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Biomedical subjects

F Keller

Publications and source records attributed to F Keller.

At least 235 records · Page 13Linked to original sources
PubMed1988

Elevated tumor markers in hemodialysis patients.

The incidence of elevated tumor markers without clinical signs of malignant disease was examined in 93 patients between the age of 29 and 79 years and on chronic dialysis for 3-240 months. Tissue polypeptide antigen was found to be elevated in 92.5%, carcinoembryonic antigen in 29.8, and alpha-fetoprotein in 6.5%. High levels of tissue polypeptide antigen were accompanied by high levels of beta 2-microglobulin (p less than 0.005). This indicates that tumor markers, and tissue polypeptide antigen in particular, may be unreliable for monitoring malignant disease in patients on hemodialysis.

Adult↗
PubMed1988

Granulomatous interstitial nephritis after nonsteroidal anti-inflammatory drugs.

Electrolyte and renal hemodynamic imbalance, acute interstitial nephritis with nephrotic-range proteinuria, papillary necrosis, tubular necrosis, and vasculitis are complications after intake of nonsteroidal anti-inflammatory drugs (NSAID). We report on 2 cases of biopsy-proven granulomatous interstitial nephritis with rapidly progressing renal insufficiency. Patient 1 was on ketoprofen for 7 months and indomethacin for 10 weeks before admission to hospital. The medication was not discontinued and renal insufficiency progressed to end-stage renal failure. Renal function did not respond to steroid and tuberculostatic treatment. Patient 2 was on diclofenac for 6 months and indomethacin for 7 weeks before admission to hospital. These drugs were withdrawn at diagnosis and renal function rapidly improved. We conclude that granulomatous interstitial nephritis may be a complication of NSAID medication indicating a cell-mediated immunologic disorder. False diagnosis (sarcoidosis, tuberculosis) may lead to end-stage renal disease (case 1). Discontinuation of medication obviates further therapy (case 2).

Adult↗
PubMed1988

Increased procollagen III production in patients with kidney disease.

Measurements of elevated procollagen III peptide (PIIIP) levels are used to monitor fibrosing activity in hepatic and various other diseases. Elevated PIIIP levels have also been reported in renal failure patients without such diseases. Therefore, the serum levels and renal clearance of PIIIP were investigated in 17 healthy volunteers and 100 patients with different types of acute (n = 15) and chronic (n = 85) kidney disease. PIIIP was measured by conventional and Fab radioimmunoassays. Median PIIIP levels in serum (18, range 5-55 ng/ml) and urine (34, range 1-110 micrograms/day) were significantly higher in kidney patients than serum (9, range 6-14 ng/ml) and urine levels (17, range 6-24 micrograms/day) in normal volunteers (p = 0.01). No significant differences (Kruskal-Wallis H test) were found, however, within the different kidney disease groups (acute, chronic/glomerulonephritis, interstitial nephritis). Median renal clearance of PIIIP-related peptides in kidney patients (1.5, range 0.5-2.4 ml/min) did not differ significantly (Wilcoxon U test) from that in normal volunteers (1.3, range 0.4-2.2 ml/min). These findings indicate that PIIIP elimination does not depend on renal function. PIIIP-related peptides in serum and urine, however, increase with renal failure irrespective of the activity or type of renal disease. This can be explained most probably by enhanced turnover of collagen type III by the affected kidney itself.

Adult↗
PubMed1988

[The depression ward--a review of the current status].

New therapeutic concepts are usually developed and realised step by step. Over the past years changes occurred mainly in two ways. There is a trend to reduce the size of the psychiatric hospital as such and/or to section off certain areas by introducing specialised units. From the experience with the so called "Affective Disorder Units" or "Mood Clinics" developed the concept of a Depression Unit, first introduced in Europe for research purposes at the Psychiatric University Hospital in Basle in 1968. In Germany the first Depression Unit was established at the PLK Weissenau in 1976. Similar units followed over the years at the PLK Reichenau, Weinsberg, the BKH Günzburg, the Landesklinik Nordschwarzwald Hirsau/Calw and the Rheinische Landesklinik Bedburg-Hau, other hospitals are planning them. Existing units are described in terms of their structural organisation, staffing situation and the service they provide. The concept of the Depression Unit according to criteria laid down agreed upon in the literature is summed up, and emotional atmosphere, structural organisation, activation, and individual therapeutic measures, discussed. Advantages are mentioned such as better understanding of patients, allowing them to let go and be cared for, aimed regression, the effects of being taken along, improved communication, and a way of dealing with suicidal thoughts and depressive behavior that reduces anxiety. Disadvantages such as the danger of spoiling patients or inducing a sense of resignation both in patients and staff are discussed.

Depressive Disorder↗
PubMed1988

[Investigations on the tissue compatibility of silicon rubber materials using experimental animals].

