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PubMed1980

[The detection of guaiacol glyceryl ether, a content of many sedatives and hypnotics in the Federal Republic of Germany].

Guaiacol Glyceryl Ether (GGE) is well known as an expectorant in a large number of cough syrups etc. More recently it was used in surgery because of its activity as a muscle relaxant and its additive effect on narcotics. Today many of the sedatives and hypnotics in the BRD, which are available without prescription, contain GGE in doses of 50 mg to 250 mg partially combined with other sedative acting substances. With regard to the abuse of sedatives and hypnotics GGE therefore will be more important in future. The analytical data of GGE (for details see key words), extraction behavior and identification of TLC combined with quantitative determination by HPLC are described.

Chromatography, Gas↗
PubMed1999

Synthesis of non proteinogenic dipeptides by asymmetric hydrogenation.

N-Boc protected non-proteinogenic dipeptides with D,L- and L,L-configuration were prepared by catalytic asymmetric hydrogenation of the corresponding dehydrophenylalanyl-(L)-phenylalanine derivatives. The configuration of the new stereogenic centre depends first of all on the catalyst configuration and is less influenced by the substrate configuration. Diastereomeric excesses in the range of 80-96% de could be increased up to 99% by recrystallization. Analytical data of selected new compounds are given.

Dipeptides↗
PubMed1992

Postmortem toxico-kinetics of co-proxamol.

Postmortem drug redistribution in suicidal poisonings by co-proxamol (dextropropoxyphene and paracetamol) has been studied. Analytical data for 8 tissue samples, including muscle and fat, up to 8 blood samples, and gastric and small bowel contents were obtained in 4 cases. Blood samples were taken from multiple sites at the start of autopsy and after 24 or 48 h. Concentrations of both drugs were site dependent with the lowest concentrations in peripheral blood. Paracetamol concentrations varied two to threefold and propoxyphene concentrations varied seven to tenfold. Pulmonary artery concentrations of paracetamol did not change significantly with time; propoxyphene concentrations typically increased twofold over 24 h and threefold over 48 h. Propoxyphene concentrations in the inferior vena cava increased unpredictably but occasionally significantly (up to sevenfold). For both drugs the most dramatic elevations of blood concentrations were seen in the aorta; in one case paracetamol rose to 1.9 g/l, 8 times the peripheral blood concentration and 4 times the liver level (454 mg/kg); propoxyphene rose to 191.5 mg/l, 55 times the peripheral blood concentration. This appears to reflect postmortem diffusion of unabsorbed drug from the gastric lumen. It is likely that markedly higher concentrations in the putrefactive fluid from the left pleural cavity as compared with the right also reflect diffusion from the stomach.

Acetaminophen↗
PubMed1981

The science of sex research: some methodological considerations.

This paper represents a review of substantive theoretical, methodological, and statistical issues relevant to conducting research on human sexual behavior. Guidelines for maintaining rigor and precision in future investigations are also proposed. So as to able to address issues that pervade all research on human sexual behavior, six topic areas are discussed: theory-related issues, issues involving research design, issues involving subject selection, measurement issues, data-analytic issues, and issues concerned with human-subject protection. The ultimate objective of this paper is to make suggestions aimed at improving the quality of research on human sexual behavior.

Female↗
PubMed1998

Inter- and intraobserver reproducibility in radiographic diagnosis and classification of femoral trochlear dysplasia.

Dejour's radiographic criteria are commonly used to diagnose and assess femoral trochlear dysplasia in case of patello-femoral instability. The aim of this study was to establish the intra- and interobserver reliability of these radiographic criteria. Sixty-eight lateral knee radiographs were examined independently by 7 observers (2 juniors, 5 seniors) to assess interobserver agreement, and the 2 juniors repeated the observations to test intraobserver agreement. These 68 true lateral views were harvested from clinical records of 64 patients who underwent a trochleoplasty because of patellofemoral instability. To evaluate the agreement on analytic data (morphologic type of trochlea) we used the kappa statistical method, and to evaluate the agreement on numerical data (depth and prominence of the trochlear groove) we used interclass correlation analysis. The "crossing sign" (between the trochlear groove and the anterior aspect of both condyles) was reliable since the probability of rating as normal a pathologic trochlea was only 3.1% (0 to 8.8%). In classifying trochlear morphology interobserver agreement was slight (kappa = 0.17) and intraobserver agreement was fair (kappa = 0.3). On the other hand, the measurements of the depth and prominence of the trochlear groove were more reliable since the interclass coefficients between observers were 0.62 and 0.38 respectively. The most frequent interobserver error was related to misdiagnosis of type II. To clarify Dejour's criteria we propose a diagnosis of type II only when 5 mm or more are measured between the intersections with the medial and lateral femoral condyles. We recommend the use of the prominence of the trochlear groove to evaluate the grade of bony trochlear dysplasia.

