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排序方式: 共有347条查询结果,搜索用时 15 毫秒
101.
Williamson LM; Wimperis JZ; Williamson P; Copplestone JA; Gooi HC; Morgenstern GR; Norfolk DR 《Blood》1994,83(10):3028-3035
To test the efficacy of poststorage bedside leucodepletion of blood products in the prevention of primary HLA alloimmunization and its clinical sequelae, 172 patients with hematologic malignancy requiring intensive red blood cell and platelet support were randomized to receive either standard or filtered red blood cells and platelets. Quality control of bedside filtration was explored by sequential sampling downstream of the filter, but this did not predict the total number of leucocytes transfused. After exclusions, 123 evaluable patients were assessed every two weeks until the end of therapy. HLA antibodies developed in 21 of 56 (37.5%) nonfilter (NF) and 15 of 67 (22%) filter (F) patients (risk ratio estimate, 0.60 [95% confidence interval, 0.34 to 1.05]; P = .07). Patients with acute myeloid leukemia (AML; n = 53) had higher alloimmunization rates in both arms of the study, with a greater effect of filtration (62.5% NF and 31.0% F; P = .025). Bedside filtration did not affect the overall incidence of febrile transfusion reactions (FTRs; 37% NF and 34% F; P = .71) or of platelet refractoriness assessed in 50 patients (30% NF and 26% F), despite an association between broad HLA reactivity and both FTRs and refractoriness. However, FTRs were also seen in 28 patients without HLA antibodies. Five alloimmunized refractory patients (2 F and 3 NF) required HLA-selected platelets. This report, the first prospective study of bedside filtration, has failed to show clear clinical benefit. Methodological limitations may account in part for this failure, notably the difficulties in accurately assessing the number of leucocytes transfused. 相似文献
102.
The alpha globin genotype of a total of 282 Indians from Orissa state has been analyzed. The overall alpha thalassemia gene frequency is 0.29, most frequently caused by the -alpha 3.7 and -alpha 4.2 deletions. In one family a novel -alpha 3.5 deletion removing the alpha 1 globin gene with some of its flanking sequences has been found, suggesting further sequence homology of the alpha globin gene cluster 3' to the alpha 1 globin gene. Patients with sickle cell disease and alpha thalassemia had higher hemoglobin (Hb) levels, RBC counts, and Hb A2 levels, and lower reticulocyte counts, MCV, MCH, and Hb F levels than those with a normal alpha genotype. The frequency of splenomegaly was not influenced by the alpha globin genotype. A higher prevalence of alpha thalassemia was found in patients greater than or equal to 10 years of age than in the younger group, suggesting a possible advantageous effect of alpha thalassemia on the survival of patients with sickle cell disease. 相似文献
103.
GR Velloso MM de Freitas ATNN Alves ARS Silva ESP Barboza V Moraschini 《Australian dental journal》2017,62(4):528-533
Invasive multiple cervical root resorptions after vital tooth bleaching is a rare condition. The aim of this article is to present a case of multiple external cervical root resorptions (ECRR) after a misguided home whitening treatment. A 34 year old male patient presented with slight sensitivity and mobility in several teeth. Despite the manufacturer's recommendations, the patient used a 22% carbamide peroxide‐based tooth bleaching gel at home for 4 days consecutively, at night, on the upper and lower arches. Clinical examination revealed gingival swelling, probing depths ranging 5–7 mm on the buccal and proximal surfaces, and grade 2 mobility of the teeth affected by ECRR. Radiographs revealed presence of ECRR in several teeth during initial examination, and development of multiple new lesions 6 months later. The teeth were subsequently extracted. Histological analysis showed multiple dentine lacunae and areas of dentine reparation. The careful use of these products can prevent sequelae such as those reported in this clinical case. As the vital bleaching has a variable success rate, patients should be informed through a consent form of the benefits and risks of tooth bleaching treatment. 相似文献
104.
Many children with acute lymphoblastic leukemia (ALL) develop a marrow relapse during or shortly following initial continuation chemotherapy. Achievement of a second complete remission is the initial step in a successful retreatment effort. Reinduction results using two or three drugs have been unsatisfactory, and previous reports of four-drug reinduction programs have included relatively small numbers of patients. Pediatric Oncology Group protocol 8303 was designed for patients with ALL in first marrow relapse during or within 6 months after cessation of chemotherapy. The results of reinduction therapy in 297 study patients are described here. Four-drug reinduction therapy consisted of daily oral prednisone, weekly vincristine and daunorubicin, and asparaginase three times weekly for 4 weeks (PVDA). CNS retreatment consisted of two doses of triple intrathecal chemotherapy. Of the 297 patients receiving reinduction, 245, or 82%, entered second complete remission, six died of infection or progressive disease, and 46 others still had M2 or M3 bone marrow status. Forty of these latter patients received four doses (during a 2-week period) of teniposide and cytarabine, after which 13 (32%) achieved complete remission status. Thus, the overall second complete remission rate with PVDA with or without teniposide/cytarabine was 258 of 297, or 87%. The treatment program was generally well tolerated. Among the numerous factors analyzed by using logistic regression, only female sex (P = .035), the presence of blasts on the blood smear at the time of relapse (P = .0002), and a length of initial complete remission less than 12 months (P = .021) were independent predictors of failure to enter second remission. We conclude that the intensive reinduction program described here is a highly effective first step in the delivery of salvage therapy to patients with ALL in first marrow relapse. The current challenge is to develop improved continuation treatment for these children. 相似文献
105.
Kitchingman GR; Mirro J; Stass S; Rovigatti U; Melvin SL; Williams DL; Raimondi SC; Murphy SB 《Blood》1986,67(3):698-703
We examined the arrangement of the mu heavy-chain immunoglobulin (Ig) genes in the leukemic blast cell DNA of 93 children with acute lymphoblastic leukemia (ALL). All cases met morphologic and cytochemical criteria for ALL, lacked detectable T cell surface antigens, and expressed HLA-DR (Ia) antigens. Eighty-three of the 93 patients (89%) were positive for the common acute lymphoblastic leukemia antigen (CALLA), and 20 of 91 (22%) tested had detectable cytoplasmic immunoglobulin. As expected, the heavy-chain lg gene was rearranged in all cases, and the pattern of rearrangements was variable; 23 had one allele rearranged and one in the germ line configuration; 15 had one rearranged and one deleted; and 37 had two rearranged. Unexpectedly, in 18 patients the presence of more than two mu gene-hybridizing bands was detected. Combinations of enzymes and heavy-chain gene probes were used to confirm that the extra bands were not the result of underdigestion of the DNA or DNA restriction site polymorphism. In eight of the 18 patients, we identified an extra chromosome 14 as a possible cause of the extra bands' hybridizing to the mu heavy-chain constant-region probe. In the remaining ten patients, the presence of three or four bands hybridizing with the mu probe suggests the presence of two populations of leukemic cells that may have arisen either by separate leukemic transformation events or by clonal evolution of one clone into two related lines. Although preliminary (2-year follow-up), our data suggest that childhood ALL of B lineage with more than two mu heavy-chain genes, but without extra copies of chromosome 14, may be more resistant to therapy. 相似文献
106.
染色体脆性位点表达与Ⅱ型糖尿病关系的探讨曾平郭英周迎生一、对象与方法1995年5~12月,我们探讨了染色体脆性位点(fra)的表达与Ⅱ型糖尿病(NIDDM)的关系。实验组为10例老年NIDDM患者,年龄60~69岁,男4例,女6例,2例并发肾病,均有... 相似文献
107.
Hemoglobin variants having electrophoretic mobility more rapid than that of HbA were identified in combination with sickle hemoglobin in two patients at the Cook County Hospital. Neither individual had symptomatic hematologic disease. In one patient, the rapidly migrating hemoglobin had the amino acid substitution characteristic of Hb Tacoma (beta-40 arg leads to ser), a mildly unstable variant. In the other patient, Hb Camden (beta-131 gln leads to glu) was identified, and the hematologic findings also indicated that he has alpha-thalassemia trait. In the patient with HbS-Camden--alpha-thalassemia, globin synthesis was unbalanced (alpha/beta 0.66), and HbS represented only 19.5% of the total hemoglobin. The latter finding suggests that under conditions of limited alpha-chain availability beta Camden may combine with alpha subunits at least as efficiently as does betaA. HbS represented 56% of the hemoglobin of the patient with HbS Tacoma, although the rate of synthesis of beta Tacoma by her reticulocytes was consistently greater than that of betaS. A time-course synthesis study demonstrated a progressive increase in the specific activity of beta Tacoma in relation to that of betaS, suggesting that the unstable beta- chains of Hb Tacoma underwent selective intracellular degradation. This process appears to explain the disparity between the rates of synthesis of the two beta chains and the relative representation of HbS and Hb Tacoma in the patient's erythrocytes. 相似文献
108.
Purification and properties of bacterially synthesized human granulocyte-macrophage colony stimulating factor 总被引:16,自引:0,他引:16
Burgess AW; Begley CG; Johnson GR; Lopez AF; Williamson DJ; Mermod JJ; Simpson RJ; Schmitz A; DeLamarter JF 《Blood》1987,69(1):43-51
Human granulocyte-macrophage colony stimulating factor (GM-CSF) has been synthesized in high yield using a temperature inducible plasmid in Escherichia coli. The human GM-CSF is readily isolated from the bacterial proteins because of its differential solubility and chromatographic properties. The bacterially synthesized form of the human GM-CSF contains an extra methionine residue at position 1, but otherwise it is identical to the polypeptide predicted from the cDNA sequence. The specific activity of 2.9 X 10(7) units/mg of protein for purified bacterially synthesized human GM-CSF indicates that despite the lack of glycosylation, the molecule is substantially in its native conformation. This molecule stimulated the same number and type of both seven- and 14-day human bone marrow colonies as the CSF alpha preparation from human placental conditioned medium. Human GM-CSF had no activity on murine bone marrow or murine leukemic cells. There was no detectable, direct stimulation of adult human erythroid burst forming units (BFU-E) by the bacterially synthesized human GM-CSF. Although impure preparations containing native human GM-CSF (eg, human placental conditioned medium) stimulated the formation of mixed colonies, even in the presence of erythropoietin, the bacterially synthesized human GM-CSF failed to stimulate the formation of mixed colonies from adult human bone marrow cells. The bacterially synthesized human GM-CSF increased N-formyl-methionyl-leucyl- phenylalanine (FMLP)-induced superoxide production and lysozyme secretion. Antibody-dependent cytotoxicity and phagocytosis by human neutrophils was stimulated by the bacterially synthesized human GM-CSF and eosinophils were also activated in the antibody-dependent cytotoxicity assay. 相似文献
109.
Retrovirus-mediated gene transfer was used to obtain expression of the macrophage colony-stimulating factor (MCSF) receptor, c-fms, on hematopoietic lineages that normally do not express this receptor. Cultures of murine fetal liver cells infected with the c-fms retrovirus developed erythroid colonies in cultures stimulated with M-CSF. However, these colonies were fewer and less hemoglobinized than colonies in parallel cultures stimulated by erythropoietin. Culture of isolated clones demonstrated a direct action of M-CSF on erythroid clones. Culture of c-fms retrovirus-infected adult murine bone marrow cells showed megakaryocyte and novel macrophage-megakaryocyte clones when stimulated by M-CSF. Culture of isolated clones again confirmed a direct action of M-CSF on megakaryocyte clones. In contrast, M-CSF stimulation of c-fms-infected granulocytes and granulocyte progenitor cells did not elicit proliferation, enhanced survival, or functional stimulation of granulocytes. These findings provide evidence for both conservation and lineage restriction of signal transduction in normal hematopoietic cells. 相似文献
110.
Immunoregulation of B lymphocyte colony formation by T cell subsets in patients with chronic lymphocytic leukemia 总被引:1,自引:0,他引:1
Normal B lymphocytes are activated, proliferate, and then differentiate into plasma cells and secrete immunoglobulin (Ig). We have reported that chronic lymphocytic leukemia (CLL) T4 cells help and CLL T8 cells lack suppressor effects on Ig synthesis by normal B cells (Blood 62:767, 1983). We have now explored the earlier phase, proliferation, using B cell colony formation; in semisolid media. B lymphocyte colonies from normal individuals and from patients with CLL were grown in 0.3% agarose overlayed with T cells or T cell subsets and the B cell mitogen staphylococcal protein A. Enriched T cells, OKT4 or OKT8, were obtained either by sheep erythrocyte rosettes or depletion of OKT8 or OKT4 cells by monoclonal antibody or complement, respectively. Twenty thousand B cells from normal subjects yielded 65 +/- 9, 64 +/- 7, and 19 +/- 6 colonies with autologous unfractionated T-, OKT4-, or OKT8- positive cells, respectively. This compared to 29 +/- 11, 81 +/- 11, and 15 +/- 4 colonies from patients with CLL with added autologous unfractionated T-, OKT4-, or OKT8-positive cells. To determine whether the fewer number of colonies in both normal subjects and patients with CLL with OKT8-positive cells was due to suppression or lack of help, the number of OKT4-positive cells was held constant, and OKT8-positive cells were added in increasing numbers. No suppression of colony formation could be demonstrated. Furthermore, the addition of increasing numbers of concanavalin A (Con A)-activated OKT8-positive cells did not suppress colony formation. These results suggest that the CLL T cell subsets behave in a functionally similar manner to normal T cell subsets, namely, (1) that normal and CLL B cell colony growth is helped by OKT4 cells; and (2) in contrast to immunoglobulin secretion by B cells, neither normal nor CLL OKT8 cells, unstimulated or activated by Con A, suppress B cell colony growth. 相似文献