The reaction of subcutaneous tissue in guinea-pigs at implants of six kinds of silicone rubber materials (VEB Chemiewerk Nünchritz) was investigated by semiquantitative and quantitative methods. These based on the "Programme to the Assessment of Subcutaneous Tissue Reactions at Implants" by Knöfler, Keller etc. The histocompatibility of the tested materials can be compared with that of titanium. One of the silicone rubbers differs from both the reference material and the other silicone rubber materials significantly and is assessed to be more suitable than the alloy Gisadent KCM 83 (chromium cobalt molybdenum alloy).

Animals↗
PubMed1988

Exponential function for calculating saturable enzyme kinetics.

Enzyme kinetics are usually described by the Michaelis-Menten equation, where the time-dependent decrease of substrate (-dS/dt) is a hyperbolic function of maximal velocity (Vmax), Michaelis constant (Km), and amount of substrate (S). Because the Michaelis-Menten function in its most general meaning requires an assumption of steady-state, it is less curvilinear than true enzyme kinetics. A saturation-type exponential function is more curvilinear than the hyperbolic function and more closely approximates enzyme kinetics: -dS/dt = Vmax [1 - exp(-S/Km)]. The mathematical representation of enzyme kinetics can be further improved by introducing a deceleration term (Vdec), to make the assumption of a steady state unnecessary. For the action of chymotrypsin on N-acetyltyrosylethylester, the Michaelis-Menten equation yields the following: Vmax = 3.74 mumol/min and Km = 833 mumol. According to decelerated enzyme kinetics, the values Vmax = 4.80 mumol/min, Vdec = 0.0118 mumol/min, and the association constant (Ka) = 0.00111/mumol are more nearly accurate for this reaction (where 1/Ka = 901 mumol approximately Km).

Chymotrypsin↗
PubMed1988

Plasma exchange and immunosuppression in rapidly progressive glomerulonephritis: a controlled, multi-center study.

In a randomized study of 26 patients with histologically confirmed rapidly progressive crescentic glomerulonephritis, 12 patients were treated with immunosuppressants alone (corticosteroids, cyclophosphamide and azathioprine) while the other 14 patients received not only the identical immunosuppressive treatment but also plasma exchange therapy for four weeks. No statistically significant difference was found between the two groups. After 8 weeks, 73% and 69% of the patients in each respective group showed recompensation of renal function; serum creatinine fell from initially 7.0 and 6.2 mg/dl mean to 2.7 and 2.3 mg/dl mean, and under continued immunosuppression did not rise in the following months. Thus, in non-autoantibody induced rapidly progressive glomerulonephritis, kidney function could be improved substantially by immunosuppressive therapy, but an advantage of supplementary plasma exchange could not be shown.

Adult↗
PubMed1988

Effects of acetate during regular hemodialysis.

The utilization of acetate and its effects on acid-base balance and on free fatty acid metabolism were investigated during regular hemodialysis (HD). Fourteen patients with chronic renal failure were studied during two successive dialysis treatments for which either acetate or bicarbonate were used as a buffer anion in the dialysate. In the acetate studies the mean plasma acetate concentration in the arterial line rose from 0.16 mM to 4.67 mM, while it rose from 0.17 mM to 0.62 mM during bicarbonate dialysis. There was a linear relationship between acetate utilization and the acetate concentration in the venous line. The increase of the blood pH during bicarbonate HD was due to an immediate increase of HCO3, whereas acetate caused a smaller HCO3 rise and a pronounced fall of the pCO2. The heart rate was higher during acetate than during bicarbonate HD. During both types of dialysis there was a twofold rise of total FFA as well as the individual fatty acids palmitate, palmitoleate, oleate, stearate and linoleate which was of similar magnitude when acetate or bicarbonate were used. The postulated antilipolytic effect of the short-chain fatty acid acetate could not be demonstrated under the circumstances of routine hemodialysis. Pre-dialysis dopamine was elevated in 7 of the 11 patients and remained high during both types of HD; other hormones were normal during acetate and bicarbonate HD.

Acetates↗
PubMed1988

Characteristics and clinical course of hemodialysis patients with analgesic-associated nephropathy.

