ROBO1 deficiency impairs HSPC homeostasis and erythropoiesis via CDC42 and predicts poor prognosis in MDS.

Myelodysplastic syndrome (MDS) is a group of clonal hematopoietic neoplasms originating from hematopoietic stem progenitor cells (HSPCs). We previously identified frequent roundabout guidance receptor 1 (ROBO1) mutations in patients with MDS, while the exact role of ROBO1 in hematopoiesis remains poorly delineated. Here, we report that ROBO1 deficiency confers MDS-like disease with anemia and multilineage dysplasia in mice and predicts poor prognosis in patients with MDS. More specifically, Robo1 deficiency impairs HSPC homeostasis and disrupts HSPC pool, especially the reduction of megakaryocyte erythroid progenitors, which causes a blockage in the early stages of erythropoiesis in mice. Mechanistically, transcriptional profiling indicates that Cdc42, a member of the Rho-guanosine triphosphatase family, acts as a downstream target gene for Robo1 in HSPCs. Overexpression of Cdc42 partially restores the self-renewal and erythropoiesis of HSPCs in Robo1-deficient mice. Collectively, our result implicates the essential role of ROBO1 in maintaining HSPC homeostasis and erythropoiesis via CDC42.

Dynamics of epigenetic regulator gene BCOR mutation and response predictive value for hypomethylating agents in patients with myelodysplastic syndrome.

BACKGROUND: BCOR (BCL6 corepressor) is an epigenetic regulator gene involved in the specification of cell differentiation and body structure development. Recurrent somatic BCOR mutations have been identified in myelodysplastic syndrome (MDS). However, the clinical impact of BCOR mutations on MDS prognosis is controversial and the response of hypomethylating agents in MDS with BCOR mutations (BCORMUT) remains unknown. RESULTS: Among 676 MDS patients, 43 patients (6.4%) harbored BCOR mutations. A higher frequency of BCOR mutations (8.7%) was investigated in patients with normal chromosome, compared to 4.2% in patients with abnormal karyotype (p = 0.040). Compared to the BCORWT patients, the BCORMUT patients showed a higher ratio of refractory anemia with excess blasts subset (p = 0.008). The most common comutations with BCOR genes were ASXL1 (p = 0.002), DNMT3A (p = 0.114) and TET2 (p = 0.148). When the hierarchy of somatic mutations was analyzed, BCOR mutations were below the known initial mutations (ASXL1 or TET2) but were above U2AF1 mutations. Transformation-free survival was significantly shorter in BCORMUT patients than that in BCORWT patients (16 vs. 35 months; p = 0.035). RNA-sequencing was performed in bone marrow mononuclear cells from BCORMUT and BCORWT patients and revealed 2030 upregulated and 772 downregulated genes. Importantly, HOXA6, HOXB7, and HOXB9 were significantly over-expressed in BCORMUT patients, compared to BCORWT patients. Eight of 14 BCORMUT patients (57.1%) achieved complete remission (CR) with decitabine treatment, which was much higher than that in BCORWT patients (28.7%, p = 0.036). Paired sequencing results (before and after decitabine) showed three of 6 CR patients lost the mutated BCOR. The median survival of CR patients with a BCORMUT was 40 months, which was significantly longer than that in patients with BCORWT (20 months, p = 0.036). Notably, prolonged survival was observed in three BCORMUT CR patients even without any subsequent therapies. CONCLUSIONS: BCOR mutations occur more frequently in CN MDS patients, predicting higher risk of leukemia transformation. BCORMUT patients showed a better response to decitabine and achieved longer post-CR survival.

Inhibition of PTEN activity promotes IB4-positive sensory neuronal axon growth.

Traumatic nerve injuries have become a common clinical problem, and axon regeneration is a critical process in the successful functional recovery of the injured nervous system. In this study, we found that peripheral axotomy reduces PTEN expression in adult sensory neurons; however, it did not alter the expression level of PTEN in IB4-positive sensory neurons. Additionally, our results indicate that the artificial inhibition of PTEN markedly promotes adult sensory axon regeneration, including IB4-positive neuronal axon growth. Thus, our results provide strong evidence that PTEN is a prominent repressor of adult sensory axon regeneration, especially in IB4-positive neurons.

