Biomedical subjects

Hong Liu

Publications and source records attributed to Hong Liu.

At least 91 records · Page 5Linked to original sources

PubMed2006

A computer-aided method to expedite the evaluation of prognosis for childhood acute lymphoblastic leukemia.

This study presented a fully-automated computer-aided method (scheme) to detect metaphase chromosomes depicted on microscopic digital images, count the total number of chromosomes in each metaphase cell, compute the DNA index, and correlate the results to the prognosis of childhood acute lymphoblastic leukemia (ALL). The computer scheme first uses image filtering, threshold, and labeling algorithms to segment and count the number of the suspicious "chromosome," and then computes a feature vector for each "detected chromosome." Based on these features, a knowledge-based classifier is used to eliminate those "non-chromosome" objects (i.e., inter-phase cells, stain debris, and other kinds of background noises). Due to the possible overlap of the chromosomes, a classification criterion was used to identify the overlapped chromosomes and adjust the initially counted number of the total chromosomes in each image. In this preliminary study with 60 testing images (depicting metaphase chromosome cells) acquired from three pediatric patients, the computer scheme generated results matched with the diagnostic results provided by the clinical cytogeneticists. The results demonstrated the feasibility or potential of using a computerized method to replace the tedious and the reader-dependent diagnostic methods commonly used in genetic laboratories to date.

Algorithms↗

PubMed2006

Inhaled sevoflurane produces better delayed myocardial protection at 48 versus 24 hours after exposure.

Ischemia preconditioning produces a delayed window of cardioprotection against subsequent ischemia and reperfusion injury. Contradictory results have been reported regarding the ability of inhaled anesthetics to produce similar effects. Our investigation was designed to test whether inhaled sevoflurane is capable of producing a delayed window of anesthetic preconditioning and to compare the differences at 24 and 48 h after exposure. Male Fischer-344 rats, 2-4 mo old, were exposed to sevoflurane (2.5% for 60 min). Twenty-four or 48 h after exposure, the hearts were isolated and perfused for 30 min (equilibration) followed by 25 min of ischemia and then 60 min of reperfusion. Control hearts received no treatment before ischemia. Left ventricular (LV) function, creatine kinase (CK), and infarct size (IS) were measured. Nuclear magnetic resonance was used to measure Na+(i), [Ca2+]i, and pH(i). There was improved LV function and significant reduction in IS and CK and in both the 24- and 48-h delayed groups compared with the controls. There was also a significant recovery of LV function and reduction in IS and CK in the 48-h group when compared with the 24-h group. There was significant adenosine triphosphate preservation in both the 24- and 48-h groups, as well as a significant reduction in acidosis, [Ca2+]I, and Na+(i) in response to ischemia in both the groups versus the control. Sevoflurane is capable of producing a delayed window of preconditioning, and it takes more than 24 h to produce maximal protective effects.

Administration, Inhalation↗

PubMed2006

Cultivation of recombinant Chinese hamster ovary cells grown as suspended aggregates in stirred vessels.

Recombinant Chinese hamster ovary (rCHO) cells capable of producing a prourokinase mutant (mPro-uk) grown as suspended aggregates in stirred vessels were described and characterized. The addition of chitosan to a mixture of DMEM and Ham's F12 (D-MEM/F-12) medium promoted cell aggregation and spheroid formation efficiently. Multicellular aggregates formed immediately after the rCHO cells were inoculated into the chitosan-added medium, and the mean diameter of the cell aggregates reflecting the aggregate size increased with culture time, shifting from 65 to 163 mum after 2 and 9 d of culture in spinner flasks. No significant difference in the metabolism performance of the rCHO cells was observed between suspended aggregates and anchored monolayers. However, the cells cultured as suspended aggregates showed a marked decrease in growth rate as evaluated from specific growth rate (mu). Replacing D-MEM/F-12 medium with CD 293 medium caused compact spherical cell aggregates to dissociate into small irregular aggregates and single cells without apparent effects on cell performance in subcultures. The perfusion culture of the rCHO cells grown as suspended aggregates in a 2-l stirred tank bioreactor for 15 d resulted in a maximum viable cell density of 5.6 x 10(6) cells ml(-1) and an mPro-uk concentration of about 2.6 x 10(3) IU ml(-1), and cell viability was remained at roughly 90% during the entire run.

Animals↗

PubMed2006

The marine viromes of four oceanic regions.

Viruses are the most common biological entities in the marine environment. There has not been a global survey of these viruses, and consequently, it is not known what types of viruses are in Earth's oceans or how they are distributed. Metagenomic analyses of 184 viral assemblages collected over a decade and representing 68 sites in four major oceanic regions showed that most of the viral sequences were not similar to those in the current databases. There was a distinct "marine-ness" quality to the viral assemblages. Global diversity was very high, presumably several hundred thousand of species, and regional richness varied on a North-South latitudinal gradient. The marine regions had different assemblages of viruses. Cyanophages and a newly discovered clade of single-stranded DNA phages dominated the Sargasso Sea sample, whereas prophage-like sequences were most common in the Arctic. However most viral species were found to be widespread. With a majority of shared species between oceanic regions, most of the differences between viral assemblages seemed to be explained by variation in the occurrence of the most common viral species and not by exclusion of different viral genomes. These results support the idea that viruses are widely dispersed and that local environmental conditions enrich for certain viral types through selective pressure.

Bacteriophages↗

PubMed2006

Photoimmunotherapy for cancer treatment.

Phototherapy, with its effective dose control and light delivery, has become a promising modality for treating malignant and nonmalignant diseases. Photochemical interaction, specifically photodynamic therapy (PDT), and photothermal interaction have been the primary mechanisms for direct cell destruction in the treatment of cancers. Preclinical studies demonstrate that, in addition to direct local cytotoxicity, PDT can also induce systemic immune responses, which may enhance therapeutic effects on primary tumors and on metastases at distant sites. Selective photothermal therapy, using an in situ application of light-absorbing dye, has also proven to be an effective method for local treatment of tumors. When combined with immunotherapy, the effects of phototherapy can be amplified, potentially making the photoimmunotherapy a systemic treatment modality. This phototherapy-immunotherapy combination, particularly in conjunction with immunoadjuvant, has been used in preclinical studies. The efficacy and long-term effects of such a combination are summarized and the recent experimental results are presented. A new immunoadjuvant, glycated chitosan (GC), has been used to enhance photochemical and photothermal therapies. The PDT-GC combination in the treatment of mammary tumors and lung tumors in mice provided significant improvement in the long-term survival of tumor-bearing animals. The use of GC in dye-assisted laser photothermal therapy also provided long-term curative effects and antitumor immune responses in the treatment of metastatic tumors in rats. The immune responses induced by phototherapy and enhanced by immunotherapy could become important mechanism in the control of metastatic tumors.

Adjuvants, Immunologic↗

PubMed2006

[Correlation between immunochemical level and patient with caries].

OBJECTIVE: To explore the relationship between immunochemical level of salivary and caries in children aged 4-6 years old. METHODS: Two groups were assorted as patients with caries and without caries. Every group included 45 people. Measurements of salivary secretory immunoglobulin A (SIgA)were performed by using radio-immunoassay and single agar diffusion assay. The levels of lysozyme (LZ), alkaline phosphatase (ALP) and lactic dehydrogenase (LDH) were studied with colorimetry and turbidimentry. RESULTS: The levels of LDH, SigA, ALP, LZ had significant difference between the two groups (P < 0.05). The level of LDH between patients and peoples without caries had little difference (P > 0.05). CONCLUSION: The incidence of caries is associated with age, and it may have association with immunochemical levels of salivary.

Alkaline Phosphatase↗

PubMed2006

Bone marrow angiogenesis in aplastic anemia.

The objective of this study was to investigate the status of bone marrow angiogenesis in aplastic anemia (AA). Bone marrow specimens from 32 patients with AA and 16 normal controls were studied. The number of bone marrow microvessels was examined by means of immunohistochemical staining for CD34. Determination of microvessel density (MVD) and angiogenesis grading were done in a blinded manner. The results showed that the bone marrow MVD in patients with AA was significantly lower than that in healthy subjects (P < 0.01). MVD in patients with severe and moderate AA was lower than that in control group, respectively (P < 0. 01). There is significant MVD difference between severe AA and moderate AA (P < 0.05). Angiogenesis grade and MVD in AA were positively correlated (r = 0.64, P < 0.01). It is concluded that bone marrow angiogenesis in AA patients is lower than that in normal controls. Defect of angiogenesis in bone marrow may play a role resulting in or aggravating hematopoietic aplasia in patients with AA.

Adult↗

PubMed2006

[Field-scale study on performance comparison of bio-augmentation and compost treatment of oily sludge].

In order to explore better treatment process of oily sludge, the field scale experiments were conducted using the sludge containing 12.68% oil. The performance of microbe preparation bio-augmentation (MPB) and compost treatment with manure (CTM) was compared. For the first experiment, 10 L solution containing 150 g microbe preparations and the nutrition were sprayed onto the MPBC cell. The initial oil content of final mixture amounted to 12.12%. The initial oil content of CTM after final mixture approximated to 10.14%. During the experimental period, same quantities of the microbe preparation and nutrient solution were sprayed on MPB at the 15th and 30th day separately. At the same days, the 10 kg manure was added to CTM cell. The degradation effect of MPB was more obvious, oil content dropped to 6.42% with a 47% removal rate of oil. The oil content in control decreased slightly to 10.15% after 56 days, while in CTM it fell down to 6.98% with a total removal rate of 31%. The pH in control fluctuated slightly between 8.28 to 7.93 while that in MPB, from 7.33 to 8.08, which might due to the addition of microbe preparation. The microbial count was analyzed weekly, which represented the adaptation ability of microbe in sludge. Temperature of compost increased rapidly up to 54 degrees C in the presence of manure. The differences of two kinds of methods were identified by GC-MS and the hydrocarbons with less 21 carbons were degraded easily.

Bacteria↗

PubMed2006

[Expression of vascular endothelial growth factor in patients with aplastic anemia and its significance].

This study was aimed to investigate the expression of vascular endothelial growth factor (VEGF) in patients with aplastic anemia. The gene expressions of VEGF in mononuclear cells of bone marrow from 7 cases of aplastic anemia and 12 normal controls were detected by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). The expressions of VEGF in bone marrow from 20 cases of aplastic anemia and 20 normal controls were also determined by immunohistochemistry assay. The results showed that expression of VEGF mRNA was found in 2 out of 7 (28.57%) bone marrow of patients and in 10 out of 12 (83.33%) bone marrow of normal controls. The VEGF mRNA in patients with aplastic anemia was significantly lower than that in normal controls (P < 0.05). No patients with aplastic anemia showed immunohistochemical staining of VEGF in bone marrow, while 5 out of 20 (25%) normal controls exhibited VEGF positive cells. Bone marrow of aplastic anemia patients contained less VEGF than that of normal persons (P < 0.05). In conclusion, when compared with normal controls, VEGF expression decreased significantly in patients with aplastic anemia at gene transcription level and protein translation level, it may be related to the defect of angiogenesis and thus hematopoiesis in bone marrow of patients with aplastic anemia.

Adolescent↗

PubMed2006

[The prognostic value of quantitative chromosomal abnormality in myelodysplastic syndromes].

