[Serum level and organ deposits of beta 2-microglobulin in dialysis patients]

In radioimmunological estimation of beta 2-microglobulin (beta 2m) significant higher serum values were found in 36 dialysis patients (44.4 +/- 20.3 mg/l) in comparison with healthy probands (1.5 +/- 0.2 mg/l). A significant relation to the duration of dialysis, diuresis, symptoms of the musculo-skeletal system, but not to radiologic changes or bone biopsy findings could be seen. Post mortem examinations carried out in 21 dialysis patients revealed AB-amyloid deposits in synovial tissue of different joints (particularly shoulder and hip joint) or intervertebral discs in eight patients (age 48 to 73 years, dialysis duration less than four years) without correlation to serum beta 2m level or radiographically suspect areas. In the tissue of cervical spine or intervertebral discs of two patients suffering from destructive spondylarthropathy no amyloid could be detected. These results suggest that AB-amyloid may occur in elderly patients early in the course of hemodialysis and may be asymptomatic in most cases.

[Drug utilization in Hvalsö. An attempt to change the attitude of the population and physicians to drug use]

All of the prescriptions, a total of 1,876, issued by the five practitioners in Hvalsø in four chosen weeks in 1987/88 were copied. The prescribed drugs, a total of 3,177, were calculated for the individual groups of drugs and corrected for the age distribution among the population as a whole and in the individual doctor's practice. The main results from the following groups of drugs are presented here: hypnotics, drugs for neurosis, antibiotics, drugs for cardiac and circulatory disease, drugs for asthma, contraceptive pills and female sex hormones. By and large, considerably more medicine was prescribed for women than for men. For example, twice as much medicine for insomnia was prescribed for women. This is enough for every fourth woman over the age for 70 years to receive a daily dose of hypnotics. Women appear to commence using hypnotics at the age of 40 years and men at 60 years. Marked differences were found in the patterns of prescription between the individual practitioners and thei is apparently greatest as regards prescriptions for men while the more liberal prescription of hypnotics to women was observed for all of the practitioners. Two groups of drugs were, however, prescribed mostly for men, viz, asthma medicine for all age groups and cardiac and circulatory medicine for persons greater than 60 years. Where all of the groups of drugs were concerned, comparisons were undertaken between the prescription habits of the individual practitioners. The results of this investigation are employed in local health work among the population, in study circle work among the practitioners and as basic ideas for the county drug committee activities.

Influence of membranes on generation of beta 2 M and release of leukocyte lysosomal enzymes

Normal leukocyte functional capacity was investigated by evaluation of phagocytosis of opsonised yeast cells in a radiometric test system. After incubation with dialysis membranes (different cellulosic membranes, polysulfon membrane (PS), polymethylmetacrylate membrane (PMMN), the phagocytosis index, expressed as percent decrease with respect to initial values without membrane, decreased by 10%-25%. The most pronounced effect was observed with PS, cuprophane, modified cellulose and PMMA. The results are not related to differences in the viability of PMN during the test procedure; dead PMN amounted to about 4-6.5%. A significant increase in beta-NAG and beta-Gluc activities was released in the supernatants of the phagocytosis suspensions. This increase activity can be explained by the phagocytosis of PMN but it was not influenced by membrane contact. There was no influence of membrane contact or phagocytosis activity of PMN on the beta 2 M concentration in the supernatant demonstrating that no in vitro generation during incubation with either membrane exists.

Calcium salts of ketoacids as a new treatment strategy for uremic hyperphosphatemia

Hyperphosphatemia and secondary hyperparathyroidism are regular complications in patients suffering from end-stage renal failure. Aluminum-containing drugs are widely used to control serum phosphate, but this therapy carries the well-known risk of aluminum toxicity. Previously we demonstrated that a mixture of ketoacids is very effective in lowering increased serum phosphate and serum PTH levels. Recent studies to clarify the underlying mechanisms whereby these compounds lower serum phosphate revealed that ketoacids act as intestinal phosphate binders. In balance studies we demonstrated that intestinal phosphorus uptake decreased in normal subjects (decrease of absorption during ingestion: 0.7-3.14 mmol/day). Additional in vitro studies not only confirmed the in vivo results but also showed that ketoacids are as efficient as calcium carbonate although they provide less calcium. It is of further interest that ketoacids reached their greatest binding efficiency when the pH is 7.0, whereas calcium carbonate binds phosphate predominantly when the pH is 2.0 or 5.0. Ketoacids represent a further therapy to lower serum phosphate in uremia. As they provide less calcium than calcium carbonate, they could be considered as an advantageous, less dangerous alternative.

