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Biomedical subjects

R Bambauer

Publications and source records attributed to R Bambauer.

At least 37 records · Page 2Linked to original sources
PubMed1996

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↗
PubMed1996

Scanning electron microscopic investigation of catheters for blood access.

Using blood-contacting catheters, infections, thromboses, and stenoses are among the most frequent complications. They are caused by surface properties of the basic material. Ion beam based processes such as ion implantation (silicone rubber) and ion beam assisted deposition (silver-based coatings) affect only the outer micron of the treated material surface; there is little effect on bulk properties. These processes were employed also in the production of large-bore catheters used for extra-corporeal detoxification. In a prospective study in 56 patients, 72 large-bore catheters were inserted into the internal jugular and subclavian veins and investigated after removal for bacterial colonization using a scanning electron microscope. In 24 patients 30 surface-treated catheters (Spi-Argent I n = 14; Spi-Silicone n = 16) were used. 42 untreated catheters used in 32 patients served as controls. Bacterial colonization was observed in 8.9% in contrast to 38.1% in untreated catheters. The scanning electron microscopic investigations showed in all catheters a low thrombogenicity. The ion beam based processes make the surface-treated catheters thrombus and infection resistant.

Catheterization, Central Venous↗
PubMed1995

LDL-apheresis in treatment of two patients with heterozygous familial hypercholesterolemia and extremely elevated lipoprotein (a) levels.

In hyperlipidemia and, in particular, elevated lipoprotein (a) [Lp(a)] levels there appears to be pronounced linkage between the development and progression of atherosclerosis. Our study concerned two Caucasian male patients with heterozygous forms of familial hypercholesterolemia and extremely high Lp(a) concentrations. Maximal diet regimens and the use of lipid lowering drugs achieved a serum total-, LDL-cholesterol and triglyceride reduction of up to 30%, but no reduction of the Lp(a) level was discernible. Both patients suffered three myocardial infarctions and several coronary angiographies with percutaneous transluminal angioplasties (PTCA) were necessary. In 1989, we commenced treatment with LDL-apheresis. At present, after 78 LDL-aphereses in the case of the 41-year-old patient (48 months, dextran sulfate adsorption, KANEKA, Japan) and 38 aphereses in the case of the 35-year old patient (8 months, immunoadsorption, special Lp[a] columns, LIPOPAK, POCARD, Russia), the Lp(a) has dropped an average of 53%, total cholesterol 31%, LDL-cholesterol 40% and triglycerides 42%. During this period neither mycardial infarctions nor cardiac complaints were observed. In the course of treatment, both patients experienced an improvement in general well-being and increased performance. These results are very encouraging: LDL-apheresis may be effective in the treatment of patients, the only risk factor for premature atherosclerosis being an extremely high Lp(a) concentration.

Adult↗
PubMed1995

Apheresis technologies: an international perspective.

The developments in apheresis techniques and their clinical applications world-wide are technologically driven. In the past, apheresis survey statistics have high-lighted both the differences by region in clinical practice and in the types of technologies utilized. Such differences have provided a basis for the scientific and clinical assessments of these apheresis technologies and their clinical outcomes and have stimulated the marketing and business development of new technologies world-wide. A review of the regional practices and technologies utilized provides a perspective on the future role of apheresis and its developments in clinical practice. While technology is a driving force for the development of new techniques for clinical practice, it is not the only market force. For technology introduction, several other important issues need to be considered. Regulations at the local and, most importantly, the federal level impact the timing for new technology introduction. Reimbursement by healthcare payers is critically important from the initiation of the development of a technology through its clinical use. Clinical trials are critically important to show the safety and clinical- and cost-effectiveness of the technology in order for payers to provide reimbursement for its use, but these trials are sometimes long and costly. Research funding availability at the governmental and commercial levels critically impacts new technology investigation and its introduction. Apheresis technology developments offer new hopes and promises for the clinical team; however, their development, introduction, and utilization will be influenced by the prevailing market forces.

Blood Component Removal↗
PubMed1995

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↗
PubMed1995

Scanning electron microscopic investigations of surface treated large-bore catheters used for extracorporeal detoxification methods.