Adult↗
PubMed1978

[Findings in quality controls of ocean fish in the Siegen district].

In quality tests on traded sea-fish, 30 fresh fish- and 20 quick-frozen fish specimens were tested for their TVB-N content, TMA-N content, as well as for TMAO-N, and were subjected to a sensorial test. Equal portions of codfish- and perch fillets were tested. According to the chemical analytic data, 13 specimens of the fresh fillets proved to be unobjectionable commercial merchandise 17 specimen had to be eliminated as being spoiled, since part of the above values for TVB-N and TMA-N had been considerable exceeded. The results differ enormously between the two species of fish. The perch fillets showed a significant better quality condition than the specimens of codfish. In the sensorial test the objective total result was confirmed in the main. On the basis of the chemical findings one specimen of codfish out of the deep-frozen fillets had to be objected. 16 fillet-specimens could sensorially be approved as being commercially marketable, 4 were tested not for sale. With codfish showing considerable better results than perch.

Animals↗
PubMed1978

[The significance of topic differences and cadaveric changes of histamine and serotonin levels for the determination of the age of wounds in animal experiments (author's transl)].

Even when the extraction method of Fazekas for the determination of the so-called free histamine and serotonin is used, different dorsal skin areas of laboratory animals show certain differences in the amine content, which reach higher values for histamine than for 5-HT. 1) Related to the animal collective, no differences in the mean values of the 5-HT and histamine content between the right and left side of damaged dorsal skin of guinea pigs resulted, although in single cases remarkable differences (up to 1.26 microgram/g) were found. Descending from nuchal to caudal a decrease of the amine content--less in case of 5-HT, more in case of histamine--is noticed. The observed topical differences possibly depend on the continous moulting of the animals. 2) From these analytical data a method for statistical prediction is derived, which allows to state, when and with which probability a single difference value exceeds the normal variance. Applied to the comparative measurements wounded skin/control skin it is thus made possible to test the validity of the findings obtained in practical cases. 3) Postmortal changes of the amine content of the wounded as well as the normal skin are not detectable for the 5-HT, while in the case of histamine solely the values of the damaged skin first show a decrease (24 h p.m.), followed by an increase (48 h p.m., bacterial neogenesis?).

Animals↗
PubMed1989

Influence of testosterone administration on the biosynthesis of unsaturated fatty acids in male and female rats.

The in vivo effect of testosterone administration to male or female rats on the biosynthesis of unsaturated fatty acids of liver was studied. Twenty-four hours after injection of testosterone (260 micrograms/kg), delta 9 desaturase activity increased significantly, whereas the activities of delta 5 and delta 6 desaturases were strongly depressed. These effects were more pronounced in female than in male animals. The fatty acid composition of plasma and liver (homogenates, crude microsomes and cytosol) showed differences between the sexes. In males, the percentage of palmitic acid and the 18:1/18:0 ratio were higher whereas the 20:4(n-6)/18:2(n-6) ratio was lower than in female rats. The administration of testosterone significantly modified the fatty acid pattern in all fractions studied. Analytical data correlated with alterations in the fatty acid desaturase activities caused by the hormone. It is suggested that the mechanism by which testosterone exerts its effect on unsaturated fatty acid biosynthesis is different that that previously demonstrated by glucocorticoid action. The effects produced by testosterone may be of biological significance in atherosclerosis pathogenesis.

Animals↗
PubMed1987

The enamel fluid in the early secretory stage of porcine amelogenesis: chemical composition and saturation with respect to enamel mineral.

