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Biomedical subjects

H E Keller

Publications and source records attributed to H E Keller.

At least 19 recordsLinked to original sources

Low-density lipoprotein apheresis in the treatment of two patients with coronary heart disease and extremely elevated lipoprotein (a) levels.

Hyperlipidemia and elevated lipoprotein (a) (Lp[a]) levels have been linked to the development and progression of premature atherosclerosis. Our study concerned 2 white male patients (aged 36 and 42 years) with heterozygous familial hypercholesterolemia and extremely elevated Lp(a) concentrations that were resistant to diet regimens and lipid-lowering drugs. The patients were treated with low-density lipoprotein (LDL) apheresis for 59 months (Liposorber system, Kaneka, Japan) and 19 months (immunoadsorption system, special Lp(a) columns; Lipopak; Pocard, Russia), respectively. The concentration of Lp(a) decreased on average by 50%, total cholesterol by 27%, LDL cholesterol by 41%, triglycerides by 43%, and fibrinogen by 16%. High-density lipoprotein (HDL) cholesterol increased by approximately 4%. Before treatment with LDL apheresis, each patient had suffered 3 myocardial infarctions, and had had 4 and 6 coronary angiographies with 2 and 4 percutaneous transluminal angioplasties (PTCAs), respectively. Since treatment with LDL apheresis, no myocardial infarctions or cardiac complaints were observed. In the course of treatment, both patients reported an increased performance. Available data suggest that LDL apheresis may be effective in the treatment of patients, the only risk factor for premature atherosclerosis being extremely elevated Lp(a) concentrations.

Adult↗

Effects of high-dose aprotinin on renal function in aortocoronary bypass grafting.

BACKGROUND: To reduce blood consumption in cardiac surgery, aprotinin has been widely used for years. Because aprotinin is metabolized in the kidney, damage of the renal system has been discussed. METHODS: To study these possibly unfavorable effects of aprotinin, a prospective, randomized, placebo-controlled study of 20 patients undergoing aortocoronary bypass operations was performed. A placebo group P was compared with group A, in which patients received high-dose aprotinin according to the "Hammersmith" regimen. Renal function was assessed for 5 postoperative days using sodium dodecyl sulfate gel electrophoresis and quantitative protein analysis of the urine. RESULTS: During and after the operation, temporary renal dysfunction was found in all patients, with a substantial increase of all investigated indices. The alpha 1-microglobulin level in the urine was significantly increased in the aprotinin group for 5 days in comparison with the placebo group, with a maximum on the third postoperative day (64.8 +/- 13.7 versus 21.0 +/- 6.5 mg/L; p < 0.05). Similarly, after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, the bands of proteins filtrated in the renal tubular system were almost tripled in the aprotinin group 5 days postoperatively (5.0 +/- 0.8 versus 2.1 +/- 0.2; p < 0.05). Although urine production was significantly increased in group A (4789 +/- 580 versus 3653 +/- 492 mL/24 h postoperatively; p < 0.05), no relevant changes in serum or urine creatinine levels could be observed in either group. CONCLUSIONS: Patients undergoing aortocoronary bypass operations demonstrate a temporary renal dysfunction. Aprotinin impairs renal function in addition by overloading the tubular reabsorption mechanisms. Patients with normal renal function preoperatively--as were included in this study--are able to compensate for both the perioperative renal dysfunction caused by the extracorporeal circulation and the additional tubular damage due to aprotinin.

Aged↗

LDL-apheresis in two patients with extremely elevated lipoprotein (a) levels.

Hyperlipidemia and elevated lipoprotein (a) [Lp(a)] levels have been linked to the development and progression of premature atherosclerosis. Two male caucasian patients (36 and 42 years old) with heterozygous familial hypercholesterolemia and extremely elevated Lp(a) concentrations, resistant to diet regimen and lipid lowering drugs, were treated with LDL-apheresis for 55 months (liposorber system, Kaneka, Japan) and 15 months (immunoadsorption system, special Lp(a) columns, Lipopak, Pocard, Russia). Lp(a) dropped on average by 50%, total cholesterol by 27%, LDL-cholesterol by 42%, triglycerides by 43% and the fibrinogen concentration by 16%. Prior to treatment, both patients had suffered three myocardial infarctions. Four and six coronary angiographies with two and four percutaneous transluminal angioplasties (PTCA) were necessary. Since the treatment with LDL-apheresis neither myocardial infarctions nor cardiac complaints have been observed, and both patients have reported better performance. Available data suggest that LDL-apheresis may be effective in the treatment of patients with extremely high Lp(a) concentration.