Typical complications caused by surface properties of synthetic catheter implants are infection, thrombosis, and stenosis. New methods for surface modification with the aim of reducing such complications are ion beam-based technologies. In our study 109 large-bore catheters without (n = 42) and with treated surfaces with silver (n = 39) or silicone (n = 28) were inserted into the interna jugular and the subclavian veins and were used for extracorporeal detoxification methods. After removal, the catheters were investigated with scanning electron microscopy (SEM) and for bacterial colonization. In 42 large-bore catheters without surface treatment deposits of fibrin, protein and blood cells were seen on the inner and outer surface. Bacterial colonization was observed in 38.1%. In contrast, the catheters with treated outer surfaces showed a very low thrombogenicity and a low contamination rate of 8.9%. The ion beam-based technologies reduce the thrombogenicity and infection rates of the catheter surfaces. In comparison to catheters without treated surfaces, catheters with surface treatment are good alternatives in blood contacting applications ranging from hemodialysis to oncology.

Adsorption↗
PubMed1995

Four years' treatment efficacy of patients with severe hyperlipidemia. Lipid lowering drugs versus LDL-apheresis.

A total of 47 patients suffering from heterozygous hyperlipidemia were treated with LDL-apheresis (24 patients, aged 49.5 +/- 11.5 years), diet and/or lipid-lowering drugs or with diet and lipid-lowering drugs only (23 patients, aged 48.0 +/- 11.9 years). After treatment periods of 44.4 +/- 14.3 (apheresis group) and 33.5 +/- 15.9 (drug group) months, respectively, the ensuing results revealed significant differences (p < 0.0001): total cholesterol decreased from 10.4 to 5.5 vs 9.9 to 8.7 mmol/l, LDL from 7.4 to 3.9 vs 6.6 to 5.2 mmol/l, triglycerides from 5.8 to 3.7 vs 4.8 to 4.1 mmol/l and the LDL/HDL-ratio decreased from 7.1 to 3.4 vs 6.7 to 5.8. In the apheresis group one patient died from myocardial infarction vs one non-fatal myocardial infarction and the manifestation of coronary heart disease in three cases in the drug group. There were no severe side-effects in either group. All patients in the apheresis group experienced an increased clinical performance. On the other hand physological well-being of these patients was lower than that of the drug group (scores 42.3 +/- 8.9 vs 50.2 +/- 9.9, p < 0.002). The present trial suggests that a continuing reduction in serum lipid concentrations may lower in a dose dependent manner the risk of development and progression of coronary heart disease. With respect to clinical and laboratory results, LDL-apheresis seems safe and appears to be the most effective therapy.

Adolescent↗
PubMed1994

Bacteria- and endotoxin-free dialysis fluid for use in chronic hemodialysis.

As the quality of water in the dialysis fluid varies considerably, dialysis fluid is contaminated with a high percentage of bacteria and endotoxins. The bacterial populations contained in the dialysis fluid are as heterogeneous as the chemical structure of the endotoxins that result. The latter can pass through the dialysis membrane whereby high-flux membranes permit a larger number of retransportable molecules than low-flux membranes. A central aim toward a future, safe dialysis process should, therefore, be the production of a dialysate that is free of bacteria and endotoxins. As we were able to demonstrate in various examinations, this goal is most likely to be achieved with the aid of sterile filtration using hollow fiber modules of polyamid. To avoid disinfection of the polyamid membrane, as this would only reach bacteria but not endotoxins, the filter was changed after at most 10 h. The achieved dialysis fluid was free of bacteria and endotoxins. We were also able to show that the release of interleukin-1 was reduced. In addition, side-effects, such as a drop in blood pressure, headaches, muscular cramps, and nausea, were reduced.

Bacteria↗
PubMed1994

Scanning electron microscopic investigation of catheters for blood access.

Large-bore catheters for extracorporeal detoxification methods without and with treated surface with silver or silicone were investigated after removal with a scanning electron microscope and for bacterial colonization. In 42 large-bore catheters of three different materials, small deposits of fibrin and protein on the inner and outer surface were seen. This second layer covered the entire surface after 3 days and increased to a thickness of 3 to 60 microns during the following days. Bacterial colonization was observed in 38.1%. In contrast to these results, the catheters with the treated outer surface showed a very low thrombogenicity and a low contamination rate of 6.7%.