OBJECTIVE: To investigate the prognostic value of quantitative chromosomal abnormality in myelodysplastic syndromes (MDS). METHODS: Chromosomal karyotypes in seventy-one MDS patients' were analyzed quantitatively. Based on the number of abnormal metaphase in 20 counted metaphases, the patients were divided into three groups: no abnormal karyotypes, abnormal metaphases less than or equal to five, and that more than five. The leukemia transformation rate, death rate and survival time between these three groups were compared. RESULTS: Forty-four cases (62.0%) had abnormal karyotypes. The incidences of abnormal karyotypes in RA, RCMD and RAEB were 76.9%, 55.8% and 75.0%, respectively, being no significant difference (P > 0.05). Among the abnormal karyotypes, complex abnormality with two or more abnormal karyotypes was most common and accounted for 47.7%. The frequencies of trisomy 8, monosomy 7 and del 20q were 18.2%, 4.5% and 4.5%, respectively. Other kinds of abnormal karyotypes totally accounted for 25%. There were 27 cases of group 1, 28 of group 2 and 16 of group 3. Eighteen cases (25.4%) transformed to acute leukemia. The incidences of leukemia transformation in group 1, 2 and 3 were 18.5%, 25% and 37.5%, and the death rates were 29.6%, 42.9% and 56.3%, respectively. The median survival times were 60, 47 and 24 months respectively. CONCLUSION: The quantitative chromosome abnormality has prognostic value in MDS.

Adolescent↗

PubMed2006

[The clinical features of the autoimmune hemolytic anemia with both warm and cold autoantibodies].

OBJECTIVE: To study the clinical characteristics of autoimmune hemolytic anemia (AIHA) with both warm and cold autoantibodies. METHODS: Clinical and laboratory characteristics of 23 cases of AIHA with both warm and cold autoantibodies admitted to our hospital between January 1994 and April 2004 were analyzed retrospectively. RESULTS: In comparison with the AIHA patients with both warm and cold autoantibodies in the 1980s, the present patients showed the following features: The proportion of this kind AIHA in all AIHA patients increased from 17.6% to 22.1%. There were more females, more primary cases (73.9%), more mixed subtypes of autoantibodies and more of IgM (56.5%). The hemolysis was related with thermal amplitude of autoantibodies and quantity of complement. The response to cortisone and other immunosuppressive drugs was good. The relapse rate was 77.8% in a median follow-up time of 4 months. CONCLUSIONS: AIHA with both warm and cold autoantibodies is related with the type and thermal amplitude of the autoantibody and the activation of complement. It can be treated effectively with combined immunosuppressive therapy, but the relapse rate is high.

Adolescent↗

PubMed2006

[Linkage analysis of the polymorphism at D17S1878 site with essential hypertension].

OBJECTIVE: To explore the linkage of the polymorphism at D17S1878 site with susceptible gene of essential hypertension. METHODS: Forty-five pedigrees from the high prevalence region of the hypertension were collected. The polymorphism of D17S1878 site was genotyped with genetic analyzer and gene-scan software. Discordant sib pair analysis and affected sib pair analysis were used in linkage analysis. RESULTS: There were significant differences in the age, male, alcohol-consuming, over-salt intake, average systolic pressure, average diastolic pressure, waist-to-hip-ratio, total cholesterol, high-density lipoprotein, and low density lipoprotein between the hypertensive sib and the normotensive sib (P < 0.05). There were eleven alleles at D17S1878 site, and the allele frequency was significantly different between the hypertensive and normotensive sibs (P < 0.05). Forty-three pedigrees were analyzed with affected sib pair analysis (t = 3.05, P < 0.05). CONCLUSION: The polymorphism of D17S1878 may be linked with susceptible genes of essential hypertension.

Adolescent↗

PubMed2006

[Correlation analysis and identification of G421C in regulatory region of CYP4F2 gene with essential hypertension].

OBJECTIVE: To investigate the correlation between G421C polymorphism in the regulatory region of CYP4F2 gene and essential hypertension and its molecular mechanism. METHODS: Totally 196 hypertensive patients (hypertension group) and 219 normotensive subjects (control group) were genotyped by polymerase chain reaction-restriction fragment length polymorphism. The promoter activity with different alleles was evaluated by reporter assay. A Myb responsive element was identified using gel retardation assay. RESULTS: Significant differences were found in distribution of genotype and allele frequency of G421C between hypertension group and control group (P < 0.05), and homozygous GG genotype was independently associated with hypertension after adjustment for age, gender, body mass index, and other risk factors (odds ratios 1.87, 95% CI 1.11-3.13, P < 0.05). 421G reporter construct showed decreased promoter activity compared with 421C reporter construct. 421G existed in Myb responsive element, whereas 421C damaged this motif. CONCLUSION: G421C polymorphism in the regulatory region of CYP4F2 gene is correlated with essential hypertension. 421G allele inhibits transcription by binding affinity of Myb responsive element.

