摘要:

AbstractThis study was aimed at purifying the progenitors of erythroid burst units (BFU‐E) from human peripheral blood. Human mononuclear leukocytes from five normal donors were fractionated into several mononuclear cell subpopulations, including null lymphocytes with (null Fc+) and without (null Fc−) receptor for the Fc fragment of immunoglobulin G, through a succession of rosetting procedures and discontinuous Ficoll‐Hypaque gradient centrifugations. The fractionated cells were separately cultured for 14 days in plasma clots in the presence of erythropoietin. Among fractionated cell subpopulations large and numerous BFU‐E derived colonies grew only from the Fc−null lymphocyte subpopulation. This fraction, representing less than 4% of all mononuclear cells, also contains cells (42 + 11%) capable to differentiation towards the B‐cell and plasma‐cell lineages. The Fc+null Imphocytes, representing less than 9% of all mononuclear cells, contained 15.2 + 3.3% cells capable of differentiation toward the T‐cell lineage. The whole null lymphocyte subpopulation generated half the number of BFU‐E colonies expected from its content in Fc−null lymphocytes. These data demonstrate that the progenitor of erythroid cells (BFU‐E) resides in a small heterogenous null Fc−subpopulation of circulating lymphocytes and suggest that its in vitro differentiation, though generally subjected to inhibitory and enhancing influences from other circulating cell subpopulations, does not necessarily require interaction with other

ISSN:0361-8609    

DOI:10.1002/ajh.2830190202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPainful vasocclusive episodes are one of the most prominent pathological features of sickle cell disease. In addition to abnormal shape and poor deformability, increased adhesion of red cells to endothelium has been reported. On several occasions, we have studied the adhesion of erythrocytes from 30 patients with mixed sickle cell syndromes to evaluate the influence of clinical conditions. The percentage of erythrocytes adhering was significantly higher when erythrocytes from sickle patients were compared with controls (p<0.01). Furthermore, adhesion was significantly higher when the patients were in crises (p<0.01), and the highest values of all were observed in patients with inflammatory conditions. To investigate the possibility that a limited population of red cells could be responsible for the increase in red cell adhesion, we have measured the HbS concentration in the different washes and found that the HbS concentration was higher in the last washes compared to the first washes. Sickle red cells capable of protein synthesis (young red cells) were labelled with [3H] leucine. The adhesion to endothelial cells of [3H] leucine‐labelled red cells was higher than that of the51Cr‐labelled red cells from the same patient. On the other hand, the most dense sickle red cells separated by density gradient adhered to a greater extent than the light red cells. This apparent discrepancy could be partly explained by the presence of [3H] leucine‐labelled red cells in the dense fractions of sickle red cells separated by stractan gra

ISSN:0361-8609    

DOI:10.1002/ajh.2830190203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effect of the thiol‐oxidizing agent diamide on erythrocyte (Ca+2+Mg+2)‐ATPase activity was measured in normal and glucose‐6‐phosphate‐dehydrogenase‐deficient (G6PD−) cells. Although the enzyme activity before the oxidative stress was similar in both groups, diamide induced a markedly greater inhibition in the enzyme activity in the G6PD−cells than in the normal controls. These data indicate dependence of erythrocyte (Ca+2+Mg+2)‐ATPase, in part, on the redox status of the cell. The increased vulnerability of (Ca+2+Mg+2)ATPase to oxidative stress in G6PD−may be of pathophysiological relevance to their premature destruction in oxidan

ISSN:0361-8609    

DOI:10.1002/ajh.2830190204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractPatients with sickle cell anemia vary in the severity of their symptoms but the basis of this variability is unknown. We have tested the hypothesis that this variability is related to differences in the activity of the antioxidant superoxide dismutase (SOD). The amount of superoxide dismutase I (SOD) enzyme activity in red cells of patients with different degrees of symptom severity and healthy black and white controls was measured and correlated with symptom severity in SCA patients. Blacks with normal (AA) hemoglobin had significantly (p<0.001) more SOD activity (1.82 U/mg Hb) than white controls (1.44 U/mg Hb). Patients with moderate or severe symptoms had less SOD activity (1.16 and 0.95 U/mg Hb, respectively) than control blacks or SCA patients with mild symptoms (1.62 U/mg Hb). The correlation of SOD activity and symptom severity was not a function of age or sex and was unrelated to reticulocyte count or fetal hemoglobin level.

ISSN:0361-8609    

DOI:10.1002/ajh.2830190205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThis study determined the prevalence and clinical significance of a positive direct antiglobulin test (DAT) observed in pretransfusion tests on red cells from patients with acquired immunodeficiency syndrome (AIDS). Transfusion service records showed that prevalence of a positive DAT on red cells was 18% (10/55) in AIDS patients compared to 0.6% in general hospital patients during a 2‐year period (1981‐1983). A similar rate of 18% (8/45) was observed in other hyperglobulinemic patients. Of the 10 AIDS patients whose red cells were DAT positive, four had IgG and complement, four had IgG, and two had complement alone on their red cells. The eluates were not reactive with normal red cells nor with penicillin or cephalothincoated red cells. Clinically, no hemolysis was observed. In this series a positive DAT in AIDS patients appeared not to be associated with autoimmune hemolytic anemia. The positive DAT in AIDS patients may be due to the hyperglobulinemic st

