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R Haeckel

Publications and source records attributed to R Haeckel.

At least 19 recordsLinked to original sources
PubMed1992

Comparison of ethanol concentration in saliva and blood from police controlled persons.

The salivary ethanol concentration correlates very well with the serum level (r = 0.98) in samples which are obtained almost simultaneously from persons undergoing a traffic control. If ethanol was referred to the aqueous compartment the saliva/plasma ratio was about 0.85; this ratio was about 11% less than the theoretical one and remained constant over the entire concentration range applied. Saliva could be taken together with breath samples from traffic participants which are controlled for ethanol consumption. The advantage of saliva in favour of blood is that it can be obtained nearly simultaneously with the breath sample without the intervention of a physician and does not hurt the person under suspicion. Furthermore saliva is suited for the voluntary surveillance of former alcoholics who are willing to prove that they are able to live abstinently.

Alcoholic Intoxication↗
PubMed1992

A multicentre evaluation of the Ektachem DT60-, Reflotron- and Seralyzer III systems.

The analytical performance of the three analytical systems Reflotron, Ektachem DT60 and Seralyzer III was studied according to ECCLS guidelines (1) and partly according to a protocol of the Société Francaise de Biologie Clinique (SFBC) (2) in a multicentre evaluation involving four laboratories. The determination of 11 analytes led to more than 180,000 data. With the Ektachem DT60, imprecision was acceptable for all analytes except for sodium. With the Reflotron, imprecision for glucose and creatinine was wider than the acceptable limits. With the Seralyzer III, imprecision for glucose, uric acid, cholesterol, creatinine and potassium was not within acceptance limits. The recovery of system assigned control sera values was acceptable for all analytes, except for glucose, creatinine and sodium with the Ektachem DT60 system, and for all but glucose and cholesterol with the Reflotron. On the Seralyzer III, the limits of acceptance were exceeded only with the creatinine assay. The recovery of the reference method values with Kontrollogen L caused problems with all three systems and for all analytes. Only 30% of the mean values of Kontrollogen L measured with the Ektachem and with the Seralyzer III were within the limits of acceptance. 40% of the mean values determined with the Reflotron were inside these limits. The upper limits of linearity as claimed by the manufacturers were obtained with all analytes and systems with the exception of cholesterol on all systems and the creatinine assay on the Seralyzer III. The systems under test and several different comparison methods showed good agreement for the analysis of patient samples, except in one laboratory for the analysis of sodium and aspartate aminotransferase with the Ektachem system and potassium with the Seralyzer III. Turbidity showed no significant influence on the measurements of all analytes and all systems. Haemolysis, hyperproteinaemia, and bilirubinaemia affected several methods on all three systems. A start time delay of up to 60 s did not affect the results of the Reflotron, except in the case of the triacylglycerol assay, which was affected by start time delays greater than 45 s. The results of 4 assays on the Seralyzer III were decreased considerably by a delayed start time (triacylglycerols and creatinine above 5 s, aspartate aminotransferase above 35 s and creatine kinase above 15 s). For reliable results from all the assays in each of the three analytical systems, it was necessary to use the prescribed sample volume within certain limits. The practicability of all analytical systems tested was found to be very good. A field study was conducted with the Reflotron system. The analyte concentration was determined in venous blood from various patients. In 25 out of 30 experiments, the results of the "field" laboratories showed a greater spread about the fitting line than those obtained in the "expert" laboratories.

Chemistry, Clinical↗
PubMed1992

Proposed quality specifications for the imprecision and inaccuracy of analytical systems for clinical chemistry.

A Working Group of the European Group for the Evaluation of Reagents and Analytical Systems in Laboratory Medicine proposes, after detailed study of the advantages and disadvantages of available strategies, the following quality specifications for analytical systems for clinical chemistry. Total imprecision should be: (a) less than one-half of the average within-subject biological variation, or (b) less than the state of the art achieved by the best 0.20 fractile of laboratories, whichever is the less stringent. The second approach may be used when data on biological variation do not exist. Inaccuracy should be: (a) less than one-quarter of the group (within- plus between-subject) biological variation, or (b) less than one-sixteenth of the reference interval, when data on group biological variation do not exist, or (c) less than twice the ideal imprecision, if the above specifications are too demanding.

