Forward genetic screening for zebrafish mutants defective in erythropoiesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To screen and identify zebrafish mutants with erythropoiesis defects by N-ethyl-N-nitrosourea (ENU) mutagenesis and large-scale forward genetic screening using beta e 1 as the marker.</p><p><b>METHODS</b>The chemical mutagen ENU was used to treat healthy wild-type male fish (AB strain, F0). The surviving ENU-treated fish were mated with wild-type female fish to generate F1, and further F2 family was generated by F1 family intercross. The adult F2 fish were intercrossed within each F2 family and the resulting F3 embryos from each crossing were subjected to whole mount in situ hybridization (WISH) with the beta e 1 probe. Mutagenesis was performed by treating the male zebrafish with ENU to induce mutations in pre-meiotic germ cells to generate the founders, which were outcrossed to obtained the F1 fish. The F1 fish from different founders were mated to generate the F2 families. F3 embryos from the sibling cross in the F2 family were examined by whole mount in situ hybridization using beta e 1-globin probe. The putative mutants were then characterized with different hematopoiesis markers.</p><p><b>RESULTS AND CONCLUSION</b>We identified 4 beta e 1-deficient mutants with erythropoiesis defects, including two with specific erythiod lineage defects and two with concurrent lymphopoiesis defects.</p>

Forward genetic screening for zebrafish mutants defective in myelopoiesis / 南方医科大学学报

<p><b>OBJECTIVE</b>To identify zebrafish mutants with myelopoiesis defects by ENU mutagenesis and large-scale forward genetic screening.</p><p><b>METHODS</b>Male zebrafish were mutagenized with N-ethyl N-nitrosourea to induce mutations in the spermatogonial cells to generate the founders, which were outcrossed with AB to raise F1 fish. The F1 fish from different founders were mated to generate the F2 families. The F3 embryos from F2 sibling crosses were screened by Sudan black B staining and neutral red staining.</p><p><b>RESULTS</b>A total of 350 F2 families from F1 sibling crosses were screened, and 1424 F2 crosses were analyzed. Six mutations were identified resulting in abnormal Sudan black B staining and neutral red staining, indicating the involvement of neutrophil deficiency or macrophage abnormalities.</p><p><b>CONCLUSION</b>It is simple and cheap to induce and screen myelopoiesis deficiency in zebrafish by ENU chemical mutagenesis and Sudan black B staining and neutral red staining. These mutants shed light on the identification of the genes important to myelopoiesis in zebrafish.</p>

Positional cloning of a novel allele of zebrafish cloche mutant / 南方医科大学学报

<p><b>OBJECTIVE</b>To perform the genetic identification of cloche(172) mutant zebrafish.</p><p><b>METHODS</b>The chemical mutagen N-ethyl-N-nitrosourea (ENU) was used to treat the AB stain male fish. Large-scale forward genetic screening was carried out to search for lyC-deficient zebrafish mutant by WISH. The morphology changes of the embryos at 3 days postfertilization (3dpf) stage were observed and the cloche(172) gene was identified by mapping and complementation test.</p><p><b>RESULTS</b>We selected 4 lyC-deficient zebrafish by WISH. cloche(172) mutant showed morphological changes similar to cloche mutant in 3dpf stage. One fourth of the embryos showed cloche phenotype as found in complementation test, and the cloche(172) gene was mapped on the telomere of zebrafish 13 chromosome where cloche gene was located. Numerous red blood cells were observed in the cloche(172) mutant, while only a few cells were found in the cloche mutant in the tail region by o-dianisdine staining.</p><p><b>CONCLUSION</b>cloche(172) gene which is responsible for the phenotype of cloche mutant may be a novel point mutation allele of the cloche mutant.</p>

Overview of chronic myelogenous leukemia and its current diagnosis and treatment patterns in 15 hospitals in China / 中华血液学杂志