The knowledge of some characteristic findings on the personality of patients with analgesic-associated nephropathy (AAN) may facilitate diagnosis of the disease at an early stage. We therefore investigated the 144 patients at our hemodialysis center and compared the AAN patients (33%) with those having other kidney diseases (controls). Patients with AAN were older (60 +/- 10 vs 52 +/- 15 years, p less than 0.001) and predominantly women. Acetaminophen and metamizol metabolites were detected more frequently in blood from the AAN patients than in that from the controls (25% vs 3%, p = 0.002). More AAN patients were smokers, and they more frequently complained of vague symptoms (pain, sensitivity to changes in weather, insomnia) and also more frequently requested prescriptions for analgesics, hypnotics, laxatives, stomachics and antipruritics. Because they were older, AAN patients had fewer occupational and financial problems. The compliance of the AAN patients was significantly better with respect to important dialysis parameters such as weight gain between dialysis treatments (3.6 +/- 1.3 vs 4.0 +/- 1.3% body weight, p less than 0.05) and diastolic blood pressure (81 +/- 12 vs 86 +/- 12 mmHg, p = 0.025). Despite an older age and higher morbidity, the cumulative 17-year survival rate of the AAN patients did not differ from that of the controls. We conclude that AAN patients have characteristic personality traits. Their better compliance, adjustment to the hemodialysis situation and social conditions are responsible for their good survival on hemodialysis.

Acetaminophen↗
PubMed1988

New perspectives in diagnosis of hemostasis disorders.

The classical coagulation analyses are performed either by using manual methods or by means of various instruments with a different degree of automation. The introduction of chromogenic peptide substrates which can be split by thrombin has led to the development of photometric assays for PT and aPTT determination independent from the fibrinogen concentration and from its conversion to fibrin. After that, turbidimetric methods for the determination of fibrinogen, thrombin time and batroxobin time have been set up allowing the use of photometry for the determination of the most important hemostaseological parameters. For such purposes a new analytical system (ChromoTimeSystem, Behringwerke AG, Marburg/FRG) based on a special instrument and reagents for chromogenic and turbidimetric methods for coagulation and fibrinolysis has been developed. The ChromoTimeSystem allows to perform by photometry all important tests for coagulation and fibrinolysis. The analytical characteristics of this new system are presented.

Blood Coagulation Disorders↗
PubMed1988

Heparin-free hemodialysis with prophylactic change of dialyser and blood lines.

Heparinization during hemodialysis may cause severe bleeding complications in patients with high bleeding risk. Heparin-free hemodialyses (n = 208) were performed in 46 unselected patients with high bleeding risk after kidney transplantation (n = 25), after major surgery (n = 10), and with bleeding disorders (n = 11). Dialyser and blood lines were primed without heparin. In addition to the established measures (high blood flow, intermittent rinsing), system clotting was prevented by prophylactically changing the dialyser and blood lines in 107 of 208 dialyses (52 percent). Total system clotting with blood loss ranging from 100 to 250 ml occurred in six cases (3 percent). Mean hemodialysis time (+/- SD) was 4.1 hours (+/- 0.4), rising volume of the extracorporeal system 1.4 liters/hour (+/- 0.6), blood flow 244 ml/min (+/- 38), clotting time 12 min (+/- 4), and weight loss 2.5 kg (+/- 1.5). Mean hemodialysis creatinine clearance was 110 ml/min (+/- 34) and BUN clearance 138 ml/min (+/- 48). Heparin-free hemodialysis with prophylactic change of system is thus a safe and practical method of treatment for patients at high bleeding risk, but it is less effective, more expensive and the patient requires closer care.

Blood Coagulation↗
PubMed1987

Effect of digitoxin on cardiac arrhythmias in hemodialysis patients.

Digitoxin is considered a risk factor for ventricular arrhythmias in hemodialysis patients. In a randomized, crossover controlled study, 55 hemodialysis outpatients with sinus rhythm were prospectively investigated in two 48-h periods of electrocardiographic monitoring, one on and one off digitoxin or vice versa. The frequency of ventricular ectopic beats (mean +/- SD) which were found in 31 of 55 patients (56%), was slightly higher on hemodialysis (10 +/- 28 beats/h) than in the following 20 h (5.4 +/- 10 beats/h) and the next day off hemodialysis (3.6 +/- 6.6 beats/h); however, no difference was seen in patients on digitoxin during hemodialysis (10 +/- 29 beats/h), in the following 20 h (4.8 +/- 15 beats/h) and on the next day off hemodialysis (1.2 +/- 6.6 beats/h). The frequency of ventricular bigemini, polymorphous ectopies, couplets, more than 30 ectopies/h, salvos and tachycardias (10 vs 9 patients) on and off digitoxin was about the same (n.s., Fisher test). Supraventricular bigemini, salvos, tachycardias, and atrial fibrillation, however, occurred in significantly fewer patients on digitoxin (3 vs 13) than in those off digitoxin (P = 0.01, Fisher test). It is concluded that digitoxin does not increase the risk of ventricular arrhythmias in hemodialysis patients. Digitoxin, however, may have a beneficial effect on the supraventricular arrhythmias frequently observed in these patients.

Adult↗
PubMed1987

[Effect of diltiazem on blood cyclosporin levels].

The simultaneous administration of the calcium channel blocker diltiazem and cyclosporin results in a significant increase of RIA cyclosporin blood levels. The HPLC cyclosporin levels are not influenced.

Acute Kidney Injury↗