Bacteria↗
PubMed1994

Complications and side effects associated with large-bore catheters in the subclavian and internal jugular veins.

Since the introduction of large-bore catheters for acute hemodialysis 30 years ago, many problems with handling, material, and contamination of these catheters exist. Nevertheless, catheterization of the inferior and superior vena cava with a large-bore catheter has proved to be suitable as a rapid connection process for hemodialysis, hemofiltration, hemoperfusion, plasmapheresis, plasmaperfusion, among others. In a retrospective study with 2,741 large-bore catheters in 1,716 patients, the frequency of infections, thrombosis, bleeding, and other side effects was investigated. All complications and side effects are presented dependent on vascular access route. In total, the complication rate was 48.9% higher in subclavian puncture than in internal jugular puncture (24.8%). The highest complication rates for both vascular access routes were infections or septicemia; infections were observed in 19.5% of subclavian catheters versus 10% of internal jugular catheters.

Bacteria↗
PubMed1994

Elimination of an artificial immune complex by plasmapheresis in rabbits.

The behaviour of an artificial immune complex was investigated in 15 rabbits. The immune complex was labelled with iodine-125 (125I). The advantage was that the immune complex could not be metabolized without being eliminated by the kidney. This artificial immune complex was injected in different dosages (0.8 micrograms-40 micrograms/rabbit) on 2 consecutive days. One group (n = 9) was treated with plasmapheresis: the other (n = 6) was a control group that did not undergo plasmapheresis. A miniaturized plasmapheresis system eliminated the immune complex very effectively. The increasing concentration of the immune complex in the blood before the next plasmapheresis treatment was probably an expression of mobilization of the immune complex from different organs. The animals of the plasmapheresis group were in better condition than the control group.

Animals↗
PubMed1992

Elimination of an artificial immune complex by plasmapheresis in rabbits.

The behavior of an artificial immune complex was investigated in 15 rabbits. The immune complex was labeled with iodine-125 (125I). The advantage was that the immune complex could not be metabolized without being eliminated by the kidney. This artificial immune complex was injected in a dosage of 0.8 microgram, in 2 rabbits, 5.0 micrograms in 4 rabbits, 10 micrograms in 3 rabbits, 20 micrograms in 2 rabbits, and 40 micrograms in 4 rabbits on two consecutive days. One group (n = 9) was treated with plasmapheresis: the other (n = 6) was a control group that did not undergo plasmapheresis. A miniaturized plasmapheresis system eliminated the immune complex very effectively with an average exchange volume of 95.7 ml per treatment. The increasing concentration of the immune complex in the blood before the next plasmapheresis treatment was probably an expression of mobilization of the immune complex from different organs. The animals of the plasmapheresis group were in better condition than the control group.

Animals↗
PubMed1992

Plasmapheresis in newborns with hyperbilirubinemia.

With a miniaturized plasmapheresis system consisting of a double head pump and balancing pump, extracorporeal detoxification treatments such as plasmapheresis, hemofiltration, and hemodialysis were carried out. In total 15 premature infants and newborns with Rherythroblastosis and hyperbilirubinemia were treated using this miniaturized system. The average birth weight of the 15 patients was 2,386 g. With a main blood flow of 5.3 ml/min and a filtrate flow of 1.3 ml/min, an average of 192.4 ml of plasma per treatment was exchanged. In all patients 1 to 10 plasmapheresis treatments were necessary to reduce the mean serum bilirubin from 15.6 +/- 4.8 to 7.3 +/- 3.2 mg/dl, and after several days the serum bilirubin subsequently normalized in 12 patients, who improved. Three patients died 5 to 18 days after birth as a result of their primary disease and immaturity. For vascular access small catheters were inserted in the umbilical or the femoral vein. All treatments were well tolerated by the patients.

Acute Kidney Injury↗
PubMed1991

Sterile and endotoxin free dialysis fluid for hemodialysis.