Decitabine treatment sensitizes tumor cells to T-cell-mediated cytotoxicity in patients with myelodysplastic syndromes.

Decitabine treatment improves immunological recognition that increases expression of cancer-testis antigens (CTAs) against solid tumors. The mechanisms of decitabine enhancement of immunogenicity when used for patients with myelodysplastic syndromes (MDS) remain unclear. In the present study, we found relatively low baseline expression of MAGE-A1, MAGE-A3, and SP17 in MDS-derived cell lines. Decitabine treatment significantly improved MAGE-A1, MAGE-A3, and SP17 expression in these cell lines and in MDS patients. Decitabine-treated K562 and SKM-1 target cells with incrementally induced MAGE-A1, MAGE-A3, or SP17 levels up-regulated T lymphocyte function. Decitabine treatment improved CTA-specific cytotoxic T lymphocyte (CTL) recognition of MDS cells via the up-regulation of CTAs. This response was accompanied by enhanced T lymphocyte function and HLA class antigen expression, and increased ICAM-1. These findings suggested that decitabine may have a broad range of therapeutic applications when it is used in association with active adaptive immunity responses against up-regulated CTAs.

Exploration of the role of gene mutations in myelodysplastic syndromes through a sequencing design involving a small number of target genes.

Novel sequencing designs are necessary to supplement the recognized knowledge of myelodysplastic syndrome (MDS)-related genomic alterations. In this study, we sequenced 28 target genes in 320 Chinese MDS patients but obtained 77.2% of recall factors and 82.8% of genetic abnormalities (including karyotype abnormalities). In addition to known relationships among mutations, some specific chromosomal abnormalities were found to link to specific gene mutations. Trisomy 8 tended to be linked to U2AF1 and ZRSR2 mutations, and 20q- exhibited higher SRSF2/WT1 and U2AF1 mutation frequency. Chromosome 7 involvement accounted for up to 50% of RUNX1 mutations and 37.5% of SETBP1 mutations. Patients carrying a complex karyotype were prone to present TP53 mutations (36.1%). However, individuals with normal karyotypes rarely possessed mutations in the TP53, RUNX1 and U2AF1. Moreover, DNMT3A, TP53, SRSF2, STAG2, ROBO1/2 and WT1 predicted poor survival and high AML transformation. By integrating these predictors into international prognostic scoring system (IPSS) or revised IPSS, we built a set of mutation-based prognostic risk models. These models could layer different degrees of risk in patients more satisfactorily. In summary, this sequencing design was able to detect a number of gene mutations and could be used to stratify patients with varied prognostic risk.

Increased PD-1/STAT1 ratio may account for the survival benefit in decitabine therapy for lower risk myelodysplastic syndrome.

Decitabine is an effective therapy for patients with lower risk myelodysplastic syndrome (MDS). However, the mechanisms of decitabine's therapeutic effect are not well established. Forty-four lower risk MDS patients received decitabine therapy. 59.1% patients achieved treatment response, and 53.8% patients who were RBC/platelet-dependent cast off the transfusion burden. The median overall survival (OS) was 19.0 months after decitabine treatment. Moreover, polarization toward type 1 in the CD8 + subset was enhanced, and a significantly increased expression of the PD-1, PD-L1, and PD-1/STAT1 ratio was observed in these lower risk MDS. The patients with amplification of PD-1/STAT1 ratio (2-4) achieved longer OS. Thus, our results suggest that the effect mechanism of decitabine toward lower risk MDS may be the moderate increase of PD-1/STAT1, which contributes to hematopoietic improvement. These findings suggest that a different PD-1-related strategy from those used to treat higher risk patients could be used for lower risk MDS patients.

Whole-exome and targeted sequencing identify ROBO1 and ROBO2 mutations as progression-related drivers in myelodysplastic syndromes.

