Epoetin alfa plus autologous blood donation in patients with a low hematocrit scheduled to undergo orthopedic surgery.

A low predonation hematocrit (Hct) can preclude the collection of sufficient autologous blood (AB) to meet the transfusion requirements of patients scheduled for orthopedic surgery. Subcutaneous (s.c.) administration of epoetin alfa, in conjunction with intravenous (i.v.) iron supplementation, has proved effective for the facilitation of AB donation by such patients. Compared with untreated controls and patients treated with i.v. iron alone, epoetin alfa 50 to 150 IU/kg SC plus i.v. iron twice weekly for 3 weeks prior to surgery significantly increased total red blood cell (RBC) production (P < .01) and the volume of RBCs donated (P < .05). Epoetin alfa was particularly effective in females and patients with a predicted blood volume (PBV) less than 5 L. Treatment with epoetin alfa led to an increase (albeit nonsignificant) in the number of AB units predonated compared with i.v. iron alone. However, in patients with a PBV less than 5 L, a substantially greater percentage of epoetin alfa-treated patients donated > or = 4 AB units (80% v 30%). Allogeneic blood requirements were reduced, albeit not significantly (P = .051), in patients treated with epoetin alfa. However, in comparison with untreated controls, there was a significant reduction in the mean volume of allogeneic blood transfused per transfused patient in the epoetin alfa groups. The optimum s.c. dose of epoetin alfa in patients with a low predonation Hct scheduled for orthopedic surgery appears to be between 100 and 150 IU/kg twice weekly for 3 weeks.

Epoetin alfa plus autologous blood donation and normovolemic hemodilution in patients scheduled for orthopedic or vascular surgery.

In previous studies, treatment with epoetin alfa facilitated preoperative donation of autologous blood (AB). However, some patients may not be able to donate sufficient AB to meet their surgical blood requirements when the time to surgery is short. In this multicenter, double-blind, placebo-controlled study, the ability of epoetin alfa combined with normovolemic hemodilution (NVHD) to facilitate the collection of > or = 4 AB units within 2 weeks of surgery was investigated in 112 nonanemic patients scheduled for elective orthopedic or vascular surgery. All patients received oral iron supplementation and were treated with three intravenous (i.v.) injections of epoetin alfa (300 or 600 IU/kg) on days 1,4, and 7; surgery, in combination with NVHD, was performed on day 13. A total of 4 units of AB were predeposited if the patient's hemoglobin (Hb) level exceeded 11 g/dL at each donation. Compared with placebo, epoetin alfa dose-dependently increased reticulocyte counts prior to surgery and significantly minimized the decrease in hematocrit (Hct) associated with AB donation, although there were no significant differences between dosages. While significantly more patients treated with epoetin alfa were able to donate > or = 4 AB units compared with placebo, there was no difference between the groups in exposure to allogeneic blood. This effect of epoetin alfa was particularly apparent in female patients. I.v. epoetin alfa 300 IU/kg, administered three times within 1 week, appears to be the optimum dose for facilitating the collection of > or = 4 units of AB in nonanemic patients scheduled for elective surgery and NVHD within 2 weeks.

Effectiveness of perioperative epoetin alfa in patients scheduled for elective hip surgery.

Several strategies have been investigated as a means of reducing allogeneic blood requirements in patients undergoing surgery, including the perioperative administration of epoetin alfa. In a multicenter, double-blind, placebo-controlled study in 208 patients undergoing elective hip replacement surgery, subcutaneous administration of epoetin alfa (300 IU/kg daily) for 14 or 9 days perioperatively (commencing 10 and 5 days preoperatively, respectively) significantly reduced the incidence of primary outcome events (any allogeneic blood transfusion or a postoperative hemoglobin [Hb] level < 8.0 g/dL) compared with placebo (P = .003). Furthermore, the transfusion requirements of epoetin alfa-treated patients were significantly lower than those of patients treated with placebo (P = .007). Preoperative and postoperative Hb levels and reticulocyte counts were higher in epoetin alfa-treated patients compared with placebo. Epoetin alfa was well tolerated, and the incidence of deep vein thrombosis (DVT) was not different from that observed in placebo recipients. Thus, perioperative administration of epoetin alfa reduces the allogeneic blood requirements of patients undergoing elective hip replacement surgery and is of particular benefit in the subgroup of patients whose baseline Hb levels are less than 13.5 g/dL.