Adult↗

Effects of fenofibrate on angiographically examined coronary atherosclerosis and left ventricular function in hypercholesterolemic patients.

Within the framework of a prospective lipid-lowering intervention study 44 patients were treated over a period of 3 years with a lipid-lowering diet and 200-400 mg fenofibrate daily. The intervention led to statistically significant decreases in total cholesterol (Chol), low density lipoprotein cholesterol (LDL-Chol) and triglycerides levels, and to a significant increase in high density lipoprotein cholesterol (HDL-Chol) levels. Despite intervention, in 8 patients the HDL-Chol levels decreased by up to 20 mg/dl, where these were mainly patients with high initial values. Likewise, the triglycerides of 4 patients whose initial levels were relatively low increased (up to 49 mg/dl) and the LDL-Chol levels of 8 patients whose initial levels were also low increased (up to 49 mg/dl). Only minor success was achieved through the 6-week diet, but this was still slightly significant for Chol and LDL-Chol levels. A total of 21 patients underwent repeat angiography within 3 years for clinical reasons. For the evaluation of the angiographic progress a total of 98 minor and moderate stenoses was measured using digital image processing and automatic contour finding. The change in the angiographic parameters 'percent diameter reduction' (%DR) and 'percent plaque area' (%PA) correlated with on-treatment LDL-Chol levels (%DR change with LDL-Chol: r = 0.67, P = 0.0005; %DR change with Chol: r = 0.61, P = 0.002; %PA change with LDL-Chol: r = 0.40, P = 0.037; %PA change with Chol: r = 0.38, P = 0.044), while for HDL-Chol and triglycerides no influence on the angiographic progress could be demonstrated. On the basis of the reproducibility of the measuring methods the patients were classified in the categories 'regression', 'unchanged' and 'progression'. The patients classified as 'regression' (parameter: %DR change) showed an LDL-Chol mean value of 162 +/- 9 mg/dl, whereas those classified as 'unchanged' or 'progression' showed values of 189 +/- 25 mg/dl and 199 +/- 21 mg/dl, respectively (P = 0.014). A negative correlation appeared between the angiographic progress parameters and the initial degree of stenosis. The left ventricular ejection fraction in the second angiography showed relationships to lipoprotein levels and angiographic progress parameters.

Coronary Angiography↗

Cold agglutinins of anti-Pr specificity in rubella embryopathy.

Cold agglutinins of anti-Pr specificity were detected in two newborn infants suffering from serologically ascertained rubella embryopathy, an IgM kappa anti-Pr(a), titer 64, and an IgM lambda anti-Pr1, titer 16. The cases are rare examples of cold agglutinin production in newborns; a possible relationship between anti-Pr specificity and rubella infection is discussed.

Agglutinins↗

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↗

Progression and regression of minor coronary arterial narrowings by quantitative angiography after fenofibrate therapy.

To study the effects of fenofibrate, a lipid-lowering medication, on patients with coronary artery disease, 191 minor coronary narrowings in 42 patients with coronary artery disease were analyzed by quantitative coronary angiography using computer-assisted contour detection. Computed parameters were percent diameter reduction and percent plaque area. A prospectively formed intervention group of 21 patients treated with special diet and fenofibrate (200 to 400 mg/day) was checked every 6 weeks with regard to risk factors. After a mean interval of 21 months, coronary angiography was repeated, using the same x-ray system and nearly identical projections. The intervention group was angiographically compared at follow-up with an untreated comparison group, also comprising 21 patients. Both groups had high initial serum cholesterol (mean 311 mg/dl) and low-density lipoprotein (LDL) cholesterol levels (mean 235 mg/dl). Only among the treated patients did lipid levels change significantly: cholesterol, -19%; LDL cholesterol, -20%; high-density lipoprotein cholesterol, +19%; and triglycerides, -30%. At angiographic follow-up, the changes in percent diameter reduction and percent plaque area correlated positively with the mean serum and LDL cholesterol levels of the intervention group. Significant differences were found in the change in percent plaque area between both groups. The intervention subgroup with angiographic regressions (11 patients) had significantly lower serum and LDL cholesterol levels than the intervention subgroup with angiographic progressions (10 patients). These results indicate the beneficial effect of fenofibrate on minor coronary narrowings. Because of its high reproducibility in measuring minor narrowings, quantitative coronary angiography proved to be a suitable method for angiographic follow-up.

