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2.
Eur J Med Res ; 2(9): 407-12, 1997 Sep 29.
Artículo en Inglés | MEDLINE | ID: mdl-9300939

RESUMEN

In this study factors possibly contributing to the development of erythrocytosis after renal transplantation (PTE) were analyzed. Out of 131 transplanted patients nine developed PTE (mean hemoglobin 17. 9 +/- 0.3 g/dl) 2 to 27 months after transplantation (group 1) and were compared to the nine with normal hemoglobin concentration (mean hemoglobin 12.4 +/- 0.2 g/dl, control group 2). The study was performed about two years after transplantation (25 +/- 3.9 months group 1 and 23.7 +/- 2.6 months group 2). Immunosuppressive therapy given in standard doses consisted of cyclosporine, azathioprine and prednisone. At the onset of the study no difference in renal graft function was noted between the groups (for group 1 sCr = 111.7 +/- 10.4 micromol/l and for group 2 sCr = 154.6 +/- 27.6 micromol/l). The mean serum immunoreactive erythropoietin (Epo) levels were significantly higher in PTE patients compared to control group of patients (33.9 +/- 4.6 mU/ml vs 21.6 +/- 2.5 mU/ml, p = 0.03). In addition, the ratio between observed to expected (O/E) Epo, a useful index in assessing Epo secretion in renal transplant patients, was ten times higher for group 1 than for group 2 (Median value 10.0 vs. 1.05). Spontaneous growth of Burst-forming unit- erythroid (BFU-E) in peripheral blood was detected in 5 out of 9 patients from group 1 and none in patients from group 2 (p = 0.04). Burst Promoting Activity (BPA) in Phytohemagglutinine Stimulated Leukocytes Condition Medium (PHA-LCM) from patients blood were higher in the PTE patients than in controls. Whole blood cyclosporine levels were higher in group 1 than in group 2 throughout the first 30 weeks after transplantation. It was concluded that sustained erythropoiesis after correction of renal anemia by kidney transplantation, leading to PTE could be explained as a consequence of increased levels of Epo and BPA and increased sensitivity of early erythroid progenitors to these stimulators induced by high cyclosporine levels.


Asunto(s)
Trasplante de Riñón/efectos adversos , Policitemia/etiología , Adulto , Ensayo de Unidades Formadoras de Colonias , Medios de Cultivo Condicionados , Ciclosporina/sangre , Ciclosporina/uso terapéutico , Eritropoyesis , Eritropoyetina/sangre , Femenino , Células Madre Hematopoyéticas/patología , Humanos , Técnicas In Vitro , Trasplante de Riñón/fisiología , Masculino , Policitemia/sangre , Factores de Riesgo
3.
Indian J Med Res ; 104: 304-10, 1996 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8979523

RESUMEN

In order to better understand the mechanisms affecting erythropoietin (Epo) synthesis and red cell mass increase under chronic hypoxia, we examined Epo production and erythroid progenitors (CFU-E) in rats exposed to normobaric hypoxia for four weeks. Hypoxia induced the rise of hematocrit (Htc), hemoglobin (Hb) concentration and the red blood cell (RBC) number with a plateau in hematocrit values after two weeks. After 24 h of hypoxia, Epo levels were increased 20 fold, followed by a significant decrease. After the first week of hypoxia, the values were still higher than in the controls, but after two weeks Epo levels did not differ significantly from the normal values. The fall of Epo levels coincided with the plateau values of hematocrit. The changes in the CFU-E number followed the changes in Epo concentration: a two fold increase after 24 h of hypoxia; a further increase during the next two weeks reaching a peak on day 14, and then a progressive decrease at the time when Epo concentration was at a normal level. Although decreased, but still higher than normal, the CFU-E number during the last two weeks of hypoxia could be necessary for the maintenance of an achieved steady state under persistent hypoxic conditions with normal Epo concentration sufficient to maintain the existing rate of erythropoiesis.


