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Biomedical subjects

L Qian

Publications and source records attributed to L Qian.

At least 55 records · Page 3Linked to original sources
PubMed1999

[Apoptosis inducing effect of meisoindigo on K562 cells].

OBJECTIVE: To study the effect of meisoindigo on human chronic myelogenous leukemia (CML) cell line K562 cells for exploring the mechanism of meisoindigo in treatment of CML. METHODS: Multiple methods, including dose-response curve, trypan blue exclusion, cytomorphology, DNA electrophoresis, flow cytometry and TUNEL (TdT mediated dUTP nick and labeling), were used to observe the effect of meisoindigo on K562 cells. RESULTS: Meisoindigo can inhibit the proliferation and induce the apoptosis of K562 cells. CONCLUSION: The therapeutic mechanism of meisoindigo in treating CML may be related with its proliferation inhibiting and apoptosis inducing effect in CML cells.

Apoptosis↗
PubMed1999

[Determination of trace selenium in spirulina by continuous-flow hydride generation atomic absorption spectrometry].

The mixed solutions of the hydrogenized element-NaOH-NaBH4 and HCI solution were fed into hydride vapor generator at the same rate by multi-flow peristaltic pump. Selenium element in the aqueous solution reacted on the nascent hydrogen to generate gaseous hydride. No separation was needed and the method was highly sensitive with little interference. The selenium content in spirulina was determined and a reliable analytical method was established. The determination limit of the method was 0.017 microg x g(-1), and the recovery of the samples was 98.89%-101.20%.

Selenium↗
PubMed1998

Mcl-1 in transgenic mice promotes survival in a spectrum of hematopoietic cell types and immortalization in the myeloid lineage.

Mcl-1 is a member of the Bcl-2 family that is expressed in early monocyte differentiation and that can promote viability on transfection into immature myeloid cells. However, the effects of Mcl-1 are generally short lived compared with those of Bcl-2 and are not obvious in some transfectants. To further explore the effects of this gene, mice were produced that expressed Mcl-1 as a transgene in hematolymphoid tissues. The Mcl-1 transgene was found to cause moderate viability enhancement in a wide range of hematopoietic cell types, including lymphoid (B and T) as well as myeloid cells at both immature and mature stages of differentiation. However, enhanced hematopoietic capacity in transgenic bone marrow and spleen was not reflected in any change in pool sizes in the peripheral blood. In addition, among transgenic cells, mature T cells remained long lived compared with B cells and macrophages could live longer than either of these. Interestingly, when hematopoietic cells were maintained in tissue culture in the presence of interleukin-3, Mcl-1 enhanced the probability of outgrowth of continuously proliferating myeloid cell lines. Thus, Mcl-1 transgenic cells remained subject to normal in vivo homeostatic mechanisms controlling viable cell number, but these constraints could be overridden under specific conditions in vitro. Within the organism, Bcl-2 family members may act at "viability gates" along the differentiation continuum, functioning as part of a system for controlled hematopoietic cell amplification. Enforced expression of even a moderate viability-promoting member of this family such as Mcl-1, within a conducive intra- and extracellular environment in isolation from normal homeostatic constraints, can substantially increase the probability of cell immortalization.

Animals↗
PubMed1998

CNI-1493 attenuates hemodynamic and pro-inflammatory responses to LPS.

The increased production of pro-inflammatory cytokines and nitric oxide have been postulated to contribute to the deleterious sequella of LPS administration. To date, clinical strategies to control these responses using individual specific inhibitors have been disappointing. The aim of the present study was to determine whether a tetravalent guanylhydrazone compound (CNI-1493) attenuates LPS-induced stress responses by suppressing multiple inflammatory mediators. Rats were injected intravenously with either CNI-1493 (10 mg/kg) or vehicle (1 mL NaCl) 60 min prior to the injection of LPS (100 microg/100 g body weight). LPS produced a 20% decrease in mean arterial blood pressure and a significant increase in circulating TNF-alpha levels as well as in tissue content of TNF-alpha, IL-1beta, and IL-6. This was associated with a marked increase in lung and gut apoptosis and myeloperoxidase (MPO) activities as well as with an increase in lung and spleen nitric oxide end products (NOx). Pretreatment with CNI-1493 attenuated the LPS-induced drop in mean arterial blood pressure (MABP) and blunted (40%) the rise in circulating TNF-alpha levels. CNI-1493 attenuated the LPS-induced increase in tissue cytokine (TNF-alpha, IL-1beta, and IL-6) content in lung and spleen but did not alter that of liver or gut. CNI-1493 pretreatment protected both lung and gut from LPS-induced apoptosis and in addition attenuated the rise in MPO activity in the gut. These results suggest diverse effects of CNI-1493 that are tissue specific and that confer protection against the hemodynamic and inflammatory responses to LPS.