The present study reports on the separation of fluid from soft, "cheeselike" enamel of porcine permanent teeth in the secretory stage, and the determination of its chemical composition. The enamel tissues were dissected from mandibles of 5 to 6-month-old piglets and pooled under mineral oil in centrifuge tubes, and then centrifuged at 1.9-2.4 X 10(5) g for 1-1.5 hours. The yields of the fluid were 44.8 +/- 2.3 (mean +/- standard error) microliter/g of enamel tissue at 1.9 X 10(5) g, and 53.9 +/- 1.9 microliter/g at 2.4 X 10(5) g. A significant finding was that the total Ca concentration of the enamel fluid (3.9-6.0 X 10(-4) M) was lower than that of porcine serum (2.9 X 10(-3) M), reflecting a distinct, compartmentalized microenvironment, isolated from the circulating blood. Another significant finding was that the ionic calcium activity (5.3 X 10(-5) M) in the enamel fluid was one order of magnitude lower than the total Ca concentration. The averaged results of other determinations were: pH, 7.26; total [P], 3.9 mM; [Mg2+], 0.8 mM; [Na+], 140 mM; [K+], 20 mM; [Cl-], 150 mM; [F-], 5 X 10(-3) mM; and osmolality of the fluid, 312 mosmol/kg H2O (in the same range as that of the serum, 310 mosmol/kg H2O). The apparent electrical unbalance of the analytical data, 8.65 meq excess of positive charges, was ascribed to the presence of HCO3- in the fluid; the computed ionic strength was 164 mM.(ABSTRACT TRUNCATED AT 250 WORDS)

Amelogenesis↗
PubMedDate not supplied

Role of the intensive care unit in the management of the poisoned patient.

By applying a sensible toxicological approach to the general principles of intensive care, an optimum setting for the treatment of poisoning is created. The intensive care unit (ICU) can perform the necessary close observation and monitoring, and thus facilitate rapid detection of symptoms, and the institution of early appropriate treatment. Diagnosis may be complex in poisoning and require continuous qualified interpretation of clinical and analytical data. Antidote therapy and treatment to enhance elimination of the poison must often be dealt with under careful supervision. The capacity of the ICU to counteract various toxic effects in a nonspecific way and to provide optimum symptomatic and supportive care is crucial. However, the ongoing toxic effects on the body must always be considered and allowed to guide symptomatic treatment. Thus, clinical toxicology appears to be a specialised branch of intensive care medicine.

Acute Disease↗
PubMed2002

Multidimensional approaches in biochemical speciation analysis.

An understanding of the mechanisms controlling the essentiality and toxicity of trace elements in biological systems at the molecular level depends critically on the possibility of the identification, characterization, and quantification of chemical forms of these elements involved in life processes. Hyphenated techniques based on the combination of (electro)chromatography with ICP MS have become a routine tool for the analysis for metallospecies present in biological tissues. Finer analytical information on the true (down to individual species) speciation of trace elements in living organisms can be obtained by adding additional dimensions to the separation and detection steps, consisting of a sequential use of different HPLC separation mechanisms and capillary electrophoresis at the separation level, and of the use of electrospray MS, including collision induced dissociation MS, on the detection level. The value of the instrumental analytical data is decisively enhanced by the complementary use of molecular biology approaches involving gene identification, cloning and in vitro reproduction of the metal-controlled processes. A brief summary of the recent progress in biochemical speciation analysis is presented in the context of the latest research carried out in the authors' laboratory.

Biochemistry↗
PubMed2003

Pressurized wet digestion in open vessels.

The High Pressure Asher (HPA-S) was adapted with a Teflon liner for pressurized wet digestion in open vessels. The autoclave was partly filled with water containing 5% (vol/vol) hydrogen peroxide. The digestion vessels dipped partly into the water or were arranged on top of the water by means of a special rack made of titanium or PTFE-coated stainless steel. The HPA-S was closed and pressurized with nitrogen up to 100 bars. The maximum digestion temperature was 250 degrees C for PFA vessels and 270 degrees C for quartz vessels. Digestion vessels made of quartz or PFA-Teflon with volumes between 1.5 mL (auto sampler cups) and 50 mL were tested. The maximum sample amount for quartz vessels was 0.5-1.5 g and for PFA vessels 0.2-0.5 g, depending on the material. Higher sample intake may lead to fast reactions with losses of digestion solution. The samples were digested with 5 mL HNO(3) or with 2 mL HNO(3)+6 mL H(2)O+2 mL H(2)O(2). The total digestion time was 90-120 min and 30 min for cooling down to room temperature. Auto sampler cups made of PFA were used as digestion vessels for GFAAS. Sample material (50 mg) was digested with 0.2 mL HNO(3)+0.5 mL H(2)O+0.2 mL H(2)O(2). The analytical data of nine certified reference materials are also within the confidential intervals for volatile elements like mercury, selenium and arsenic. No cross contamination between the digestion vessels could be observed. Due to the high gas pressure, the diffusion rate of volatile species is low and losses of elements by volatilisation could be observed only with diluted nitric acid and vessels with large cross section. In addition, cocoa, walnuts, nicotinic acid, pumpkin seeds, lubrication oil, straw, polyethylene and coal were digested and the TOC values measured. The residual carbon content came to 0.2-10% depending on the sample matrix and amount.