Pharmacokinetics and pharmacodynamics of recombinant human erythropoietin after single and multiple subcutaneous doses to healthy subjects.

OBJECTIVES: To understand the pharmacokinetic and pharmacodynamic properties of recombinant human erythropoietin (epoetin alfa) and to continue to optimize dosing regimens by determining whether administration of single high doses of epoetin alfa is as effective as repeated administration. METHODS: Epoetin alfa was administered as single subcutaneous doses of 300, 450, 600, 900, 1200, 1350, 1800, and 2400 IU/kg and in multiple subcutaneous dose regimens: 150 IU/kg 3 times a week for 4 weeks and 600 IU/kg once per week for 4 weeks in 2 open-label, randomized placebo-controlled studies in healthy volunteers. RESULTS: The absorption rate of epoetin alfa after subcutaneous administration was independent of dose, whereas clearance was dose-dependent in that it decreased with increasing dose. There was a linear relationship between response measured as percentage of reticulocytes area under the curve (AUC) and erythropoietin AUC for single doses up to 1800 IU/kg. Beyond the 1800 IU/kg dose, there was a saturation of response. The mean percentage of reticulocytes after single-dose regimens began to increase by days 3 to 4, reached their maximum at days 8 to 11, and returned to baseline values by day 22. In contrast, the mean percentage of reticulocytes after both multiple-dose regimens were maintained above baseline values through day 22 as both regimens stimulated modest but sustained increases in percentage of reticulocytes (1% to 2%). The mean percentage of reticulocytes AUC for 600 IU/kg epoetin alfa given once a week for 4 weeks was apparently greater than the mean percentage of reticulocytes AUC for 150 IU/kg 3 times a week for 4 weeks. Although daily oral iron supplementation was given, mean serum ferritin levels declined by approximately 75% through day 22 in subjects treated with multiple doses of epoetin alfa. CONCLUSIONS: These findings show that the pharmacologic response to epoetin alfa is a function of dose and dosing regimen. Repeated administration of epoetin alfa was more effective in stimulating a reticulocyte response than single-dose administration of the same total amount of epoetin alfa.

Recombinant human erythropoietin stimulates erythropoiesis and reduces erythrocyte transfusions in very low birth weight preterm infants.

DESIGN AND METHODS: We hypothesized that treatment with recombinant human erythropoietin (r-HuEPO) would stimulate erythropoiesis and would thereby reduce the need for erythrocyte transfusions in preterm infants. We treated 157 preterm infants born at 26.9 +/- 1.6 weeks of gestation who weighed 924 +/- 183 g at birth with either subcutaneous r-HuEPO (100 U/kg/d, 5 days per week) or placebo for 6 weeks in a randomized, double-blind, controlled clinical trial. All patients received oral iron and were managed according to uniform conservative transfusion guidelines. RESULTS: Treatment with r-HuEPO was associated with fewer erythrocyte transfusions (1.1 +/- 1.5 per infant in the r-HuEPO group versus 1.6 +/- 1.7 per infant in the placebo group; P = .046) and with a reduction in the volume of packed erythrocytes transfused (16.5 +/- 23.0 mL versus 23.9 +/- 25.7 mL per infant; P = .023). Overall, 43% of the infants in the r-HuEPO group and 31% of placebo-treated infants were transfusion-free during the study (P = .18). The volume of blood removed for laboratory tests and the need for respiratory support at the start of treatment had major effects on transfusion requirements independent of r-HuEPO. Reticulocyte counts were higher during treatment in the r-HuEPO group (P = .0001), and r-HuEPO-treated infants had higher hematocrit values at the end of the study (32% versus 27.3% in the placebo group; P = .0001). We found no differences in the incidence of major complications of prematurity between the treatment groups. CONCLUSION: We conclude that treatment with r-HuEPO at a weekly dose of 500 U/kg stimulates erythropoiesis, moderates the course of anemia, is associated with a reduction in erythrocyte transfusions, and appears safe in very low birth weight preterm infants who are receiving iron supplements. Conservative transfusion criteria, minimization of phlebotomy losses, and treatment with r-HuEPO are complementary strategies to reduce erythrocyte transfusions in these infants.