Animals↗
PubMed1998

Immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications.

OBJECTIVE: To explore the immunophenotype of myeloid cells in myelodysplastic syndyomes (MDS) and its clinical implications. METHODS: A panel of monoclonal antibody was used to detect CD13+, CD33+, CD15+ and CD14+ antigens on the membrane surfaces of myeloid cells in the bone marrow from 51 MDS, 21 aplastic anemia (AA), 21 paroxysmal nocturnal hemoglobinuria (PNH) patients. 10 acute myeloblastic leukemia (AML) patients and 15 normal subjects by immunoenzymatic assay. The morphology and chromosome karyotype of bone marrow cells of MDS patients were also examined. RESULTS: CD14+, CD13+ and CD33+ cells in the bone marrow were more in MDS patients than in normal controls, AA patients and PNH patients. CD15+ cells in the bone marrow were less in MDS patients than in normal controls. CONCLUSIONS: The percentages of CD14+, CD13+ and CD33+ positive cells in the bone marrow of MDS patients were related to the percentage of myeloblasts, the chromosomal aberrations and the response to treatment. It indicated that there is immunophenotypic misexpression of myeloid cells in MDS patients. Immunophenotype analysis of myeloid cells might be useful for the diagnosis and treatment of MDS patients.

Adolescent↗
PubMed1998

[Genetic instability of microsatellites Mfd41 and DCC in the evolution of chronic myelogenous leukemia].

OBJECTIVE: To explore the relationship between the genetic instability of microsatellite and the evolution of chronic myelogenous leukemia(CML). METHODS: The loss of heterozygosity(LOH) and the microsatellite instability(MSI) of two polymorphic microsatellite markers, DCC and Mfd41, which located on chromosome 18q and 17p respectively, were assayed by standard PCR-silver staining analysis in bone marrow cells from 17 CML patients progressing from chronic phase to accelerated phase or blast crisis. RESULTS: LOH or MSI of the two microsatellites were demonstrated in 8/17 (47.5%) patients in accelerated/blastic phases. For DCC, genetic instability was revealed in 2 of 9 patients in accelerated phase and in 4 of 8 in blast crisis. For Mfd41, genetic instability was revealed in 1 of 9 patients in accelerated and in 1 of 8 in blast crisis. CONCLUSION: Genetic instability of DCC and Mfd41 may play a role in the evolution of CML.

Adolescent↗
PubMed1998

[A study on the anti-metastatic effects of CD3Ak cells in nude mice].

OBJECTIVE: To investigate whether cancer draining lymph node lymphocytes activated by CD3 McAB in vitro have anti-tumor effects in vivo. METHODS: Nude mice with highly metastatic human ovarian cancer were treated with CD3 McAB activated killer cells (CD3AK) from human ovarian cancer draining lymph node lymphocytes. 31 experimental nude mice were divided into 4 groups; the cisplatin group (7 mice), the CD3AK cells group (7 mice), the combined treatment group (7 mice), and control group (10 mice). Treatment began on the 10th day after tumor transplantation for a total of 80 days. RESULTS: The transplanted tumors disappeared in 1 mouse of CD3AK group, significant difference in the anti-metastatic effect was found between the CD3AK group (2/7 mice with metastasis) and the control group (8/10 mice with metastasis). Significant difference in average tumor volume was found between the CD3AK group (0.5788 +/- 0.2549) and the control group (1.5685 +/- 0.283). The tumor growth inhibition rate reached 63.1% in the CD3AK group. Significant difference in the serum level of progesterone was found between the CD3AK group (3.3843 +/- 0.5314) and the control group (6.3480 +/- 0.7615). Significant difference in the histiocyte increase in the lymph node sinuses was found between the CD3AK group (59/69) and the control group (55/94). CONCLUSION: These results suggest that CD3AK cells appear to be effective in tumor growth inhibition, anti-metastasis and enhancing host immunologic function.