Visual cerebral lateralization over phases of the menstrual cycle: a preliminary investigation

This study investigated whether visual cerebral asymmetries would change in phase with hormonal variations during the menstrual cycle. Lexical decision and line orientation tasks were administered during follicular, luteal, and menstrual phases of each woman's cycle. These tasks were also administered to a reference group of male subjects. Signal detection analyses indicated an unvarying RVF advantage in word/nonword discriminability (d') throughout the menstrual cycle, but a phase-dependent shift in left hemisphere response criterion (log beta). Gender differences were present for discriminability of line orientation, and female performance on this task varied over the cycle. The results imply that the neural systems subserving some cognitive functions are sensitive to fluctuations in gonadal steroids and suggest a hormonal basis for gender differences in some visual-spatial functions.

Atrial natriuretic peptide plasma levels during hemodialysis and hemofiltration in patients with end-stage renal disease

Using a cross-over protocol we repeatedly measured the plasma levels of alpha-hANP (atrial natriuretic peptide) during one week by radio-immunoassay in eight patients with end-stage renal disease treated with chronic hemodialysis or hemofiltration. Before each hemodialysis or hemofiltration session mean plasma ANP levels (353 +/- 112, and 337 +/- 99 pg.ml-1, respectively) were significantly above normal (50 - 166 pg.ml-1). In all but one patient, the values fell significantly towards but not reaching the normal range. Plasma ANP concentrations returned to normal at the end of the treatment in only two of the eight subjects. There was a positive correlation between the increase in body weight from one treatment to the next and the plasma ANP concentration (r = +0.35, p less than 0.05). The net loss of fluid volume during each treatment did not correlate significantly with the change in plasma ANP levels. There was no difference between hemodialysis and hemofiltration. Plasma ANP measurement may be helpful in the judgement of volume status in patients with end-stage renal disease treated by hemodialysis or hemofiltration.

[Clinical significance of beta 2 microglobulin determination in dialysis patients]

In radioimmunological estimation of beta 2-microglobulin significant higher serum values were found in 36 dialysis patients (44.4 +/- 20.3 mg/l) in comparison with healthy probands (1.5 +/- 0.2 mg/l). A significant relation to the duration of dialysis, rest diuresis and serum level of aluminium was found. Significant higher concentrations were observed in patients suffering from pain in the shoulder-limb-region and with ostealgia in other regions, but not in radiological verified destructive arthropathy and spondylarthropathy. The used dialyzers MLW 1.3/1.8 m2 did not eliminate the beta 2-microglobulin from the blood.

Acute renal failure due to uric acid nephropathy in a patient with renal hypouricemia

This report is about a 23-year-old man who required hemodialysis in connection with an acute renal failure resulting from uric acid nephropathy without hyperuricemia. After recovering renal function he showed extreme hypouricemia (0.1-0.3 mg/dl) and elevated uric acid clearance (100-300 ml/min). The fractional excretion of uric acid (Cua/Ccr) could be suppressed by oral pyrazinamide and enhanced by probenecid. As no other renal tubular or metabolic abnormalities were detected, it is suggested that a markedly increased renal tubular urate secretion was responsible for the hypouricemia and also for the rare side-effect of an uric acid nephropathy in this patient.

Dietary treatment as seen by German nephrologists. Results of a questionnaire

The majority of German nephrologists consider a protein restriction for patients with advanced renal failure as necessary. However, there was no consensus with regard to the diet, which should be finally applied. It was of further interest that the majority of physicians believe that only 50% of their patients adhere consistently to the diet.

The beneficial effect of ketoacids on serum phosphate and parathyroid hormone in patients with chronic uremia

Hyperphosphatemia and secondary hyperparathyroidism are regular complications in patients suffering from advanced renal failure. As aluminum-containing drugs carry the well-known risk of aluminum intoxication, we were interested in testing in a prospective study a mixture of ketoanalogues and amino acids which have been shown to lower the serum phosphate and parathyroid hormone in uremic patients. For 3 months, in addition to their diet, 17 uremic patients and 12 hemodialysis patients received a daily supplement of this mixture. Although no additional phosphate binders were administered, serum phosphate decreased significantly in the former group and was slightly lower in the latter. The serum parathyroid hormone level was consistently lowered when the initial concentration was not higher than 20 times normal.