Combination therapy with G-CSF and erythropoietin after autologous bone marrow transplantation for lymphoid malignancies: a randomized trial.

Previous studies have shown that, unlike in patients submitted to allogeneic BMT, administration of recombinant erythropoietin (Epo) after autologous BMT (ABMT) had no significant effect on erythroid recovery and transfusional requirements. On the other hand, it has also been shown that combining Epo with recombinant granulocyte colony-stimulating factor (G-CSF) in patients with the acquired immunodeficiency syndrome (AIDS) and with myelodysplastic syndromes resulted in additive effects on erythropoiesis. To test the effects of combined G-CSF + Epo therapy on erythroid recovery after autologous bone marrow transplantation a pilot randomized, three-arm trial was designed. Thirty patients suffering from lymphoid malignancies submitted to ABMT were randomly assigned to receive G-CSF alone (5 micrograms/kg, from day + 1 up to reaching an ANC > or = 10(9)/1), G-CSF + Epo (150 U/kg, from day +1 to +21), or neither of these (controls). Patients receiving G-CSF + Epo had significantly more reticulocytes on day +21 and reached 30 x 10(9)/1 reticulocytes earlier when compared to both G-CSF and control patients; however, the number of red blood cell (RBC) transfusions was not modified by the addition of Epo to G-CSF, although both groups had significantly fewer units transfused than controls. No effect on platelet recovery or platelet transfusional requirements was observed. Myeloid recovery was comparable in the G-CSF and G-CSF+Epo groups, and significantly accelerated as compared to controls. We conclude that the addition of Epo to G-CSF causes a slight acceleration of erythroid recovery after ABMT, but is not associated with transfusional benefits. Therefore, the present data do not support the use of Epo in association with G-CSF to hasten erythroid recovery after ABMT.

HPMA-based biodegradable hydrogels containing different forms of doxorubicin. Antitumor effects and biocompatibility.

Novel hydrogels based on N-(2-hydroxypropyl)methacrylamide (HPMA) and N,O-dimethacryloylhydroxylamine containing either doxorubicin (DOX) or water-soluble HPMA carrier-bound doxorubicin (P-GlyPheLeuGly-DOX; HPMA-DOX) were synthesized. The cross-linkages are susceptible to hydrolytic cleavage at physiological pH 7.4. Hydrogels in the form of rods or discs loaded with DOX or P-GlyLeuGly-DOX were implanted subcutaneously on the back of C57BL/10 mice on day 1 or on day 9 after inoculation with EL4 mouse T-cell lymphoma. The implanted hydrogels varied in the total load of DOX and rate of hydrolysis, which is dependent on the crosslinking density of the gels. The effect of HPMA based hydrogels containing DOX or HPMA carrier-bound DOX on tumor growth, animal life span, leukocyte populations in peripheral blood and bone marrow function evaluated by reticulocyte count was investigated. It was shown that: a) DOX and HPMA carrier-bound DOX administered in the form of HPMA-based hydrogels has better antitumor activity against experimental EL4 mouse T-cell lymphoma than soluble forms of the drug, b) hydrogels with shorter degradation rate (16-17 h) show better antitumor activity than hydrogels with longer duration time (48-52 h), c) the therapeutic effect of hydrogels with rate 16-17 h is directly related to the doxorubicin content; the higher the doxorubicin content, the better antitumor activity, d) the gel containing free doxorubicin showed significant antitumor activity even when implanted on day 9, i.e., in the time when tumor growth is already established, e) the hydrogel matrix without drug does not induce release of IL-1 or IL-6 into peripheral blood, does not induce formation of antibodies, and it is not mitogenic. Use of doxorubicin in the form of HPMA-based hydrogels allows a several-fold increase in the administered dose compared to soluble forms without detectable serious toxic side-effects.