Animals↗
PubMed1998

[Virilizing and feminizing adrenal syndrome].

OBJECTIVE: To inquire into diagnosis, differential diagnosis and treatment of virilizing and feminizing adrenal syndrome especially differential diagnosis between benign and malignant of sex hormone producing adrenal neoplasma and treatment principles of congenital adrenal hyperplasia (CAH). METHOD: Eight cases of CAH and five cases of sex hormone producing adrenal neoplasma were presented during 1986-1996. The former included 3 rare cases of 17 alpha hydroxylase deficiency and others. The latter included 3 cases of feminizing adrenal tumors and 2 cases of virilizing adrenal tumors. RESULT: Weight and diameter of tumor, DHEA, 17-ks and sex hormone levels, appearance of CT imaging, infiltration and metastasis, were closely related to differentiation of benign and malignant tumors. CONCLUSION: Some standards are not absolute because of limited practice, follow-up is very important. Adrenal virilizing and feminizing neoplasms were surgically resected by different incision. Modified subcostal incision is recommended as a best choice for huge adrenal mass. Corticoadrenal hormone treatment of CAH should select different kind of corticoadrenal medicine for different kind of CAH. Treatment of sex hormones is not suitable for children suffered from 17 hydroxylase deficiency until prepuberty.

Adrenal Gland Neoplasms↗
PubMed1997

Mcl-1, a Bcl-2 family member, delays the death of hematopoietic cells under a variety of apoptosis-inducing conditions.

Mcl-1 is a member of the Bcl-2 family that was identified based on increased expression in myeloblastic leukemia cells undergoing differentiation. Mcl-1 was previously found to be similar to Bcl-2 in causing a delay in apoptotic cell death in Chinese hamster ovary cells. The work described here was aimed at determining whether Mcl-1 could also exert such an effect in hematopoietic cells, because endogenous Mcl-1 expression is prominent in the hematopoietic system. A further aim was to assess the effects of Mcl-1 in cells exposed to a variety of cytotoxic stimuli, because Bcl-2 is known to have a broad spectrum of activity. To approach these aims, FDC-P1 murine myeloid progenitor cells were transfected with vectors driving either constitutive or inducible expression of Mcl-1. The introduced Mcl-1 gene was found to cause a prolongation of viability under various conditions that cause apoptotic cell death, including exposure to cytotoxic agents (the chemotherapeutic drug etoposide, calcium ionophore, or UV irradiation) and the withdrawal of required growth factors. In addition, Mcl-1 was found to interact with Bax, a member of the Bcl-2 family that promotes cell death as a homodimer but that can heterodimerize with Bcl-2 to promote cell viability. Although Mcl-1 prolonged cell viability, it did not prevent eventual cell death upon continuous exposure to a cytotoxic agent. Prolongation of viability was maximal when expression of Mcl-1 was induced before the application of the apoptotic stimulus, although some increase occurred if Mcl-1 was induced shortly thereafter and before overt apoptosis. Taken as a whole, these findings provide further parallels between Mcl-1 and Bcl-2, showing that Mcl-1 can interact with Bax in hematopoietic FDC-P1 cells and can prolong cell viability under a variety of cytotoxic conditions.

Animals↗
PubMed1997

Comparison of moyamoya disease in Japan and moyamoya disease (or syndrome) in the People's Republic of China.

To find out the causes of many epidemiological differences in Moyamoya disease in Japan and in the People's Republic of China, we performed a bibliographical investigation and an actual survey and reached the following conclusions: (1) Leptospiral infection can cause Moyamoya syndrome which cannot be differentiated from Moyamoya disease unless confirmed through the patients past history and a positive serum test; and (2) Moyamoya disease reported in China may include Moyamoya syndrome caused by leptospiral or other cerebral arteritis.