Asunto(s)
Hipoxia de la Célula/fisiología , Células Precursoras Eritroides/metabolismo , Eritropoyetina/biosíntesis , Animales , Enfermedad Crónica , Femenino , Ratas , Ratas Wistar
4.
Biol Neonate ; 66(1): 50-5, 1994.
Artículo en Inglés | MEDLINE | ID: mdl-7948440

RESUMEN

Plasma erythropoietin (Ep) was determined in umbilical cord blood in 18 infants with Down's syndrome. The 16 infants with Down's syndrome who were delivered after labor had significantly elevated plasma Ep levels compared to 36 control infants born after labor (p < 0.001). Six of the ten infants with Down's syndrome who had their packed cell volume (PCV) measured in the first 24 h of life were polycythemic based on a PCV of > or = 0.65. The presence of congenital heart disease in 9 of the 18 infants with Down's syndrome was not associated with a higher plasma Ep or PCV levels. Plasma Ep was correlated with neonatal PCV in the combined group of control and Down's syndrome infants (p = 0.003). Increased plasma Ep levels observed in infants with Down's syndrome suggested chronic fetal hypoxemia as a likely explanation for the high incidence of neonatal polycythemia observed in this group.


Asunto(s)
Síndrome de Down/sangre , Eritropoyetina/sangre , Sangre Fetal/metabolismo , Síndrome de Down/complicaciones , Cardiopatías Congénitas/sangre , Cardiopatías Congénitas/complicaciones , Hematócrito , Humanos , Recién Nacido , Policitemia/sangre , Policitemia/complicaciones
5.
J Physiol ; 472: 55-60, 1993 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-8145160

RESUMEN

1. Fetal sheep at 120 days gestation were fitted with upper and lower body arterial and venous catheters in addition to a flow sensor and occluder placed around the aorta below the renal arteries. 2. After 7 days of recovery, the occluder was partially inflated to reduce aortic blood flow to 70% of control. Blood flow reduction was maintained at this level for the remainder of the experiment. 3. Blood samples were taken after 60 min of blood flow reduction and again after 3 or more days of blood flow reduction. 4. There was no change in upper body arterial or venous blood pressure. Lower body arterial blood pressure decreased, as expected. Arterial PO2 decreased while packed cell volume and haemoglobin concentration increased. There was no change in plasma erythropoietin concentrations or plasma renin activity. 5. While both red cell mass and haemoglobin mass increased during the period of the study, the rate of increase was no different from the rate of blood volume increase.


Asunto(s)
Eritrocitos/patología , Sangre Fetal/citología , Hipoxia Fetal/sangre , Hipoxia/sangre , Animales , Velocidad del Flujo Sanguíneo , Presión Sanguínea , Volumen Sanguíneo , Eritropoyetina/sangre , Femenino , Hipoxia Fetal/fisiopatología , Frecuencia Cardíaca , Hematócrito , Hemoglobinas/metabolismo , Hipoxia/fisiopatología , Embarazo , Ovinos
6.
Obstet Gynecol ; 82(3): 353-8, 1993 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-8355933

RESUMEN

OBJECTIVE: To determine whether plasma erythropoietin is increased in fetuses with anemia due to Rh isoimmunization. METHODS: Hemoglobin and erythropoietin were measured in samples obtained by funipuncture from 15 fetuses with Rh isoimmunization (gestational age 26.2 +/- 5.0 weeks, mean +/- standard deviation) and from 13 control fetuses (23.1 +/- 6.7 weeks). Hemoglobin and erythropoietin also were determined in umbilical cord blood collected at birth from 20 term fetuses delivered by elective cesarean. RESULTS: Fetuses with Rh isoimmunization had lower hemoglobin and higher plasma erythropoietin measurements than mid-gestation controls (6.1 +/- 3.9 versus 10.7 +/- 1.5 g/dL and 105.5 +/- 168.1 versus 12.5 +/- 3.1 mU/mL, P < .05, respectively). Hemoglobin and plasma erythropoietin increased with gestational age in control fetuses. There was an inverse association between hemoglobin and plasma erythropoietin in control and Rh-isoimmunized fetuses (r = -0.56, P < .005). Using multiple linear regression, hemoglobin and gestational age were associated independently with plasma erythropoietin (overall F2,25 = 12.3, multiple r2 = 0.49, P < .001). Despite marked decreases in hemoglobin, fetuses below 24 weeks' gestation had minimal increases in plasma erythropoietin compared to fetuses above that gestational age. Mildly anemic Rh-isoimmunized fetuses (hemoglobin 11.6 +/- 2.0 g/dL) delivered vaginally had significantly higher erythropoietin levels in umbilical cord plasma than Rh-isoimmunized fetuses with comparable hemoglobin (10.9 +/- 3.5 g/dL) delivered by elective cesarean without labor (1246 +/- 856 versus 106 +/- 66 mU/mL, respectively, P < .05). CONCLUSION: Fetuses with anemia at mid to late gestation respond with increases in plasma erythropoietin, but these changes are substantially attenuated before 24 weeks' gestation.