ISSN:0361-8609    

DOI:10.1002/ajh.2830190206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe influence of Zn+2on fibrin clot formation was investigated by measuring its effect on the clotting times of fibrinogen exposed to thrombin. It was observed with either human or bovine thrombin that 0.01‐0.1 mM Zn+2induced significant reductions of clotting times in a concentration‐dependent manner. The procoagulant effect of Zn+2occurred in the presence of Ca+2but was inhibited by metal chelating agents. Higher levels of Zn+2(>0.2 mM final concentration) were required to accelerate thrombin‐induced clot formation in the presence of citrate or oxalate. Similarly with oxalated human plasma,>0.2 mM Zn+2decreased the clotting time. Cations such as Mg+2and Mn+2caused little change in clotting times. As an extension of these findings, we examined the effect of Zn+2on the in hibition of thrombin by antithrombin‐III (AT‐III). The presence of as little as 0.006 mM Zn+2in an incubating mixture of thrombin and AT‐III severely reduced the inhibitory activity of AT‐III towards thrombin. It was observed that the relative intrinsic fluorescence emission of human thrombin decreased upon exposure to Zn+2but was unaffected by Mg+2or Mn+2. It is suggested that Zn+2can form a complex with thrombin, which results in altered reactivity towards fibrinogen and decreased inhibit

ISSN:0361-8609    

DOI:10.1002/ajh.2830190207

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe role of the spleen as a reservoir capable of adding platelets to the circulating blood cells has been well documented in animals but poorly documented in humans. As part of a program of platelet cryopreservation, we have intensively plateletpheresed a group of patients with acute leukemia in remission who had undergone splenectomy. The results of the 64 plateletphereses in these 11 patients (average platelet yield 4.2 × 1011± 2.4, range 1.2‐12.4) were compared with 50 consecutive plateletphereses in nonsplenectomized leukemia patients (average yield 4.9 × 1011± 3.2, range 2.1‐18.3) and 50 consecutive plateletphereses in normal donors (average yield 3.8 × 1011± 1.4, range 1.7‐7.6). There was no difference in the prepheresis platelet counts among the three groups. Plateletphereses were done in 1.5‐3 hr by intermittent flow differential cell centrifugation technique. The expected platelet yield was calculated by multiplying the pre‐platelet count –(pre‐hct/post‐hct × post plt count) by the estimated blood volume (70 ml/per kg body weight). The mean ratios of the observed platelet yield to expected platelet yield were similar for the nonsplenectomized leukemia patients (mean ratio = 1.32 ± 0.50, range 0.73‐3.04) and normal donors (mean ratio = 1.31 ± 0.49, range 0.52‐2.9), implying mobilization of platelets from outside of the blood pool. In contrast, in the splenectomy group, the mean ratio (0.76 ± 0.32, range 0.31‐2.9) was significantly lower (p<0.001). These data indicate that there is replenishment of the circulating platelet pool by the spleen in response to

ISSN:0361-8609    

DOI:10.1002/ajh.2830190208

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractForty patients with acute nonlymphocytic leukemia (ANLL) in first relapse were treated at eight member institutions of the Leukemia Intergroup with a 10‐day continuous intravenous infusion of cytosine arabinoside and an anthracycline antibiotic administered on days 1, 2, and 3. Twenty of the 40 patients achieved a complete response. Seven of the patients who did not enter remission were drug‐resistant failures, while 13 patients failed to enter remission for reasons other than persistent leukemia. Pretreatment parameters such as age, presence of infection, platelet count, and liver function tests were important predictors of survival. The percent bone marrow cellularity, the percent circulating abnormal (leukemic) cells, and the height of the white blood cell count prior to treatment were helpful in distinguishing patients who would enter remission from those who would not enter remission because of persistent leuke

ISSN:0361-8609    

DOI:10.1002/ajh.2830190209

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractIn 22 patients with CLL given 30 courses of spleen irradiation, 23 responses were observed (77%, 95% confidence limits, 58‐90%). Response was defined as reduction in palpable spleen size accompanied by relief of symptoms (pain, abdominal discomfort, and sweating) or improvement in hypersequestration or hemolytic anemia. Reduction in leukocyte count alone was not regarded as response. All responses were partial. The median response duration was 1 year. Subsequently, three patients underwent splenectomy. The median survival from the beginning of spleen irradiation was 2.5 years (range: 1 month‐>5 years). Only six patients had minor side effects from the gastrointestinal tract. The hematologic effect was most pronounced on the white blood cell count, but also the platelet count was affected. It is concluded that spleen irradiation is a gentle and effective alternative in CLL patients suffering from splenomegaly (pain and hypersplenism), refractory to chemotherapy and glucocorti‐costeroids and unfit for splenectomy. Splenic irradiation may also be used with benefit preoperatively before splenectomy in patients with excessive splenomegaly and hyperspl

ISSN:0361-8609    

DOI:10.1002/ajh.2830190210

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractIn a patient with pulmonary hypertension and a history of recurrent venous thrombosis, plasma concentrations of all known coagulant and inhibitor proteins were normal except for severe deficiency of plasminogen. Repeated analyses showed the circulating plasma plasminogen level to be 30% of normal by either functional or immunologic methods. We sought evidence for either increased activation of plasminogen or for dysplasminogen. There was no evidence for the former. Purified plasminogen studies disclosed a normal number of active sites and normal activation. Generated plasmin had normal catalytic activity. Isoelectric focusing disclosed normal distribution of isoforms. Affinity chromatography with lysine‐sepharose showed the presence of the two variant forms; however, an increased proportion of the protein eluted in the first peak. Danazol administration induced an increase in circulating plasminogen, but the differences in affinity chromatography elution profile remained. We conclude that this patient has a deficiency of normally functioning plasminogen, probably due to decreased synthesi

ISSN:0361-8609    

DOI:10.1002/ajh.2830190211

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY