Physiological neutrophilia of pregnancy is not associated with a rise in plasma granulocyte colony-stimulating factor (G-CSF)

A patient with neutropenia and life-threatening infections secondary to T-γ lymphoproliferative disease, who did not respond to treatment with recombinant human G-CSF (filgrastim), was treated with filgrastim plus cyclosporine A (CyA). The patient achieved a good response in the absolute neutrophil count and subsequently required a dose reduction in the filgrastim. The patient was eventually discontinued from the CyA but continues on filgrastim alone. While on therapy, the large granular lymphocytes disappeared from the circulation and the beta-TCR rearrangement, which was present prior to beginning therapy, became undetectable. The patient had no significant toxicity to the CyA or the filgrastim and he has not experienced any serious infections or required hospitalization. Filgrastim has proven to be relatively nontoxic and of some benefit to patients with this disease and should probably be utilized first when treatment is necessary. However, if improvement is not observed, these findings suggest that a trial of the combination of CyA plus filgrastim may be beneficial.     

Utility of clinical comprehensive genomic characterization for diagnostic categorization in patients presenting with hypocellular bone marrow failure syndromes

Bone marrow failure (BMF) related to hypoplasia of hematopoietic elements in the bone marrow is a heterogeneous clinical entity with a broad differential diagnosis including both inherited and acquired causes. Accurate diagnostic categorization is critical to optimal patient care and detection of genomic variants in these patients may provide this important diagnostic and prognostic information. We performed real-time, accredited (ISO15189) comprehensive genomic characterization including targeted sequencing and whole exome sequencing in 115 patients with BMF syndromes (median age 24 years, range: 3 months - 81 years). In patients with clinical diagnoses of inherited BMF syndromes, acquired BMF syndromes or clinically unclassifiable BMF we detected variants in 52% (12 of 23), 53% (25 of 47) and 56% (25 of 45) respectively. Genomic characterization resulted in a change of diagnosis in 30 of 115 (26%) including the identification of germline causes for 3 of 47 and 16 of 45 cases with pre-test diagnoses of acquired and clinically unclassifiable BMF respectively. The observed clinical impact of accurate diagnostic categorization included choice to perform allogeneic stem cell transplantation, disease-specific targeted treatments, identification of at-risk family members and influence of sibling allogeneic stem cell donor choice. Multiple novel pathogenic variants and copy number changes were identified in our cohort including in TERT, FANCA, RPS7 and SAMD9. Whole exome sequence analysis facilitated the identification of variants in two genes not typically associated with a primary clinical manifestation of BMF but also demonstrated reduced sensitivity for detecting low level acquired variants. In conclusion, genomic characterization can improve diagnostic categorization of patients presenting with hypoplastic BMF syndromes and should be routinely performed in this group of patients.     

Studies of oral neutrophil levels in patients receiving G-CSF after autologous marrow transplantation

Patients are at risk of mucositis and infections in the oral cavity during the neutropenic period after chemotherapy, which are significant causes of morbidity. In phase I/II studies with the haemopoietic growth factor granulocyte colony stimulating factor (G-CSF), a reduction in post-chemotherapy mucositis has been observed in addition to haematologic effects. To understand this phenomenon better in patients receiving G-CSF following high-dose chemotherapy with autologous bone marrow transplantation (ABMT), we studied the effects of G-CSF on levels of neutrophils recoverable from the oral cavity using a quantitative mouthrinse assay. In normal subjects, mouthrinses contained 472 +/- 329 x 10(3) neutrophils/mouthrinse. After chemotherapy followed by ABMT, mouthrinse neutrophil levels decreased to undetectable levels during the neutropenic period, but recovered 1-2 and 3-9 d before circulating neutrophil levels reached 0.1 and 1 x 10(9)/l respectively, whether or not patients received G-CSF. In patients who received G-CSF, the mean cumulative mucositis score was reduced from 35 +/- 9 to 21 +/- 12 (P < 0.05), and the maximum mean daily mucositis score was reduced from 2.8 +/- 0.5 to 1.7 +/- 0.9 (P < 0.01), compared to patients who did not receive G-CSF after ABMT. These studies provide in vivo evidence that neutrophils produced during G-CSF therapy are available to leave the circulation and enter tissues where their function is required for host defence. Since the usual temporal relationship between oral and peripheral blood neutrophil recovery was preserved during G-CSF administration after ABMT, these data support the hypothesis that the reduction in post-ABMT mucositis observed with G-CSF therapy may reflect a beneficial effect of G-CSF on the kinetics of oral mucosal neutrophil recovery in addition to the effect of G-CSF to accelerate peripheral blood neutrophil recovery.     

Thrombolysis in acute stroke under dual antiplatelet therapy: perspectives arising from translational studies

正We have recently established a mouse model of focal stroke under dual antiplatelet therapy (DAPT) to study tissue plasminogen activator (tPA)-associated hemorrhagic transformation.The purpose of this short perspective is to discuss the rationale for establishing the model,highlighting its relevance for addressing unresolved clinical questions.Hemorrhagic conversion of the ischemic stroke remains one of the major liabilities of thrombolytic therapy with tPA,contributing to unfavorable outcomes and failed regeneration.This was recognized early on,and the resulting restrictions on t PA usage have led to only a minor percentage of stroke patients receiving any kind of     

Comparison of effects of the tyrosine kinase inhibitors AG957, AG490, and STI571 on BCR-ABL--expressing cells, demonstrating synergy between AG490 and STI571

STI571 (formerly CGP57148) and AG957 are small molecule inhibitors of the protein tyrosine kinase (PTK) p145(abl) and its oncogenic derivative p210(bcr-abl). AG490 is an inhibitor of the PTK Janus kinase 2 (JAK2). No direct comparison of these inhibitors has previously been reported, so this study compared their effects on factor-dependent FDC-P1, 32D, and MO7e cells and their p210(bcr-abl)-expressing factor-independent derivatives. STI571 was a more potent inhibitor of (3)H-thymidine incorporation in p210(bcr-abl)-expressing cells than was AG957, and it showed superior discrimination between inhibitory effects on parental cell lines and effects on their p210(bcr-abl)-expressing derivatives. Assays performed with and without growth factor demonstrated that STI571 but not AG957 reversed the p210(bcr-abl)-driven factor independence of cell lines. p210(bcr-abl)-expressing cells were less sensitive to AG490 than to AG957 or STI571. However, for p210(bcr-abl)-expressing clones from all 3 cell lines, synergistic inhibition was demonstrated between STI571 and concentrations of AG490 with no independent inhibitory effect. Inhibition of nucleic acid synthesis with AG957 treatment was associated with reduced cell numbers, reduced viability, and small pyknotic apoptotic cells. At concentrations of STI571 that reversed the p210(bcr-abl) factor-independent phenotype, STI571 treatment and growth factor deprivation together were sufficient to induce apoptosis. This study concludes that, for the cell lines studied, (1) STI571 is a more potent and more selective inhibitor of a p210(bcr-abl)-dependent phenotype than AG957; (2) AG490 synergizes with STI571 to enhance its inhibitory effect on p210(bcr-abl)-driven proliferation; and (3) the combination of p210(bcr-abl)-tyrosine kinase inhibition and growth factor signal withdrawal can be sufficient to induce apoptotic death of transformed cells. (Blood. 2001;97:2008-2015)     

BCR-ABL酪氨酸激酶抑制剂STI571选择性诱导K562细胞凋亡

目的 探讨STI571抑制慢性髓性白血病（CML）细胞株增殖的机理及特异性。方法 选用非特异性的凋亡诱导剂阿霉素和BCR－ABL阴性的白血病细胞株MO7E作为对照，观察两种抑制剂作用下两种细胞形态学的改变和胞浆DNA电泳图的改变。结果 STI571可诱导K562细胞凋亡，而对MO7E细胞无致凋亡作用；阿霉素可诱导MO7E细胞凋亡，而对K562细胞无诱导凋亡作用。结论 STI571通过阻断BCR－ABL酪氨酸激酶活力，促进K562细胞凋亡达到抑制细胞增殖的目的，而对不表达BCR－ABL的细胞株无诱导凋亡的作用，提示STI571的作用具有一定的特异性。