The progressive mechanism underlying myelodysplastic syndrome remains unknown. Here we identify ROBO1 and ROBO2 as novel progression-related somatic mutations using whole-exome and targeted sequencing in 6 of 16 (37.5%) paired MDS patients with disease progression. Further deep sequencing detects 20 (10.4%) patients with ROBO mutations in a cohort of 193 MDS patients. In addition, copy number loss and loss of heterogeneity (LOH) of ROBO1 and ROBO2 are frequently observed in patients with progression or carrying ROBO mutations. In in vitro experiments, overexpression of ROBO1 or ROBO2 produces anti-proliferative and pro-apoptotic effects in leukaemia cells. However, this effect was lost in ROBO mutants and ROBO-SLIT2 signalling is impaired. Multivariate analysis shows that ROBO mutations are independent factors for predicting poor survival. These findings demonstrate a novel contribution of ROBO mutations to the pathogenesis of MDS and highlight a key role for ROBO-SLIT2 signalling in MDS disease progression.

Establishment and validation of an updated diagnostic FCM scoring system based on pooled immunophenotyping in CD34+ blasts and its clinical significance for myelodysplastic syndromes.

Abnormal immunophenotypes of hematopoietic cells can be detected by flow cytometry (FCM) to assist the diagnosis of myelodysplastic syndromes (MDS). We previously established a FCM scoring system for the diagnosis of low-grade MDS. In this study, additional valuable antigens were involved in an updated FCM scoring system (u-FCMSS) for all MDS subtypes. The u-FCMSS showed better sensitivity and specificity (89.4% and 96.5%) in distinguishing MDS from non-clonal cytopenia diseases. Validation analysis of u-FCMSS exhibited comparable sensitivity and specificity (86.7% and 93.3%) and high agreement rate (88.9%) of FCM diagnosis with morphological diagnosis at optimal cut-off (score 3). The distribution of FCM scores in different disease stages was also analyzed. The results suggested that early scoring from abnormal expression of mature myeloid/lymphoid antigens and advanced scoring from abnormal expression of stem/progenitor antigens expression constituted the majority of FCM scores of low-grade and high-grade MDS, respectively. High early scoring was generally accompanied by low IPSS-R score and superior survival, whereas high advanced scoring was accompanied by high IPSS-R score and inferior survival. In addition, the low-risk MDS patients with high early scoring and low advanced scoring were revealed as candidates for immunosuppressive therapy, whereas those with high advanced scoring and low early scoring may be more suitable for decitabine treatment. In conclusion, the u-FCMSS is a useful tool for diagnosis, prognosis and treatment selection in MDS. Differences in classes of antigens expressed and in distribution of FCM scores may reflect distinctive stage characteristics of MDS during disease progression.

Distinct clinical and experimental characteristics in the patients younger than 60 years old with myelodysplastic syndromes.

Myelodysplastic syndromes (MDS) mainly occur in elderly individuals in Western countries. However, MDS is commonly found in young individuals (<60 years) in Asia. The reason for the high incidence in younger individuals is still unclear, and the differences in disease features between young and elderly patients with MDS have been not well recognized. To explore these issues, in this study, we analyzed the clinical and experimental characteristics of MDS in the patients younger and older than 60 years old and characterized the potential age-associated differences. The results showed that over half of the patients with MDS (61.9%) were younger than 60 years old upon the first diagnosis. The younger patients were more likely to be female, who have lower risk and less advanced MDS. The occurrence of trisomy 8 and bone marrow failure were more frequent in the younger patients than the older ones. The marrow CD34+ cells in the younger patients showed lower proliferation and higher apoptosis in comparison with that in the older ones. Obvious amplification of T cells and low CFU formation could be found in the younger patients. CFU formation was significantly increased in the younger patients after the removal of activated T cells. In addition, the younger patients had a lower frequency of p15(INK4B) methylation, longer survival expectancy and less AML transformation. In summary, the younger patients with MDS in China may show more benign disease features than the older ones. Enhanced immunological response may be involved in the pathogenesis of MDS in the patients younger than 60 years.