Adult↗

PubMed2006

[Mechanism of low intensity ultrasound enhanced biological treatment of wastewater].

Low intensity ultrasonic irradiation can improve activity of microorganisms effectively, and thus it can be used to enhance the biological treatment of wastewater and increase the treatment efficiency through improving microbial activity in the biological reactor. The research achievements from home and abroad on the application of ultrasound (US) in bioengineering and biology were comprehensively summarized. The biological effect of low intensity US and the main mechanisms of biological activity enhancement were discussed, and the future application of low intensity US in biological wastewater treatment was analyzed accordingly.

Bacteria↗

PubMed2006

[Effect of the NHE-1-specific inhibitor DMA on pHi, proliferation and apoptosis of HL-60/ADM cells in vitro].

The aim of this study was to evaluate the effect of dimethyl amiloride (DMA), a specific inhibitor of Na(+)/H(+) exchanger-1 (NHE-1), on intracellular pH value (pHi), proliferation and apoptosis of HL-60/ADM cells in vitro. After treatment with DMA at different doses, pHi of HL-60 and HL-60/ADM cell lines were determined by using pH-sensitive fluorescence dye BECEF-AM; the rate of growth inhibition of cells was detected with MTT assay; cell cycle was detected by flow cytometric DNA analysis; cell apoptosis was observed with terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). The results showed that pHi in HL-60/ADM cells was higher than that in HL-60 cells. After treatment with DMA at different doses, pHi decreased, the rate of growth inhibition and the rate of apoptotic cells in HL-60/ADM cells were all higher than those in HL-60 cells. Meanwhile, after treatment with DMA during 100 micromol/L to 150 micromol/L, the increase amplitude of G(0)/G(1) phase cells and the decrease amplitude of S + G(2)/M cells in HL-60/ADM cells were higher than those in HL-60 cells. It is concluded that by causing intracellular acidification, the NHE-1-specific inhibitor DMA inhibits proliferation of HL-60/ADM cells and induces apoptosis of HL-60/ADM cells, and the degree of this growth inhibition of HL-60/ADM cells is higher than that of HL-60 cells.

Amiloride↗

PubMed2006

Burden of abnormal hematopoietic clone in patients with myelodysplastic syndromes.

OBJECTIVE: To investigate the role of the burden of abnormal hematopoietic clone in the development of myelodysplastic syndromes (MDS). METHODS: The ratio of the bone marrow cells with abnormal chromosomes to the total counted bone marrow cells was regarded as the index of MDS clone burden. The disease severity related parameters including white blood cell count, hemoglobin, platelet count, lactate dehydrogenase level, bone marrow blast, myeloid differentiation index, micromegakaryocyte, transfusion, interleukin-2, tumor necrosis factor (TNF), CD4+ and CD8+ T cells of MDS patients were assayed, and the correlations between those parameters and MDS clone burden were also analyzed. RESULTS: The clone burden of MDS patients was 67.4% +/- 36.2%. MDS clone burden positively correlated with bone marrow blasts (r = 0.483, P < 0.05), negatively with hemoglobin level (r = -0.445, P < 0.05). The number of blasts, hemoglobin, and erythrocytes in high clone burden (> 50%) and low clone burden ( < or = 50%) groups were 7.78% +/- 5.51% and 3.45% +/- 3.34%, 56.06 +/- 14.28 g/L and 76.40 +/- 24.44 g/L, (1.82 +/- 0.48) x 10(12)/L and (2.32 +/- 0.66) x 10(12)/L, respectively (all P < 0.05). CD4+ T lymphocytes of MDS patients and normal controls were (0.274 +/- 0.719) x 10(9)/L and (0.455 +/- 0.206) x 10(9)/L, respectively (P < 0.05). CD8+ T lymphocytes of MDS patients and normal controls were (0.240 +/- 0.150) x 10(9)/L and (0.305 +/- 0.145) x 10(9)/L, respectively. The serum level of interleukin-2 of MDS patients (6.29 +/- 3.58 ng/mL) was significantly higher than normal control (3.11 +/- 1.40 ng/mL, P < 0.05). The serum level of TNF of MDS patients and normal control group were 2.42 +/- 1.79 ng/mL and 1.68 +/- 0.69 ng/mL, respectively. The ratio of CD4 to CD8 was higher in high clone burden MDS patients (1.90 +/- 0.52) than that in low clone burden patients (0.97 +/- 0.44, P < 0.05). CONCLUSION: The quantitive clonal karyotype abnormalities and deficient T cell immunity are important parameters for evaluating MDS severity and predicting its progression.