Asunto(s)
Anemia Hemolítica Autoinmune/sangre , Eritropoyetina/sangre , Enfermedades Fetales/sangre , Hemoglobinas/análisis , Hidropesía Fetal/sangre , Isoinmunización Rh/sangre , Anemia Hemolítica Autoinmune/complicaciones , Anemia Hemolítica Autoinmune/terapia , Transfusión de Sangre Intrauterina , Sangre Fetal , Enfermedades Fetales/terapia , Edad Gestacional , Humanos , Hidropesía Fetal/complicaciones , Hidropesía Fetal/terapia , Análisis de Regresión , Isoinmunización Rh/complicaciones , Isoinmunización Rh/terapia
7.
Pediatr Nephrol ; 7(3): 281-3, 1993 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-8518099

RESUMEN

Higher hematocrit and serum erythropoietin (EPO) levels have previously been shown in end-stage renal disease patients treated with continuous ambulatory peritoneal dialysis (CAPD) compared with hemodialysis. We investigated whether EPO was produced intraperitoneally in CAPD patients. EPO concentration was 3.5 +/- 0.3 mU/ml by radioimmunoassay in 26 samples of peritoneal dialysis effluent obtained from 15 CAPD patients. EPO was not detectable in the fresh unused dialysate. No correlation was observed between EPO levels in the serum and dialysis effluent. Peritoneal macrophages were isolated from the dialysis effluent of 9 CAPD patients after an overnight dwell. The culture supernatant obtained after 24 h of in vitro culture of a million cells yielded EPO of 3.5 +/- 0.3 mU/ml. Our study demonstrated that peritoneal macrophages from CAPD patients produce EPO on in vitro stimulation, and EPO is present in the dialysis effluent of CAPD patients.


Asunto(s)
Eritropoyetina/biosíntesis , Fallo Renal Crónico/metabolismo , Diálisis Peritoneal Ambulatoria Continua , Adolescente , Adulto , Células Cultivadas , Preescolar , Soluciones para Diálisis , Femenino , Humanos , Fallo Renal Crónico/terapia , Macrófagos/metabolismo , Masculino , Persona de Mediana Edad , Cavidad Peritoneal/citología , Radioinmunoensayo
8.
Blood ; 81(4): 1067-76, 1993 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-8427988

RESUMEN

We evaluated the quantitative value of a simple model of erythropoiesis, based on the basic assumptions that the red blood cell (RBC) mass determines erythropoietin (Epo) production, which in turn stimulates erythropoietic activity. The RBC mass was quantitated by direct isotopic measurement (RCM), Epo production by serum Epo levels, and erythropoiesis by the ferrokinetic measurement of the erythron transferrin uptake (ETU), the serum transferrin receptor (TfR) level, and the reticulocyte (retic) index, and was completed by an evaluation of overall marrow erythron cellularity. We studied a total of 195 subjects, including 31 normal individuals, 38 patients with polycythemia, and 126 patients with various forms of anemia. Instead of only quantitating Epo and erythropoiesis in absolute terms, we also evaluated them in relation to the degree of anemia or polycythemia, and expressed the results as a ratio of observed values to values predicted from the regression equations between hematocrit (Hct) on the one hand, and Epo, TfR, and ETU on the other, obtained in a carefully selected subpopulation. The slope of the regression of TfR (as well as ETU) versus Hct was very similar to the slope of the regression of Epo versus Hct. Average EPO and TfR (as well as ETU) values predicted from the regression equations were quite comparable to observed values in most groups of subjects, with exceptions predictable from knowledge of the pathophysiology of these hematologic disorders. We identified four major patterns of erythropoiesis, ie, normal, hyperdestruction (with variants of hemolysis or ineffective erythropoiesis), intrinsic marrow hypoproliferation, and defective Epo production. Dissecting out groups of patients showed much greater heterogeneity than when patients were analyzed by group. This was particularly true in the case of a hypoproliferative component being combined with hyperdestruction, giving what we called a "mixed disorder of erythropoiesis." We conclude that the pathophysiology of anemia can be assessed by a simple measurement of Hct, retic index, Epo, and TfR levels, with Epo and TfR being more informative when expressed in relation to the degree of anemia. The model is particularly useful for detecting the presence of multiple mechanisms of anemia in the same patient. However, it has limitations inherent to the relative invalidity of TfR in iron deficiency, the imprecision of a retic count, and the difficulty in distinguishing hemolysis from ineffective erythropoiesis in some patients and in recognizing a component of hyperdestruction in hypoproliferative anemia.


