ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Advances in the treatment of iron overload hold the promise of making long-term transfusion therapy a safer approach to the management of thalassemia major, sickle cell disease, and numerous other hematologic disorders. The responsibility now placed on the treating physician is to monitor iron stores carefully, to begin chelation therapy at an appropriate time, and to encourage regular use of deferoxamine. For the clinical investigator, the success of chelation therapy with deferoxamine should prompt an intensive search for new chelators. These new chelators should be not only effective but also inexpensive, readily available, safe, and easy to administer.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Deferoxamine has been extensively used as chelation therapy in iron-overloaded states. Recently, some investigators have explored the potential usefulness of deferoxamine as an antiproliferative, antiinflammatory, and immunosuppressive agent. The studies of deferoxamine have indicated that the drug blocks DNA synthesis by inhibition of ribonucleotide reductase. Deferoxamine has also shown antiinflammatory properties, possibly by inhibition of polymorphonuclear neutrophil function. Analysis of possible antiinflammatory effects of deferoxamine has been complicated by concomitant immunosuppressive effects of the drug. Deferoxamine inhibits T lymphocyte proliferation, both by ribonucleotide reductase inhibition and by preventing the expression of interleukin 2 receptor-alpha chain. The use of iron-chelating agents in non-iron-overloaded patients carries the risk of neurologic, metabolic, and infectious complications. The clinical usefulness of deferoxamine in these novel applications will require careful study of both efficacy and any toxic effects.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Recombinant human erythropoietin (r-HuEPO) is of interest to pediatric hematologists and neonatologists because it may prove to be an effective alternative to blood transfusions in preventing and treating anemia in premature infants. The anemia of prematurity is the most promising setting for initial clinical trials. However, it is conceivable that recombinant erythropoietin will be given at birth to low-birth-weight infants in an effort to stimulate endogenous erythropoiesis and thereby prevent some of the erythrocyte transfusions required to replace blood sampled for laboratory tests. Beyond its appeal as a therapeutic alternative to red blood cell transfusions, recombinant human erythropoietin is likely to be the first member of an entirely new class of drugs to be used widely in neonatal medicine. These are drugs produced by cloning normal human genes and expressing them in the laboratory. Because many of the problems of premature birth are caused by developmental immaturity, transiently replacing crucial proteins with exact copies produced by the techniques of recombinant DNA technology is an approach that may have a major impact on morbidity and mortality of neonates. Carefully designed, controlled clinical trials wil be essential to determine the role of new agents like r-HuEPO in the treatment of medical problems of premature infants.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