Adolescent↗

PubMed2006

[Optimization of irradiation cycle for enhancement of biological treatment of wastewater by low intensity ultrasound].

This work aims to optimize one of the critical technological parameters--ultrasound (US) irradiation cycle for utilizing the low intensity ultrasound to enhance biological wastewater treatment. The aerobic activated sludge from domestic wastewater treatment plant was used for this study as an experimental material. Oxygen uptake rate (OUR) and 2, 3, 5-triphenyl tetrazoliumchloride-dehydrogenase activity (TTC-DHA) were determined to indicate the changes of biological activity (within 48 h) after US irradiation at 0.3 W/cm2 in irradiation time of 10 min. The activity of sludge took 8 h after irradiation to reach peak level, and the enhancement effects induced by US faded away 24 h after irradiation. In addition, 8 h and 24 h were used as irradiation cycle respectively to carry out repeated US treatment. Results showed that when 8 h cycle was used, sludge activity decreased quickly after second US irradiation, and after third US exposure, sludge activity decreased even less than 50% of the control. When 24 h was used as the irradiation cycle, sludge activity increased after each US irradiation, but the extent of each increase declined with the increase of the number of US exposure. In consideration of US equipment costs and stability of treatment effects, 8 h should be selected as the US irradiation cycle and each time we can expose only a part of activated sludge in the biological reactor to avoid the decrease of sludge activity induced by repeated US treatment. The paper also analyzed the mechanism of biological activity enhancement by US according to above phenomena.

Bacteria, Aerobic↗

PubMed2006

[Optimization of the proportion of irradiated sludge for enhancement of sludge activity in biological treatment of wastewater by low intensity ultrasound].

The proportion of irradiated sludge (percentage that the irradiated sludge account for the total sludge in the reactor) for enhancement of biological treatment of wastewater by ultrasound (US) was optimized through contrast experiments between two sequenced batch reactors (SBR) with and without US. During the experiment, the US with intensity of 0.3 W/cm2 and frequency of 35 kHz was employed to irradiate a certain percentage of sludge in the US-SBR reactor for 10 minutes every 8 h. The results showed that the removal rate of COD and NH3-N could be increased of 5% and 0.5% respectively when the proportion of exposed sludge was 10%. A significant increase of sludge activity was also obtained with this proportion and more than 12% increase of OUR ( Oxygen Uptake Rate, OUR) was achieved when 10% of sludge was irradiated. Moreover, the growth rate of activated sludge was decreased of 11% when the proportion of irradiated sludge was 10%, which can reduce the subsequent procedure of sludge treatment. With the increase of proportion of the irradiated sludge, SVI (sludge volume index) of the sludge in the US-SBR increased continuously, but it had little influence when the proportion of the irradiated sludge was no more than 10%. Therefore, to improve the treatment efficiency of biological reactor, US with intensity of 0.3 W/cm2 could be employed to irradiate 10% of the sludge in the biological reactor for 10 minutes every 8 h.

Bacteria, Aerobic↗