Toxicity of dolastatin 10 in mice, rats and dogs and its clinical relevance.

PURPOSE: Dolastatin 10 (DOL 10), an oligopeptide isolated from the sea hare Dolabella auricularia, has been shown to be a highly potent cytotoxic agent in a variety of human tumor cell lines. The purpose of this study was to conduct preclinical toxicity evaluations to determine the target organ(s) of toxicity and its reversibility, the dose-limiting toxicity and the maximum tolerated dose (MTD), and to use this information for arriving at a safe starting dose and dose schedule for phase I clinical trails. METHODS: DOL10 was administered as a single intravenous bolus dose to CD2F1 mice, Fischer-344 rats and beagle dogs. Endpoints evaluated included clinical observations, body weights, hematology, serum clinical chemistry, and microscopic pathology of tissues. RESULTS: The MTD (i. e. the highest dose that did not cause lethality but produced substantial toxicity) was approximately 1350 microg/m(2) body surface area (450 microg/kg) in mice, 450 microg/m(2) (75 microg/kg) in rats and /=1350 microg/m(2) in mice, >/=150 microg/m(2) in rats and >/=400 microg/m(2) in dogs. Decreased weight gain or actual weight loss was observed at doses >/=1350 microg/m(2) in mice, >/=600 microg/m(2) in rats and >/=450 microg/m(2) in dogs. In all three species, the primary target organ of toxicity was the bone marrow, as indicated by decreases in the numbers of erythroid cells, myeloid cells, and megakaryocytes in the femoral bone marrow and by decreased white blood cell (WBC) and reticulocyte counts in peripheral blood. Marked neutropenia (i.e. >50% decrease compared to control animal or baseline values) was the principal effect on WBCs and occurred within a week of dosing. A mild anemia was evident 1 week after administering the drug to rats and dogs. The hematologic effects were transient and reversed by study termination. Other lesions at the MTD levels were cellular depletion and necrosis in lymphoid organs (rats and dogs), marked depletion of extramedullary hematopoietic cellular elements in the spleen (rats), thymic atrophy (mice and dogs), and minimal cellular necrosis in the ileum (rats). More extensive and severe pathology was observed in animals sacrificed in a moribund condition or found dead. CONCLUSIONS: Myelotoxicity was dose-limiting in all three species with mice being the least sensitive. In a phase I clinical trial, granulocytopenia was dose-limiting. Moreover, the MTD of DOL10 for rats and dogs is comparable to the human MTD. Therefore, the results from the preclinical toxicology studies correctly predicted a safe starting dose, the dose-limiting toxicity, and the MTD in humans.

Haematopoietic radioprotection by Cremophor EL: a polyethoxylated castor oil.

The polyethoxylated castor oil, Cremophor EL (Cremophor) is approved for human use as a vehicle for oral and intravenous administration of water-insoluble compounds. Cremophor has also previously been shown to reverse the multidrug resistance phenotype at clinically acceptable doses. This study demonstrates that doses of Cremophor in the range of 25-50 microliters/kg intravenously (i.v.) administered 1 day prior to near-lethal irradiation protected the regenerative capacity of the marrow, resulting in haematopoietic radioprotection and long-term survival of near-lethally-irradiated mice. In normal mice, Cremophor administration (1) markedly reduced the level of serum haematopoietic inhibitory activity 4-8 h following injection; (2) resulted in a transient decrease in femoral bone marrow cellularity and upregulated B220 (B cells), and 7/4 (neutrophils and activated macrophages), but not Thy-1 (T-cells) surface antigen expression in bone marrow cells within 24 h of injection; and (3) transiently elevated the incidence of both primitive and committed haematopoietic progenitor cells detected in clonal agar culture within 48 h of injection. Bone marrow progenitor cell content, and peripheral blood white cell, platelet and reticulocyte counts were unaffected. This suggests that the haematopoietic radioprotection and recovery observed in irradiated mice pretreated with Cremophor may be the result of accessory cell activation and/or modulation of accessory factors regulating haematopoietic progenitor cells. Our data suggest a potential clinical use of Cremophor as an adjunct to, or as a substitute for, cytokines to minimize myelosuppression following cytotoxic therapy.

