the Russian Mir Space Station are analyzed routinely at the NASA-Johnson Space Center as part of an ongoing effort to verify water quality and monitor the environment of the spacecraft. Water quality monitoring is particularly important for the Mir water supply because approximately half of the water consumed is recovered from humidity condensate. Drinking water on Shuttle is derived from the fuel cells. Because there is little equipment on board the spacecraft for monitoring the water quality, samples collected by the crew are transported to Earth on Shuttle or Soyuz vehicles, and analyzed exhaustively. As part of the test battery, anions and cations are measured by ion chromatography, and carboxylates and amines by capillary electrophoresis. Analytical data from Shuttle water samples collected before and after several missions, and Mir condensate and potable recovered water samples representing several recent missions are presented and discussed. Results show that Shuttle water is of distilled quality, and Mir recovered water contains various levels of minerals imparted during the recovery processes as designed. Organic ions are rarely detected in potable water samples, but were present in humidity condensate samples.

Chromatography, Ion Exchange↗
PubMed1999

Determination of total chromium in phosphate rocks by ion chromatography.

Chromium(VI) is one of seven elements which is classified in the fertilizer industry as being harmful to plants and biological systems. Phosphate rocks represent the raw material for complex fertilizer production in the world. This paper investigates for the first time the determination of total chromium in phosphate rocks by ion chromatography. The developed analytical method involves the digestion of phosphate rocks with nitric acid followed by sample treatment of the resulting solution. The digestion solution obtained was treated with an oxidising agent (potassium peroxosulphate) to convert all chromium to the hexavalent state. The analytical method developed utilizes anion-exchange ion chromatography to achieve the separation and spectrophotometric post-column reaction for detection with diphenylcarbazide. The relative standard of deviation from analytical data comparison of six different phosphate rocks with atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry techniques, and cross-analysis data against an internationally certified phosphate rock standard were between 0.58 and 1.45%. Calibration curve between 0.2 and 0.9 microgram/ml was excellent, and the method has a detection limit for Cr(VI) of 0.05 ng. The developed method offers a fast, a reliable and an alternative procedure for the determination of total chromium in phosphate rock deposits by ion chromatography.

Chromatography, Ion Exchange↗
PubMed2003

Arsenic pollution in Patos Lagoon estuarine sediments, Brazil.

Arsenic distribution in sediments of the Mirim-Patos lagoonal system is investigated. Deposits of fresh water Mirim Lagoon and those of the fresh water part of the Patos Lagoon contain 2.5 and 7.7 mg kg(-1), respectively, on average of total arsenic. In contrast, estuarine sediments of the Patos Lagoon are evidently contaminated by arsenic in high concentrations (up to 50 mg kg(-1)), and about 80% of the arsenic there is found in a bioavailable form. Analytical data coupled with direct, visual observations of estuarine water contamination by raw phosphorites and fertilizers suggest that the major source of arsenic in the estuarine sediments originated from the fertilizer industry.

Arsenic↗
PubMed2000

[Clinical relevance of immunoglobulin A deficiency in celiac disease].

BACKGROUND: To determine the prevalence of the IgA deficiency in patients with celiac disease and its influence on the presentation and evolution of celiac disease. PATIENTS AND METHOD: 47 patients with clinical and histological diagnosis of celiac disease were included. Seric immunoglobulin levels were determined in all patients. RESULTS: Five patients presented a low level of IgA (IgA-deficient group) and 42 patients presented normal levels (non-IgA-deficient group). The age and the relation male/female were similar between both groups. Presentation, clinical manifestations, analytic data of intestinal malabsorption, and the radiologic pattern were also similar between both groups of patients. There were bronchiectasies in two out of 5 IgA-deficient patients and in only one out of 42 non-IgA- deficient patients (p < 0.05). None of the IgA-deficient group showed complications due to the celiac disease, meanwhile 3 non-IgA deficient patients developed intestinal lymphoma (p = NS). CONCLUSIONS: The IgA deficiency is frequently associated to celiac disease. This association does not seem to influence in a significant way the presentation or the evolution of celiac disease.

Adult↗
PubMed2003

Osteoarticular pain and bone mineral density in renal transplantation.

INTRODUCTION: The reduction of bone mineral density (BMD) levels is an important complication after renal transplantation. The prevalence of nontraumatic lesions may reach 22%. Patients with lower osseous mass suffer the highest number of lesions. OBJECTIVE: Evaluate BMD in patients over 30-years old who have undergone renal transplantation more than 1 year prior, who attend a medical facility complaining of osteoarticular pain and were prescribed rest or any analgesia. PATIENTS AND METHODS: One hundred twenty-three patients who received a renal transplant from a cadaveric donor from 1980 through 2000 were included in the present study to measure BMD levels in the hips and the vertebral column using a densitometer (Hologic 4500 QDR). Our study complied with WHO recommendations, which define normal values as a T score >-1 SD osteopenia as a (T score between <-1 and >-2.5 SD), and osteoporosis as a T score <-2.5 SD. Patients were divided into three groups according to gender and hormonal status. The following clinical and analytic data were collected: age, gender, race, age at onset of menopause, diabetes mellitus (DM), weight, size, retransplantation, period of evolution after transplantation, and parathormone (PTH), creatinine, and renal clearance values. RESULTS: There were 51 men (41.1%) included. Forty postmenopausal (32.5%) and premenopausal women (26%) were also included. In all patients we observed a correlation between a reduction in BMD values and age, duration post-transplantation, and body weight (P<.05). Reduced BMD levels in premenopausal women were related with lower body weight, (P<.05) and elevated PTH levels (P<.024). CONCLUSIONS: We observed that patients who had undergone transplantation displayed a moderately higher risk of suffering a fracture. Such risk increased in the case of women with more frequent fractures in the vertebral column. In 23.8% of patients reporting osseous pain, there was no reduction in BMD levels. Therefore, we must look for other disorder, responsible for the pain and prescribe adequate treatment.

Adult↗