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Biomedical subjects

A Blumberg

Publications and source records attributed to A Blumberg.

At least 37 records · Page 2Linked to original sources
PubMed1990

[The treatment of anemia of hemodialysis patients using recombinant human erythropoietin: comparison between intravenous and subcutaneous administration].

Recombinant human erythropoietin (r-huEPO) is now an established therapy for anemia of hemodialysis patients. However, questions remain concerning the optimal maintenance dose as well as the route and frequency of administration. This prospective study was designed to determine whether subcutaneous r-huEPO at a reduced dosage was as effective as intravenous r-huEPO in maintaining constant hemoglobin levels. It involved 12 patients on hemodialysis, previously treated with intravenous r-huEPO for 11.8 +/- 7 months (mean +/- SD). For 3 months hemoglobin was kept at a stable level of 10-13 g/dl with individually titrated intravenous r-huEPO administered thrice weekly after each hemodialysis. Patients were then switched to subcutaneous r-huEPO. Initially, approximately 50% of the previous weekly dose was given as twice weekly subcutaneous injections. During the following 3 months the r-huEPO dosage was adapted to maintain the target hemoglobin level. 3 patients did not complete the second period due to acute intercurrent complications not related to therapy. 9/12 patients completed the study. The hemoglobin concentration was kept at a constant level of (mean +/- SD) 10.5 +/- 1.1, 10.6 +/- 0.9 and 11.1 +/- 0.6 g/dl with 233 +/- 110, 246 +/- 118 and 233 +/- 116 U/kg/week of intravenous r-huEPO for the first 3 months. In the second period hemoglobin was kept at 11.5 +/- 1.2, 11.3 +/- 1.4 and 11.1 +/- 0.9 g/dl with 119 +/- 61, 118 +/- 60 and 137 +/- 78 U/kg/week of subcutaneous r-huEPO. 2 patients required an increase in the r-huEPO dose during the third month of the second period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Treatment of anemia in hemodialysis patients using recombinant human erythropoietin: advantages and disadvantages].

18 anemic patients undergoing maintenance hemodialysis were treated with recombinant human erythropoietin (EPO) 1-3 times per week for 10.7 +/- 3 months. 4 patients underwent renal transplantation whereas 14 patients could be followed up during 12 months of EPO treatment. Hemoglobin concentration rose (from 7.0 +/- 0.7 to 11.0 +/- 1.1 g/dl, p less than 0.001) with an EPO maintenance dose of 298 units/kg/week. Blood transfusions were totally eliminated. 12 patients without iron overload required iron supplements. In the course of an infectious episode and notwithstanding an increase in EPO dosage, 2 patients exhibited a fall in hemoglobin which rose again after successful treatment of the infection. The few complications observed in connection with the rise in hemoglobin were: 1. deterioration of arterial hypertension in 7/18 with hypertensive encephalopathy in 3 patients, 2. thrombotic occlusion of the vascular hemodialysis access (a-v fistula) in 3/18, 3. periarticular inflammation with calcified deposits due to an elevated calcium-phosphorus product of 6.8 mmol/l in 4/18, 4. occurrence of hyperkalemia (6.9 +/- 0.3 mmol/l) in 7/18. These complications were more frequent during the first 3 months. They were corrected with close monitoring, drug therapy for hypertension, and intensification of dialysis and of treatment with phosphate binding substances, with the result that no differences were found in 14 patients before and after 12 months of treatment with EPO (blood pressure 133 +/- 25/77 +/- 9 vs 139 +/- 26/79 +/- 13 mm Hg [ns], potassium 5.4 +/- 0.4 vs 5.6 +/- 1.0 mmol/l [ns] and calcium-phosphorus product 4.3 +/- 1.0 vs 4.6 +/- 1.3 [ns]).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Pathogenesis of anemia due to kidney disease].

Several factors contribute to the pathogenesis of anemia due to renal failure. Hypoproliferation of red cell progenitors may be caused partially by an inhibitory effect of some 'uremic toxins' whose existence certainly is very controversial. Iron deficiency due to gastrointestinal and dialysis-related blood losses and occasionally aluminum intoxication may interfere with the maturation of the erythron. Moderate hemolysis with shortening of red cell survival to some 50% of normal may be an additional factor. The main cause of anemia is, however, inadequate production of erythropoietin by the diseased kidney. This latter factor has now become amenable to treatment.