[Comparison of bone marrow biopsy and smear efficacy in patients with multiple myeloma].

This study was aimed to explore the significance of the bone marrow biopsy for the diagnosis of multiple myeloma. Bone marrow smears and bone marrow biopsy originated from 279 cases of multiple myeloma were detected and compared in term of bone marrow hyperplasia, bone marrow plasma cell infiltration, proliferation mode, pathological changes in the bone marrow stroma and myelofibrosis. The results indicated that the levels of proliferation in bone marrow biopsy was significantly higher than that in bone marrow smears. Plasma cell proliferation mode in bone marrow biopsy was not completely consistent with the proportion of plasma cells in bone marrow smears. The myelofibrosis level displayed influence on the consistency of the proliferation between bone marrow smears and biopsies. It is concluded that as compared with bone marrow smears the bone marrow biopsy can more accurately reflect the levels of bone marrow hyperplasia and bone marrow plasma cell infiltration, proliferation mode and so on. Bone marrow biopsy is valuable for multiple myeloma diagnosis.

[Cytogenetic study of autosomal monosomies among myelodysplastic syndrome patients].

Monosomic karyotype (MK) has recently been associated with poor prognosis of myelodysplastic syndromes (MDS). The objective of the current study was to investigate the prevalence and spectrum of autosomal monosomies in an unselected cohort of patients with known or suspected MDS by using retrospective analysis. The results showed that bone marrow cytogenetic studies (1532 cases) were performed between 2004 and 2012, and an abnormal karyotype was found in 538 cases (35.1%). In the 538 cases, 202 (37.5%) cases had autosomal monosomies including sole (n = 47, 23.3%), part of two (n = 33, 21.3%) or more (n = 122, 78.7%) anomalies. Almost all 22 autosomes were involved, but monosomy 7 was by far the most frequent, constituting 66.1% of all isolated monosomies and the highest fraction of those with two or more abnormalities. Other recurrent sole monosomies included chromosomes 20 (15.0%) and 13 (8.5%). Monosomy 13 (12.5%), 18 (8.3%), 20 (6.3%), 17 (7.3%), 21 (5.2%), 5 (5.2%) and 12 (5.2%) were also recurrent in the setting of 3 abnormalities. Bone marrow histology and clinical information were reviewed in all cases with isolated monosomy; associated clinical phenotypes were found in RCMD (n = 20, 13 were -7), RAEB (n = 12, 11 were -7), RA (n = 9, 3 were -7) and chronic myelomonocytic leukemia (CMML, n = 6, 4 were -7) cases. Sole monosomy 20 (n = 7, RA 3 case and RCMD 4 cases) was not detected in RAEB or CMML cases. It is concluded that the presence of at least 1 autosomal monosomy was documented in approximately 37.5% of all abnormal cases, which has potential impact on a more than trivial fraction of patients with MDS. The preponderance of monosomy 7 implicates a pathogenetic role for haploinsufficiency of genes associated with chromosome 7. The rarity of sole monosomy involving other chromosomes other than 7, 20, and 13 suggests that haploinsufficiency involving entire chromosomes is detrimental to cell survival, unless their effect is overcome by the presence of other genetic changes that are often associated with additional chromosomal abnormalities. The observation is consistent with the usually favorable prognostic profile associated with sole monosomy 20.

[Expression of p57kip2 in patients with de novo myelodysplastic syndrome and its relationship with SDF-1/CXCR4 axis].

