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Biomedical subjects

D Falkenhagen

Publications and source records attributed to D Falkenhagen.

At least 91 records · Page 5Linked to original sources
PubMed1985

[Behavior of the hypothalamo-hypophyseal unit to stimulation with arginine, GnRH and TRH in patients with chronic uremia].

In 11 women aged from 20 to 47 years (average age 33,1 years) with chronic uremia, treated by hemodialysis, a sequential stimulation test (SST) with 0.5 g arginine hydrochloride per kg body weight, 25 micrograms GnRH and 200 micrograms TRH was performed to examine the responsibility of the hypothalamo-pituitary unit. For evaluation of basal and stimulated secretion of PRL, LH, FSH, TSH, and HGH the corresponding serum levels were determined by RIA. 10 of the 11 women showed a galactorrhoea. No correlation between levels of PRL and creatinine could be found. Menstrual disorders in women with chronic uremia are discussed in the context of basal LH serum levels nearly always unphysiologically increased. In a few cases disturbances of basal secretion of TSH and HGH, respectively, could be observed.

Adult↗
PubMed1984

[Behavior of copper and manganese in serum in hemodialysis].

The extent to which chronic dialysis alters the serum copper and manganese content was examined. The copper content was not significantly altered, whereas the level of manganese in the blood rose highly significantly. This manganese originates from the dialysis fluid. The behaviour of the manganese level during dialysis treatment suggests that the element is deposited in the body. Its transport is clearly connected with protein, since the manganese is not found in the ultrafiltrate. The is no fear of manganese intoxication.

Copper↗
PubMed1984

Activated charcoal and resin haemoadsorbents: in vitro drug removal and blood compatibility studies.

An investigation has been made of the drug removal properties and blood compatibility of activated charcoal and resin haemoadsorbents . The adsorbents were Norit RBX1 peat-based extruded charcoal, spherical charcoal as used in the Sorin Biomedica Detoxyl 2 column and 2 cross-linked polystyrene-based macroreticular resins. Drug removal properties were assessed in terms of in vitro adsorption efficiency of each adsorbent for 11 different drugs. The blood compatibility of the charcoals and macroreticular resins was evaluated in an in vitro haemoperfusion circuit by measuring the changes in platelet and leucocyte levels in human blood caused by contact with the adsorbent. The results of the investigation indicate advantages in using spherical charcoal haemoadsorbents .

Blood Grouping and Crossmatching↗
PubMed1983

[Possibilities for using extracorporeal circulation in the rat].

An extracorporal system of freely mobile, unanaesthetized rats is presented. This model was used in experiments on the biocompatibility of silicone rubber and new types of hollow membranes. The results confirm a sensitive reaction of haematological parameters to various test substances, thus indicating that the model is very suitable. Carrying out a membrane plasma separation in rats makes it possible also to use rats for studies on detoxification and thus to use the advantages offered by this experimental animal to the full.

Animals↗
PubMed1983

[What is the current outlook for an implantable artificial kidney?].

Considering the homeostatic demands made by the organism on an artificial eliminating substitute kidney system, it seems that the haemofiltrative principle for transporting matter is the most suitable for simulating the natural glomerular kidney function in an implantable artificial kidney. Biophysical laws can be used to influence long-term filtrative efficiency and the blood-flow in the haemofilter system can be controlled by technical feedback regulation. Endogenically, the filtration process is, in terms of energy, driven by the aterial blood pressure (specifically, by the trans-membrane pressure thus generated). The definitive ultrafiltrate treatment takes place by intestinal reabsorption and elimination of the end products, whereby these functions may be assisted by the use of sorbents etc. or an adequate substitution therapy if reabsorption is insufficient. These processes can reasonably be triggered by neurohormonal feedback regulation if the homeostasis situation is greatly disturbed by the haemofiltration process. The implantable artificial kidney is thus a biochemical hybrid kidney.

Animals↗
PubMed1982

In vitro assessment of charcoal and resin hemoadsorbents.

An in vitro assessment has been made of the blood compatibility and efficiency of different charcoal and resin hemoadsorbents. The charcoals vary in source, shape, size, nature and amount of polymer coating. The resins are the macroreticular adsorbents XAD-4 and Y56 and a carbonized resin. The effect on Y56 of albumin coating has been studied. The assessment has demonstrated that a reduction in platelet drop is accompanied by a decrease in the adsorption of fibrinogen. The results confirm the potential advantages of spherical charcoal and that coating with an ultrathin layer of polymer or with albumin does not seriously reduce efficiency. For Y56 resin, treatment with an albumin solution of 1-2 g/100 ml appears to be a suitable procedure if clinical use is considered.

Antigen-Antibody Complex↗
PubMed1982

Tc-99m-DTPA--a new test substance for detoxification devices.

Tc99m labeled diethylenetriaminepentaacetic acid (Tc-99m-DTPA) is an appropriate in vivo test solute for all extracorporeal detoxification procedures. The molecular weight of the Tc-99m-DTPA complex is within the biologically relevant middle molecular range of 400 to 700 daltons. Tc-99m-DTPA is distributed in the extracellular space in the same way as inulin. Regarding its localization in the gel filtration spectra and plasma clearance, Tc-99m-DTPA corresponds to middle molecule peak 2. The evaluation of elimination rate and plasma clearance CP of Tc-99m-DTPA is possible by measuring the pulse rates before and after the detoxification device. Taking into account the corrections for Ht and UFR, the Tc-99m-DTPA plasma clearances were calculated for different dialyzers, high flux dialyzers, hemofilters and a hemoperfusion device. The continuous measurement of pulse rates and the use of a UFR-controller (A2008) allow an exact tracking of CP vs. time, the estimation of CP (QB), CP(UFR) and of the sieving coefficient. Examples are given for these cases. It was shown that an increase in plasma clearance to more than about 100 ml/min does not greatly increase the Tc-99m-DTPA elimination rate.