Journal Article↗
PubMed2004

Removal of major interference sources in aqueous near-infrared spectroscopy techniques.

This work describes a hybrid procedure for eliminating major interference sources in aqueous near-infrared (NIR) spectra, that include aqueous influence, noise, and systemic variations irrelevant to concentration. The scheme consists of two parts: extension of wavelet prism (WPe) and orthogonal signal correction (OSC). First, WPe is employed to remove variations due to aqueous absorbance and noise; then OSC is applied to remove systemic spectral variations irrelevant to concentration. Although water possesses strong absorption bands that overshadow and overlap the absorption bands of analytes, along with noise and systematic interference, successful calibration models can be generated by employing the method proposed here. We show that the elimination of major interference sources from the aqueous NIR spectra results in a substantial improvement in the precision of prediction, and reduces the required number of PLS components in the model. In addition, the strategy proposed here can be applied to various analytical data for quantitative purposes as well.

Fructose↗
PubMed2005

Comparison of mild extraction procedures for determination of plant-available arsenic compounds in soil.

In this work three mild extraction agents for determination of plant-available fractions of elements in soil were evaluated for arsenic speciation in soil samples. Pepper (Capsicum annum, L.) var. California Wonder was cultivated in pots, and aqueous solutions of arsenite, arsenate, methylarsonic acid, and dimethylarsinic acid, at a concentration of 15 mg As kg(-1) soil, were added at the beginning of the experiment. Control pots (untreated) were also included. Deionized water, 0.01 mol L(-1) CaCl2, and 0.05 mol L(-1) (NH4)2SO4 were used to extract the plant-available fraction of the arsenic compounds in soil samples collected during the vegetation period of the plants. Whereas in control samples the extractable arsenic fraction did not exceed 1% of total arsenic content, soil amendment by arsenic compounds resulted in extraction of larger amounts, which varied between 1.4 and 8.1% of total arsenic content, depending on soil treatment and on the extracting agent applied. Among arsenic compounds determined by HPLC-ICPMS arsenate was predominant, followed by small amounts of arsenite, methylarsonic acid, and dimethylarsinic acid, depending on the individual soil treatment. In all the experiments in which methylarsonic acid was added to the soil methylarsonous acid was detected in the extracts, suggesting that the soil bacteria are capable of reducing methylarsonic acid before a further methylation occurs. No significant differences were observed between analytical data obtained by using different extraction procedures.

Arsenic↗
PubMed2006

An adaptive strategy for selecting representative calibration samples in the continuous wavelet domain for near-infrared spectral analysis.

Sample selection is often used to improve the cost-effectiveness of near-infrared (NIR) spectral analysis. When raw NIR spectra are used, however, it is not easy to select appropriate samples, because of background interference and noise. In this paper, a novel adaptive strategy based on selection of representative NIR spectra in the continuous wavelet transform (CWT) domain is described. After pretreatment with the CWT, an extension of the Kennard-Stone (EKS) algorithm was used to adaptively select the most representative NIR spectra, which were then submitted to expensive chemical measurement and multivariate calibration. With the samples selected, a PLS model was finally built for prediction. It is of great interest to find that selection of representative samples in the CWT domain, rather than raw spectra, not only effectively eliminates background interference and noise but also further reduces the number of samples required for a good calibration, resulting in a high-quality regression model that is similar to the model obtained by use of all the samples. The results indicate that the proposed method can effectively enhance the cost-effectiveness of NIR spectral analysis. The strategy proposed here can also be applied to different analytical data for multivariate calibration.