This study was purposed to explore the expression of p57kip2 in the bone marrow of patients with de novo myelodysplastic syndrome (MDS) and its role in MDS pathogenesis, as well as the relationship between the expression of p57kip2 and SDF-1/CXCR4 signal. The expression of p57kip2 and CXCR4 in 67 de novo MDS patients was measured by real-time quantitative PCR. The percentage of CD34(+) cells in the bone marrow from MDS patients was measured by flow cytometry. 18 healthy volunteers were recruited for control. The effect of SDF-1 on p57kip2 expression in bone marrow mononuclear cell (BMMNC) from MDS or normal controls was investigated in vitro, and difference between them was compared. The results showed that low-risk MDS and high-risk MDS displayed a significant reduction of p57kip2 mRNA expression in BMMNC compared with that in control group (P < 0.001) and there was a negative correlation between p57kip2 expression and percentage of CD34(+) (r = -0.458, P < 0.001); the patients with abnormal karyotype showed lower expression of p57kip2 gene, compared to patients with normal karyotype (P = 0.045). Although the expression of CXCR4 had no difference between MDS patients and normal controls, a positive correlation between p57kip2 and CXCR4 in MDS patients was still found (r = 0.609, P < 0.001). Moreover, SDF-1 increased p57kip2 expression in normal BMMNC in dose-dependent manner, but BMMNC from MDS patients showed no response to SDF-1. SDF-1-induced p57 expression was blocked by AMD3100. It is concluded that the low expression of p57 gene in MDS may play a role in the pathogenesis of MDS. Furthermore, SDF-1-induced p57kip2 expression in BMMNC, and the decreasing response of BMMNC to SDF-1 may contribute to the low expression of p57kip2 in MDS patients.

[Yield of CD34(+) cells in graft can be increased significantly by G-CSF used at appropriate time after chemotherapy for AutoPBSCT].

This study was aimed to investigate the influence of timing using G-CSF after chemotherapy on graft yield of mobilized peripheral blood stem cells for autoPBSCT. 39 patients with lymphoma or multiple myeloma (MM) received the same chemotherapy mobilization regimen, including CTX 400 mg/m² d1; VLB 2 mg/m(2) d1; Ara-C 60 mg/m ²× d1-5; VP-16 60 mg/m² × d1-5; and prednisone 40 mg/m² × d1-5. The historical control group (12 cases) received G-CSF subcutaneously (filgrastim) at the first restoration after the initial nadir of the peripheral WBC count. The experimental group (27 cases) received G-CSF during the steady rise of the WBC count (end of fluctuating after initial nadir). G-CSF was given in a single daily subcutaneous dose of 5 µg/kg until the final PBSC apheresis. When the peripheral WBC and mononuclear cell (MNC) counts reached 10 × 109/L and 1.0 × 109/L respectively, leukapheresis was carried out using the COBE Spectra blood cell separator. The results indicated that despite there was comparable treatment with alkylating agents between 2 groups, a significantly increased yield of CD34 positive cells was observed in the experimental group (26.4 × 106/kg), as compared to the historical control group (3.1 × 106/kg) (p = 0.0031). It is concluded that the appropriate timing for the use G-CSF mobilization after chemotherapy is important to increase the CD34(+) cell yield in auto-graft.

[Correlation between clinical outcome of 115 patients with idiopathic thrombocytopenic purpura and megakaryocyte counts in bone marrow biopsy].