Asunto(s)
Anemia/sangre , Anemia/clasificación , Eritropoyesis , Eritropoyetina/sangre , Receptores de Transferrina/análisis , Adolescente , Adulto , Anciano , Recuento de Eritrocitos , Hematócrito , Hemólisis , Humanos , Persona de Mediana Edad , Policitemia/sangre , Policitemia/clasificación , Análisis de Regresión , Reticulocitos
9.
Pathobiology ; 61(3-4): 211-5, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8216843

RESUMEN

Erythropoiesis in the fetus is controlled by erythropoietin (Ep). To determine the role of maternal Ep in this process, we used catheterized preparations of sheep and monkey fetuses to assess the ability of Ep administered to the mother to cross the placental barrier into the fetus. Ep was injected into pregnant sheep (3,600 IU/sheep) or monkeys (800-2,000 IU/animal) as a single intravenous dose, or into sheep in intravenous doses of 2,000 IU once every 12 h for a total of 4 injections. Maternal and fetal blood samples for Ep and reticulocyte determinations were obtained before and at intervals after Ep injections. The administration of Ep resulted in significant increases in maternal circulating Ep levels in sheep and monkeys. Despite the presence of high levels of maternal Ep, however, no increase in fetal plasma Ep levels was detected. The administration of Ep to the mother caused significant increases in reticulocyte production in the mother but not the fetus; injection of Ep directly to the fetus stimulated fetal erythropoiesis. These results demonstrate that Ep does not cross the placenta into the fetus even under conditions of chronically elevated maternal Ep levels, and suggest that red cell production in the fetus is regulated by Ep produced from sites within the fetus.


Asunto(s)
Eritropoyetina/metabolismo , Feto/metabolismo , Intercambio Materno-Fetal , Placenta/metabolismo , Animales , Eritropoyetina/sangre , Femenino , Sangre Fetal/metabolismo , Macaca mulatta , Embarazo , Ovinos
10.
Exp Hematol ; 20(11): 1257-62, 1992 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-1493855

RESUMEN

In this study, the extent to which growth factor production and microenvironment might be responsible for defective erythropoiesis and granulopoiesis in anemic b/b rats is investigated. Radioimmunoassay-determined serum erythropoietin (Epo) levels are high in b/b rats and closely related to degree of anemia. The low number of erythroid progenitors in b/b rats despite a high Epo level suggested that the defective erythropoiesis could be due to a low level of burst-promoting activity (BPA). A pokeweed mitogen-stimulated medium (PWM-SCM) was prepared with b/b rat spleen cells and used in normal and anemic rat bone marrow and spleen cultures to determine BPA and other growth factor levels. No erythroid burst-forming unit-derived colonies were found but granulocyte-macrophage colony-forming units were counted in significant number, suggesting that the production of growth factors that supports the growth of granulopoietic progenitors is not significantly disturbed. Because BPA is produced mainly by T-lymphocytes, the low BPA level in b/b rat PWM-SCM raised the question of the functional capacity of T-lymphocytes. Investigations showed a decrease in the proliferative activity of b/b rat spleen mitogen-activated T-lymphocytes to about 20% of controls as well as a decrease in interleukin-2 activity in b/b rat spleen cell supernatants. These results point to defective T-lymphocytes. A study of bone marrow fibroblastoid cell colonies (CFU-F) revealed significantly lower CFU-F counts in the b/b rats. This finding is indicative of a disturbed microenvironment, which could also to some extent be responsible for decreased growth factor production and depressed hematopoiesis in the b/b rat.


Asunto(s)
Anemia/metabolismo , Hematopoyesis , Factores de Crecimiento de Célula Hematopoyética/biosíntesis , Anemia/tratamiento farmacológico , Anemia/patología , Animales , Médula Ósea/patología , Células Cultivadas , Ensayo de Unidades Formadoras de Colonias , Medios de Cultivo Condicionados , Células Precursoras Eritroides/patología , Eritropoyesis , Eritropoyetina/metabolismo , Femenino , Granulocitos/patología , Células Madre Hematopoyéticas/patología , Hierro/uso terapéutico , Macrófagos/patología , Masculino , Mitógenos de Phytolacca americana/farmacología , Ratas , Ratas Mutantes , Bazo/patología , Linfocitos T/fisiología
11.
Health Phys ; 63(4): 427-42, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1526784

