Establishment of the human acute promyelocytic leukemia pathological model in the SCID beige mice by using NB4 cell line / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to establish a stable, effective and reproducible human acute promyelocytic leukemia model in severe combined immunodeficient (SCID) mice by using NB4 cell line, and to investigate the disease course character and biological behaviors.</p><p><b>METHODS</b>Three-five-week-old SCID beige mice were divided randomly into two groups: experimental and control group. SCID mice of experimental group were transplanted by tail vein (iv) injection of 5×10(6) NB4 cells. The WBC cell count and the positive rate of promyelocytes in peripheral blood were dynamically monitored by using smears. Morphological examination and histopathological assay were employed to confirm NB4 cell infiltration in organs (liver, spleen, lung, kidney and brain). The expression level of PML-RARα fusion protein was detected by Western blot.</p><p><b>RESULTS</b>Within two weeks there was no significant difference in peripheral blood WBC count between two groups (P > 0.05), meanwhile, NB4 cells were not found. At the day 21 and 28 after inoculation, the peripheral blood white blood cell count of experimental group reached to (4.79 ± 1.13)×10(9)/L and (7.62 ± 2.24)×10(9)/L respectively, which were significantly higher than that in control group (P < 0.05); simultaneously, the positive rates of promyelocytes on smears were (2.14 ± 0.63)% and (6.6 ± 2.76)%, respectively. Morphological observation showed single or multiple tumor lumps at day 21 after inoculation; HE staining of tissue biopsies demonstrated a large number of promyelocyte in the liver, spleen, lung, kidney and brain tissue. Cell immunofluorescence results showed that the CD33 expression of bone marrow cells in mice of experimental group was strongly positive (P < 0.05). Western blot confirmed that the PML-RARα fusion protein was expressed variously in liver, kidney and brain tissue.</p><p><b>CONCLUSIONS</b>The human acute promyelocytic leukemia SCID mouse model is succesfully established by tail vein injection of NB4 cells. This model can mimic the characters of involved bone marrow and diffuse growth of cells. This model is a useful tool to explore the pathogenic mechanism and experimental treatment of human leukemia.</p>

Apoptosis of retinoic acid-resistant APL NB4-R1 cells induced by As4S4 and its molecular mechanism / 中国实验血液学杂志

<p><b>OBJECTIVE</b>This study was to investigate the apoptosis-inducing effect of As(4)S(4) on the retinoic acid-resistant acute promyelocytic leukemia (APL) NB4-R1 cells and its potential mechanisms.</p><p><b>METHODS</b>The leukemia cell line NB4-R1 was cultured in vitro and divided into control group and treatment group. The apoptosis rate and cell cycle were detected by flow cytometry. The apoptotic DNA fragments were analyzed by agarose gel electrophoresis. The changes of BCL-2, BAX and Caspase-3 were determined by Western blot.</p><p><b>RESULTS</b>After NB4-R1 cells were treated with As(4)S(4)(25 µmol/L) for 0 h, 24 h, 48 h, the percentage of early apoptotic cells was obviously raised from 0% to 24.49% and 47.41%, the percentage of late apoptotic cells were elevated from 0.08% to 14.72% and 20.70%. Compared with control group, the DNA degradation revealed a characteristic DNA ladder during agarose gel electrophoresis after treatment for 24 h. The drug significantly induced an accumulation of the S phase cell population from 31.85% of the untreated cells to 42.53% and 55.12% treated with the different time whereas the NB4-R1 cells in G0/G1 phase decreased from 57.30% to 37.56% and 28.51%. As(4)S(4) could decrease the expression of BCL-2 and increase the level of BAX. Pro-caspase-3 could be cleaved into small active fragments under the apoptotic stimulation.</p><p><b>CONCLUSION</b>As(4)S(4) can efficiently induce NB4-R1 cell apoptosis, which may be related with the down-regulation of BCL-2 and the up-regulation of BAX, as well as the activation of Caspase-3.</p>

Experimental study of rat cerebral hemorrhage model via autologous blood injection / 中国康复理论与实践

@#ObjectiveTo observe the effect of rat cerebral hemorrhage model via autologous blood injection.MethodsBlood extracted from rats' cardiac ventricles was injected into the right caudate nucleus via stereotactic method. Pathological examination,ultrastructural visualization and motor functional test were applied to validate the feasibility of this method.ResultsRats showed paralysis of left extremities rapidly after surgery. Pathological examination confirmed the formation of hematoma in caudate nucleus. The deviation of hematoma volume and location among individuals was significantly lower than that of rats made by collagenase injection. Transmission electron microscopy showed wide mylin degeneration in right caudate nucleus. Motor functional test revealed the dysfunction of left extremities with marked lower deviation among individuals compared with that of collagenase injection (P<0.05).ConclusionAutologous blood injection can result in significantly lower deviation of hematoma volume and location as well as dysfunctional degree compared with that of collagenase injection.