[Efficacy and safety analysis of venetoclax combined with hypomethylating agents for the treatment of higher-risk myelodysplastic syndromes in the real world]

Objective: To investigate the efficacy and safety of combining venetoclax (VEN) with hypomethylated drugs (HMA) in the treatment of higher-risk (IPSS-R score >3.5) myelodysplastic syndromes (MDS) . Methods: From March 2021 to December 2022, forty-five MDS patients with intermediate and high risk were treated with VEN in combination with HMAs. Clinical data were collected and analyzed retrospectively, including gender, age, MDS subtype, IPSS-R score, treatment regimen, and efficacy, etc. Kaplan-Meier method and Cox regression model were used to analyze univariate and multivariate of survival prognosis. Results: ①Forty-five patients with MDS, including ninety-one percent were classified as high or very high risk. According to the 2023 consensus proposal for revised International Working Group response criteria for higher-risk MDS, the overall response rate (ORR) was 62.2% (28/45), with the complete response rate (CR) was 33.3% (15/45). For twenty-five naïve MDS, the ORR was 68% (17/25) and the CR rate was 32% (8/25). In nonfirst-line patients, the ORR and CR were 55% (11/20) and 35% (7/20) respectively. The median cycle to best response was 1 (1-4). ②With a median followup of 189 days, the median overall survival (OS) time was 499 (95% confidence interval, 287-711) days, and most patients died from disease progression. Responders had a significantly better median OS time than nonresponders (499 days vs 228 days, P<0.001). Multifactor analysis revealed that IPSS-R score and response to treatment were independent prognostic factors for OS; the presence of SETBP1 gene mutations was associated with a longer hospital stay (51.5 days vs 27 days, P=0.017) . Conclusions: There is clinical benefit of venetoclax in combination with hypomethylated agents in patients with higher-risk MDS, but adverse events such as severe hypocytopenia during treatment should be avoided.

[Molecular features of 109 patients with chronic myelomonocytic leukemia in a single center]

Objective: To explore the molecular features of chronic myelomonocytic leukemia (CMML) . Methods: According to 2022 World Health Organization (WHO 2022) classification, 113 CMML patients and 840 myelodysplastic syndrome (MDS) patients from March 2016 to October 2021 were reclassified, and the clinical and molecular features of CMML patients were analyzed. Results: Among 113 CMML patients, 23 (20.4%) were re-diagnosed as acute myeloid leukemia (AML), including 18 AML with NPM1 mutation, 3 AML with KMT2A rearrangement, and 2 AML with MECOM rearrangement. The remaining 90 patients met the WHO 2022 CMML criteria. In addition, 19 of 840 (2.3%) MDS patients met the WHO 2022 CMML criteria. At least one gene mutation was detected in 99% of CMML patients, and the median number of mutations was 4. The genes with mutation frequency ≥ 10% were: ASXL1 (48%), NRAS (34%), RUNX1 (33%), TET2 (28%), U2AF1 (23%), SRSF2 (21.1%), SETBP1 (20%), KRAS (17%), CBL (15.6%) and DNMT3A (11%). Paired analysis showed that SRSF2 was frequently co-mutated with ASXL1 (OR=4.129, 95% CI 1.481-11.510, Q=0.007) and TET2 (OR=5.276, 95% CI 1.979-14.065, Q=0.001). SRSF2 and TET2 frequently occurred in elderly (≥60 years) patients with myeloproliferative CMML (MP-CMML). U2AF1 mutations were often mutually exclusive with TET2 (OR=0.174, 95% CI 0.038-0.791, Q=0.024), and were common in younger (<60 years) patients with myelodysplastic CMML (MD-CMML). Compared with patients with absolute monocyte count (AMoC) ≥1×10(9)/L and <1×10(9)/L, the former had a higher median age of onset (60 years old vs 47 years old, P<0.001), white blood cell count (15.9×10(9)/L vs 4.4×10(9)/L, P<0.001), proportion of monocytes (21.5% vs 15%, P=0.001), and hemoglobin level (86 g/L vs 74 g/L, P=0.014). TET2 mutations (P=0.021) and SRSF2 mutations (P=0.011) were more common in patients with AMoC≥1×10(9)/L, whereas U2AF1 mutations (P<0.001) were more common in patients with AMoC<1×10(9)/L. There was no significant difference in the frequency of other gene mutations between the two groups. Conclusion: According to WHO 2022 classification, nearly 20% of CMML patients had AMoC<1×10(9)/L at the time of diagnosis, and MD-CMML and MP-CMML had different molecular features.

[Clinical characteristics and prognostic factors of patients with Philadelphia-negative myeloproliferative neoplasm accelerated/blast phase]

Objective: To evaluate the clinical characteristics and prognostic factors of patients with Philadelphia-negative myeloproliferative neoplasm-accelerated phase/blast phase (MPN-AP/BP) . Methods: A total of 67 patients with MPN-AP/BP were enrolled from February 2014 to December 2021 at the Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences. Their clinical features and prognostic factors were analyzed retrospectively. Results: ① Sixty-seven patients with MPN-AP/BP with a median age of 60 (range, 33-75) years, including 31 males (46.3% ) and 36 females (53.7% ) , were analyzed. Forty-eight patients progressed from primary myelofibrosis (PMF) , and 19 progressed from other myeloproliferative neoplasms (MPNs) , which included polycythemia vera, essential thrombocythemia, and MPN unclassifiable. Patients who progressed from PMF had higher lactate dehydrogenase (LDH) levels than those who progressed from other MPNs (925.95 vs. 576.2 U/L, P=0.011) , and there were higher proportions of patients who progressed from PMF with splenomegaly (81.4% vs. 57.9% , P=0.05) , a myelofibrosis grade of ≥2 (93.6% vs. 63.2% , P=0.004) , and a shorter duration from diagnosis to the transformation to AP/BP (28.7 vs. 81 months, P=0.001) . ② JAK2V617F, CALR, and MPLW515 were detected in 41 (61.2% ) , 13 (19.4% ) , and 3 (4.5% ) patients, respectively, whereas 10 (14.9% ) patients did not have any driver mutations (triple-negative) . Other than driver mutations, the most frequently mutated genes were ASXL1 (42.2% , n=27) , SRSF2 (25% , n=16) , SETBP1 (22.6% , n=15) , TET2 (20.3% , n=13) , RUNX1 (20.3% , n=13) , and TP53 (17.2% , n=11) . The ASXL1 mutation was more enriched (51.1% vs. 21.1% , P=0.03) , and the median variant allele fraction (VAF) of the SRSF2 mutation (median VAF, 48.8% vs. 39.6% ; P=0.008) was higher in patients who progressed from PMF than those who progressed from other MPNs. ③ In the multivariate analysis, the complex karyotype (hazard ratio, 2.53; 95% confidence interval, 1.06-6.05; P=0.036) was independently associated with worse overall survival (OS) . Patients who received allogeneic stem cell transplantation (allo-HSCT) (median OS, 21.3 vs. 3 months; P=0.05) or acute myeloid leukemia-like (AML-like) therapy (median OS, 13 vs. 3 months; P=0.011) had significantly better OS than those who received supportive therapy. Conclusion: The proportions of patients with PMF-AP/BP with splenomegaly, myelofibrosis grade ≥2, a higher LDH level, and a shorter duration from diagnosis to the transformation to AP/BP were higher than those of patients with other Philadelphia-negative MPN-AP/BP. The complex karyotype was an independent prognostic factor for OS. Compared with supportive therapy, AML-like therapy and allo-HSCT could prolong the OS of patients with MPN-AP/BP.