During the last several years, studies in humans and experimental animals have identified several compounds that induce fetal hemoglobin in the adult. These include: cell-cycle-specific drugs, other cytotoxic drugs, butyric acid analogs, and erythropoietin. Several of these compounds induce fetal hemoglobin indirectly by triggering kinetics of rapid erythroid regeneration. High doses of erythropoietin increase the frequency of erythroid progenitors programmed to hemoglobin F. This results in transient increases of hemoglobin F-containing cells (F cells) in the peripheral blood. Erythropoietin and hydroxyurea increase F cells in a cooperative fashion. Although high doses of erythropoietin can induce F cell production in humans, the practical relevance of such observations is unclear.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Acute megakaryoblastic leukemia (AMkL), defined by the presence of the platelet-associated glycoprotein IIb/IIIa complex on malignant cells, was diagnosed in 4 (4%) of 103 consecutive children with untreated acute leukemia or 4 (21%) of 19 children with acute nonlymphoblastic leukemia (ANLL). Particular features in the four children with AMkL were an age below 12 months at diagnosis (two patients), the absence of a significant hepatosplenomegaly (three patients), a leukocyte count below 20 x 109/L with only a few blast cells in the peripheral blood (four patients), a technically difficult bone marrow aspiration (three patients), the presence of many megakaryocytes in marrow particles (two patients), and an inconclusive cytochemistry (four patients). The four children with AMkL were treated according to protocols for ANLL and a complete remission was obtained in all patients. One patient died from relapse after 3 months, one patient is a long-term survivor (38+ months), and two patients still on chemotherapy are disease-free for 11 + and 13+ months.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The present study was undertaken in an attempt to reclassify the 19 cases of childhood acute undifferentiated leukemia (AUL) diagnosed at our institution during the past 12 years. Based on ultrastructural and immunophenotypic data, seven of the cases were reclassified as lymphoid, nine as myeloid, and three remain unclassifiable. Clinical features, clonal karyotypes, and responses to treatment were also examined. Abnormal clonal karyotypes were found in 16 of 17 cases, including eight cases with translocations, three with monosomy 7 or 7q, and one with numerous complex structural rearrangements. Fourteen patients had > 10% French-American-British L2blasts in bone marrow. Although nine of 15 patients who initially received induction therapy for acute lymphoblastic leukemia (ALL) achieved remission, only one patient is a long-term survivor. Only one of 10 patients who received therapy for acute nonlymphoblastic leukemia during the course of their disease remains a long-term survivor. These data suggest that the majority of cases of AUL can be reclassified as either myeloid or lymphoid leukemias, that AUL is associated with a high frequency of chromosomal abnormalities, and that AUL carries a very poor prognosis.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Changes in intellectual function during the course of treatment for acute lymphocytic leukemia were studied. Twenty-four children had baseline psychological evaluations and annual reevaluations for 3–6 years postdiagnosis. Treatment in all patients included combination chemotherapy, 2.400 cGy prophylactic cranial irradiation, and intrathecal methotrexate. Central Nervous System (CNS) relapse occurred in eight of these children. It was then treated with 3,000 cGy cranial plus 1,800 cGy spinal irradiation. Patients who remained in continuous complete remission showed no decline in global intelligence quotient (IQ). Patients who experienced CNS relapse had a mean decline of 16 IQ points by 3 years postdiagnosis and the long-term survivors displayed a mean loss of 25 IQ points 5–6 years postdiagnosis. Three of the five long-term survivors of CNS relapse function within the retarded range of mental ability and require special education. The other two have learning problems and display poor academic performance relative to same-age peers. There was no association noted between age at diagnosis and ultimate loss of IQ points. This prospective study suggests that children who receive a second course of cranial irradiation for treatment of CNS relapse are at high risk for significant and progressive intellectual loss.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

The clinical features of sickle cell disease (SCD) in Saudi Arab children of eastern origin are presented. One hundred and seventy-three children were diagnosed at birth and followed prospectively from 3 months to up to 4 years of age. There were 87 boys and 86 girls. Genotype distribution included 146 sickle cell anemia, 24 sickle+-thalassemia, two sickle ±0-thalassemia, and one sickle hemoglobin C disease. Of our patients, 7% presented in the first 12 months of age and 27% remained asymptomatic at 4 years. Painful crises of bones and joints were the most common initial symptoms, followed by dactylitis, abdominal crises and acute splenic sequestration (ASS), occurring in 60%, 31.6%, 6.7%, and 1.7% of the patients, respectively. None of the patients presented with severe bacterial infections. During this study, 175 sickle cell crises were documented, but only 16 (9.1%) required hospital admissions. There were no deaths in this series. High hemoglobin F levels correlated with delayed clinical presentation and reduced number of crises. We conclude that SCD in children of eastern origin is clinically milder than earlier descriptions from the Eastern Province of Saudi Arabia.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID

摘要:

Cardiac dysfunction is the most common cause of death in patients with homozygous ±-thalassemia. We studied a group of 10 older patients (mean age 17.5 years) with and without preexisting cardiac dysfunction who had begun chelation therapy on the average of 10 years after regular transfusions were initiated. Over the 4-year study period, two patients were noncompliant with deferoxamine therapy. Their clinical status and cardiac function deterio rated, and both died with evidence of arrhythmia and congestive heart failure. The remaining eight patients were compliant. Despite a drop in mean serum ferritin from 3,814 ± 577 (SE) ng/ml to 1,056 ± 146 ng/ml (p < 0.01), two patients with preexisting cardiac problems and one patient without preexisting heart disease developed further abnormalities. Of the three patients whose status declined, one ultimately improved with alternative chelation therapy. These data suggest that for a few older patients, improvement or stabilization of cardiac status may not be achieved with improved compliance and reduced serum ferritin levels. For these patients, new approaches appear to be warranted. On the other hand, we have demonstrated that in most cases, older patients who began chelation therapy years after transfusions began have benefited from compliance with standard subcutaneous deferoxamine regimens.

ISSN:0192-8562    

出版商:OVID    

年代:1990

数据来源: OVID