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D Matthaei

Publications and source records attributed to D Matthaei.

72 records · Page 4Linked to original sources

[Calcium and phosphate metabolism in hemofiltration (author's transl)].

In 10 patients undergoing hemofiltration treatment acute changes of parameters in the calcium-phosphate metaboism were investigated. Balance studies were also performed in all patients. Control studies were conducted after a 3-month interval in 7 patients. Whereas ionized calcium and 25-HCC remained constant, there was a significant decrease in phosphate, magnesium, fluoride and parathyroid hormone. Corresponding to these results, negative balances could be seen during the course of a hemofiltration treatment: for phosphate a mean value of -593 mg, for magnesium -8.4 mEq and for fluoride -458 microgram. When a calcium content of 3.75 mEq/l was used in the substitution solution, an only slightly positive calcium balance of +1.51 mEq/l (mean value) was found. A significant correlation between calcium and fluid balance was demonstrated by means of 197 filtration treatments of one patient: the calcium balance became negative whenever the fluid loss was greater than 3.86 liters. After a 3-month period no significant changes in the above parameters were found, which indicates, that disturbances in the calcium-phosphate-parathyroid hormone metabolism do not only lie in a reduced renal elimination. Even though our results do not indicate that hemofiltration treatment induces or increases the chances of renal osteodystrophy, the calcium concentration of the substitution solution should be increased to 4.0 mEq/l, in order to guarentee a positive calcium balance even by forced filtration.

Adolescent

[Profiles in chronic diseases. I. Investigations of steroid profiles in uremia (author's transl)].

Steroid profiles of hemofiltrates of uremic patients contain as main steroids the sulfates of 11beta-hydroxyetiocholanolone, 11-ketoetiocholanolone, 11beta-hydroxyandrosterone and 11-ketoandrosterone. In blood of uremic patients androstenediol is the main steroid of the sulfate fraction, while in blood of healthy persons dehydroepiandrosterone sulfate is the main steroid. The gradual decrease of the kidney function is characterized by an increase of 11-oxigenated androstane conjugates in urine.

Androstenediols

Assessment of hormone loss through hemofiltration.

The concentrations of testosterone, cortisone, gastrin, insulin, gastric inhibitory polypeptide (GIP), somatomedin B, parathyroid hormone (PTH), human growth hormone (HGH) and thyroid stimulating hormone (TSH) have been determined in the plasma and the ultrafiltrate of five uremic patients undergoing intermittent hemofiltration treatment. There was a considerable loss of gastrin, insulin, GIP, somatomedin B and PTH by hemofiltration treatment. The plasma concentrations, however, did not decrease except for immunoreactive-PTH (IR-PTH) which returned from elevated to normal levels. Cortisone, HGH and TSH concentrations in the ultrafiltrate were below the measureable range. A significant elimination of 11-hydroxylated androstans by hemofiltration may have a positive effect on the disturbed steroid metabolism. Results indicate that hemofiltration does not cause a hormone deficiency syndrome. On the contrary, the loss of degradation products of hormones with disturbing biological activity may be a favorable effect of the hemofiltration treatment.

Cortisone

Clinical experience with continuously monitored fluid balance in automatic hemofiltration.

Automatic fluid balancing, as obtained with the hemofiltration machines from Sartorius (Göttingen, West Germany) and Dialysetechnik (Karlsruhe, West Germany), is accurate enough to replace bed scales, which have been necessary in conventional hemodialysis for patients who are confined to beds. Side effects such as hypotension, nausea and muscle cramps during treatment may be reduced with these new machines, compared to conventional methods, provided that the rate of effective fluid withdrawal does not exceed 0.5 L/hr. In particular, the constant weight loss associated with automatic hemofiltration seems to be well tolerated by the patients with fewer side effects.

Body Weight

[Arteriovenous haemofiltration: a new and simple method for treatment of over-hydrated patients resistant to diuretics].

Fluid withdrawal in over-hydrated patients resistant to diuretics was obtained by means of a capillary haemofilter, using the arterio-venous pressure gradient for blood perfusion at a rate of 100 ml/min. The ultrafiltration rate was 200-600 ml/h and could be maintained as long as 48 h without changing the haemofilter. This method, which needs no technical investment, is easy and simple to handle for the physician, bears only a very low risk for the patient, and ensures a negative fluid balance even at a mean blood pressure of only 60 mm Hg.

Edema

Alterations of clotting factors and platelets during hemofiltration.