[Sternal bone marrow cell morphology evaluation utility for diagnostic categorization in patients with acquired hypocellular bone marrow failure syndromes]

Objective: Diagnostic value assessment of sternal bone marrow cell morphology in patients with acquired hypocellular bone marrow failure syndromes (BMFS) characterized by normal cytogenetics. Methods: A total of 194 eligible patients with an acquired hypocellular BMFS pre-sternum diagnosis in Institute of Hematology and Blood Diseases Hospital, Chinese Academy of Medical Science & Peking Union Medical College from June 2014 to January 2019 were reviewed. Sternal bone marrow evaluation was performed, and a post-sternum diagnosis was made. Clinical characteristics and overall survival (OS) were then compared among patients with different post-sternum diagnosis. Binary logistic regression was used to develop a predictive scoring system. Results: In 152 patients with pre-sternum AA diagnosis, 29 patients with a pre-sternum idiopathic cytopenia of undetermined significance (ICUS) diagnosis, and 13 patients with a pre-sternum clonal cytopenia of undetermined significance (CCUS) diagnosis, sternal bone marrow evaluation resulted in a change of diagnosis to hypocellular myelodysplastic syndrome (hypo-MDS) in 42.8% (65/152) , 24.1% (7/29) , and 30.8% (4/13) , respectively. Patients with a post-sternum hypo-MDS diagnosis showed a significant difference in OS compared with patients with a post-sternum AA diagnosis (P=0.005) . Patients with ICUS/CCUS showed no difference in OS compared with AA and hypo-MDS (P=0.095 and P=0.480, respectively) . A 4-item predictive scoring system to identify hypocellular BMFS patients that need sternal bone marrow evaluation was developed, including age > 60 years old (OR=6.647, 95% CI 1.954-22.611, P=0.002, 2 points) , neutrophil alkaline phosphatase score ≤ 160 (OR=2.654, 95% CI 1.214-5.804, P=0.014, 1 point) , abnormal erythroid markers evaluated by flow cytometry on iliac bone marrow (OR=6.200, 95% CI 1.165-32.988, P=0.032, 2 points) , and DAT (DNMT3A, ASXL1, TET2) genes mutation (OR=4.809, 95% CI 1.587-14.572, P=0.005, 1 point) . The Akaike information criterin (AIC) was 186.1. Conclusion: Patients with a pre-sternum acquired hypocellular BMFS diagnosis characterized by normal cytogenetics may not reach accurate diagnostic categorization without sternal bone marrow cell morphology evaluation, which could be considered a diagnostic tool for this patient population. A predictive scoring system was developed, and when the total score is ≥ 2 points, sternal bone marrow evaluation should be performed for accurate diagnostic categorization that is critical to optimal patient care.

[Clinical and laboratory features compared between JAK2 exon12 and JAK2 V617F mutated polycythemia vera]

Objective: To compare clinical and laboratory features between JAK2 exon12 and JAK2 V617F mutated polycythemia vera (PV) . Method: We collected data from 570 consecutive newly-diagnosed subjects with PV and JAK2 mutation, and compared clinical and laboratory features between patients with JAK2 exon12 and JAK2 V617F mutation. Results: 543 (95.3%) subjects harboured JAK2 V617F mutation (JAK2 V617F cohort) , 24 (4.2%) harboured JAK2 exon12 mutations (JAK2 exon12 cohort) , and 3 (0.5%) harboured JAK2 exon12 and JAK2 V617F mutations. The mutations in JAK2 exon12 including deletion (n=10, 37.0%) , deletion accompanied insertion (n=10, 37.0%) , and missense mutations (n=7, 25.9%) . Comparing with JAK2 V617F cohort, subjects in JAK2 exon12 cohort were younger [median age 50 (20-73) years versus 59 (25-91) years, P=0.040], had higher RBC counts [8.19 (5.88-10.94) ×10(12)/L versus 7.14 (4.11-10.64) ×10(12)/L, P<0.001] and hematocrit [64.1% (53.7-79.0%) versus 59.6% (47.2%-77.1%) , P=0.001], but lower WBC counts [8.29 (3.2-18.99) ×10(9)/L versus 12.91 (3.24-38.3) ×10(9)/L, P<0.001], platelet counts [313 (83-1433) ×10(9)/L versus 470 (61-2169) ×10(9)/L, P<0.001] and epoetin [0.70 (0.06-3.27) versus 1.14 (0.01-10.16) IU/L, P=0.002] levels. We reviewed bone marrow histology at diagnosis in 20 subjects with each type of mutation matched for age and sex. Subjects with JAK2 exon12 mutations had fewer loose megakaryocyte cluster (40% versus 80%, P=0.022) compared with subjects with JAK2 V617F. The median follow-ups were 30 months (range 4-83) and 37 months (range 1-84) for cohorts with JAK2 V617F and JAK2 exon12, respectively. There was no difference in overall survival (P=0.422) and thrombosis-free survival (P=0.900) . Conclusions: Compared with patients with JAK2 V617F mutation, patients with JAK2 exon12 mutation were younger, and had more obvious erythrocytosis and less loose cluster of megakaryocytes.

[The relationship between symptom burden and hematologic responses after treatment with interferon/hydroxyurea in patients with polycythemia vera]

Objective: To explore the relationship between symptom burden and hematologic responses after treatment with interferon and/or hydroxyurea in patients with polycythemia vera (PV) . Methods: Hematologic responses after continuous treatment with interferon and/or hydroxyurea for six months were evaluated in 190 patients with PV using the Myeloproliferative Neoplasm Symptom Assessment Form Total Symptom Score (MPN-10 score) . In all patients, the PV diagnosis was based on the 2016 World Health Organization diagnostic definitions. Results: The study cohort comprised 93 (48.9% ) male and 97 (51.1% ) female patients. The median age at the time of MPN-10 assessment was 60 (32-82) years. The median MPN-10 score of the entire cohort was 9 (range, 0-67) . The median MPN-10 score of patients treated with interferon plus hydroxyurea (n=27) was 11 (0-67) , which was significantly higher than those of patients treated with interferon only (n=64) (6[0-56], P=0.019) or hydroxyurea only (n=99) (9[0-64], P=0.047) , whereas the median MPN-10 score was not significantly different between those treated with interferon only and hydroxyurea only (P=0.421) . The rate of severe symptom burden (i.e., any single symptom burden score ≥ 7 and/or total score ≥ 44) was 28.9% (55/190) in the entire cohort, whereas the rate of severe symptom burden was not significantly different among the interferon only (23.4% ) , hydroxyurea only (29.3% ) , and interferon plus hydroxyurea (40.7% ) groups (P>0.05 for all two-group comparisons) . When evaluating MPN-10 score, 37.4% (71/190) of the patients achieved complete hematologic remission (CHR) . Only 28.9% (55/190) patients had adequate disease control, defined as CHR without severe symptom burden. Reasons for inadequate disease control were evaluating blood counts alone, severe symptom burden alone, and evaluating blood counts accompanied with severe symptom burden in 42.1% (80/190) , 8.4% (16/190) , and 20.5% (39/190) of the patients, respectively. Compared to the patients with a platelet count ≤ 400×10(9)/L, those with a platelet count > 400×10(9)/L had a significantly higher rate of severe symptom burden (40.8% [20/49] vs 24.8% [35/141], P=0.044) and a higher median MPN-10 score (14[0-67] vs 7[0-56], P=0.038) . Platelet count > 400×10(9)/L was associated with an increased risk of severe symptom burden (hazard ratio, 2.089; 95% confidence interval, 1.052-4.147, P=0.035) . Conclusions: Symptoms related to disease after treatment with interferon and/or hydroxyurea were rather universal in patients with PV. Some patients still experienced severe symptom burden despite achieving CHR. Platelet count > 400×10(9)/L was associated with an increased risk of severe symptom burden in patients with PV treated with interferon and/or hydroxyurea.

[Evaluation of the prognostic value of MIPSS70-plus in Chinese patients with primary myelofibrosis]

目的

评价MIPSS70-plus预后积分系统对中国原发性骨髓纤维化（PMF）患者的预后评估价值。

方法

回顾性分析113例PMF患者的临床资料，应用Log-rank和COX回归模型进行预后相关因素分析；应用似然比检验比较MIPSS70-plus和动态国际预后积分系统（DIPSS）的预后评估效能。

结果

113例PMF患者中男71例，女42例，中位年龄55（20～70）岁。依据MIPSS70-plus染色体核型分组标准，染色体核型预后良好组90例（79.6%），预后不良组23例（20.4%）。二代测序基因突变检测结果示，JAK2V617F突变63例（55.8%），CALR外显子9突变20例（17.7%）（其中1型CALR突变15例，2型CALR突变5例），MPLW515突变5例（4.4%），25例（22.1%）未检测到JAK2、MPL和CALR基因突变（三阴性）。高分子风险（HMR）突变检出率依次为ASXL1突变44例（38.9%）、SRSF2突变8例（7.1%）、IDH1/2突变5例（4.4%）、EZH2突变4例（3.5%）；51例患者（45.1%）有1种以上高危基因突变。MIPSS70-plus预后积分低危组、中危组、高危组、极高危组分别为28例（26.7%）、20例（19.0%）、41例（39.0%）、16例（15.3%），2年预期总生存率分别为100%、89.7%（95%CI 76.2%～100.0%）、64.8%（95%CI 47.0%～82.6%）、35.0%（95%CI 10.3%～59.7%）（P<0.001）。MIPSS70-plus的-2log似然比显著低于DIPSS（86.355对95.990，P＝0.001），表明MIPSS70-plus较DIPSS有更准确的预后分组预测效能。

结论

MIPSS-70plus较DIPSS预后积分系统对中国PMF患者有更好的预后评估效能。

[Genetic characteristics and prognostic values of RAS mutations in patients with myelofibrosis]

目的

分析骨髓纤维化（MF）患者RAS基因突变的分子特征及其临床特点和预后意义。

方法

收集2011年12月至2019年12月在我中心有二代基因测序数据的226例MF患者临床资料，回顾性分析RAS基因突变特征、与临床和实验室参数之间的关系，及对总生存（OS）期的影响。

结果

226例原发性骨髓纤维化（PMF）及真性红细胞增多症（PV）或原发性血小板增多症（ET）后骨髓纤维化（post-PV/ET MF）患者中，共14例（6.2％）检出RAS基因突变：NRAS突变9例（4.0％），KRAS突变8例（3.5％），NRAS及KRAS突变并存3例（1.3％）。所有NRAS突变均发生在第12-13号密码子。RAS基因突变多为亚克隆突变，常与SETBP1、SRSF2、MPL共同发生。伴RAS基因异常患者平均突变基因个数（3.36个）与无RAS基因异常组（1.77个）相比，差异有统计学意义（P<0.001）。RAS基因突变患者与无突变患者相比，外周血单核细胞水平升高（P＝0.003），血小板水平减低（P＝0.026），骨髓原始细胞比例升高（P＝0.022），脾脏肋缘下≥10 cm患者比例更高（P＝0.005）。突变组患者非常高危（VHR）染色体核型比例（18.2％，2/11）显著高于无突变组患者（2.3％，3/133）（P＝0.031）。单因素分析中，NRAS基因突变的MF患者及PMF患者的OS时间较无突变患者显著缩短（P＝0.001，P＝0.008）。多因素分析显示，NRAS突变是影响OS的独立预后不良因素。

结论

RAS突变常与外周血单核细胞水平升高、血小板计数减低、骨髓原始细胞比例升高、VHR染色体核型等高危临床特征及实验室参数相关，多为发生在MF晚期的亚克隆突变。伴NRAS基因突变PMF及MF患者的OS时间显著缩短。

[Pathological characteristics of megakaryocytes in myeloproliferative neoplasms and their correlation with driver gene mutations]

Objective: To investigate the pathological characteristics of megakaryocytes in myeloproliferative neoplasms(MPN)and their correlations with driver gene mutations. Methods: Trephine specimens administered for 160 patients with MPN from February 2012 to October 2017 were reevaluated according to the World Health Organization(WHO)'s(2016)diagnostic criteria. Results: This cohort of patients included 72(45.0%)men, with the median age of 59(range, 13-87)years, comprising 39 with polycythemia vera(PV), 33 with essential thrombocythemia(ET), 37 with prefibrotic/early-primary myelofibrosis(pre-PMF), 37 with overt PMF, 1 with post-ET MF, 2 with post-PV MF, and 11 with MPN-unclassifiable(MPN-U)after the re-diagnosis. With PV, ET, pre-PMF, and overt PMF changes, proportions of dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes gradually increased, whereas erythropoiesis gradually decreased. Proportions of reticulin, collagen, and osteosclerosis grades of ≥1 also increased. Dense clusters, hypolobulated nuclei, and naked nuclei of megakaryocytes were negatively correlated with erythropoiesis and positively correlated with granulopoiesis and fibrosis. In patients with pre- and overt PMF, dense clusters and naked nuclei of megakaryocytes were positively correlated with fibrosis. Patients with JAK2V617F MPN had significantly increased erythropoiesis(P=0.022). Patients with CALR-mutated MPN were characterized by increased loose and dense clusters; paratrabecular distribution and naked nuclei of megakaryocytes(P=0.055, P=0.002, P=0.018, P=0.008); and increased reticulin, collagen, and osteosclerosis(P=0.003, P<0.001, P=0.001). In patients with pre- and overt PMF, patients with JAK2V617F had increased cellularity(P=0.037). CALR-mutated patients had increased dense clusters and giant sizes of megakaryocytes, collagen, and osteosclerosis(P=0.055, P=0.059, P=0.011, P=0.046). Conclusion: Megakaryocytes showed abnormal MPN morphology and distribution, which were related to fibrosis. CALR mutation was probably associated with abnormal morphology and distribution of megakaryocytes and fibrosis.