Anemia↗
PubMed1989

Human recombinant erythropoietin treatment in transfusion dependent anemic patients on maintenance hemodialysis.

Six anemic hemodialysis patients dependent on regular blood transfusions and with massive iron overload were treated with recombinant human erythropoietin (r-huEPO). The effect on absolute reticulocyte count, hemoglobin and serum ferritin was studied during a twenty-week period. Red-cell volume and red-cell life span were measured with 51Cr-tagged erythrocytes at baseline and after twenty weeks of r-huEPO. Absolute reticulocyte counts and hemoglobin concentration rose markedly (from 55.6 +/- 31.2 to a maximum of 174.9 +/- 31.0 x 10(9)/l at 4 weeks and from 6.8 +/- 0.3 to a maximum of 11.2 +/- 1.3 g/dl at 12 weeks, respectively, p less than 0.001) without any further need for transfusions. Red-cell volumes increased concomitantly (from 58 +/- 4 to 81 +/- 11% of normal, p less than 0.005), in spite of a persistent shortening of red-cell life span (45 +/- 18 and 47 +/- 4 days before and after r-huEPO). Markedly elevated serum ferritin concentrations indicating iron overload decreased slowly from 3,550 +/- 1,615 to 2,721 +/- 1,506 micrograms/l (p less than 0.05). It is concluded that r-huEPO is very effective in treating the anemia of patients maintained on hemodialysis. The favorable effects on hemoglobin and red-cell volumes occur in spite of persistent hemolysis and lead to a slow reduction of iron overload.

Adult↗
PubMed1988

[Cerebrovascular incidents in 4 hemodialysis patients treated with erythropoietin].

Human recombinant erythropoietin (r-huEPO) is very effective in the treatment of anemia of hemodialyzed patients. We describe 4 patients who developed symptoms of central nervous dysfunction during r-huEPO therapy. Three exhibited typical hypertensive encephalopathy, whereas signs of cerebral ischemia were found in the fourth. The increase in blood viscosity with r-huEPO treatment, leading to a rise in peripheral vascular resistance and blood pressure especially in previously hypertensive patients, may be of importance in the pathogenesis of these cerebrovascular incidents; preexistent arteriosclerosis is an possible additional risk factor.

Adult↗
PubMed1988

Lethal osteogenesis imperfecta: abnormal collagen metabolism and biochemical characteristics of hypophosphatasia.

We have examined collagen from a patient with the rare type IIC form of perinatally lethal osteogenesis imperfecta, in whom biochemical characteristics of hypophosphatasia were also apparent. In addition to normal alpha 1(I) and alpha 2(I) chains, there were chains overmodified along their lengths. Unexpectedly, the thermal stability of molecules containing these chains was normal. This suggests the existence of a structural mutation causing delayed triple helix formation, situated in either the alpha 1(I) or alpha 2(I) C-terminal propeptide. Since collagen synthesised by fibroblasts from each of the patient's parents was normal, the mutation was probably newly arising and dominant. In contrast to other reported cases of lethal osteogenesis imperfecta, not only was the secretion of collagen by cultured fibroblasts considerably retarded, but that of non-collagenous proteins was also severely impaired.

Alkaline Phosphatase↗
PubMed1988

Long-term treatment of central precocious puberty with an intranasal LHRH analogue: control of pituitary function by urinary gonadotropins.

Daily subcutaneous doses of luteinizing hormone-releasing hormone (LHRH) analogues are a well-established therapy for gonadotropin-dependent precocious puberty. Reports on intranasally administered analogues, however, are controversial. We studied the effect of intranasal D-Ser(TBU)6-LHRH(BUS) on growth rate, skeletal maturation, and urinary gonadotropins in five girls and one boy with central precocious puberty (CPP) who had been treated for 1.4-2.3 years (mean 1.9). Because of the potential antifertility effects of LHRH analogues, testicular histology was analysed in the boy. In the five children with accelerated growth, the bone age-related velocity of height gain decreased from 10.58 +/- 2.77 to 5.82 +/- 1.8 cm/year (means +/- SD, P less than 0.01), and the ratio of change in bone age to change in chronological age fell below 1. Basal luteinizing hormone (LH), and LHRH-stimulated LH and follicle stimulating-hormone, at pubertal levels before treatment, decreased significantly in all children, normalizing in four (P less than 0.04). During therapy, pituitary function was best controlled by urinary LH, which correlated with clinical data. After 13 months of therapy, testicular histology showed degenerated Sertoli cells, and absence of B- and Ap-spermatogonia and of primary spermatocytes in the boy. We conclude that: (1) Efficient long-term suppression of central precocious puberty--including accelerated growth and skeletal maturation--can be maintained by intranasal dosage of BUS. (2) Urinary LH reflects pituitary function and proves to be a reliable guide to adjustment of the LHRH-analogue dose regimen.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Intranasal↗
PubMed1988

Effect of various therapeutic approaches on plasma potassium and major regulating factors in terminal renal failure.

PURPOSE: The development of life-threatening hyperkalemia poses a risk for patients with chronic preterminal renal failure. Various therapeutic options have been suggested for hyperkalemic emergencies in these patients; to date, however, no study has evaluated the relative efficacies of these measures in the presence of renal failure. Our goal was to examine the acute effects of a variety of therapeutic approaches, as well as those of hemodialysis, on plasma potassium levels in a hemodialysis population. PATIENTS AND METHODS: Ten patients with terminal renal failure undergoing maintenance hemodialysis were enrolled in the study. Blood gas parameters and plasma sodium, potassium, glucose, osmolality, renin, aldosterone, epinephrine, norepinephrine, dopamine, and insulin were measured before, during, and after 60-minute infusions of bicarbonate, epinephrine, and insulin in glucose, and before, during, and after performance of regular hemodialysis for one hour. RESULTS: Hypertonic as well as isotonic intravenous bicarbonate (2 to 4 mmol/minute) induced a marked rise in plasma bicarbonate and pH, but failed to lower the plasma potassium level (5.66 versus 5.83 mmol/liter before and after). Epinephrine, 0.05 microgram/kg/minute administered intravenously, decreased plasma potassium only slightly from 5.57 to 5.25 mmol/liter, and five patients showed no decline. On the other hand, insulin in glucose, 5 mU/kg/minute intravenously, effectively lowered plasma potassium levels from 5.62 to 4.70 mmol/liter, and hemodialysis induced the most rapid decline from 5.63 to 4.29 mmol/liter. Plasma aldosterone was elevated before treatment; it correlated with plasma potassium and dropped during intravenous bicarbonate administration or hemodialysis. Pretreatment plasma renin activity, insulin, epinephrine, norepinephrine, and dopamine levels were generally normal. CONCLUSION: We conclude that in patients with terminal renal failure undergoing maintenance hemodialysis, intravenous bicarbonate is ineffective in lowering plasma potassium rapidly, and epinephrine is effective in only half the patients, whereas insulin in glucose is a fast and reliable form of therapy for hyperkalemic emergencies. Plasma aldosterone levels are appropriate in relationship to plasma potassium levels, and levels of other potassium-influencing hormones are generally normal.

Adult↗
PubMed1988

Human recombinant erythropoietin in anaemic patients on maintenance haemodialysis. Secondary effects of the increase of haemoglobin.

Twelve anaemic patients on haemodialysis were treated with recombinant human erythropoietin, starting with 72 IU/kg/week. The dose was doubled after 2 weeks until an increase of 2 g/dl of haemoglobin was observed. The effects on various parameters were studied during a 3-month period. Haemoglobin increased from 6.70 +/- 0.74 to 10.49 +/- 1.04 g/dl (mean +/- SD, P less than 0.001), potassium from 5.51 +/- 0.50 to 6.06 +/- 0.65 mmol/l (P less than 0.005), phosphate from 1.78 +/- 0.40 to 2.17 +/- 0.40 mmol/l (P less than 0.001) and the calcium phosphorus product from 4.3 to 5.2 (P less than 0.001). Three patients developed marked periarticular inflammation due to calcified deposits with a high calcium-phosphorus product of 6.8. An increase in arterial blood pressure was observed in three previously well-controlled hypertensive patients, one of whom developed hypertensive encephalopathy. We conclude that recombinant human erythropoietin is very effective in treating the anaemia of end-stage renal failure on haemodialysis. Regular estimations of serum potassium and phosphate are mandatory. In hypertensive individuals a further increase in blood pressure is possible.

Adult↗
PubMed1988

Effectiveness of single versus double volume exchange transfusion in newborn infants with AB0 hemolytic disease.

The effectiveness of early single volume exchange transfusion (ET; 80 ml/kg) was compared with that of early double volume exchange transfusion (160 ml/kg) for treatment of hemolytic disease of the newborn caused by AB0 incompatibility. Twenty full-term infants with AB0 hemolytic disease were randomized into the two treatment groups. The groups were comparable for gestational age, body weight, hemoglobin values, reticulocyte count, maximum serum bilirubin levels, rate of rise of serum bilirubin before ET, antibody titer, and age at time of ET (all p greater than 0.05). The efficacy of treatment was similar in both groups taking into account the mean bilirubin level after ET, post-ET bilirubin, duration of phototherapy following ET, and frequency of second ET (all p greater than 0.05). However, platelet count immediately after ET was lower in the double volume ET group as compared to the single volume ET group (p less than 0.01). Hemoglobin values immediately after ET were higher in the double volume ET group (p less than 0.01). At ten days of life no differences were detectable. The results of this study indicate that the effectiveness of single volume ET for treatment of full-term infants with jaundice due to AB0 incompatibility is at least comparable to that of double exchange ET. Furthermore, the lesser aggressive approach determines less complications such as a decrease of platelet count.

Bilirubin↗
PubMed1987

[Mitral annular calcification in dialysis patients].

Degenerative mitral anular calcifications (MAC) are most often found between the posterior mitral anulus and the left ventricular posterior wall. In advanced stages they may encircle the mitral valve and thus involve the insertion of the anterior mitral leaflet and the posterior part of the aortic root. They are usually found only after the age of 70. Among 33 patients on chronic dialysis for renal failure who were investigated by echocardiography (2-D and m-mode) we found an MAC incidence of 55% but no cases among a control population of the same age and sex (p less than 0.001). The diameter of the calcification exceeded 5 mm in 9 cases out of 18. Four of these calcifications extended in a circular fashion around the mitral valve. Additional significantly associated echocardiographic features included dilatation of the left atrium and sclerosis of the aortic root and valve. Furthermore, 12 patients with MAC had dysfunction of the mitral valve (p less than 0.05), viz. 10 isolated mitral valve regurgitations and 2 mitral stenosis, combined with regurgitation. The patients with MAC were older than those without MAC, their mean duration of dialysis was longer and parathormone level higher. The incidence of mitral anular calcifications is much higher among patients on chronic dialysis. The clinical significance of these calcifications lies primarily in the consequent dysfunction of the mitral valve.

Adult↗
PubMed1987

[Diagnosis of glomerular and non-glomerular erythrocyturia using phase contrast microscopy of the urine sediment].

Recently the appearance of deformed polymorphous erythrocytes in the urinary sediment has been described as characteristic of glomerular bleeding. We studied 30 patients with histologically confirmed glomerular disorders and 25 patients with urological diseases and with hematuria. In the sediment of 10 ml urine 200 erythrocytes were counted under phase-contrast microscopy and evaluated relative to their morphology. The number of glomerular erythrocytes was expressed as a percentage. In all groups of glomerular disorders (mesangial-proliferative, membranous and membrano-proliferative glomerulonephritis, focal segmental glomerulosclerosis, glomerulonephritis of systemic disease, thinning of the glomerular basement membrane) the percentage of glomerular erythrocytes varied widely between 2 and 100%. In 7 cases less than 10% of glomerular erythrocytes were found. There was no correlation between the percentage of glomerular erythrocytes and the degree of renal insufficiency, hematuria or proteinuria. On the other hand, in patients with hematuria from the lower urinary tract, erythrocytes were uniformly non-glomerular in shape (95-100%). We conclude that 10-20% or more of glomerular erythrocytes in the urinary sediment are a good indicator of glomerular disease, whereas lower figures do not definitely rule out a glomerular origin for hematuria.

Erythrocytes↗
PubMed1987

[Glomerulonephritis in chronic bacterial infections].

Five patients with chronic bacterial infections (two with osteomyelitis, two with infected vascular prostheses, one with soft tissue abscess), but without endocarditis, developed signs of glomerulonephritis and renal failure. Histological examination in three revealed mainly proliferative glomerular alterations. The outcome of glomerulonephritis paralleled the course of infection. Recovery or marked improvement occurred in three patients in whom the infection was cured, one case with smoldering infection eventually developed endstage renal failure, and one with persistent infection died from severe complications with acute renal failure. If renal failure occurs in the setting of suppurative infection, so-called infection-associated glomerulonephritis must be considered. Prompt and effective eradication of infection has an important bearing on the course of renal function.

Abscess↗