Journal Article↗
PubMed2001

Progress in multi-ion counting spark-source mass spectrometry (MIC-SSMS) for the analysis of geological samples.

Spark source mass spectrometry (SSMS) has experienced important and significant improvements in nearly all analytical features by the use of a multiple ion counting (MIC) system. Two procedures have recently been developed to further increase the analytical capabilities of MIC-SSMS in geochemistry. These are a mathematical correction of interferences, which is often necessary for the ultra trace element analysis of Nb, Ta, Zr, Hf and Y, and the development of an autospark system to hold the total ion beam constant. New analytical data for geological samples, especially international reference materials, are presented using the improved MIC-SSMS technique. The data set consists of high precision and low abundance data for Zr, Nb and Y in depleted reference materials. The MIC-SSMS results are compared with those of conventional SSMS using photoplates for ion detection. The precision of the MIC-SSMS isotope ratio measurements (about 1%) is more than a factor of 3 better than that of conventional SSMS, as demonstrated by analyses of Hawaiian samples. Total uncertainties of MIC-SSMS concentration data including all sources of error are generally between 2 and 5% for concentrations higher than about 0.3 microg/g and about 10% for trace element abundances in the ng/g range.

Journal Article↗
PubMed2001

Grading in soft tissue tumors: principles and problems.

Histologic grading has been considered the most important prognostic factor for soft tissue sarcomas. Several grading systems have been proposed based on the assessment of morphologic features in heterogeneous groups of sarcomas. Currently, the French Federation of Cancer Centers (FNCLCC) and the National Cancer Institute (NCI) grading systems are the most commonly used. These systems are based on a few morphologic predictors of biologic behavior, which is justifiable because of the rarity of soft tissue sarcomas. Nonetheless, over- or underestimation of prognosis may occur because of an uneven representation of specific sarcomas with rather distinct biologic behaviors among studies of grading systems. In addition, lack of standardization of morphologic criteria and frequent omission of the influence of clinical factors on the final survival analyses preclude universal acceptance of a particular grading system. New advances in diagnostic imaging, quantitative morphometric technologies, cytogenetics, and molecular genetics, allied with alternative analytic data systems, may provide better validation, reproducibility, and prognostic capabilities for current and future grading systems. This article summarizes and critically analyzes the various important grading systems that have thus far been proposed and suggests alternatives for the elaboration of more reproducible systems with higher predictive capabilities.

Adolescent↗
PubMed1998

Lymphocyte profiles in multiple myeloma and monoclonal gammopathy of undetermined significance: flow-cytometric characterization and analysis in a two-dimensional correlation biplot.

The distribution of 27 T-, B-, and natural killer-cell subsets in the peripheral blood of 40 patients with multiple myeloma (MM), ten patients with monoclonal gammopathy of undetermined significance (MGUS), and 40 healthy donors was investigated by means of classical univariate statistics and advanced multivariate data-analytical techniques. The latter approach was used to describe, represent, and analyze lymphocyte subset distribution in a two-dimensional correlation biplot, allowing comparison of complex lymphocyte profiles (i.e., compound lymphocyte subset distributions) of individual subjects rather than isolated subset values of selected patient and/or donor groups. The correlation biplot revealed that, in accordance with the univariate statistics, the MM patients were characterized by marked shifts towards CD8+, CD57+, CD62L-, CD(16+56)+, and HLA-DR+ T cells, suggesting in vivo immune activation. The activation profile was most markedly observed in treated MM patients in the advanced disease stage category. The lymphocyte profiles of MGUS patients were heterogeneous, with approximately half of them located in the swarm of MM patients and the other half in the swarm of healthy donors. Although the univariate statistics revealed significant differences between MGUS patients and healthy donors only within the B-cell compartment, the correlation biplot revealed that two MGUS patients clearly had a typical T-cell activation profile similar to that of the MM patients. One MGUS patient with a T-cell activation profile progressed 13 months later to a stage IA MM and required chemotherapy. A marked lymphocyte profile shift in one MM patient was associated with terminal and aggressive disease transformation. Our study illustrates further the practical use of correlation biplots for the detection of aberrant lymphocyte profiles and/or profile shifts in individual patients.

Analysis of Variance↗