The effects of recombinant human erythropoietin on perioperative transfusion requirements in patients having a major orthopaedic operation. The American Erythropoietin Study Group.

Two hundred patients who were scheduled for a major elective orthopaedic operation were enrolled in a prospective study and were randomly assigned to one of three treatment groups. Group 1 consisted of sixty patients who received recombinant human erythropoietin, 300 international units per kilogram of body weight per day; Group 2, seventy-one patients who received recombinant human erythropoietin, 100 international units per kilogram of body weight per day; and Group 3, sixty-nine patients who received a placebo. A total of fifteen doses was given subcutaneously, beginning ten days before the operation and extending through the fourth postoperative day. Patients who declined or were unable to donate autologous blood preoperatively were included in the study and were maintained on iron supplementation orally. The decision to transfuse red blood cells depended on the physician, however, physicians were encouraged not to do so if the hematocrit was more than 0.27 (27 per cent), unless the clinical symptoms warranted it. Of the 185 patients who were evaluable with regard to efficacy, significantly fewer patients received homologous red-blood-cell transfusions in Groups 1 and 2 (17 per cent [nine] and 25 per cent [sixteen], respectively) than in Group 3 (54 per cent [thirty-six]) (p < 0.001). When the patients were stratified into two groups on the basis of the pre-treatment hemoglobin level (more than 100 to 130 grams per liter or more than 130 grams per liter), we found that patients who had received a placebo and had a baseline hemoglobin level of more than 100 to 130 grams per liter were at significantly higher risk for transfusion (78 per cent [twenty-one]) than those who had received a placebo and had a baseline level of more than 130 grams per liter (36 per cent [fourteen]). For patients who had a baseline hemoglobin level of more than 100 to 130 grams per liter, the higher dose of recombinant human erythropoietin appeared somewhat more effective than the lower dose, with 14 per cent (three) of the patients in Group 1 and 39 per cent (nine) in Group 2 needing a transfusion; however, the difference was not significant (p = 0.09). For patients who had a baseline hemoglobin level of more than 130 grams per liter, the two doses of recombinant human erythropoietin produced similar results, with 14 per cent (four) of the patients in Group 1 and 11 per cent (four) in Group 2 needing a transfusion; this was in contrast to a rate of transfusion of 36 per cent (fourteen) in Group 3 (the patients who received the placebo) (p = 0.03). The recombinant human erythropoietin was generally well tolerated, although one patient, who did not have a history of hypertension, had an increase in blood pressure, from a baseline level of 142/78 millimeters of mercury (18.93/10.40 kilopascals) to a level of 220/100 millimeters of mercury (29.33/13.33 kilopascals), after ten days of treatment with the higher dose. These data suggest that recombinant human erythropoietin, administered before and after major orthopaedic operations, can minimize the need for homologous red-blood-cell transfusion.

Distribution characteristics of entrapped recombinant human erythropoietin in liposomes and its intestinal absorption in rats.