RESUMEN

The laboratory mouse is a primary animal model for experimental radiation biology and pharmacology. The usefulness of the mouse for those purposes is enhanced if detailed data are available to define a Reference Mouse [weight and composition of soft tissues and bones and their in-life content of plasma and extracellular water (ECW)]. Only fragmentary data are available for wet weights and plasma volumes of soft tissues and bones of mice; there are no reports of total volume or distribution of ECW in mouse tissues. To remedy those defects, wet weight and composition of all major organs and soft tissues were measured, and measurements were made or estimates obtained for wet weights and composition of all bones of the young adult (12 to 13 wk old) female Swiss-Webster mouse. 125I-transferrin was used as a tracer for plasma, and 22Na was used as a tracer for ECW. Tissue weight and tracer measurements were conducted using the metabolic balance approach and a freezing technique that avoids blood loss during dissection. Results compare favorably with published weights and plasma volumes of tissues of mature mice of both genders and other strains. Total plasma volume (48.9 +/- 4.4 microL g-1) and Na-space (232 +/- 15 microL g-1), and the specific plasma and ECW volumes of vascular mouse tissues, exceed those of rat tissues. Applications of the data are presented: (1) interpretation of plutonium uptake kinetics in the mouse; (2) estimation of masses of mineralized bone tissue (1.92 g), bone marrow (1.2 g), and endosteal (BS) cells (0.2 g) of the mouse.


Asunto(s)
Apoproteínas/farmacocinética , Sangre/metabolismo , Agua Corporal/metabolismo , Espacio Extracelular/metabolismo , Ratones/metabolismo , Modelos Biológicos , Sodio/farmacocinética , Transferrina/farmacocinética , Animales , Médula Ósea/anatomía & histología , Huesos/anatomía & histología , Huesos/metabolismo , Femenino , Tamaño de los Órganos , Ratas , Valores de Referencia , Distribución Tisular
12.
J Dev Physiol ; 18(3): 129-36, 1992 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-1338733

RESUMEN

In all mammalian species studied the haematocrit (hct) declines after birth in the absence of any known nutritional deficiencies. The glycoprotein hormone, erythropoietin (Epo), is essential for normal red blood cell production. The aims of this study were 1) to investigate the changes in plasma Epo during the normal post-natal decrease in hct in lambs; 2) to compare the effects of chronic and acute haemorrhage in neonatal lambs; and 3) to test the hypothesis that the Epo response to haemorrhage is blunted in the neonatal period. Twenty-one lambs (0-9 weeks of age) were studied; group I (n = 8) were used to document normal post-natal changes (98 samples); group II (n = 7) lambs were haemorrhaged repetitively during weeks 3-6 (95 samples); group III (n = 6) lambs were bled once in the first 3-week period. In the group I (control lambs) the hct decreased from 30.6 +/- 1.3 (weeks 1 & 2) to a nadir of 23.2 +/- 0.8 (75.8% of initial value) in the 6th week, and the plasma Epo declined from 25.7 +/- 4.9 (week 1) to 12.3 +/- 1.0 mU/ml (week 6). In group II, the lambs were bled repetitively, a total of 510 +/- 32 ml blood being removed during weeks 3-6, the hct was 18.7 +/- 0.8 (81% of hct at nadir in controls) in week 6, and Epo was 26.9 +/- 13.3 in week 3, 23.4 +/- 3.6 mU/ml in week 6.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Animales Recién Nacidos/sangre , Eritropoyetina/sangre , Hemorragia/sangre , Enfermedad Aguda , Hormona Adrenocorticotrópica/sangre , Animales , Animales Recién Nacidos/crecimiento & desarrollo , Dióxido de Carbono/sangre , Enfermedad Crónica , Globinas/análisis , Globinas/química , Hematócrito , Hidrocortisona/sangre , Oxígeno/sangre , Valores de Referencia , Ovinos
13.
J Appl Physiol (1985) ; 72(6): 2354-63, 1992 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-1629091