Chemistry, Clinical↗
PubMed1991

Influence of captopril on glucose and fatty acid oxidation in human thrombocytes and mononuclear leucocytes.

Captopril (CAS 62571-86-2) may be beneficial for the treatment of diabetes because of its activating effect on peripheral glucose consumption besides its well known blood pressure degradation. The glucose oxidation has been found to be activated by captopril in thrombocytes and mononuclear leucocytes, cell types which are usually considered to be independent from insulin. Because the oxidation of pyruvate labelled in position C-1 but not of 2-14C-pyruvate and of 1-14C-acetate was enhanced, captopril most probably stimulated the pyruvate decarboxylation reaction. The metabolism of glucose labelled in positions 1 and 6 was equally activated by captopril indicating another step which may be affected by captopril.

Blood Platelets↗
PubMed1991

Multicentre evaluation of the blood gas-electrolyte-analyser "BGE".

A multicentre evaluation of the blood gas-electrolyte-haematocrit-analyser BGE (Fa. Instrumentation Laboratory), following as far as possible the ECCLS guidelines for multicentre evaluation of blood gas analysers, was performed by three laboratories. The rules of the evaluation protocol were extended to the electrolyte and haematocrit determinations. The BGE proved to be easy to operate and maintain. The stability of the measuring system was good. The within-run imprecision of all electrodes was excellent. The same applies to the between-day imprecision, except for the calcium measurements. The systematic deviation of the gas electrodes was very small. Comparison studies revealed clinically significant deviations only for ionized calcium. Some suggestions for further improvements are made.

Blood Gas Analysis↗
PubMed1991

European multicentre evaluation of the Du Pont Dimension 380 under the auspices of the European Group for the Evaluation of Analytical Systems in Laboratory Medicine (EGE-Lab).

The Clinical Chemistry Analyzer Dimension 380 manufactured by Du Pont de Nemours was tested in a multicentre evaluation according to the guide-lines of the European Committee for Clinical Laboratory Standards (ECCLS) and in part to the protocol of the Société Française de Biologie Clinique (SFBC). The instrument and the reagents were evaluated as a system, since both reagents and reagent cartridges are specifically designed for the instrument. Fourteen analytes including electrolytes, substrates and enzymes were tested. The evaluators summarized their experience as follows: 1. All parameters tested yield results comparable to established procedures. 2. Very good performance of the ion-selective-electrode unit. 3. The imprecision data of the system are, for most parameters, between 1 and 4% CV and thus equal to or better than those of the instruments compared. 4. No reagent or sample carry-over was detected after a minor modification of the instrument. 5. The linearity of Dimension test methods in general covers the range stated by the manufacturer. 6. Very good stability of the calibration curves (up to 2 months). 7. Good practicability of the whole system, including handling of reagents and a very user-friendly software.

Blood Chemical Analysis↗
PubMed1990

Inhibition of mitochondrial carnitine acylcarnitine translocase by hypoglycaemia-inducing substances.

The rate of mitochondrial carnitine-carnitine exchange mediated by carnitine acylcarnitine translocase was measured in the presence of the two hypoglycaemia-inducing drugs, 2-(3-methyl-cinnamyl-hydrazono)-propionate and 2-(3-phenylpropoxyimino)-butyric acid (BM 13.677). Both substances caused a concentration-dependent decrease in the rate of carnitine uptake in guinea pig liver mitochondria. Apparent initial influx rates were decreased by 75% and 80% at a concentration of 2 mmol/l 2-(3-methyl-cinnamyl-hydrazono)-propionate and 2-(3-phenylpropoxyimino)-butyric acid, respectively. Intraperitoneal injections of 212 mumol 2-(3-phenylpropoxyimino)-butyric acid or 21 mumol 2-(3-methyl-cinnamyl-hydrazono)-propionate per kg body weight caused a noticeable decrease in blood glucose concentration. A significant fall of the blood ketone body concentration was achieved with 2-(3-methyl-cinnamyl-hydrazono)-propionate or 2-(3-phenylpropoxyimino)-butyric acid, at dosages of 21 and 255 mumol/l, respectively. Furthermore there was a dose-dependent increase in the plasma free fatty acid concentration in the presence of 2-(3-methyl-cinnamyl-hydrazono)-propionate. This increase, however, was much less pronounced with 2-(3-phenylpropoxyimino)-butyric acid. Metabolic effects of 2-(3-methyl-cinnamyl-hydrazono)-propionate are consistent with an inhibition of long-chain fatty acid transport, whereas an additional mechanism of action has to be assumed for 2-(3-phenylpropoxyimino)-butyric acid.