Easy production of sterile, pyrogen-free dialysate

Hemodialysis (HD) hypotension is frequently encountered during conventional acetate HD. Recently it has been suggested that monocytes that adhere to the dialysis membrane are also stimulated by endotoxins diffusing from the dialysate side. Stimulated monocytes, however, release interleukin-1, which mediates fever and hypotension through its action on the cyclo-oxygenase cascade. To prevent this endotoxin-induced stimulation of monocytes, a hemofilter with a polyamide membrane (FH 88, Gambro, Lund, Sweden, cut-off 20,000 daltons, surface area 2.0 m2) was interposed between the dialysate outlet of the HD machine and the dialyzer. The data obtained clearly show that the filtered dialysate was always pyrogen-free when tested with a limulus-amebocyte-lysate assay. In addition, in 80% of cases no bacteria were detected after the sterilizing filter. Almost no febrile episodes were observed when sterile dialysate was used.

Different handling of beta 2-microglobulin during hemodialysis and hemofiltration

Very recently it was reported that the amyloid associated with chronic hemodialysis contains, as a major component, a new form of amyloid fibril protein which is homologous to beta 2-microglobulin. As beta 2-microglobulin has a molecular weight of 11,600 daltons, investigations were carried out to see whether or not this protein would be handled differently by hemodialysis and hemofiltration, because the latter method especially is capable of eliminating solutes with such a high molecular weight. The results clearly indicate that hemofiltration removes substantial amounts of beta 2-microglobulin (about 190 mg per treatment, which represents 80% of daily production). It remains to be clarified whether or not hemofiltration is therefore superior to hemodialysis with regard to amyloid deposit formation.

Treatment of uremic hyperphosphatemia--is there still a need for aluminum salts?

Aluminum-containing phosphate binders have been widely employed in the past in the management of uremic hyperphosphatemia. However, an increasing number of reports on aluminum toxicity has stimulated efforts to replace this therapy by safer methods. The aim of the present review is to critically evaluate other treatment strategies. It appears that aluminum-containing phosphate binders should no longer be considered the treatment of choice for controlling uremic hyperphosphatemia. Calcium carbonate, calcium citrate, magnesium carbonate and a mixture of ketoanalogues and amino acids present important therapeutical alternatives which could replace aluminum-containing phosphate binders in the majority of patients. However, it is mandatory, as these therapies also carry some risks, that side effects are detected early.

Glomerular filtration rate in response to an acute protein load

The effect of a protein load on the glomerular filtration rate (measured as creatinine clearance) was studied in normal subjects, healthy vegetarians, patients with advanced liver disease, patients with moderate renal failure and in normal volunteers being pretreated with aspirin or sulindac. Only patients with liver disease were not capable of increasing their glomerular filtration rate after the protein challenge, a finding which suggests that the liver might be of importance for the adequate renal reserve. It is of note that neither the application of nonsteroidal anti-inflammatory drugs nor the existence of a moderate renal failure modify the response to a protein load.

Good biocompatibility of the polyamide hemofilter

Chronic hemofiltration (HF) is now a well-established method, especially for elderly uremic patients and those suffering from cardiovascular problems. This is due to the fact that chronic HF offers superior treatment comfort with less hypotensive episodes, vomiting, muscle cramps and febrile reactions. Apart from the different blood purification techniques involved in chronic HF compared to hemodialysis (i.e. convection versus diffusion), it might well be that the better treatment comfort is attributable to a certain extent to the polyamide HF membrane used in our HF treatments. We studied different biocompatibility parameters and received the following data: (a) leukocytes and thrombocytes remained unchanged during a treatment session; (b) elastase increased slightly but there was no difference between the polyamide and polycarbonate membrane, and (c) arterial and venous concentrations of C5a and C3d remained almost unchanged. The superior treatment comfort and better vascular stability of HF over hemodialysis might also be due to the improved biocompatibility of the applied hemofilter as the polyamide membrane induces no changes in different biocompatibility parameters such as leukocytes, thrombocytes, C5a or C3d.