RESUMEN

Hilltop (H) and Madison (M) strains of Sprague-Dawley rats exhibit strikingly different susceptibilities to the effects of chronic altitude exposure. The H rats develop greater polycythemia, hypoxemia, and pulmonary hypertension. We studied ventilation, pulmonary gas exchange, tissue oxygenation, and hematologic adaptations in the two rat strains during a 50-day exposure to a simulated altitude (HA) of 5,500 m (18,000 ft). There were no strain differences among the variables we studied under sea level (SL) conditions. Within the first 14 days of hypoxic exposure, the only significant strain differences were that erythropoietin (EPO) rose much higher and erythroid activity was greater in the H rats, even though arterial Po2 and PCo2 (Pao2 and PaCo2, respectively), renal venous PO2 (Prvo2), and ventilation (VE) were equivalent in the two strains during this time. By day 14 at HA, the H rats had significantly higher erythroid activity, hematocrit (Hct), and EPO levels, significantly lower PaO2 and PrvO2, but equivalent VE and PaCO2. These changes persisted for the remainder of the exposure, except that the Hct continued to rise and the increase was greater in H rats. Despite the greater O2-carrying capacity of H rats in the later stages of hypoxic exposure, PaO2 and PrvO2 were significantly lower in H rats. There were no strain differences at either SL or HA in ventilatory responses to hypercapnia or hypoxia, in blood O2 affinity or 2,3-diphosphoglycerate, in extrarenal production of EPO, or in EPO clearance. We conclude that early in the hypoxic exposure the H rats produce more EPO at apparently equivalent levels of hypoxia, and this is the first step in the pathogenesis of the maladaptation to HA manifest by H rats. We find no consistent evidence that differences in VE contribute to the variable susceptibility to hypoxia in the two rat strains.


Asunto(s)
Hematopoyesis/fisiología , Hipoxia/fisiopatología , Respiración/fisiología , Mal de Altura/sangre , Mal de Altura/etiología , Mal de Altura/fisiopatología , Animales , Modelos Animales de Enfermedad , Eritropoyetina/biosíntesis , Hipoxia/sangre , Riñón/metabolismo , Masculino , Oxígeno/sangre , Ratas , Ratas Endogámicas , Especificidad de la Especie
14.
Exp Hematol ; 20(3): 350-3, 1992 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-1348981

RESUMEN

We have previously reported the successful development of hematopoietic chimerism after the in utero transplantation of fetal hematopoietic stem cells (HSC) in rhesus monkeys (Macaca mulatta). These animals exhibit sustained engraftment without immunosuppression or graft-versus-host disease (GVHD). To assess the functional response of the donor-derived erythropoietic population, we assayed the relative expression of donor and recipient hematopoietic progenitors in chimeric monkeys before and after anemic stress. Anemia in our chimeric animals resulted in increased erythropoietin (EPO) production comparable to controls. This was accompanied by changes in erythroid progenitor profiles, again similar to controls. Chimeric animals demonstrated normal reticulocytosis and reconstituted their hematocrit after hemorrhage at the same rate as controls. The donor-derived erythropoietic population exhibited normal responses to recipient regulatory signals and did not seem to expand at the expense of other hematopoietic lineages. Thus the proportions of engraftment for the myeloid and erythroid precursors in bone marrow and for blood lymphocytes remained stable. Our results demonstrate that the in utero transplantation of fetal HSC results in stable engraftment of donor erythropoietic progenitors, which appear to be fully integrated within the recipient's regulatory system. The abnormalities reported in the postnatal transplantation setting can then be attributed to immunologic reactions requiring conditioning myeloablative regimens. Fetal transplantation bypasses all these factors.


Asunto(s)
Quimera/fisiología , Eritropoyesis/fisiología , Trasplante de Tejido Fetal/fisiología , Trasplante de Células Madre Hematopoyéticas , Macaca mulatta/fisiología , Anemia/sangre , Anemia/patología , Anemia/fisiopatología , Animales , Recuento de Células Sanguíneas , Eritropoyetina/metabolismo , Femenino , Hematócrito , Células Madre Hematopoyéticas/metabolismo , Células Madre Hematopoyéticas/patología , Células Madre Hematopoyéticas/fisiología , Hemorragia/patología , Hemorragia/fisiopatología , Linfocitos/patología , Linfocitos/fisiología , Embarazo , Reticulocitos/patología
15.
Biomed Pharmacother ; 46(1): 37-43, 1992.
Artículo en Inglés | MEDLINE | ID: mdl-1421034