Animals↗
PubMed1990

European Multicentre Evaluation of the ESAT 6660.

The analytical performance of the glucose analyser ESAT 6660 from Eppendorf was studied according to the ECCLS guidelines and partly according the SFBC protocol in a multicentre evaluation involving laboratories from three European countries. The glucose determination in serum and in haemolysate was studied. The following results were obtained. 1. The precision was as good as or better than the precision of the comparison instruments. The coefficients of variation were between 1.1 and 3.4% for the between-days imprecision and between 0.35 and 1.45% for the within-run imprecision experiment. 2. The recovery of control sera values compared with the hexokinase method was between 94.3 and 102.6%. 3. With patient specimens as good agreement was found between the results obtained with the ESAT 6660 and the different comparison instruments (ASTRA, Hitachi 737 and ACP 5040). 4. A drift effect of 1.1-2.3% occurred in 5 of 21 experiments, depending on the individual enzyme membrane. 5. Sample carry-over was not observed. 6. A linearity between 0.5 and 50 mmol/l was found, exceeding the manufacturer's claims. 7. Several different endogenous and exogenous interferences were investigated. No interfering effect was detected for endogenous substances. A positive interference was observed by ascorbic acid at a concentration above 350 mg/l. 8. The practicability of the instrument was judged as very good. It was considered as a disadvantage that the instrument is not capable of piercing sample lids. Also the numeration of samples is not very convenient.

Blood Chemical Analysis↗
PubMed1990

Relationship between intraindividual variation of the saliva/plasma- and of the arteriovenous concentration ratio as demonstrated by the administration of caffeine.

The use of saliva instead of venous blood for monitoring drugs has many advantages. Its usefulness has, however, been questioned, because of the variability of the intraindividual saliva/plasma ratio. Among other reasons, this variability can result from the fluctuation of the arteriovenous blood concentration ratio. The present work represents a detailed investigation of this phenomenon, using caffeine as an example. This phenomenon is observed when the concentration of free diffusible substances differs in the central and peripheral compartment, depending on the pharmacokinetic phase. In such cases, the salivary concentration more closely reflects the cellular concentration in organs of the central compartment than that of peripheral venous blood.

Adult↗
PubMed1990

Stimulation of glucose metabolism in human blood cells by inhibitors of carnitine-dependent fatty acid transport.

According to a well accepted hypothesis, increased fatty acid oxidation can lead to hyperglycaemia by stimulating gluconeogenesis and reducing glycolysis. Therefore, inhibitors of fatty acid metabolism should cause hypoglycaemia by inhibiting gluconeogenesis and activating glycolysis. Various substances were tested to validate this hypothesis with regard to glucose oxidation in human mononuclear leukocytes and thrombocytes. 2-(3-Methyl-cinnamyl-hydrazono)-propionate, an inhibitor of the carnitine acyltransfer system was found to cause hypoglycaemia in whole animals and to inhibit gluconeogensis in the perfused guinea pig liver, while the acetyl-CoA/CoASH ratio was decreased. This substance stimulated the metabolism of glucose to CO2 in human mononuclear leukocytes and especially in platelets. This effect could be potentiated if concanavalin A and 2-(3-methyl-cinnamyl-hydrazono)-propionate were applied simultaneously. Under these conditions, however, fatty acid oxidation was no longer inhibited. From these results, it can be concluded that the activation of glucose oxidation by 2-(3-methyl-cinnamyl-hydrazono)-propionate is independent of its effect on fatty acid metabolism. Other inhibitors of fatty acid metabolism which were also investigated behaved similarly.

Blood Glucose↗
PubMed1989

Reasons for intraindividual inconstancy of the digoxin saliva to serum concentration ratio.