Recombinant human erythropoietin (Epo) is frequently administered by intravenous (i.v.) injection for the clinical treatment of renal anemia. Oral (per os; p.o.) administration is desired as an alternative route to i.v. administration, and liposomes have been chosen as a drug carrier. We found previously that after a p.o. administration to rats of Epo entrapped in liposomes before gel filtration, the Epo was absorbed, but variability in the number of days of appearance and in the levels of pharmacological effects, i.e. , the peak of circulating reticulocyte counts (RTC), was observed. The purpose of the present study was to examine the distribution characteristics of Epo in liposomes and intestinal absorption of liposomal Epo in rats by using purified Epo entrapped in liposomes after gel filtration (Epo/liposomes). The distribution characteristics of Epo/liposomes were determined by measuring the Epo in liposomes by a radioimmunoassay, high-performance liquid chromatography and zeta potential measurements. We observed that the protein part of Epo was mostly entrapped in liposomes, and was not adsorbed by the liposomal membrane at middle and high Epo p.o. doses, but the zeta potential of the Epo/liposomes increased negatively with the increase in the Epo p.o. doses. These results suggest that the sialic acid part of Epo entrapped in liposomes may project out from liposomes, depending on the entrapped Epo concentration. Little Epo was adsorbed or penetrated into liposomes when it was added to empty liposomes. After the p. o. administration of Epo/liposomes, the peak of RTC appeared at a 2-day delay on day 6, without variation and without dose dependency in comparison with that after i.v. administration. These results suggest that one of the reasons for the variability may be because the non-entrapped Epo and/or Epo/liposomes itself affected the intestinal absorption of Epo/liposomes. In conclusion, Epo/liposomes without nonentrapped Epo may be clinically useful for the oral administration of Epo.

Reticulocyte measurements as a bioassay for erythropoietin.

The possibility of using reticulocyte counts in peripheral blood to assay erythropoietic activity of recombinant human erythropoietin (r-HuEPO) was evaluated in normal mice. Mice were injected subcutaneously with r-HuEPO on days 0, 1 and 2 and bled on day 4 for reticulocyte count determinations, using an automated counting system with thiazole orange fluorescent staining and flow cytometric analysis. Reticulocyte counts increased in a dose-dependent fashion upon administration of r-HuEPO. The reticulocyte count was unaffected by asialylated EPO as well as other substances tested (interleukin-1, interleukin-3, dexamethasone, human chorionic gonadotropin). These data demonstrate the usefulness of employing reticulocyte counts as a rapid, specific and reproducible assay for in vivo erythropoietic activity of r-HuEPO.

Influence of erythropoietin treatment on hemoglobin A1c levels in patients with chronic renal failure on hemodialysis.

We studied the influence of erythropoietin (EPO) treatment on hemoglobin A1c (HbA1c) levels under conditions which eliminate the effect of changes in the blood glucose concentration. HbA1c levels, blood glucose, hematocrit (Hct) and reticulocyte counts were serially measured every two weeks after starting or stopping EPO administration in 15 non-diabetic hemodialysis patients. EPO treatment significantly influenced HbA1c levels, and the more erythropoiesis fluctuated by changing the dose of EPO, the more HbA1c levels changed, though there were no significant changes in blood glucose levels during the study period. The changes in HbA1c during the 2-week period correlated inversely with both the changes in Hct during the same 2 weeks and the reticulocyte counts at that time. We concluded that the change in Hct should be kept in mind when the HbA1c level is evaluated in EPO-treated patients and a formula should be proposed to correct HbA1c levels based on the change in Hct or the reticulocyte count.

Influence of Ukrain on immunological blood parameters in vitro and in vivo.

Immunological changes are often seen in subjects suffering from oncological disease. Decreased NK activity, alterations of the T4/T8 quotient, decreased phagocytic activity, low reactivity and decreased recognition of the "foreign" are common features seen in these patients. Cytostatic therapy (chemotherapy and radiation therapy) very often enhance these negative properties, thus limiting therapeutic possibilities by highly toxic sequels. Ukrain, being cytostatic and immune-stimulating and modulating, has no adverse effects on the organism.

Comparative immunotoxicity assessment of N4-Trimethoxybenzoyl-5'-deoxy-5- fluorocytidine (Ro 09-1390) and 5'-deoxy-5-fluorouridine (5'-DFUR) in BDF1 mice.