<p><b>OBJECTIVE</b>To explore demographic characteristics, current diagnosis and treatment patterns of chronic myelogenous leukemia (CML) patients in China.</p><p><b>METHODS</b>Data of hospitalized CML patients in 2005 whole year and outpatient information (July 1 through September 30, 2006) from 15 hospitals throughout China were analyzed.</p><p><b>RESULTS</b>A total of 1824 CML cases were analyzed, including 722 inpatients and 1102 outpatients. The male/female ratio was 1.78:1. The median age at diagnosis was 40.02 (2.45 - 83.29) years old, 90.41% of the patients were diagnosed at chronic phase. Proportion of accelerated phase or blast crisis patients increased to 21.66% during study period. 93.20% of the patients received blood routine and bone marrow morphologic examination at diagnosis and in monitoring; 70.29% were performed cytogenetic analysis and 51.54% performed molecular measurement in addition. The most common therapy for CML treatment was hydroxycarbamide. The proportion of patients treated with imatinib and interferon was 37.45% and 25.55%, respectively. Of 722 inpatients, 164 (22.72%) received hemotopoietic stem cell transplantation (HSCT). The proportions of accelerated phase and blast crisis patients treated with imatinib were 48.28% and 48.42%, respectively, being significantly higher than that of chronic phase patients (35.9%) (P < 0.05). The mean imatinib dosage administered in the three phases patients did not differ significantly. Imatinib resistance rates were 6.87% and 16.28% for outpatient and inpatient, respectively. In the outpatient group, the primary resistance to imatinib occurred comparably to the secondary resistance (68.75%), while primary resistance was predominant in inpatient group (65.71%). The intolerance rates of imatinib for outpatient and inpatient were 3.21%, 11.63%, respectively. The majority of patients treated with imatinb were not monitored in time: 63.38% patients evaluated hematologic response after 3 months of treatment, proportions of patients received cytogenetic examination after 6 months and 12 months of treatment were 41.41% and 27.35%, respectively. Mean cost for HSCT was 213 092 +/- 125 890 RMB.</p><p><b>CONCLUSIONS</b>CML in China tends to afflict younger population than in Western countries. Most patients were diagnosed in the chronic phase. Due to restriction of financial support, only one third of CML patients were treated with imatinib, and the majority of the treated were not monitored in time. Clinicians should pay attention to resistance and intolerance to imatinib treatment in accelerated phase or blast crisis patients.</p>

Correlation between expression of apoptosis-related gene pnas-2 and leukemia / 中国实验血液学杂志

The study was purposed to explore the correlation between apoptosis-related gene pnas-2 and leukemia. The RT-PCR was performed to detect the expression levels of pnas-2 gene in NB4, K562, U937 cells before and after treatment with AS(4)S(4), and to analysis the expression change of pnas-2 gene in bone marrow cells from patients with acute leukemia before and after chemotherapy. The results showed that the expression of pnas-2 gene in arsenic sulfide treated NB4 cells was down regulated in time-dependent manner, but the same outcome in K562 and U937 cells after being treated with AS(4)S(4) was not found. The positive expression rate of pnas-2 in cells from untreated patients with acute leukemia was 100%, and was significantly higher than that in normal control group. After chemotherapy, the expression was negative in complete remission patients, whereas in no-remission patients there were no significant differences of expression of pnas-2 before and after treatment. It is concluded that the pnas-2 gene may be closely related with apotosis of arsenic sulfide treated APL cells, and may consider as a molecular biological remission marker in acute leukemia.

Effect of recombinant human granulocyte colony-stimulating factor on neutrophil morphology, function and phenotype in patients with acute leukemia undergoing chemotherapy / 中国实验血液学杂志

This study was to explore the effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) on neutrophil morphology, function and phenotype in patients with acute leukemia undergoing chemotherapy. Neutrophil morphology was observed under microscope with oil immersion; phagocytotic function was examined by measuring the amount of hydrogen peroxide produced by neutrophil; chemotaxis was analyzed by agarose method; oxidative burst was analyzed by flow cytometry using immunofluorescence technique; neutrophil phenotype was analyzed by flow cytometry and immunofluorescence techniques. The results showed that after rhG-CSF administration, the increased "toxic" granulation, vacuoles and Döhle bodies were observed in neutrophils of patients with acute leukemia. Compared with normal control, the functions of phagocytosis, chemotaxis, oxidative burst of neutrophil were impaired after chemotherapy, while these functions were enhanced and returned to normal level or even to be exceeded after administration of rhG-CSF. In patients with acute leukemia the neutrophil presented significantly higher expression of CD64 and CD62L than that in normal control, and a mild increase of CD64 expression and significant increase of CD62L expression were found in patients after rhG-CSF treatment. No modifications of CD16, CD32, CD14 and CD11b expression were detected in these patients before or after G-CSF administration. It is concluded that rhG-CSF administration can modify the morphology, function and phenotype of neutrophils in the patients with acute leukemia undergoing chemotherapy, and these modifications of neutrophil behavior may be supposed to be a reason for the enhancement of organism anti-infection ability.