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M Haller

Publications and source records attributed to M Haller.

At least 91 records · Page 5Linked to original sources
PubMed1993

[Fulminant pulmonary embolism in the 35th gestational week. Sonographic detection of a thrombus in the inferior vena cava with normal cavography].

Pulmonary embolism is the most common cause of maternal death during pregnancy. CASE REPORT. We report a 28-year-old obstetric patient (35th gestational week) who was admitted to the hospital because of intermittent vaginal bleeding caused by placenta totalis et accreta. Eleven days after admission she suffered a cardiac arrest. After cardiopulmonary resuscitation, an emergency caesarian section was performed and a healthy child was delivered. Abdominal sonography (B-mode) showed a floating thrombus in the inferior vena cava. Perfusion scintigraphy and cavography were normal; a computed tomography i.v. contrast medium study confirmed the presence of the thrombus. An open thrombectomy was performed to protect the patient from further pulmonary emboli. After 8 days she left the intensive care unit without residual complications. CONCLUSION. This case emphasises the importance of bedside sonography as a diagnostic method of identifying the source of a thrombus in patients with suspected pulmonary embolism.

Adult↗
PubMed1992

Substrate specificity of purified rabbit liver esterase ES-1.

1. Substrate hydrolysis by two purified rabbit liver esterase-1 allozymes (ES-1A and ES-1B) was compared under conditions differing in substrate, pH and temperature. ES-1A and ES-1B activities had a similar pH and temperature dependency and similar thermal stability profile. 2. There were marked differences in specific activity of ES-1A and ES-1B. ES-1A hydrolysed procaine more rapidly than ES-1B, but was less active towards aspirin. The acetate and propionate esters of p-nitrophenyl were hydrolysed slower by ES-1A than by ES-1B. 3. The effect of substrate concentration on ES-1A activity did not comply with the Michaelis-Menten kinetics, which may be due to so-called substrate activation. 4. At identical substrate concentration, pH and temperature, selected artificial esters were better substrates for ES-1A than selected physiological substrates. Beta-Naphthyloctanoate was found to be a suitable substrate for ES-1A. 1,3-Dioctanoylglycerol was hydrolysed at a rate of only 2% of that of beta-naphthyloctanoate. 5. With methyl, p-nitrophenyl, beta-naphthyl and 4-methylumbelliferyl esters as substrates, ES-1A activity is influenced by length and structure of the acyl moiety. Likewise, ES-1A activity is influenced by the nature of the alkyl moiety of acetate esters. With acetate and methyl esters, branched chains when compared with unbranched chains reduced the esterase activity of ES-1A. Elongation of the acyl moiety up to four or five C atoms gradually raised the velocity of methyl, p-nitrophenyl, and 4-methylumbelliferyl ester hydrolysis by ES-1A. A similar pattern was found for the length of the alkyl moiety of acetate esters. 6. The high degree of similarity between the observed substrate specificity of rabbit ES-1A and that reported earlier for rat ES-10, suggests that these two esterases have a common evolutionary origin.

Animals↗
PubMed1992

The use of three ferguson-plot-based calculation methods to determine the molecular mass of proteins as illustrated by molecular mass assessment of rat-plasma carboxylesterases ES-1, ES-2, and ES-14.

The molecular masses of three rat-plasma carboxylesterases (ES-1, ES-2, and ES-14) were estimated by transverse-gradient polyacrylamide gel electrophoresis and subsequent application of Ferguson-plot-based calculation methods. Two electrophoretic buffer systems were used and the data subjected to either weighted or unweighted regression analysis. The Tris-boric acid buffer system produced significantly higher retardation coefficients than the Tris-glycine system. Molecular mass estimates were significantly higher with the Tris-glycine buffer system. Unweighted instead of weighted analysis produced significantly higher molecular mass estimates. Molecular mass estimates also depended on the calculation method, that is, the choice of calibration relationship with molecular size as a function of retardation coefficient. Three commonly used calibration relationships were compared. On the basis of their accuracy, both the weighted log[retardation coefficient] versus log[molecular mass] plot and the square root of retardation coefficient versus molecular radius were found suitable, provided that the Tris-boric acid buffer was used for electrophoresis. Using the former calibration relationship, the molecular masses of rat-plasma ES-1, ES-2, and ES-14 were 55.5, 61.1, and 65.3 kDa, respectively.

Animals↗
PubMed1992

Plasma esterase-1 (ES-1) activity in rats is influenced by the amount and type of dietary fat, and butyryl cholinesterase activity by the type of dietary fat.

In previous work, we studied, under conditions of ad libitum food consumption, the effect of amount and type of dietary fat on plasma esterase-1 (ES-1) and butyryl cholinesterase activity in rats. This was done by the isoenergetic replacement of dietary fat by carbohydrates or by another fat source. The observed change in enzyme activity could theoretically be determined by either the dietary omission or the addition or by the combination. In the present work, we studied under restricted feeding conditions the effect of supplemental energy in various forms to determine the effect of the supplement alone. Supplemental coconut fat, but not isoenergetic amounts of either glucose or casein, raised plasma ES-1 activity. None of these supplements influenced butyryl cholinesterase activity. In a second experiment, we demonstrated that the ES-1 enhancing effect of supplemental coconut fat also occurred with fish oil, whereas the stimulatory effects of olive oil and corn oil were less pronounced. Supplemental fish oil, but not the three other fats, significantly reduced the depression in butyryl cholinesterase activity. Plasma cholesterol concentration was negatively associated with butyryl cholinesterase activity, but was not related to ES-1 activity. The two esterases were not correlated with plasma triglyceride concentration. We conclude that both the amount and type of fat in the diet of rats have specific influences on plasma ES-1 activity and that butyryl cholinesterase activity is affected by the type of fat.

Animal Feed↗
PubMed1992

Fat intake and clofibrate administration have interrelated effects on liver cholesterol concentration and serum butyryl cholinesterase activity in rats.

Rats were fed for 15 d purified diets with different amounts of coconut fat, and with or without clofibrate. Fat was added at the expense of an isoenergetic amount of glucose. The hypolipidemic action of clofibrate was not influenced by the amount of fat in the diet. Clofibrate did not affect liver cholesterol concentration in rats fed the low fat diet, but it counteracted the rise in liver cholesterol seen in rats fed the high fat diet. This could relate to the observed raised intestinal clofibrate-hydrolyzing activity of rats fed the high fat diet, because hydrolysis of clofibrate gives rise to its biologically active form. In rats fed the low fat diet, but not in those fed the high fat diet, clofibrate raised the activity of serum esterase-1, which (unlike esterase-2) does not hydrolyze clofibrate. Possibly, the dramatic stimulatory effect of fat feeding on serum esterase-1 activity had overruled any influence of clofibrate. Clofibrate elevated serum butyryl cholinesterase activity, with this effect being amplified by fat feeding. High levels of dietary fat in the absence of dietary clofibrate did not alter serum butyryl cholinesterase activity. Clofibrate did not change butyryl cholinesterase and esterase-1 activities in small intestine. The high fat diet caused slightly higher levels of butyryl cholinesterase activity in small intestine, but markedly raised intestinal esterase-1 activity. This study shows that certain effects of clofibrate and a high fat diet are interrelated.

Animals↗
PubMed1992

A framework for the knowledge-based interpretation of laboratory data in intensive care units using deductive database technology.

In co-operation with the Institute of Anaesthesiology of the Ludwig-Maximilians-University in Munich a computer-based system for the analysis and interpretation of renal function, fluid and electrolyte metabolism of critical care patients has been developed. This paper focuses on the requirements and implementation aspects of the knowledge-based interpretation for this particular system. Objective of the proposed approach is, to transform an enormous--and constantly increasing--amount of raw data available in modern intensive care units (ICUs) into relevant, patient-oriented information, which is easy to understand by the medical staff. The essential features of a knowledge-based system at an ICU are outlined. A system is described where these features are realized using deductive database technology as a specification paradigm and extended relational databases as an implementation platform. The integration into the hospital information system is highlighted.

Artificial Intelligence↗
PubMed1992

[The determination of plasma volume using indocyanine green in man].