The aim of study was to explore the influence of the number of megakaryocytes in bone marrow smear and trephine biopsy on clinical outcome of idiopathic thrombocytopenic purpura (ITP). The clinical outcome of 115 patients with ITP was compared by different clinical subtype, number of blood platelet, number of megakaryocyte in bone marrow smear and trephine biopsy. The results showed that: (1) the clinical outcome of acute ITP was better than that of chronic ITP, the short clinical outcome of acute ITP and chronic ITP were 86.6% vs 60.4% respectively (p < 0.01), the long clinical outcome of them were 82.5% vs 68.9% respectively (p < 0.05); (2) different number of blood platelet at occurrence of diseases had no obviously influence on clinical outcome of patients with ITP; (3) all cases were subgrouped according to number of megakaryocyte in bone marrow smear, the number of megakaryocyte in bone marrow smear less than 7/4.5 cm(2) was defined as group I, the number of megakaryocyte between 7/4.5 cm(2) to 35/4.5 cm(2) was defined as group II, and the number of megakaryocyte in bone marrow smear greater than 35/4.5 cm(2) was defined as group III. The effective rates of 3 groups in short term treatment were 53.3%, 73.8% and 86.2% respectively, and there were statistical difference between these 3 groups (p < 0.01), the effective rates of these 3 groups in long term treatment were 42.8%, 84.6% and 85.5% respectively, and there was no statistical different between group II and group III (p > 0.05), but both had statistical difference, as compared with group I (p < 0.01). (4) all cases were subgrouped by the number of megakaryocyte in trephine biopsy on time of disease occurrence, the number of megakaryocyte in bone marrow smear less than 8/mm(2) was defined as group I, the number of megakaryocyte between 8/mm(2) to 15/mm(2) was defined as group II, the number of megakaryocyte greater than 15/mm(2) was defined as group III. The effective rate of these 3 groups in short term treatment were 53.8%, 85.0% and 90.3% respectively, group II and III had no statistical difference each other (p > 0.05), but both groups had statistical difference as compared with group I (p < 0.01). Effective rate of these 3 groups in long term treatment were 33.3%, 63.1% and 87.9% respectively, and there were statistical difference between them (p < 0.01). (5) the number of blood platelet at time of disease occurrence was not related to number of megakaryocyte in bone marrow smear and in trephine biopsy section(r = 0.31, p > 0.05; r = 0.41, p > 0.05). The number of megakaryocyte in bone marrow smear had positive correlation to that in trephine biopsy slides (r = 0.52, p < 0.01). In case to use single factor Logistic regression, the results showed that number of megakaryocyte in bone marrow smear and trephine biopsy had obvious influence on long term treatment of ITP. It is concluded that the number of megakaryocyte in trephine biopsy can be used as a available supplement method for bone smear, and can forecast the therapeutic effect of patients with ITP.

[The affection of bisphosphonates combined with chemotherapy on bone metabolism index in multiple myeloma].

OBJECTIVE: To explore the clinical value of urine N-telopeptides of type I collagen (uNTX) and serum bone specific alkaline phosphatase (sBAP) in myeloma bone disease, and to understand the role of bisphosphonates therapy for multiple myeloma(MM) osteolytic bone lesion. METHODS: Thirty-three MM cases were treated with bisphosphonates combined with chemotherapy (considered as treatment group), and 20 untreated MM cases with chemotherapy alone considered as control group. uNTX was detected by ELISA, and sBAP by chemiluminescence analysis. RESULTS: (1) There was no significant differences in uNTX between treatment \[(173.74 ± 14.55) µg/L\] and control groups \[(129.79 ± 12.13) µg/L\] before bisphosphonates treatment (P > 0.05). After six-month treatment, there was significant differences between two groups \[(85.71 ± 8.23) µg/L and (121.59 ± 12.43) µg/L, respectively\] (P < 0.05); Meanwhile, there were significant differences in uNTX between before and after three-month treatment (P = 0.045) and between before and after six-month treatment (P < 0.01) in treatment group. (2) There was no significant differences in sBAP concentration between treatment and control groups \[(4.78 ± 0.55) µg/L and (8.42 ± 1.32) µg/L, respectively\] before treatment (P > 0.05). After six-month treatment, there were significant differences between them \[(16.01 ± 0.52) µg/L and (9.62 ± 1.29) µg/L, respectively\] (P < 0.01). Meanwhile, in treatment group, there was no significant differences between before and after three-month treatment (P > 0.05), but being significant difference between before and after six-month treatment (P < 0.01). CONCLUSION: uNTX, sBAP are important early sensitive index to measure the osteolytic bone lesion in MM patients. Bisphosphonates can significantly improve the osteopathy in MM cases.

[Efficacy of induction chemotherapy for patients with high-risk myelodysplastic syndrome (MDS) or MDS-transformed acute myeloid leukemia with CHG regimen and its comparison with regimen GAG and HA].