[Molecular features and prognostic value of RAS mutations in patients with myelodysplastic syndromes]

Objective: To explore the molecular features and prognostic value of RAS mutations in patients with myelodysplastic syndromes (MDS) . Methods: 112-gene targeted sequencing was conducted to detect RAS mutations in 776 patients with newly diagnosed primary MDS from December 2011 to December 2018. The mutual exclusivity and co-occurrence in gene mutations and clonal architecture were explored. Moreover, the prognostic significance of RAS mutations in MDS was analyzed. Results: RAS gene mutations were found in 52 (6.7% ) cases, 38 (4.9% ) of whom harbored NRAS mutation, 18 (2.3% ) KRAS mutation, and 4 (0.5% ) both NRAS and KRAS mutations. All the NRAS mutations and 65% of the KRAS mutations were located in codons 12, 13, and 61. PTPN11, FLT3, U2AF1, RUNX1, WT1, ETV6, and NPM1 mutations were enriched in patients with RAS mutations (Q<0.05) . Around 80% of RAS mutations represented subclonal lesions in patients who harbored at least two different mutations. Patients with RAS mutations were more frequently diagnosed with MDS with excess blast (MDS-EB) (82.7% vs. 35.2% , P<0.001) and had higher levels of white blood cell count (4.33×10(9)/L vs. 2.71×10(9)/L, P<0.001) , neutrophil absolute count (2.13×10(9)/L vs. 1.12×10(9)/L, P<0.001) , and bone marrow blast percentage (7% vs. 2% , P<0.001) but lower levels of platelet count (48×10(9)/L vs. 62×10(9)/L, P=0.048) . RAS mutations were correlated with higher-risk categories in the Revised International Prognostic Scoring System (IPSS-R) (71.1% vs. 37.9% , P<0.001) . The median overall survival of patients with NRAS mutations was shorter than the others (P=0.011) , while the significance was lost in the multivariable model. Conclusion: RAS gene mutations always occurred in the late-stage MDS and co-occurred with other signal transduction- and transcription factor-related gene mutations. PTPN11, a RAS pathway-related gene, is an independent poor prognostic factor in MDS patients.

[Analysis of regional differences in influencing factors of self-reporting rate of respiratory symptoms among employees in bathing place]

Objective: To understand the self-reporting rate of respiratory symptoms in bathing staff, and analyze the differences and influencing factors in the eastern, central and western regions. Methods: From April to December 2017, adopt the method of multistage random sampling, the selection of the national 3865 effective questionnaires were bathing places practitioners, survey from personnel of course of demographic characteristics, cultural degree, family income, living habits, since the evaluation of environmental factors and respiratory symptoms such as self-reported rate content, using logistic regression model to analyze its influencing factors and regional differences. Results: The prevalence of self-reported respiratory symptoms among employees in the eastern, central, and western regions was 17.86% (269/1 506) , 10.66% (126/1 182) , and 31.01% (365/1 177) respectively. The influencing factors in the eastern region are "age", "family income", "whether drinking", "environment is suddenly cold and hot", "dust in the air" (P<0.05) ; the influencing factors in the central region are "whether drinking", "environment suddenly cold and hot", " poor ventilation", "dust in the air" (P<0.05) . The influencing factors in the western region are "gender", "whether drinking", "environment suddenly cold and hot", "poor ventilation" (P<0.05) . There are statistically significant differences in eastern, central and western regions (P<0.01) . Conclusion: The prevalence of respiratory symptoms among bathing practitioners in China varies from region to region. Economic conditions, living habits, and environmental factors are the main influencing factors.

[Features and clinical significance of gene mutations in patients with myelodysplastic syndromes with ring sideroblasts]

Objective: To explore the features and clinical significance of gene mutations in patients with myelodysplastic syndromes with ring sideroblasts (MDS-RS) . Methods: A total of 255 newly diagnosed primary MDS-RS patients were retrospectively reviewed from our center from January2001 to June 2019. SF3B1 gene mutations were detected by Sanger sequencing in 129 patients, and next generation sequencing (NGS) was performed in the other 126 patients using a set of selected 112-genes. Results: A total of 193 (75.7%) patients presented with SF3B1 mutation, predominantly mutant at amino acid position 700 (K700E) (n=147, 76.2%) . Non-SF3B1 gene mutations were TET2 (16.7%) , ASXL1 (14.3%) , U2AF1 (11.1%) , TP53 (7.9%) , SETBP1 (6.3%) , and RUNX1 (6.3%) . RS 5%-<15% patients had a higher SETBP1 mutation frequency than RS≥15% patients (21.4% vs 4.5%, P=0.044) . Mutation frequencies of other genes were similar in both groups (all P>0.05) . SF3B1 variant allele frequencies (VAF) had positive correlation with marrow RS percentage but without statistical significance in RS 5%-<15% group (P=0.078, r=0.486) . SF3B1 mutant patients presented with higher marrow RS percentage compared with wild-type patients[40.0% (15.0%-80.0%) vs 25.5% (15.0%-82.0%) , P<0.001], and SF3B1 VAF positively correlated with RS percentage (P=0.009, rs=0.261) in RS≥15% group. Age, ANC, PLT, mean RBC corpuscular volume, RS percentage, IPSS-R cytogenetics, and IPSS-R risk score were significantly different between patients with SF3B1 mutations and wild-type SF3B1 (all P<0.05) . Multivariable survival analyses adjusted by age and IPSS-R cytogenetics revealed that SF3B1 mutation was an independent favorable prognostic factor (HR=0.265, 95% CI 0.077-0.917, P=0.036) , and TP53 mutation was an adverse variable independent of SF3B1 mutation (HR=6.272, 95% CI 1.725-22.809, P=0.005) . According to the mutant status of SF3B1 and TP53, MDS-RS patients were categorized into 4 groups, namely, with SF3B1 and TP53 mutation, with wild-type SF3B1 and TP53, with wild-type SF3B1 but TP53 mutation, and with SF3B1 mutation but wild-type TP53. There was a significant difference for OS among these 4 groups (P<0.001) . The former 3 groups showed no significant difference in OS in multiple comparisons. However, the SF3B1 mutation but wild-type TP53 group had a better OS than wild-type SF3B1 but TP53 mutation group and wild-type SF3B1 and TP53 group, whereas a similar OS compared with SF3B1 and TP53 mutation group. Conclusion: SF3B1 mutations were prevalent in MDS-RS patients with the most common mutation at amino acid position 700 (K700E) . SF3B1 mutation was an independent favorable prognostic variable, whereas TP53 mutation was an independent adverse variable. SF3B1 mutation could coordinate with TP53 mutation for more sophisticated prognosis stratification in MDS-RS patients.

[Mean corpuscular volume ≤100 fl was an independent prognostic factor in patients with myelodysplastic syndrome and bone marrow blast<5 percent]

目的

探讨平均红细胞体积（MCV）对骨髓增生异常综合征（MDS）预后的影响。

方法

收集2009年12月至2017年12月我中心新诊断、无红细胞输注史的321例原发性MDS患者，回顾性分析MCV水平对整体及不同骨髓原始细胞水平患者总生存（OS）期的影响。

结果

全部患者按照MCV水平高低分为MCV≤100 fl组（148例）和MCV>100 fl组（173例）。MCV≤100 fl组患者中位OS时间为27（95%CI 19~35）个月，MCV>100 fl组患者中位OS时间为72（95%CI 5~139）个月，差异有统计学意义（P<0.001）。亚组分析示，在骨髓原始细胞<5%的患者中，MCV≤100 fl患者的中位OS期较MCV>100 fl者显著缩短（P=0.002）；而在骨髓原始细胞≥5%的患者中，MCV水平对OS的影响不显著（P=0.078）。在纳入其余临床指标及基因突变校正后，MCV≤100 fl仍为骨髓原始细胞<5%患者的独立不良预后因素（HR=1.890，95%CI 1.007~3.548，P=0.048）。对不同MCV水平骨髓原始细胞<5%的MDS患者的临床及实验室指标进行分析，结果显示MCV≤100 fl组患者外周血HGB高于MCV>100 fl组[90（42~153）g/L对78.5（28~146）g/L，P=0.015]，IPSS-R高危/极高危组比例及IPSS-R染色体核型分组差/很差比例明显高于MCV>100 fl组，差异有统计学意义（28.8%对10.8%，P=0.003；24.7%对12.9%，P=0.049）。MCV≤100 fl组患者平均基因突变数目较MCV>100 fl组多（0.988个对0.769个，P=0.064），SF3B1突变较MCV>100 fl组少见（4.7%对15.4%，P=0.018）。

结论

MCV≤100 fl为骨髓原始细胞<5%的MDS患者独立于基因突变及其他临床指标的预后不良因素。

[Analysis of clinical characteristics, treatment response rate and survival of 77 myelodysplastic syndrome patients with del (5q) syndrome]

目的

探讨符合WHO（2016）诊断分型标准的骨髓增生异常综合征（MDS）5q−综合征患者的临床特征、来那度胺（LEN）疗效和生存情况。

方法

回顾性分析2008年1月至2018年4月于中国医学科学院血液病医院就诊的77例符合WHO（2016）诊断分型标准的MDS 5q−综合征患者临床资料，比较单纯5q−与5q−伴1个非−7/7q−的其他染色体异常（ACA）患者临床特征、疗效及生存情况，并比较LEN与非LEN药物治疗的疗效与生存情况。

结果

77例患者中，单纯5q−者64例，5q−伴ACA者13例，确诊时5q−伴ACA患者的中位年龄显著低于单纯5q−患者[58（29~64）岁对63（31~82）岁，z=2.164，P=0.030]。5q−伴ACA患者CD41免疫组化染色小巨核细胞（直径≤40 µm）检出率（91.7%，11/12）显著高于单纯5q−患者（60.0%，33/55）（P=0.046）。可评估LEN疗效的29例患者中，单纯5q−患者（19例）与5q−伴ACA患者（10例）血液学总反应率（78.9%对80.0%）、血液学完全缓解（CR）率（57.9%对60.0%）、细胞遗传学反应（CyR）率[69.2%（9/13）对66.7%（4/6）]、完全细胞遗传学反应（CCyR）率[61.5%（8/13）对33.3%（2/6）]相当。单纯5q−与5q−伴ACA患者中位总生存（OS）时间差异无统计学意义（62个月对78个月，P=0.313）。29例LEN组患者的血液学总反应率（79.3%对36.0%）、CR率（58.6%对8.0%）、CyR率[68.4%（13/19）对11.1%（1/9）]、CCyR率[52.6%（10/19）对0（0/9）]均高于非LEN组患者（25例），但两组患者中位OS时间差异无统计学意义（78个月对62个月，P=0.297）。

结论

单纯5q−与5q−伴ACA患者临床特征大体相似，两组患者LEN疗效、中位OS时间无明显差异。LEN治疗5q−综合征患者的疗效肯定，优于非LEN药物。

[Clinical implications and prognostic value of TP53 gene mutation and deletion in patients with myelodysplastic syndromes]

目的

探讨伴TP53基因异常骨髓增生异常综合征（MDS）患者的临床特征及预后。

方法

回顾性分析2009年10月至2017年12月中国医学科学院血液病医院新诊断的584例原发性MDS患者临床资料，采用包含112个血液肿瘤相关基因的靶向测序技术进行突变分析，并采用间期荧光原位杂交（FISH）技术检测TP53基因缺失。分析TP53基因突变和（或）缺失与临床特征之间的关系及其对患者总生存（OS）的影响。

结果

42例（7.2%）伴TP53基因异常，其中单纯基因突变31例（5.3%），单纯基因缺失8例（1.4%），同时伴有突变和缺失3例（0.5%）。34例伴TP53基因突变患者中共检测到37个TP53突变，其中35个位于DNA结合结构域（第5~8号外显子），1个位于第10号外显子，1个为剪切位点突变。伴TP53基因异常组的平均基因突变数目（2.52个）显著高于无异常组（1.96个）（z=−2.418，P=0.016）。伴TP53基因异常患者的中位年龄[60（21~78）岁]高于无异常患者[52（14~83）岁]（z=−2.188，P=0.029）；伴TP53基因异常组中复杂核型比例、IPSS较高危组（中危-2及高危）比例显著高于无异常组（P值均<0.001）。伴TP53基因异常组的中位OS期[13（95%CI 7.57~18.43）个月]较无异常组（未达到）显著缩短（χ²=12.342，P<0.001），但多因素模型纳入复杂核型进行校正后，TP53突变不再是独立预后因素。

结论

伴TP53基因异常MDS患者中基因突变较基因缺失常见，突变位点主要分布于DNA结合结构域。TP53基因异常与复杂核型相关，且常与多个基因突变相伴出现。在多因素模型纳入复杂核型校正后，TP53基因异常则不再是独立的预后因素。

[A study of clinical characteristics and prognosis of primary myelofibrosis patients with thrombocytopenia in varied degrees]

目的

探讨不同血小板水平原发性骨髓纤维化（PMF）患者的临床特征及其预后。

方法

对1990年5月1日至2017年4月30日在中国医学科学院血液病医院就诊的1 305例PMF患者进行回顾性分析。

结果

1 305例PMF患者中，重度血小板减少（PLT<50×10⁹/L）、轻度血小板减少［PLT（50～99）×10⁹/L］、无血小板减少患者（PLT≥100×10⁹/L）分别为320例（24.5％）、198例（15.2％）和787例（60.3％）。在血小板计数越低的组别中，HGB<100 g/L患者比例、WBC<4×10⁹/L患者比例和外周血原始细胞≥3％患者比例、异常染色体核型患者比例和预后不良染色体核型患者比例越高（P<0.001，P<0.001，P＝0.004，P<0.001，P<0.001），JAK2V617F突变阳性率越低（P<0.001）。血小板计数与脾肿大、HGB、WBC呈正相关（P值均<0.001，相关系数分别为0.131、0.445、0.156），与体质性症状和外周血原始细胞比例呈负相关（P值分别为0.009、0.045，相关系数为−0.096、−0.056）。重度血小板减少、轻度血小板减少、无血小板减少组患者中位生存时间分别为32、67、89个月（P<0.001）。血小板减少程度分组［HR＝1.693（95％CI 1.320～2.173），P<0.001］和动态国际预后积分系统（DIPSS）预后分级［HR＝2.051（95％CI 1.511～2.784），P<0.001］均为PMF患者独立不良预后因素。

结论

血小板计数越低的PMF患者出现贫血、白细胞减少和外周血原始细胞比例增高的比例越高、临床表现越重、预后越差，临床上应采取更加积极的治疗措施。

[Ruxolitinib combined with prednisone, thalidomide and danazol for treatment of myelofibrosis: a pilot study]

Objective: To evaluate the efficacy and tolerability of ruxolitinib combined with prednisone, thalidomide and danazol for treatment of in myelofibrosis (MF). Methods: Patients of MF according to the WHO 2016 criteria, received ruxolitinib (RUX) combined with prednisone, thalidomide and danazol (PTD). The response, changes of blood counts and adverse events were evaluated. Results: Six PMF and one post-ET MF patients were enrolled. Four patients presented JAK2V617F mutation, one CALR mutation, one MPL mutation, one triple-negative. Responses per IWG-MRT criteria were clinical improvement in 5 patients, stable disease in 2 ones, spleen response in 6 ones. All of 7 patients were symptomatic responses, four patients achieved at least 50% improvement from baseline on MPN-SAF TSS. Three patients initially treated with RUX alone, all of 3 patients experienced treatment-associated anemia and thrombocytopenia. Then these 3 patients received RUX combined with PTD, both hemoglobin and platelet increased significantly. Four patients initially treated with RUX combined with PTD. Increased levels of hemoglobin and platelet were seen in all of 7 patients received RUX combined with PTD with maximum increased hemoglobin of 30(18-54) g/L and maximum increased platelets of 116(13-369)×10(9)/L, respectively from baseline. The treatment dose of RUX increased due to improved platelet count in 3 patients. The frequent non-hematologic adverse events grade 1-2 were constipation, abdominal distension, crura edema and increased ALT. Conclusions: RUX combined with PTD for treatment of MF may modulate initial hematologic toxicity observed when RUX alone, and may increase response due to improved levels of hemoglobin or platelet.

[Targeted sequencing analysis of hyper-eosinophilic syndrome and chronic eosinophilic leukemia]

Objective: Analysis of the molecular characteristics of eosinophilia. Methods: Targeting sequence to 24 patients with chronic eosinophilic leukemia (CEL) with rearrangement of PDGFRA, PDGFRB, or FGFR1 and 62 patients with hyper-eosinophilic syndrome (HES). Mutation annotation and analysis of amino acid mutation using authoritative databases to speculate on possible pathogenic mutation. Results: Thirty-seven kinds of clonal variant were detected from 17 patients with CEL, no recurrent mutation site and hot spot region were found. No pathogenic mutation was detected in 19 patients with PDGFRA rearrangement, but pathogenic mutations of ASXL1, RUNX1 and NRAS were detected from 2 patients with FGFR1 rearrangement who progressed to acute myeloid leukemia and 1 patient with PDGFRB rearrangement who progressed to T lymphoblastic lymphoma, respectively. One hundred and two kinds of clonal abnormalities were detected in 49 patients with HES. The main hot spot mutation regions included: CEBPA Exon1, TET2 Exon3, ASXL1 Exon12, IDH1 Y208C, and FGFR3 L164V. CRRLF2 P224L and PDGFRB R370C point mutations were detected separately in 2 patients with HES who treated with imatinib monotherapy and achieved hematologic remission. Conclusion: The pathogenesis of CEL with PDGFRA, PDGFRB or FGFR1 rearrangement is usually single, and the progression of the disease may involve other driver mutation. A variety of genes with hot mutation regions may be involved in the pathogenesis of HES, and some mutation sites are sensitive to tyrosine kinase inhibitors.

[Analysis of the impact of decitabine treatment cycles on efficacy and safety in patients of myelodysplastic syndrome-refractory anemia with excess blasts]

目的

评估地西他滨治疗骨髓增生异常综合征(MDS)难治性贫血伴有原始细胞过多(RAEB)患者的疗效和不良反应与治疗疗程数的关系。

方法

2008年12月至2016年3月中国医学科学院血液病医院MDS诊疗中心共有56例RAEB患者接受了地西他滨20 mg·m⁻²·d⁻¹×5 d方案治疗，回顾性分析其临床特征、疗效、疗效影响因素及不良反应。

结果

RAEB-1 25例，RAEB-2 31例。中位治疗3(1~15)个疗程。总有效[完全缓解(CR)＋骨髓完全缓解(mCR)+血液学改善(HI)]率为67.9%(38/56)，其中10例(17.8%)CR, 8例(14.3%)mCR但无HI，17例(30.4%)mCR同时有HI, 3例(5.4%)单纯HI。中位随访7.9(1.0~56.3)个月，中位生存期为21.1(95%CI 16.0~26.1)个月。RAEB-1患者的疗效(总有效率为88.0%)显著优于RAEB-2患者(总有效率为51.6%)(P=0.004)，多因素分析证实其为影响疗效的独立预后因素(OR=6.03，95%CI 1.39~26.09，P=0.016)。地西他滨治疗有效的38例患者中，37例(97.4%)在1~2个疗程起效，25例(65.8%)在2个疗程内达到最佳疗效，37例(97.4%)在4个疗程内达最佳疗效。主要不良反应为3级以上血细胞减少及感染，在治疗早期(第1~2疗程)中较常见，治疗有效后随疗程增加，发生率逐渐下降，其他非血液学不良反应发生率低。

结论

地西他滨标准剂量5天方案治疗RAEB疗效肯定。治疗有效患者常在第1~2个疗程起效，4个疗程内达最佳疗效。主要不良反应为血细胞减少及感染，常见于前2个疗程，起效后后续疗程不良反应发生率显著降低。

[Gene mutations from 511 myelodysplastic syndromes patients performed by targeted gene sequencing]

Objective: To study the characteristics of gene mutations in Chinese myelodysplastic syndromes (MDS) patients. Methods: A total of 511 Chinese patients with MDS performed 112-gene targeted sequencing were retrospectively analyzed. Results: Eighty-three distinct mutant genes were found in 511 patients with MDS. Amongst these, the most frequent mutations was associated with epigenetics (50%) , followed by spliceosome (37%) , signal transduction (34%) , transcription factors (24%) and cell cycle/apoptosis (17%) . 439 subjects (86%) had at least one gene mutation. The mean number of mutations in refractory anemia with unilineage dysplasia (RCUD) was 1.25, refractory anemia with multilineage dysplasia (RCMD) was 1.73, refractory anemia with ring sideroblasts (RARS) was 2.79, refractory anemia with excess blasts-1 (RAEB-1) was 2.22, RAEB-2 was 2.34, MDS with isolated 5q- was 2.67, MDS, unclassified (MDS-U) was 2.00. U2AF1 mutant subjects were more likely to have isolated+8[Q<0.001, OR=4.42 (95% CI 2.23-8.68) ]and less likely to have complex karyotypes[Q=0.005, OR=0.22 (95% CI 0.04-0.72) ]. According to the number of gene mutations, all subjects were categorized into three groups, namely group with 0-1 mutation, with 2 mutations and with three or more mutations. There was a significant difference in overall survival (OS) among three groups (P=0.041) . Conclusion: About 90% patients with MDS have at least one gene mutation. Genes associated with epigenetics and spliceosome are most common mutated genes in MDS. The increased numbers of gene mutations accompany with disease evolution and associate with poor prognosis.

[Prognostic value of JAK2, MPL and CALR mutations in Chinese patients with primary myelofibrosis]

目的

评价JAK2、MPL和CALR基因突变在中国原发性骨髓纤维化（PMF）患者中的预后意义。

方法

回顾性分析402例PMF患者的临床资料及JAK2、MPL和CALR基因突变，应用Kaplan-Meier、Log-rank和Cox回归模型进行相关预后因素分析。

结果

402例PMF患者中男209例，女193例，中位年龄55(15~89）岁。JAKV617F基因突变189例（47.0%），MPLW515基因突变13例（3.2%），CALR基因突变81例（20.1%）[1型突变30例（37.0%），2型突变48例（59.3%），少见型突变3例（3.7%）]，119例（29.6%）未检测到JAK2、MPL和CALR基因突变。单因素分析显示，2型CALR突变或未检测到JAK2、MPL和CALR基因突变的患者中位生存期（74个月）短于检测到JAK2、MPL或1型及少见型CALR基因突变的患者（168个月）[HR=2.990（95% CI 1.935~4.619），P <0.001]。因此，将基因突变类型分为预后不良组（2型CALR突变和未检测到JAK2、MPL和CALR基因突变）和预后良好组（JAKV617F、MPLW515、1型及少见型CALR基因突变）。经多因素分析提出了中国PMF患者的动态国际预后积分系统（DIPSS-Chinese）分子预后积分系统，各参数赋值如下：DIPSS-Chinese低危组0分，中危组1分，高危组2分，2型CALR突变或未检测到JAK2、MPL和CALR基因突变积1分。402例患者中，低危组（0分）132例（32.8%），中危-1组（1分）143例（35.6%），中危-2组（2分）106例（26.4%），高危组（3分）21例（5.2%）。低危组中位生存时间未达到，中危-1组为156(95% CI 117~194）个月，中危-2组为60(95% CI 28~91）个月，高危组为22（95% CI 10~33）个月，总生存差异具有统计学意义（P<0.001）。DIPSS-Chinese分子预后积分系统较DIPSS-Chinese有更准确的预测能力（−2 log似然比分别为855.6和869.7，P=0.005）。

结论

在中国PMF患者中，2型CALR突变和未检测到JAK2、MPL和CALR突变是独立的不良预后因素，DIPSS-Chinese分子预后积分系统有更好的预测价值。

[The clinical characteristics, gene mutations and prognosis of chronic neutrophilic leukemia]

Objective: To investigate the clinical manifestation, cytogenetics, gene mutations and prognostic factors of chronic neutrophilic leukemia (CNL) . Methods: 16 CNL cases, according to WHO (2016) -definition, were reviewed retrospectively. Identifications of the CSF3R, ASXL1, SETBP1, CALR and MPL mutations were performed by direct sequencing. JAK2 V617F mutation was detected by AS-PCR. Results: Of the 16 CNL patients, the median age was 64 (43-80) years with a male predominance of 75% (12/16) . The median hemoglobin was 114 (81-154) g/L, with median WBC of 41.20 (26.05-167.70) (10(9)/L and median PLT of 238 (91-394) ×10(9)/L.The median level of marrow fibrosis (MF) was 1 (0-3) degree. There was no other cytogenetic abnormalities except t (1;7) (p32;q11) , +21 and 14ps+ for each. All the 16 CNL patients harbored CSF3R T618I mutation. ASXL1 mutations were identified in 81% (13/16) , while SETBP1 mutations were confirmed in 63% (10/16) . The CALR K385fs*47 mutation was found. There was no mutation in JAK2 V617F or MPL in the above 16 patients. The median overall survival (OS) of patients presented with WBC≥50×10(9)/L at diagnosis (11 months) was significantly shorter than of WBC<50×10(9)/L (39 months, P=0.005) . Conclusion: CSF3R T618I mutation was specific for CNL. The median OS of CNL patients was 24 months, and WBC≥50×10(9)/L at diagnosis was an unfavorable prognostic factor.

[The key problems in the population exposure assessment of hazardous chemicals accidents]

Serious accidents of hazardous chemicals can cause a variety of acute or chronic impairment in human health. The effects of hazardous chemicals on human health can be identified by carrying on population exposure assessment. Through analyzing the domestic and overseas population exposure assessment cases related to hazardous chemicals accidents, we summarized that the base and key of the population exposure assessment were to identify the characteristics of the chemicals , delimit the area and the population exposed to the chemicals, and collect the data of the monitored chemicals and the population health in the polluted area.

Effect of different time phases of radionuclide hepatobiliary scintigraphy on the differential diagnosis of congenital biliary atresia

To investigate the value and essentiality of 6- and 24-h delay hepatobiliary scintigraphy in the differential diagnosis of biliary atresia (BA), we retrospectively analyzed 197 infants (121 boys/76 girls; age range, 3-205 days; average age, 63.9 days) admitted to Jiangxi Children's Hospital for persistent jaundice (> 2 weeks), hepatosplenomegaly, and abnormal liver function. After receiving anti-inflammatory treatment and cholagogic pre-treatment for 7-10 days without a clear diagnosis, the children underwent 99mTc-labeled diethylacetanilide-iminodiacetic acid hepatobiliary scintigraphy. BA and infant hepatitis syndrome were diagnosed in 107 and 90 infants, respectively after laparoscopic cholangiography, surgical pathology, or 6-month clinical follow-up. The diagnostic efficiencies of hepatobiliary scintigraphy for BA were evaluated within 50 min and at 6 and 24 h. The areas under the receiver operating characteristic curves within 50 min, at 6 and 24 h were 0.696, 0.829 , and 0.779 , suggesting poor diagnostic value within 50 min, but improvement at 6 and 24 h. The compliance rate of 6- and 24-h imaging for BA diagnosis was 89.34% (176/197; paired chi-square test Kappa value, 0.77; P > 0.05), signifying high consistency. The diagnostic efficiency values of 6-/24-h imaging for BA diagnosis were sensitivity (90.65/89.72%), specificity (74.44/78.89%), accuracy (83.25/84.77%), positive and negative predictive values (80.83/83.48% and 87.01/86.59%), with no significant difference (P > 0.05). To provide optimal treatment in early BA, the- 6-h hepatobiliary scintigraphy had practical value, especially when combined with tomographic or dynamic imaging; 24-h delay imaging was deemed unnecessary because it was not significantly superior.

Search for R-parity violating supersymmetry in two-muon and four-jet topologies

We present results of a search for R-parity-violating decay of the neutralino chi;01, taken as the lightest supersymmetric particle, to a muon and two jets. The decay proceeds through a lepton-number violating coupling lambda(')(2jk) (j=1,2; k=1,2,3), with R-parity conservation in all other production and decay processes. In the absence of candidate events from 77.5+/-3.9 pb(-1) of data collected by the D0 experiment at the Fermilab Tevatron in pp collisions at sqrt[s]=1.8 TeV, and with an expected background of 0.18+/-0.03+/-0.02 events, we set limits on squark and gluino masses within the framework of the minimal low-energy supergravity-supersymmetry model.

Search for leptoquark pairs decaying into nunu+jets in pp collisions at square root[s] = 1.8 TeV

We present the results of a search for leptoquark (LQ) pairs in (85.2+/-3.7) pb(-1) of pp* collider data collected by the D0 experiment at the Fermilab Tevatron. We observe no evidence for leptoquark production and set a limit on sigma(pp*-->LQLQ-->nunu+jets) as a function of the mass of the leptoquark (m(LQ)). Assuming the decay LQ-->nuq, we exclude scalar leptoquarks for m(LQ) < 98 GeV/c(2), and vector leptoquarks for m(LQ) < 200 GeV/c(2) and coupling which produces the minimum cross section, at a 95% confidence level.