Cholesterol↗

[Quantitative coronary angiography: progression and regression of coronary stenoses--an intervention study with fenofibrate].

In order to examine the effect of fenofibrate on coronary narrowings, within the framework of a prospective intervention study, we treated a total of 44 hypercholesterolemic patients (who were in our clinic to undergo PTCA) with diet and fenofibrate (200-400 mg/day) over a period of 3 years. After a mean interval of 21 months, control angiographies were performed in nearly identical projections for 21 patients on clinical grounds. The minor and medium-grade narrowings of the reangiographed patients at the beginning and at the end of the intervention interval were measured by means of digital image processing and automatic contour detection. The measuring parameters were percent diameter reduction (% DR) and percent plaque area (%PA). With regard to their angiographic progression, the 21 reangiographed patients of the intervention group were compared to a comparison group consisting likewise of 21 patients of similar age and sex distribution and persistently high lipid and lipoprotein levels. During the intervention period, the reangiographed patients of the intervention group showed the following changes of the lipid and lipoprotein levels in contrast to the outset values: cholesterol -19 +/- 8%, LDL -20 +/- 14%, HDL +19 +/- 44%, triglycerides -30 +/- 31%.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon, Coronary↗

Simultaneous determination of retinol, tocopherols, carotenes and lycopene in plasma by means of high-performance liquid chromatography on reversed phase.

The determination of the vitamins A and E as well as of carotenes and lycopene is important for studies of cardiovascular diseases and cancer. A method for laboratory routine is reported to separate simultaneously retinol, tocopherols, alpha- and beta-carotene, lycopene and beta-cryptoxanthin in human plasma or serum by HPLC on reversed phase starting from one extract. Two detectors with programmable wavelength are used sequentially, a spectrophotometer for the detection of the carotenoids in the visible region and a fluorometer for the assay of retinol and the tocopherols.

Carotenoids↗

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↗

Electrocardiographic monitoring in children with chronic renal failure.

Continuous electrocardiographic (ECG) monitoring was performed over 24 h in 44 children at various stages of chronic renal failure in order to determine the incidence and nature of cardiac dysrhythmias. In addition the ECG was followed during haemodialysis sessions and during dialysate exchanges in continuous ambulatory peritoneal dialysis (CAPD) patients. In contrast to adult patients on haemodialysis life-threatening dysrhythmias were not observed. The proportion of children with premature ventricular complexes (41%) was at the upper limit of that in healthy children. A relatively high heart rate was found in children on CAPD, which varied during the exchange procedure. In 57% of all patients a transient marked prolongation of the QT interval up to 40% greater than normal was observed without obvious changes in the serum electrolyte levels. Continuous ECG monitoring is a useful tool for detecting alterations of cardiac rhythm and conduction in at-risk children with renal failure.

Adolescent↗

Elevated serum CK-BB levels in patients with cerebral transtentorial herniation after ischemic stroke.

We examined the time course of CK and its isoenzymes in 15 patients with severe ischemic stroke. Patients with cerebral transtentorial herniation (n = 7) had the highest CK-BB activity during herniation (1.54 +/- 0.6 U/L, mean +/- SD; range: 1.0-2.6 U/L). These values were distinctly above the values of a control group of 20 patients with non-neurological diseases (0.39 +/- 0.2 U/L, mean +/- SD). In patients with smaller lesions without herniation (n = 8) the maximum CK-BB increase was lower (0.56 +/- 0.26 U/L, mean +/- SD).

Aged↗

Indications of plasmapheresis and selection of different substitution solutions.

Substitution solutions used for plasmapheresis (PH) may be human albumin, serum protein conserves or plasma. 746 plasmapheresis carried out on 88 patients with a variety of diseases were examined and the side effects due to the substitution solutions were investigated. Side effects occurred in less than 10% of the cases where the four substitution solutions were used. The least side effects were observed in treatments using human albumin as substitution. Side effects increased for serum protein conserves, followed lyophilised plasma and were highest for fresh frozen plasma. In view of these possible side effects the criteria for PH should be strictly observed and the substitution solution should meet clinical requirements.

Albumins↗