The importance of circulating blood (BV) and plasma volume (PV) in critically ill patients and physiological research is unchallenged. Recently, Evans blue (EB) [8, 25] and radioactively labelled serum albumin (RIHSA) [20] have mostly been used as tracers for PV determination. However, the disadvantages of radioactive contamination (RIHSA) and dye accumulation (EB), especially in repeated measurements, are obvious. In addition, recent reports show a possible carcinogenic potential for EB [15, 21]. This has prompted us to examine the feasibility of indocyanine green (ICG), a tricarbocyanine dye currently used for cardiac output and liver blood flow measurements, for the determination of PV. The volume of distribution of ICG has been reported to represent PV [5, 26]. METHODS. In 23 healthy volunteers (19 men and 4 women), PV was determined in duplicate (PV1, PV2) with an interval of 30 min. Before injection a tourniquet was put around the arm and a pressure above the systolic arterial pressure was applied for 2 min. During recirculation, ICG (2.5 mg/ml) was administered in a dose of 0.25 mg/kg as a bolus injection over 5 s via an antecubital vein. Blood was drawn from an antecubital vein of the contralateral arm at 1 min intervals. After centrifugation, the optical density (corrected for blank) was read in a densitometer. Third- to ninth-minute plasma samples were used to calculate monoexponential plasma decay curves. The ICG concentration at injection time was achieved by extrapolation. A calibration curve was generated using 5 different known ICG concentrations. PV was calculated from injected ICG dose divided by ICG concentration at injection time. BV and red cell volumes (EV) were derived from measured PV and hematocrit (hct). RESULTS. Between minutes 3 and 9, tracer decay was monoexponential in all but 1 subject. From minute 10 on the plasma decay of ICG represented another, slower compartment (Fig. 1). The plasma half-life of ICG was 3.2 +/- 0.6 min (mean +/- SD). Mean PVs per body weight and body surface area (BSA) were 44 +/- 5 ml/kg and 1662 +/- 176 ml/m2, respectively. Linear regression revealed PV2 = 0.92.PV1 + 226 (r = 0.92) (Fig. 2). The mean percentage of difference (D) was -0.6%, the methodologic error (SD) +/- 5.7% [27]. Linear regression of PV and BSA revealed PV = 1885.BSA -416 (r = 0.71, P less than 0.0001) (Fig. 3). BV and EV estimates (Table 2) obtained from PV and hct showed reproducibility in the range of the PV determination because of excellent reproducibility of hct measurements. DISCUSSION. ICG plasma half-life times in our experiments were comparable to those reported by other authors [18, 19, 24]. Reproducibility of PV determination was good and was well within the limits of other tracer methods (EB, RIHSA) [17, 27]. Using exclusively peripheral veins for ICG injection and blood withdrawal did not seem to affect the accuracy of PV determination. PV estimates obtained by the ICG method showed good agreement with those known from the literature [7, 10, 25]. Our results correspond especially well with the data reported by Hurley [14] obtained from 481 healthy men using different methods (Evans blue, RIHSA, or labelled red cells).

Adult↗
PubMed1991

Determination of rat plasma esterase-1 (ES-1) activity by scanning densitometry of gradient polyacrylamide gels with zymogram detection.

There is no specific assay for rat plasma esterase-1 (ES-1) activity. Plasma contains many esterases, while known substrates do not discriminate between esterases. With gel electrophoresis, plasma esterase isozymes can be separated. Thus, a method consisting of gradient polyacrylamide gel electrophoresis, visualization of the enzyme with a staining technique based on substrate conversion, and densitometric scanning of the stained gel has been developed for quantitative measurement of rat plasma ES-1 activity. ES-1 activities were expressed as total peak areas. Reproducibility of the method was found to be about 10% (expressed as apparent between-gel coefficient of variation). When the ES-1 zone areas was expressed relative to that of a plasma ES-1 standard, reproducibility was about 3%. The kinetics of catalysis of alpha-naphthyl acetate hydrolysis by ES-1 could be determined with the gel scanning assay; the Km was 0.76 mM. At the alpha-naphthyl acetate concentration of 2.69 mM, total peak areas of the ES-1 zone were linearly associated with the staining time (up to at least 40 min) and amount of plasma (up to 26.25 microL). The pH of the staining buffer influences the ES-1 zone area, the largest areas being obtained when the pH ranged between 7.0 and 7.8. With propionate as acyl moiety of the alpha-naphthyl ester substrate, ES-1 zone areas were higher than with either acetate, butyrate or hexanoate.

Animals↗