When a constant dose of digoxin was administered orally over several days, the digoxin concentration in saliva and erythrocytes rose faster than in serum. Thus, the saliva/serum concentration ratio was below 1.0 after a single dose and above 1.0 in the steady state. The digoxin concentration was relatively high in "unstimulated" (more or less spontaneous) saliva and decreased with stimulation of the salivary flow rate. It therefore appeared that the actual salivary digoxin concentration depended on 2 components: the digoxin concentration in "stimulated" saliva depended only on the rapid diffusion from the blood into saliva, and the concentration in the "unstimulated" saliva depended on the rapid diffusion and on a slower exchange with the intracellular compartment. It is suggested that unstimulated saliva reflects the intracellular digoxin concentration and stimulated saliva reflects the free digoxin concentration of the serum. Both effects must be taken in account when interpreting the saliva/serum ratio, and they may explain conflicting results in the literature.

Digoxin↗
PubMed1989

Measurement of proteins with the Behring Nephelometer. A multicentre evaluation.

The selective multi-protein analyser Behring Nephelometer was examined according to the ECCLS guidelines in a multicentre evaluation involving five laboratories. IgG, IgA, IgM, C-reactive protein, C3c, C4, apolipoprotein A-I and B were measured in serum, and albumin and IgG were measured in cerebrospinal fluid. All values obtained were included in the evaluation without correcting for outliers. The trial, which lasted three months and involved over 20,000 analyses, basically yielded the following results: 1. The precision was generally better than that of comparative procedures. For the majority of methods, the between-day coefficients of variation were below 4.5%. The highest coefficient of variation was 7.2% (for C-reactive protein) and the lowest 1.35% (for C3c). 2. The fraction of assigned values of control materials varied between 0.95 and 1.08. 3. Good agreement was found with results from the comparison procedures: Beckman ICS, Behring Laser Nephelometer, Hyland Laser Nephelometer. 4. No carry-over effects were observed. 5. No interferences were observed for IgG, IgA and IgM determinations using hyperbilirubinaemic or haemolytic samples. In contrast lipaemic samples and some with monoclonal immunoglobulin M showed an influence on the immunoephelometric reaction. 6. Because of the large measuring range, it is necessary to repeat analyses only in extremely rare cases. 7. During the entire evaluation period no instrument malfunctions or interruptions occurred. As a result of its reliability, the Behring Nephelometer is well suited for routine operation and emergency analyses in medium and large-sized laboratories.

Albumins↗
PubMed1989

European multicentre evaluation of the ABBOTT Spectrum clinical chemistry analyzer.

The analytical performance of the selective multitest ABBOTT Spectrum analyser was studied according to the ECCLS guidelines and partly the CERMAB protocol in a multicentre evaluation involving laboratories from six European countries. Fifteen analytes, including the electrolytes sodium, potassium and chloride, were measured each in at least 3 laboratories, all at 37 degrees C, except the electrolytes, which are measured at room temperature. The trial lasted approximately three months and involved the collection of over 60,000 data points. It yielded the following results: 1. The precision was at least as good as the precision obtained with the comparison instruments. The majority of the coefficients of variation were between 1 and 4%. 2. The recovery for method assigned control sera values was, with few exceptions, within 10%. 3. Good agreement with respect to the method assigned values of control materials and method comparison with patient specimens to different instruments (e.g. SMAC, Hitachi 737, RA 1000) was found. 4. No drift was observed. 5. Reagent-related carry-over was not found. Specimen-related carry-over was detected in some cases, the deviation being of little or no clinical significance. 6. The manufacturer's claims regarding method linearity were as stated or exceeded. 7. The open system capability was tested and rated as very convenient. 8. The practicability of the instrument was very good.

Blood Chemical Analysis↗
PubMed1989

Measurement of leukocyte elastase/alpha 1-proteinase-inhibitor complex using a homogeneous and a heterogeneous enzyme-immunoassay.

The heterogeneous 2 h elastase/alpha 1-proteinase-inhibitor enzyme-linked immunosorbent assay was compared with a newly developed homogeneous 20 min immunoactivation test. The within-run and between-days coefficients of variation for both tests were satisfactory. Good agreement was found between the two tests, using specimens from 140 patients. In conclusion, the 20 min immunoactivation test is able to replace the 2 h elastase/alpha 1-proteinase-inhibitor enzyme-linked immunosorbent assay.

Adolescent↗