Adolescent↗
PubMed1997

Compensation for displacement of the focal point in cone beam single photon emission computed tomography reconstruction.

This study examined the effects of focal point displacement on image quality in cone beam single photon emission computed tomography (SPECT). A new image reconstruction algorithm that accounts for the focal point shift was derived and three shift geometries were investigated. The geometries included a lateral shift with a fixed focal length but off-center focusing, a linear axial shift with a variable focal length that depends linearly on the distance between a bin of the detector and the center of the detector, and a random axial shift with a randomly varying focal length. Computer simulation was conducted to evaluate the shift effects with a phantom that was composed of 118 small spherical sources. The results demonstrated that the lateral shift of the focal point was more critical to image quality than was the axial shift. With a 0.64 cm (1 pixel) lateral shift, noticeable artifacts was observed, while an axial shift resulted in minimal changes in image quality until it reached 8 cm (12.5 pixels). The derived reconstruction algorithm eliminated most of the artifacts caused by a fixed lateral shift or a linear axial shift of the focal point, but failed to do so for a random axial shift since the linear distribution assumed in image reconstruction did not match the random shift occurred in acquisition of the data.

Algorithms↗
PubMed1997

A triple-head SPECT system with parallel-hole collimators of different acceptance angles.

We proposed to use three different parallel-hole collimators for a triple-head SPECT system. One of the collimators had a small collimator acceptance angle to provide ultra-high spatial resolution and the other two had larger collimator acceptance angles to achieve high counts. A new 2D reconstruction algorithm that combined the data acquired from different collimators was derived to take advantages of both high resolution and high sensitivity. The algorithm was evaluated using a computer-simulated matrix of spherical sources. For noise-free data, the accuracy (mainly determined by spatial resolution) obtained from combination of the collimator acceptance angles of 1.35, 4.05 and 6.75 degrees (or 1.35, 5.40 and 9.45 degrees) was slightly inferior to that obtained from three same LEHR collimators (with a 2.70 degrees collimator acceptance angle). This is because the modulation transfer function (MTF) resulting from three different collimators decreases more quickly at low frequencies but becomes comparable at high frequencies as compared with the MTF of the 2.70 degrees collimator. With noisy data, however, the image quality obtained with three different collimators was better than that resulting from any combinations of three same collimators. The improvement was only achieved by using the derived algorithm, while the conventional FBP algorithm did not improve image quality even with the same collimator configuration.

Algorithms↗
PubMed1997

[In vitro study on the effects of the novel retinoids on the proliferation and differentiation of normal and leukemic cells].

OBJECTIVE: To evaluate the prospect for clinical use of four novel retinoid compounds (retinoid 1, retinoid 2, retinoid 3 and retinoid 4), which were different structurally from all-trans retinoic acid. METHODS: The effects of the four retinoids on the differentiation and clonal proliferation of NB4 cells and fresh acute promyelocytic leukemia (APL) cells and on the proliferation of normal hematopoietic cells were studied. Cell morphological examination,nitro tetrazolium blue reduction test, cell cycle dynamics, and colony formation assay were used in the study. RESULTS: Novel retinoids induced differentiation of NB4 and fresh APL cells, and markedly inhibited CFU-L growth of NB4 and fresh APL cells. The activity related to their chemical structures and retinoid 2 was more active. The novel retinoids enhanced the growth of CFU-GM, CFU-E and CFU--Meg of normal bone marrow cells. CONCLUSION: These novel retinoids, especially retinoid 2, may regulate the proliferation and differentiation of normal hematopoiesis, induce APL cell differentiation and maturation, and are worthy of further study for clinical use.

Cell Differentiation↗
PubMed1997

[Study on the immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications].