N4-Trimethoxybenzoyl-5'-deoxy-5-fluorocytidine (Ro 09-1390) and 5'-deoxy-5-fluorouridine (5'-DFUR) are 5-fluorouracil (5-FU) derivatives developed as anti-tumor pharmaceuticals. To evaluate immunotoxicities of these compounds, BDF1 mice were administered vehicle, 300-2700 mg (0.68-6.14 mmol)/kg/day of Ro 09-1390, or 100-900 mg (0.41-3.66 mmol)/kg/day of 5'-DFUR for 1 to 7 days, and effects on cellularity in lymphoid organs were assessed by immunohistochemistry as well as general toxicologic parameters. To distinguish compound-specific direct action from nonspecific indirect action caused by dietary reduction, dietary restriction groups were also included as control groups. Final body weight, thymus weight, bone marrow cell number (BMC), and leukocyte number were reduced with high dose of both compounds. Reduction of BMC in groups administered with Ro 09-1390 or 5'-DFUR was more severe than in dietary restriction groups given comparative amount of diet with compound-administered groups. Diffuse thymic cortical hypoplasia was observed in the highest dose of both compounds and more apparent in the Ro 09-1390 than in the 5'-DFUR. Focal nodular thymocyte hyperplasia was observed especially in the lower dose of 5'-DFUR. The results indicate that immunotoxic profiles of Ro 09-1390 and 5'-DFUR are very similar and characterized primarily by myelotoxicity and Ro 09-1390 is approximately two-times less toxic than 5'-DFUR on a molar basis in BDF1 mice.

Disturbances of morphological parameters in blood of rats orally exposed to aluminum chloride.

The aim of this work was to assess changes of morphological parameters in the blood of rats after oral (po) administration of aluminum (Al), in relation to the time and the administered dose. The experiment was performed on female Wistar rats. The animals were administered aluminum chloride (100 mg Al/kg) daily for 21 d. Morphological assays: red blood cells (RBC), hemoglobin (HGB), hematocrit (HCT), iron serum concentration (Fe), MCH, MCHC, absolute corrected reticulocyte count (ACRC), white blood cells (WBC), and platelet count (PLT) were estimated on d 3, 7, 14, and 21, both in the control group and in intoxicated rats. After wk 1 of aluminum administration we observed a decrease of RBC, HCT, HGB and serum iron concentration in the blood of rats. The increase of the platelet count was observed earlier than changes in other parameters. Investigation has proved that the exposure of rats to aluminum administered orally results in normocytic anemia.

Expression and bioactivity of recombinant canine erythropoietin.

OBJECTIVE: To produce recombinant canine erythropoietin (rcEPO) and compare its biological activity with that of recombinant human EPO (rhEPO). ANIMALS: C57BL/6J mice. PROCEDURE: The gene encoding cEPO was isolated from a genomic library and subcloned into an eucaryotic expression vector. Production of rcEPO was achieved by stable transfection of the expression construct into Chinese hamster ovary cells. Biological activity was evaluated in vitro by analyzing the mitogenic activity of rcEPO on murine erythroid progenitor cells. In vivo bioactivity was assessed in mice by measuring the ability of rcEPO to increase blood reticulocyte counts. RESULTS: Size and glycosylation of rcEPO expressed in Chinese hamster ovary cells were similar to values for commercial rhEPO. Canine and human EPO stimulated proliferation of murine erythroid progenitor cells in vitro and murine reticulocytosis in vivo in a dose-dependent manner. CONCLUSIONS: Comparable biological activity was observed for rcEPO and rhEPO in the 2 murine-based assay systems studied. By avoiding interspecies variation in protein structure and the resulting potential for immunogenicity, rcEPO should represent a better option than rhEPO for treatment of dogs with erythropoietin-dependent anemia. CLINICAL RELEVANCE: Therapeutic use of rhEPO in companion animals is limited by its immunogenicity and the resulting potential to induce pure red cell aplasia. Development and availability of species-specific EPO preparations should avoid this problem.

Comparison of biological activity and safety of recombinant canine erythropoietin with that of recombinant human erythropoietin in clinically normal dogs.