As the quality of water in dialysis fluid varies considerably, and, in view of the fact that endotoxin or active derivates can cause acute and chronic side effects in patients under hemodialysis treatment, the dialysis fluid must be sterile and endotoxin-free. The predialyzer fluid in 20 hemodialysis patients was investigated. The bacterial loading was between 5/ml and 12,000/ml, the endotoxin concentration was high and extremely variable. Therefore we introduced the ultrafiltration of the dialysis fluid by a polyamide hollow fiber membrane before entering the dialyzer. All samples were free of bacteria, and the concentration of endotoxin was lower than the detectable limit. With this procedure we can obtain sterile dialysis fluid, which is endotoxin free. Our preliminary results showed that Interleukin-1 in the patients was significantly (p less than 0.005) lower under ultrafiltration of the dialysis fluid than without ultrafiltration.

Colony Count, Microbial↗
PubMed1991

[Hydroxyethyl starch-induced transient renal failure in preexisting glomerular damage].

Hemorheological therapy through hemodilution has been gaining importance for several years and been applied to an ever increasing degree in stationary as well as in ambulant treatment. While renal insufficiency without previously established nephropathy is known to be a side effect of dextrans, cases of HES-induced nephropathy have so far not been reported. Two cases are presented in which in the course of stationary hemodilution therapy with HES an acute deterioration of an already exiting nephropathy was noted. Possible pathophysiological causes for such a deterioration are most likely to be found in an increased permeability of the glomerular basal lamina. Hydroxyethyl starch molecules are filtered above the physiological renal threshold which increases the viscosity of the primary urine. This can be counteracted by increasing diuresis. This conclusion can be drawn from our own observations which proved that renal insufficiency can be avoided through sufficient fluid intake (approx. 3 liters/day). In patients with creatinine values above 1.5/dl and arterial hypertension the indication for hemodilution therapy must be analysed carefully. If hemodilution therapy proves to be necessary, sufficient fluid intake must be guaranteed. Retention parameters must be controlled every other day in the course of the therapy. As an alternative, the administration of gelatin preparations should be considered as it does not cause cumulation.

Acute Kidney Injury↗
PubMed1990

Ultrafiltration of dialysis fluid to obtain a sterile solution during hemodialysis.

As the quality of water in the dialysis fluid varies considerably, and in view of the fact that endotoxin or active derivates can cause acute and chronic side effects in patients under chronic hemodialysis treatment, the dialysis fluid must be sterile and endotoxin free. The predialyzer fluid in 20 hemodialysis patients was investigated. The bacterial load was between 5/ml and 12,000/ml, the endotoxin concentration was high and extremely variable. Therefore, we introduced the ultrafiltration of the dialysis fluid by a polyamide hollow fiber membrane before entering the dialyzer. All samples were free of bacteria, and the concentration of endotoxin was lower than the detectable limit. With this procedure, we can obtain sterile dialysis fluid, which is endotoxin free. Our preliminary results showed that interleukin-1 in the patients was significantly (p less than 0.005) lower under ultrafiltration of the dialysis fluid than without ultrafiltration.

Bacteria↗
PubMed1990

[Recombinant human erythropoietin (rh-EPO) in chronic, dialysis-dependent renal failure: effects on macro- and microcirculation and hematologic parameters].

Recombinant human erythropoietin (rh-EPO) has been shown to be effective in the treatment of renal anemia. Additionally, rh-EPO improves the hemostatic defect of uremia. On the other hand, a hypertensinogen effect and an increased risk for thrombosis have been reported in hemodialysis (HD) patients with rh-EPO. 20 HD patients in Homburg were recruited for a multicenter, placebo-controlled study (MF 3981), aiming to assess the risk of rh-EPO. Initially, 10 patients received rh-EPO at a dose of 3 x 80 U/kg body weight and week which was subsequently adjusted according to the hematocrit. After 6 months, the patients receiving placebo were changed to rh-EPO therapy. Clinical and laboratory data were obtained before, as well as 1, 3, 6 and 12 months after beginning of the study. Erythrocyte counts increased significantly in the rh-EPO group. Also, an increase of platelet count, fibrinogen and plasma viscosity was observed during rh-EPO. Tissue type plasminogen activator and plasminogen activator inhibitor as well as von-Willebrand-factor remained unchanged, although a shortening of the bleeding time was observed. Blood pressure and arterial blood flow were not influenced by rh-EPO.

Blood Viscosity↗