RESUMEN

In anemic patients on regular hemodialysis (HD), correction of anemia with recombinant human erythropoietin (rHuEpo) administered intravenously (iv) or subcutaneously (sc) was followed over a 2-month period. Monitoring serum Epo post-dose concentrations after the first iv rHuEpo injection and following another regular injection after 2 months of therapy with rHuEpo iv in 9 patients showed that the Epo elimination half-life was reduced from 7.48 h to 4.68 h. In the same patients the initially low percentage of erythroblasts and mature erythroid progenitors increased during 2 months of rHuEpo therapy. Because Epo molecules bound to Epo receptors are internalized in target cells we suggest that the expansion of the Epo responsive cell pool could explain the shorted Epo elimination time after 2 months of rHuEpo treatment. By monitoring serum Epo concentration following sc rHuEpo injection in 7 HD patients it was found that the modest increase in serum Epo levels (30-60 mU/ml) was sufficient to correct anemia.


Asunto(s)
Eritropoyetina/sangre , Diálisis Renal , Adulto , Anemia/tratamiento farmacológico , Femenino , Humanos , Inyecciones Intravenosas , Inyecciones Subcutáneas , Masculino , Persona de Mediana Edad , Proteínas Recombinantes
16.
Kidney Int Suppl ; 34: S46-8, 1991 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-1762334

RESUMEN

The severity of anemia in patients at different stages of the evolution of two tubulointerstitial nephropathies, Balkan endemic nephropathy and chronic pyelonephritis, was compared to clarify the previous observations that anemia appears earlier and is more severe in Balkan endemic nephropathy than in other renal diseases. The role of erythropoietin insufficiency as the cause of anemia in endemic nephropathy was studied as well. The severity of anemia increased with the impairment of renal function in endemic nephropathy and was similar to anemia in chronic pyelonephritis. However, in patients with endemic nephropathy at the initial stage of renal insufficiency significantly lower red cell concentrations were found compared with control subjects from the endemic region. In contrast, patients with pyelonephritis did not have decreased red cell concentrations at the early phase of their renal failure, suggesting that earlier appearance of anemia is characteristic for endemic nephropathy. To confirm this finding a study involving larger number of patients would be necessary. The serum erythropoietin levels, inappropriately low for the degree of anemia in patients with renal failure, were unrelated to the type of tubulointerstitial nephropathy.


Asunto(s)
Anemia/complicaciones , Nefropatía de los Balcanes/complicaciones , Adulto , Anciano , Anemia/sangre , Nefropatía de los Balcanes/sangre , Recuento de Eritrocitos , Eritropoyetina/sangre , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pielonefritis/sangre , Pielonefritis/complicaciones
17.
Blood ; 77(4): 868-73, 1991 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-1847085

RESUMEN

We studied 24 recipients of autologous bone marrow transplantation (ABMT) or allogeneic BMT (BMT) to determine whether impaired erythropoietin (Epo) response to anemia could delay full erythropoietic recovery. Observed Epo levels were compared with predicted levels based on the relationship between Epo and hematocrit in 125 control subjects. Circulating Epo levels were normal during conditioning and the early posttransplant period. Between days 21 and 180, Epo levels remained normal in ABMT patients but were inappropriately low for the degree of anemia in BMT patients. Median time to full erythropoietic engraftment was longer in BMT than in ABMT recipients. Circulating Epo returned to appropriate levels after day 180, except in patients with active cytomegalovirus infection. We conclude that impaired Epo response to anemia can contribute to delayed erythropoietic recovery after allogenic BMT. Renal toxicity of ciclosporin, interaction between host and donor marrow, and cytomegalovirus infection might play a role. This study could support the use of recombinant human Epo to accelerate erythropoietic engraftment after BMT.


Asunto(s)
Anemia/sangre , Trasplante de Médula Ósea , Eritropoyetina/sangre , Adolescente , Adulto , Trasplante de Médula Ósea/efectos adversos , Niño , Preescolar , Infecciones por Citomegalovirus/sangre , Infecciones por Citomegalovirus/etiología , Femenino , Supervivencia de Injerto , Enfermedad Injerto contra Huésped/sangre , Hematócrito , Enfermedades Hematológicas/cirugía , Humanos , Masculino , Persona de Mediana Edad , Trasplante Autólogo , Trasplante Homólogo
18.
Acta Med Iugosl ; 45(2): 151-60, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1887810

RESUMEN

Two groups, with 4 patients each were selected for study out of 155 patients on regular hemodialysis (HD): Group I, with hematocrit (PCV) less than 20% and group II, with PCV greater than 30%. The patients in both groups had been anemic at the start of HD treatment, but a significant improvement in their anemia had occurred only among the patients in the Group II. The main difference between the two patient groups, other than the degree of anemia, was found to be in serum erythropoietin (Ep) levels. No significant differences were observed between the two groups in serum urea, creatinine, parathyroid hormone or CFU-E growth inhibition. Acquired cystic disease of the kidney was found in five patients from group I, and in 11 patients from group II. The correlation between the number of cysts in the kidneys and the patient's PCV and serum Ep levels proved significantly positive. The results presented could be regarded as another proof that diseased kidney is capable of functioning as an Ep producing organ despite the loss of excretory function.


Asunto(s)
Anemia/sangre , Eritropoyetina/sangre , Diálisis Renal , Anciano , Anemia/etiología , Femenino , Hematócrito , Humanos , Fallo Renal Crónico/sangre , Fallo Renal Crónico/complicaciones , Fallo Renal Crónico/terapia , Masculino
19.
J Dev Physiol ; 14(5): 259-65, 1990 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-2129243

RESUMEN

This study examines the hypotheses that (i) erythropoietin (the hormone responsible for red blood cell production) is higher in the fetus (at low PO2) than in the neonate (at high PO2); and (ii) that the level of erythropoietin in the neonate is influenced by the presence of high oxygen affinity haemoglobin. Haematocrit (PCV), PO2 and plasma immunoreactive erythropoietin were measured in 4 chronically cannulated fetal sheep (120 days to birth, n = 22) and in 7 neonatal lambs until 233 days post-conception (75-85 days after birth, n = 83). The percentage of globin chains (alpha, gamma, beta A, beta B, beta C) was quantitated by gel electrophoresis. Plasma erythropoietin values, in 4 fetuses were 9.8 +/- 1.3 mU/ml at 120-132 days of gestation, declined significantly (P less than 0.01) to 5.2 +/- 0.4 at 133 days until birth, then increased significantly (P less than 0.001) to 24.2 +/- 5.5(5), 26.3 +/- 7.3 (6), and 24.8 +/- 8.5 (6), respectively in weeks 1, 2 and 3 of postnatal life. By weeks 5-8 the erythropoietin was 13 +/- 0.6 (4) mU/ml. PO2 was 17.4 +/- 0.9 mmHg before birth and 88.0 +/- 10.7 in the first week after birth. PCV was constant until three weeks after birth and then declined. Fetal haemoglobin had virtually disappeared from the circulation by 166 days (3 weeks after birth); in the 4 heterozygotes (beta A beta B) beta C was expressed transiently, with a maximum value of 4%, whilst in the homozygote lamb (beta A beta A) the maximum beta C was 12%.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Envejecimiento/fisiología , Eritropoyetina/sangre , Sangre Fetal/química , Hemoglobinas/genética , Análisis de Varianza , Animales , Animales Recién Nacidos , Análisis Químico de la Sangre , Análisis de los Gases de la Sangre , Dióxido de Carbono/sangre , Genotipo , Hematócrito , Hemoglobinas/análisis , Concentración de Iones de Hidrógeno , Oxígeno/sangre , Ovinos
20.
Obstet Gynecol ; 76(2): 219-22, 1990 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-2371024

RESUMEN

The erythropoietin levels in mixed cord serum of 40 infants born to drinking women were compared with those of 24 infants born to abstinent women. Twenty infants born to drinkers had signs of fetal alcohol effects. Thirty-five percent of the erythropoietin levels in mixed cord serum of infants of drinking mothers were above the normal range. Further, the elevation in fetal erythropoietin level correlated with maternal alcohol intake; infants of mothers consuming at least 300 g of ethanol weekly (28) had significantly higher (P less than .025) umbilical erythropoietin levels (median 66 mU/mL, range 10-2500) compared with infants of mothers consuming 150-300 g of ethanol weekly (median 37 mU/mL, range 23-215) or infants of control women (median 32 mU/mL, range 11-73). The subgroup analysis between infants with and without fetal alcohol effects showed no differences in umbilical erythropoietin levels. Maternal alcohol ingestion during pregnancy is associated with elevated umbilical erythropoietin levels, but whether this is a direct effect of ethanol or is induced by chronic fetal hypoxemia remains unclear.


Asunto(s)
Alcoholismo , Eritropoyetina/sangre , Sangre Fetal/análisis , Complicaciones del Embarazo , Adulto , Puntaje de Apgar , Femenino , Humanos , Recién Nacido , Intercambio Materno-Fetal , Embarazo
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