OBJECTIVE: To determine whether recombinant canine erythropoietin (rcEPO) stimulates erythropoiesis in dogs without causing the immunogenicity problem (ie, erythroid hypoplasia) associated with recombinant human erythropoietin (rhEPO). ANIMALS: 13 clinically normal dogs. PROCEDURE: Dogs were randomly assigned to 2 groups; 1 group (n = 6) received rhEPO, whereas the other group (7) received rcEPO. Both groups received SC injections of diluent for 4 weeks before initiating treatment with erythropoietin (100 U/kg of body weight, SC, 3 times/wk). Hematocrit and absolute reticulocyte count were monitored weekly, CBC were done monthly, and bone marrow aspirates for cytologic evaluation were obtained before and at 4, 8, 16, and 24 weeks during treatment. RESULTS: Weekly mean Hct and absolute reticulocyte count increased in both groups of dogs during the first 2 weeks of treatment. For dogs receiving rhEPO, precipitous decreases in reticulocyte number and more gradual decreases in Hct were associated with development of erythroid hypoplasia. Dogs receiving rhEPO developed erythroid hypoplasia by week 4 (n = 4), 8 (1), or 16 (1). With cessation of rhEPO treatment after diagnosis of erythroid hypoplasia, RBC production recovered 5 to 11 weeks (median, 7 weeks) later. In contrast, rcEPO treatment caused sustained increases in Hct and reticulocytosis. None of the dogs receiving rcEPO developed erythroid hypoplasia. CONCLUSIONS: rcEPO stimulated erythrocyte production in clinically normal dogs during a 24-week period without causing the erythroid hypoplasia encountered in rhEPO-treated dogs. CLINICAL RELEVANCE: Because rcEPO did not cause erythroid hypoplasia, rcEPO may represent an improved option, compared with rhEPO, for treatment of erythropoietin-dependent anemia in dogs.

Subcutaneous r-HuEPO therapy in CAPD patients: dose determination and clinical experience.

We present our results on the efficacy and safety of low dose r-HuEPO given subcutaneously in the treatment of anaemia in CAPD. We have studied 10 stable patients (5 males, 5 females) on CAPD. In our study subcutaneous r-HuEPO was administered twice a week for 6 months. Mean initial dose of r-HuEPO was 67.3+/-21.7 U/kg/week, and maintenance dose was 35.8+/-12.1 U/kg/week. The target Hb concentration was 10-12 g/dl. All patients responded to r-HuEPO. During treatment significant increases of haemoglobin concentration (p<0.05), haematocrit (p<0.05), red cell count (p<0.05) and reticulocyte count (p<0.05) were observed. We found no significant changes in total white cell or platelet counts. Long-term r-HuEPO treatment did not influence significantly plasma levels of electrolytes (Na, K, Ca), urea and creatinine. We found no significant changes in ultrafiltration volumes. In the present study the mean systolic and diastolic blood pressures did not change. Liver function tests were normal at the beginning and at the end of the study. r-HuEPO treatment was associated with a decrease of ferritin (455+/-90 vs. 224+/-83 microg/l. Oral or intravenous iron substitution became necessary in 6 patients. Side effects in our study were minimal; one patient had myalgia after the first seven doses but this disappeared as treatment was continued. Two patients reported pain (mild) at the injection site. In the present study, the correction of anaemia was accompanied by a substantial improvement in the quality of life, mainly in capacity for work, household and social activities.

[The effect of exogenous iron on levels of adenosinetriphosphate and 2,3-diphosphoglycerate in erythrocytes of men during extreme physical exertion]. / Wplyw egzogennego zelaza na stezenie adenozynotrifosforanu I 2,3-difosfoglicerynianu w erytrocytach mezczyzn przy duzych obciazeniach fizycznych.

Nine men were examined during a three-week training requiring much physical effort. They were given nutrient, "LIVEX", enriched with iron. Hematological parameters as well as concentration of erythrocyte ATP and 2,3-DPG were determined before and after the experiment. Hematological parameters were determined using standard methods while Boehringer's test (Germany) was used for determining ATP and 2,3-DPG. The level of reticular cells was statistically higher after the experiment, and the increase in ATP and 2,3-DPG concentration was insignificant. A positive adaptation of energy metabolism after exogenous iron administration during physical effort was discussed.