[Balloon dilatation in unstable angina pectoris and acute myocardial infarct]

Early results after percutaneous transluminal coronary angioplasty (PTCA) in patients with unstable angina or acute myocardial infarction were compared with those in patients with stable angina. The primary success rate in 115 patients with unstable angina was 72%, in 73 with acute myocardial infarction 78%, and in 213 with stable angina 79%, i.e. there was no difference between the three groups. In patients with acute myocardial infarction and primary successful PTCA control angiography was performed one month after PTCA, in patients with unstable and stable angina 6 months after PTCA. Angiographic findings were identical in the three groups. But the results after successful balloon dilatation were dependent on the extent of primary success: in all three groups, patients in whom the post-dilatation control angiography revealed recurrence of stenosis the primary results were worse than in those without. There was no difference between those patients with lasting success and those with recurrence as regards cholesterol level, arterial hypertension, diabetes, and smoking habits. It is concluded that in every patient with acute symptoms of coronary heart disease the indication for PTCA should be considered.

Iron overload, but not treatment with desferrioxamine favours the development of septicemia in patients on maintenance hemodialysis

During a 19-month period we determined the incidence of bacterial infection among 39 patients treated with desferrioxamine who had end-stage renal disease and were undergoing maintenance hemodialysis. Twenty-three received desferrioxamine because of aluminum-related bone disease, and 16 because of iron overload. A control group of 193 patients on maintenance hemodialysis but without desferrioxamine was used. No difference was found in the incidence of septicemia or of all bacterial infections between the patients with aluminum-related bone disease treated with desferrioxamine and the control patients (0.12 vs. 0.12 septicemia per patient-therapy-year, p greater than 0.05; 0.23 vs. 0.26 bacterial infections per patient-therapy-year, p greater than 0.05). The incidence of septicemia in patients treated with desferrioxamine for iron overload, however, was almost three times that in the control patients (0.36 vs. 0.12 septicemia per patient-therapy-year, p less than 0.01). To assess the effect of iron overload itself, we determined the frequency of bacterial infection in patients on regular hemodialysis who have never received desferrioxamine. These were subdivided into three groups according to serum ferritin level which indicated normal or low iron stores (Group I: serum ferritin 10-330 micrograms/l, n = 125), moderate (Group II: serum ferritin 331-1000 micrograms/l, n = 49) or more advanced iron overload (Group III: serum ferritin 1001-2000 micrograms/l, n = 10). Compared to patients with normal or low serum ferritin levels (Group I), we found a significantly higher rate of bacterial infection among patients in Group II compared with Group I (0.18 vs. 0.34 infections per patient-therapy-year, p less than 0.05) and Group III compared with Group I (0.18 vs. 0.58 infections per patient-therapy-year, p less than 0.01). These results suggest that treatment with desferrioxamine does not favour the development of septicemia or bacterial infection independently of iron overload and that iron overload itself may predispose patients on regular hemodialysis to bacterial infection.

Unintentional Weight Loss in Chronic Hemodialysis Patients - A Diagnostic Dilemma

Reasons for an unintentional weight loss were investigated in a retrospective study of 26 (13.5%) patients who, out of 192 patients, had revealed a continuous linear weight loss of more than 4 kg since commencing hemodialysis treatment. The investigated serum parameters were not indicative, nor were the regularly performed tuberculin tests and the computer tomography helpful for the diagnosis. However, from the analysis of the causes for hospital admission it appears that hemodialysis patients with wasting suffer especially frequently from a sepsis. Physicians should be aware of this complication which induces further body weight loss.

Unintentional weight loss in chronic hemodialysis patients--a diagnostic dilemma

Reasons for an unintentional weight loss were investigated in a retrospective study of 26 (13.5%) patients who, out of 192 patients, had revealed a continuous linear weight loss of more than 4 kg since commencing hemodialysis treatment. The investigated serum parameters were not indicative, nor were the regularly performed tuberculin tests and the computer tomography helpful for the diagnosis. However, from the analysis of the causes for hospital admission it appears that hemodialysis patients with wasting suffer especially frequently from a sepsis. Physicians should be aware of this complication which induces further body weight loss.