Humans↗
PubMed1982

Volumetrically controlled ultrafiltration. Current experiences and future prospects.

Exact control of ultrafiltration (UF) is a prerequisite for high flux dialysis and hemodiafiltration. Volumetric dialysate balancing is the best current method for the use of dialyzers with high water permeabilities. The precision of UF control by volumetric dialysate balancing is in agreement with all medical requirements. A positive influence of volumetric UF control on patients undergoing chronic hemodialysis can be shown by the frequencies of dialysis side effects. Volumetric UF control is only a first step towards an intelligent UF module to correlate water removal, solute removal and sodium balance.

Body Water↗
PubMed1981

Continuous measurement of DTPA-clearance in extracorporeal detoxification circuits.

A new method for investigating clearances is described. DTPA labelled with technetium 99m (MW: 496 daltons) is used as an agent to be measured. Continuous determination of the DTPA-clearance is possible in extracorporeal detoxification circuits including dialyzers, hemofilters and hemoperfusion columns. As an example, DTPA-clearances are given for two different dialyzers. In comparison to clearance measurements of peak 7, DTPA-clearance was very similar to that obtained for peak 7.

Autoanalysis↗
PubMed1980

[Developmental tendencies of hemadsorption in uremia treatment].

After at first having dealt with the present stage of haemoperfusion in the therapy of chronic renal insufficiency, the developmental tendencies for the haemoadsorbers to be expected are mentioned which in future allow to think of a diminution of the artificial kidney. Own results concerning the behaviour of blood compatibility and the effectivity of different active charcoals show that it is to be reckoned with the further development of unstratified adsorbents or such ones with ultra-thin layer. Comparative examinations of 4 patients from the chronic haemodialytic programme, who were treated for 4 months with the CDAK 1.8 and then for 4 months with the sorbent dialyser 1.3, could not show any essential differences in the behaviour of the low-molecular substances urea, creatinine and uric acid and of the clinical condition of the patients.

Creatinine↗
PubMed1980

[Technics and indications for hemofiltration treatment].

Technique, possibilities of application, advantages and disadvantages of haemofiltration are described. A convective mass transport underlies the method. By this means the elimination of molecules of different size takes place with the same speed and the removal of so-called middle molecules is performed more effectively than in the usual method of dialysis.

Acute Kidney Injury↗
PubMed1980

[Technic and indication for controlled ultrafiltration].

The isolated ultrafiltration with commercial dialysators gives a possibility of the massive dehydration in a short time without disturbing the well-being of the patient. If in patients undergoing a dialysis a following haemodialysis (sequential ultrafiltration haemodialysis) is necessary, particularly in patients with acute complications hypotonic circulatory conditions may develop. An infusion of a fourfold concentrated human dry plasma during the ultrafiltration may prevent these hypotensions, since reduction of osmolality and losses of circulation-effective substances are prevented during haemodialysis. With the help of this kind of treatment conditions of hyperhydration of different genesis may be removed also in patients with inclination to hypotension.

Acute Kidney Injury↗
PubMed1980

[Hemodialysis with Bi-Flo cannulas].

It is reported on the use of the double-lumen Bi-Flo-puncture canule in chronic haemodialysis patients. In a sufficient flow through the atrioventricular fistula no significant decrease of the effect of dialysis was the result. It is recommended to render the proof of a perhaps existing shunt volume between the two lumina of the Bi-Flo-canule before the permanent use of it, in case of the existence of an only moderately functioning atrioventricular fistula.

Arteriovenous Shunt, Surgical↗
PubMed1979

[Possibilities of using hemoperfusion in the treatment of chronic kidney insufficiency].

A survey of the administration possibilities of the activated charcoal haemoperfusion in the treatment of the chronic renal insufficiency is given. Various coating methods for activated charcoal as well as important adsorption abilities of the activated charcoal for uraemia-specific metabolites are described in detail. Then comes a classification of the haemoperfusion in the treatment of ureamia. The result is that at present the use of haemoperfusion with activated charcoal in the therapy of uraemia may be regarded only as a supplementary therapy of the haemodialysis and the haemofiltration, respectively.

Adsorption↗
PubMed1979

[Serum complement and protein metabolism in chronic dialysis patients].

1. When a so-called free diet is granted there is the danger of a protein deficit, which can be proved in a significant decrease of the serum transferrin and of the complement factor E3c, in patients in the chronic haemodialysis programme. 2. Within the group undergoing dialysis a correlation analysis did not result in a statistically ascertained connection between the complement factor C3c and the total haemolytic activity and the transferrin, respectively. 3. On the basis of a diet analysis a connection between the protein supply and the serum transferrin level could be established, which was not to be proved for the complement factor C3c and the total haemolytic activity, respectively. 4. Low transferrin values in the serum seem to be followed by a deterioration of the anaemia situation of the patient undergoing haemodialysis. 5. Compared with the total haemolytic activity and the complement factor C3c the determination of the serum transferrin allows an essentially exacter information about the protein metabolism of the patient undergoing a chronic haemodialysis.

Blood Proteins↗