The influence of hemofiltration on the number of platelets and on coagulation factors was investigated in patients with chronic renal insufficiency. These investigations were done on 12 patients during 22 treatments with hemofiltration. Blood samples were taken before hemofiltration, 10, 30 and 120 minutes after the beginning of the treatment and at the end of hemofiltration. In comparison to the original values we found a loss of platelets, a small decrease in the concentration of fibrinogen and a small increase in the fibrin monomer complex, plasminogen, antithrombin III, alpha1-antitrypsin and in alpha2-macroglobulin. The thrombin time, the partial thromboplastin time and Quick's test showed that the blood of these patients contained sufficient hepatin. Use of fibrin plates (Astrup) showed no signs of fibrinolytic activity. Compared to the results, which were obtained some years ago during hemodialysis, we found a smaller extent of alterations of blood coagulation factors and number of platelets.

Antithrombins

Elimination of hormones through hemofiltration.

The concentrations of testosterone, cortisone, gastrin, GIP, somatomedin B, insulin, HGH, and TSH have been determined in the plasma and the ultrafiltrate of five uremic patients undergoing intermittent hemofiltration treatment. There was a considerable loss of gastrin, GIP, somatomedin B, and insulin by hemofiltration treatment; the plasma concentrations, however, did not decrease. Cortisone, HGH, and TSH were not detectable in the ultrafiltrate. Our results therefore indicate that hemofiltration does not cause a hormone deficiency syndrome. On the contrary, the loss of degradation products of hormones with disturbing biological activity may be a favourable effect of the hemofiltration treatment.

Cortisone

Elimination of cardiac glycosides through hemofiltration.

Elimination of three different cardiac glycosides by hemofiltration was investigated using the flat bed RP-6 (Rhône-Poulenc, Paris). At a filtration rate of 59 +/- 9 ml/min the mean clearance of 3-H-g-strophanthin was 54.9 +/- 10.4, that of a 3-H-digoxin and unlabelled digoxin 36.7 +/- 6.6 and that of digitoxin 4.6 +/- 2.8 ml/min. It is concluded from these results that hemofiltration is able to eliminate more than 50% of the amount excreted during the same period of time by normal kidneys. Elimination of cardiac glycosides by continuous hemofiltration is high enough to justify its use in digitalis intoxication, particularly because of the excellent control of electrolyte balance with this new method of detoxification.

Cardiac Glycosides

Dialysance of molecules of different size in reused Kiil, Ab-Gambro, and Rhône-Poulenc dialysers.

Dialysances of urea, creatinine, ethylenediamine tetraacetic acid, and ouabain were determined in three different flat-bed dialysers during three successive uses on 15 patients. There were no untoward reactions. A significant decrease in dialysing efficiency was observed only with the Ab-Gambro dialyser, in which the dialysance of the small molecules decreased more than that of the large. This is thought to result from blood deposits on the membrane surface inhibiting exchange.

Creatinine

Rapid three-dimensional MR imaging using the FLASH technique.

Fast low-angle shot (FLASH) imaging is a new technique for rapid magnetic resonance (MR) imaging that reduces acquisition times to seconds while retaining spatial resolution. This article deals with a three-dimensional (3D) variant of the FLASH method that allows the recording of a 3D-data set of 128 X 128 X 128 pixels within an acquisition time of only 4 min. The method is demonstrated using a 2.35 T 40 cm bore MR system. Experiments are carried out on rabbit head and human extremities. Depending on the field of view, the isotropic resolution is 1 mm or even less leading to cross-sectional images with a 1 mm slice thickness. In principle, FLASH imaging techniques are applicable to any MR system without the need of major hardware modifications. However, high-speed computers, large storage capacity, and rapid image display routines greatly facilitate an advantageous use of the 3D-FLASH variant.

Animals

Inversion recovery snapshot FLASH MR imaging.

Snapshot fast low angle shot (FLASH) magnetic resonance (MR) imaging techniques have been developed to enable real time imaging of MR parameters. The method is based on a 64 x 128 FLASH tomogram acquired within less than 200 ms. This work describes snapshot FLASH MR using a single 180 degrees pulse prior to the acquisition of a series of FLASH images. The experiment creates continuous dynamic inversion recovery (IR) T1 contrast in successive images. The total acquisition time of 16 images displaying the IR behavior is less than 4 s. Representative snapshot FLASH IR MR images of the abdomen of healthy rats and of an implanted hepatic tumor are illustrated.

Animals