This study was aimed to investigate the efficacy of moderate intensity regimen, CHG (homoharringtonine, cytarabine and granulocyte colony-stimulating factor (G-CSF)) on the patients with high-risk MDS or MDS-transformed acute myeloid leukemia. 30 newly diagnosed adult patients with high-risk MDS or MDS-transformed AML were enrolled in this clinical trial to evaluate the efficacy of sequential low-dose homoharringtonine/cytarabine chemotherapy combined with G-CSF priming. Homoharringtonine and Ara-C were injected intravenously at doses of 1 mg and 25 mg daily for 14 consecutive days respectively, G-CSF was injected subcutaneously once daily at a dose of 300 microg on 12 hours prior to chemotherapy and continued given until the end of chemotherapy or when the peripheral WBC count reached > 20 x 10(9)/L. This regimen was given only for one course, and followed by conventional chemotherapy as maintenance or consolidation therapy when CR achieved. 33 patients with high- risk MDS and MDS-transformed AML were injected aclarubicin/Ara-C intravenously at doses of 10 mg and 25 mg for 8 and 14 consecutive days respectively, G-CSF was used at the same dose and the same way as the CHG regimen. 33 patients with high-risk MDS and MDS-transformed AML were treated with HHT/Ara-C intravenously at doses of 2 - 3 mg and 100 - 150 mg daily for 7 consecutive days respectively, G-CSF was injected when WBC count was below 4 x 10(9)/L, and it was stopped to be used when WBC count was > 4 x 10(9)/L. The results showed that (1) 14 patients achieved complete remission (CR) (46.67 %) and 7 patients achieved partial remission (PR) (23.33 %) with one course of CHG regimen, total effective rate was 70%; 14 patient achieved CR (42.4%) and 9 patients achieved PR (27.3%) with one course of CAG regimen, total effective rate was 69.7%; 7 patient achieved CR (33.3%) and 3 patients achieved PR (9.1%) with one course of HA regimen, total effective rate was 42.4%. There was no statistical difference between the effective rate of CHG and CAG, but difference was significant between CHG and HA. (2) Agranulocytosis (neutrophil < 0.5 x 10(9)/L) occurred in 12 cases (40%) of CHG-treated patients with a mean 8 days of agranulocytic period, so the infectious complications were less serious and tolerable without treatment-related death. (3) Among 14 out of 30 patients with CR, 9 relapsed, the mean duration from CR to replace was 8.2 months. All relapsed patients reusing CHG regimen did not achieved CR again. (4) Among 13 cases with CR, 6 patients just received HA or DA regimens as consolidatory and intensive chemotherapy after CR have relapsed, the mean CR time was only 6.1 months. Otherwise, the mean CR time of 7 CR patients received alternative succeeded chemotherapy containing mitoxantrone/idarubicin/THP/homoharringtonine/daunorubicin/aclarubicin after CR was 10.6 months; and among them 4 are still in continuous CR. It is concluded that the CHG chemotherapy regimen has a similar effect with CAG but better than HA, and in a saft chemotherapy regimen with slight myelosuppression in clinical application, strong and alternative succeeded chemotherapy is necessary for CR patients to keep longer CR and survival.

[Selection of surgical procedure for the treatment of idiopathic scoliosis].

OBJECTIVES: To discuss and evaluate the selection of surgical procedure for the treatment of idiopathic scoliosis according to the location and degree of the deformity. METHODS: 175 patients with idiopathic scoliosis underwent surgical treatment with correction and fusion. The patients were divided into four groups according to the location and degree of the deformity and four different procedures were used for each group. For each group, the blood loss, surgery time, correction rate, loss of correction at final follow up and complications were compared and analyzed. RESULTS: All patients underwent surgery safely and no neurological complication occurred. The correction rate was 81% for Group I, 86% for Group II, 68% for Group III and 72% for Group IV. All patients were followed up at least 2 years and the average time was 38 months (24 approximately 52). CONCLUSION: Proper selection of surgical procedure according to the location and degree of the scoliotic deformity, satisfactory results can be achieved in the treatment of idiopathic scoliosis.