ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeGlanzmann thrombasthenia is a well-defined inherited disorder of platelet function characterized by a decrease or absence of functional platelet glycoprotein (GP) GPIIbIIIa. The diagnosis must be considered in patients presenting with mucocutaneous bleeding, purpura, a normal platelet count, abnormal platelet aggregation, and a prolonged bleeding time. In most of the patients, the presence of small amounts of either GPIIb or GPIIIa was detected in their platelets. These observations could provide a basis for determining the clinical and laboratory heterogeneity of the disease.Patients and MethodsWe studied 10 patients of seven unrelated families with the usual methods and an immunoalkaline phosphatase technique (APAAP) to analyze the biosynthesis of GP in megakaryocytes.ResultsThe results allowed us to classify six patients as GT type I, three as type II, and one as a variant.ConclusionThe nature and severity of the bleeding manifestations, in our patients, were not predictible by the laboratory findings. These confirm the clinical and laboratory heterogeneity of the disease.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeBurkitt's lymphoma is a malignancy of mature, immunoglobulin (Ig)-bearing B cells characterized by translocation between c-mycand Ig gene loci. A role for the juxtaposed Ig genes in the mutation and deregulation ofc-mycexpression typical of endemic Burkitt's lymphoma (eBL) has been proposed, but never proven. Our objective was to determine whether Ig gene hypermutation is ongoing in eBL.MethodsWe isolated Ig heavy-chain sequences from K962 eBL tumor cells using reverse transcription and polymerase chain reaction (PCR) amplification. The PCR product was ligated into Bluescript II vectors. Multiple subclones were sequenced and the variable regions were compared for evidence of ongoing Ig hypermutation.ResultsSix total single base substitutions were observed within four of the nine subclones studied. Four substitutions resulted in amino acid changes and two were silent. There was no clustering of mutations in hypervariable regions, or a high incidence of amino acid replacement or link substitutions, all of which are characteristic of Ig hypermutation. The observed mutations occurred at a rate consistent withTaqpolymerase error.ConclusionsOur data indicate that in the eBL tumor sample K962, the mechanism underlying c-mycmutation is distinct from that which gives rise to Ig hypermutation.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeIn this article we describe the success of a unique newborn screening program for sickle cell disease and other hemoglobinopathies. We will present and discuss 4 years of experience from the California Newborn Hemoglobinopathy Screening Program.MethodsSeveral aspects that ensure the success of the program will be reviewed. These aspects include (a) the use of high-pressure liquid chromatography as the initial screening technique, (b) a confirmatory testing laboratory that incorporates DNA technology and innovative protein analysis using electrospray mass spectrometry, and (c) a complex follow-up strategy that employs regional nurses to track positive results and ensure timely enrollment of infants into treatment systems.ResultsOf these 2 million infants screened, 492 were diagnosed with some form of sickle cell disease; 290 (58.9%) were diagnosed with hemoglobin SS, 143 (29.0%) were diagnosed with hemoglobin SC, and 47 (9.5%) were diagnosed with Sβ+thalasemia.ConclusionThe prevalence and ethnicity data presented here demonstrate the ineffectiveness of targeted screening and justify universal screening. Had targeted screening been performed in California during the past 4 years, 58 nonblack infants with sickle cell disease would have gone undiagnosed, and 6,921 nonblack infants with sickle cell trait would not have been identified.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeOtotoxicity often limits the dose of desferrioxamine (DFO) tolerated by patients who are transfusion dependent. Current recommendations advise doses ofMethodsWe followed 28 patients who were chronically chelated with serial audiograms over a 5-year period. Patients with and without ototoxicity were compared with respect to age, disease, DFO dose, peak DFO dose, length of DFO therapy, ferritin, and therapeutic index.ResultsEight of the 28 patients (29%) had an abnormal audiogram during threshold testing. Two patients had two separate episodes with hearing deficit. Nine of the 10 episodes were highfrequency losses, with seven being moderate and three mild. All deficits were rapidly reversible with DFO dose reduction. No significant differences were found between the affected and unaffected groups with respect to age, DFO dose or duration, feritin, or therapeutic index. Numbers of afected patients were small, but patients with SCD differed from patients with thalassemia in that they developed ototoxicity earlier and with lower doses of DFO and lower therapeutic indexes.ConclusionsDespite DFO doses usually felt to be low risk for ototoxicity, we found a high rate of ototoxicity in our patients who we've chronically chelated. No variables were identified that reliably predicted ototoxicity. We stress the need for regular audiological exams and feel no dose of DFO is “safe” from the development of ototoxicity.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeThis research was undertaken to determine the advantages, complications, costs, and efficacy of erythrocytapheresis in young pediatric patients who receive chronic erythrocyte transfusion therapy.Patients and MethodsWe retrospectively analyzed data for 10 children who received erythrocytapheresis for an average of 16 months. Erythrocytapheresis was compared to simple transfusion therapy with respect to annual blood unit exposure, occurrence of alloimmunization, and costs. Serum ferritin levels were compared before and after the period of erythrocytapheresis.ResultsErythrocytapheresis was well tolerated, even in children as young as 5 years or as small as 20 kg. It required a greater annual unit exposure than simple transfusions, but did not increase alloimmunization. Ferritin levels decreased significantly in children receiving concurrent deferoxamine, and decreased or stablized in those not on chelation therapy. Children started on erythrocytapheresis soon after stroke have not developed iron overload. Although the costs of erythorocytapheresis exceed that of simple transfusion, the substantial costs of deferoxamine therapy should be considered; one child on erythrocytapheresis has been able to discontinue chelation therapy following normalization of his ferritin level.ConclusionErythrocytapheresis is a safe and effective method for young patients receiving chronic erythrocyte transfusions. Erythrocytapheresis can reduce total iron burden and may obviate the need for expensive chelation therapy.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID

摘要:

PurposeThis research was undertaken to determine the relative sensitivity of scintigraphic and radiographic bone survey examinations in detecting bone lesions in various regions of the skeleton in patients with a histopathologic diagnosis of Langerhans cell histiocytosis (LCH).Patients and MethodsRadionuclide skeletal scintigraphy (RNSS) and x-ray skeletal surveys (XRSS) of 42 children with a histopathologic diagnosis of LCH were evaluated retrospectively.ResultsOf the 191 lesions detected in 42 patients, 36 (19%) were missed on RNSS and 55 (29%) were missed on XRSS. Most of the missed lesions on RNSS were in the skull (26 of 36). XRSS also missed 13 skull lesions seen on RNSS. Most of the lesions missed on XRSS were in the ribs (20 of 30 rib lesions), where as RNSS identified 29 of them. XRSS also missed 13 of 38 lesions in the spine and pelvis, while RNSS demonstrated all of them. Both modalities showed comparable sensitivity in the extremities.ConclusionRNSS has a greater value in detecting sites of bone involvement with LCH than reported previously. RNSS is more sensitive than XRSS in detecting histiocytic lesions in the ribs, spine and pelvis and less sensitive in identifying lesions in the skull.

ISSN:1077-4114    

出版商:OVID    

年代:1996

数据来源: OVID