Search for the scalar top quark in pp collisions at square root[s] = 1.8 TeV

We have performed a search for scalar top quark (stop) pair production in the inclusive electron-muon-missing transverse energy final state, using a sample of pp events corresponding to 108.3 pb(-1) of data collected with the D0 detector at Fermilab. The search is done in the framework of the minimal supersymmetric standard model assuming that the sneutrino is the lightest supersymmetric particle. For the dominant decays of the lightest stop, t-->b chi+1 and t-->blnu, no evidence for signal is found. We derive cross-section limits as a function of stop ( t ), chargino ( chi+1), and sneutrino ( nu) masses.

Direct search for charged higgs bosons in decays of top quarks

We present a search for charged Higgs bosons in decays of pair-produced top quarks in pp collisions at sqrt[s] = 1.8 TeV recorded by the D0 detector at the Fermilab Tevatron collider. With no evidence for signal, we exclude most regions of the ( M(H+/-),tan(beta)) parameter space where the decay t--> H(+)b has a branching fraction >0.36 and B(H+/--->tau(nu)(tau)) is large.

Ratio of isolated photon cross sections in pp macro collisions at square root of s = 630 and 1800 GeV

The inclusive cross section for production of isolated photons has been measured in pp macro collisions at square root of s = 630 GeV with the D0 detector at the Fermilab Tevatron Collider. The photons span a transverse energy (E(T)) range from 7-49 GeV and have pseudorapidity absolute value of eta < 2.5. This measurement is combined with the previous D0 result at square root of s = 1800 GeV to form a ratio of the cross sections. Comparison of next-to-leading-order QCD with the measured cross section at 630 GeV and the ratio of cross sections show satisfactory agreement in most of the E(T) range.

Search for new physics using QUAERO: a general interface to D0 event data

We describe QUAERO, a method that (i) enables the automatic optimization of searches for physics beyond the standard model, and (ii) provides a mechanism for making high energy collider data generally available. We apply QUAERO to searches for standard model WW, ZZ, and t t macro production, to searches for these objects produced through a new heavy resonance, and to the first direct search for W'-->WZ. Through this interface, we make three data sets collected by the D0 experiment at square root of [s] = 1.8 TeV publicly available.

Search for heavy particles decaying into electron-positron pairs in pp collisions

We present results of searches for technirho (rho(T)), techniomega (omega(T)), and Z' particles, using the decay channels rho(T),omega(T),Z'-->e(+)e(-). The search is based on 124.8 pb(-1) of data collected by the D0 detector at the Fermilab Tevatron during 1992-1996. In the absence of a signal, we set 95% C.L. upper limits on the cross sections for the processes pp-->rho(T),omega(T),Z'-->e(+)e(-) as a function of the mass of the decaying particle. For certain model parameters, we exclude the existence of degenerate rho(T) and omega(T) states with masses below about 200 GeV. We exclude a Z' with mass below 670 GeV, assuming that it has the same couplings to fermions as the Z boson.

Quasi-model-independent search for new high p(T) physics at D0

We apply a quasi-model-independent strategy ("Sleuth") to search for new high p(T) physics in approximately 100 pb(-1) of pp collisions at square root of (s) = 1.8 TeV collected by the D0 experiment during 1992-1996 at the Fermilab Tevatron. We systematically analyze many exclusive final states and demonstrate sensitivity to a variety of models predicting new phenomena at the electroweak scale. No evidence of new high p(T) physics is observed.

Ratio of jet cross sections at square root of s = 630 GeV and 1800 GeV

The D0 Collaboration has measured the inclusive jet cross section in barpp collisions at square root of s = 630 GeV. The results for pseudorapidities (eta)<0.5 are combined with our previous results at square root of s = 1800 GeV to form a ratio of cross sections with smaller uncertainties than either individual measurement. Next-to-leading-order QCD predictions show excellent agreement with the measurement at 630 GeV; agreement is also satisfactory for the ratio. Specifically, despite a 10% to 15% difference in the absolute magnitude, the dependence of the ratio on jet transverse momentum is very similar for data and theory.

Ratios of multijet Cross Sections in p p collisions at radical(s) = 1.8 TeV

We report on a study of the ratio of inclusive three-jet to inclusive two-jet production cross sections as a function of total transverse energy in p&pmacr; collisions at a center-of-mass energy sqrt[s] = 1.8 TeV, using data collected with the D0 detector during the 1992-1993 run of the Fermilab Tevatron Collider. The measurements are used to deduce preferred renormalization scales in perturbative O(alpha(3)(s)) QCD calculations in modeling soft-jet emission.

Inclusive jet production in pp(macro) collisions

We report a new measurement of the pseudorapidity (eta) and transverse-energy ( E(T)) dependence of the inclusive jet production cross section in pp(macro) collisions at square root of s = 1.8 TeV using 95 pb(-1) of data collected with the D0 detector at the Fermilab Tevatron. The differential cross section d(2)sigma/(dE(T)d eta) is presented up to eta = 3, significantly extending previous measurements. The results are in good overall agreement with next-to-leading order predictions from QCD and indicate a preference for certain parton distribution functions.

Search for large extra dimensions in dielectron and diphoton production

We report a search for effects of large extra spatial dimensions in pp collisions at a center-of-mass energy of 1.8 TeV with the D0 detector, using events containing a pair of electrons or photons. The data are in good agreement with the expected background and do not exhibit evidence for large extra dimensions. We set the most restrictive lower limits to date, at the 95% C.L. on the effective Planck scale between 1.0 and 1.4 TeV for several formalisms and numbers of extra dimensions.

Probing Balitsky-Fadin-Kuraev-Lipatov dynamics in the dijet cross section at large rapidity intervals in pp collisions at sqrt[s]=1800 and 630 GeV

Inclusive dijet production at large pseudorapidity intervals (Deltaeta) between the two jets has been suggested as a regime for observing Balitsky-Fadin-Kuraev-Lipatov (BFKL) dynamics. We have measured the dijet cross section for large Deltaeta in pp collisions at sqrt[s]=1800 and 630 GeV using the D0 detector. The partonic cross section increases strongly with the size of Deltaeta. The observed growth is even stronger than expected on the basis of BFKL resummation in the leading logarithmic approximation. The growth of the partonic cross section can be accommodated with an effective BFKL intercept of alphaBFKL(20 GeV)=1.65+/-0.07.

[Effect of hemin in treating hemorrhagic anemia and toxicity]

AIM

To study the effect of hemin in treating hemorrhagic anemia and toxicity.

METHODS

Fifty rats with hemorrhagic anemia were randomly divided into 5 groups with different dosage of hemin (93, 168, 300 mg.kg-1.d-1), ferrous gluconate (FG 300 mg.kg-1.d-1), and water, ig for 7 d. Twenty mice fed with hemin (6.0 g.kg-1.d-1) in 24 h for observing acute toxicity effects. Long-term toxicity were observed in 80 rats given hemin (0.65, 1.3, 2.6 g.kg-1.d-1) in 3 months.

RESULTS

Hb of the rats of corresponding groups were 66-->121, 71-->141, 66-->148, 69-->140, and 67-->112 g.L-1. There were no adverse effects observed on acute toxicity test. No abnormalitis were found in hemogram, liver renal function test, and autopsy.

CONCLUSION

Hemin had a better effect than FG and no adverse effect was found in hemin.