OBJECTIVE: To explore the immunophenotype of myeloid cells in myelodysplastic syndromes and its clinical implications. METHODS: A panel of monoclonal antibodies was used to detect CD13, CD33, CD15 and CD14 on the membrane surfaces of myeloid cells in the bone marrow from 51 patients with myelodysplastic syndromes (MDS), 21 with aplastic anemia (AA), 21 with paroxysmal nocturnal hemoglobinuria (PNH), and 15 normal subjects, by immunoenzymatic assay. The morphology and chromosome karyotype of bone marrow cells of MDS patients were also examined. RESULTS: CD14+ cells, CD13+ cells and CD33+ cells in the bone marrow were more in MDS patients than in normal controls, AA patients and PNH patients. CD15+ cells in the bone marrow were less in MDS patients than in normal controls. The percentages of CD14, CD13 and CD33 positive cells in the bone marrow of MDS patients were related to the percentage of myeloblast, the chromosomal aberrations and the response to treatment. CONCLUSION: There was an immunophenotypic misexpression of myeloid cells in MDS patients. Immunophenotype analysis of myeloid cells might be useful for the diagnosis and directing treatment in MDS patients.

Adolescent↗
PubMed1997

[Studies on expansion ex vivo of murine bone marrow cells and its hematopoietic reconstitution capacity].

OBJECTIVE: To investigate the effects of stem cell factor (SCF) in combination with interleukin-1 (IL-1) or/and interleukin-3 (IL-3) on ex vivo expansion of 5FU treated bone marrow cells and hematopoietic recovery in lethally irradiated mice transplanted with the expanded cells. METHODS: 5FU treated bone marrow cells (d3-5FU-BMC) were cultured in a cytokines-containing medium, and the net increments of CFU-GM and high proliferative potential colony forming cell (HPP-CFC) were evaluated. RESULTS: CFU-GM increased by 33.7 +/- 18.1- or 18.1 +/- 6.3- fold, and HPP-CFC by 17.8 +/- 10.5- or 12.7 +/- 9.1- fold, respectively, in cultures containing SCF with IL- or IL-3, as compared with that in control; while SCF alone had little effect. Compared with fresh d3-5FU-BMC, transplantation of the expanded bone marrow cells accelerated the recovery of recipients' peripheral blood cell counts by 1 approximately 3 days and increased the survival rate of the transplanted animals (d3-5FU-BMC group 50% vs expansion group 8U approximately 100%). CONCLUSION: SCF in combination with IL-1 or IL-3 synergetically ex vivo expands hematopoietic cells. Transplantation of the expanded bone marrow cells accelerates the recipient's hematopoietic reconstitution.

Animals↗
PubMed1996

Changes in lCBF, morphology and related parameters by fluid percussion injury.

We investigated the pathophysiological and morphological responses of anaesthetized rats to fluid percussion brain injury generated by an original midline fluid percussion injury device. Following different grades of trauma, lCBF was measured continuously in the right parietal cortex through a burr hole using laser Doppler flowmeter, and physiological parameters were monitored. Pathological changes also were evaluated microscopically. During the first 2 hours following trauma, we found four patterns of cerebral circulatory responses. Little measurable pathophysiological response occurred after percussion pulses of less than 1.33 atmospheres (atm). In animals subjected to pulses of greater than 4.30 atm, lCBF increased synchronously with blood pressure, and then both parameters decreased continuously until death. In animals subjected to pulses of 1.53 to 2.33 atm, trauma produced a transient increase in lCBF with no synchronous rise in blood pressure. In animals subjected to pulses of 2.70 to 3.87 atm, lCBF increased synchronously with blood pressure immediately following the injury, but had decreased markedly by 60 seconds and remained below the pre-injury baseline. Blood pressure recovered to baseline within 4 minutes of the injury. The transient increase in lCBF occurred within 5 seconds following percussion pulses of greater than 1.53 atm and appeared to be independent of the rise in systemic blood pressure. Apnoea occurred in animals subjected to pulses of greater than 1.53 atm, and the duration of apnoea and mortality rate correlated with the magnitude of the applied injury. A power decrease in the electroencephalogram post-injury and a delay in its recovery, both depended on the magnitude of the injury with few regional differences in the beta-2 band power. The distribution and extent of blood-brain barrier disruption and small haemorrhages also correlated with the magnitude of the injury. The number of neurons decreased significantly in both hippocampi by 2 weeks following moderate trauma. The four patterns of lCBF changes demonstrated in the present study, as well as the other responses to injury, may be useful for studying graded models of various diffuse brain injuries.

Animals↗