Conservation of the genomic structure and receptor-mediated signaling between human and rat IL-24

IL-24/MDA-7 is a new member of the IL-10 family of cytokines, which signals through two heterodimeric receptor complexes (IL-20R1/IL-20R2 and IL-22R/IL-20R2). Previously, we identified a rat gene named mob-5, which encodes a secreted protein that shares a high degree of homology with human IL-24. Expression of mob-5 and its putative cell surface receptors was shown to be upregulated by oncogenic ras. Here we show that not only do rat mob-5 and human IL-24 share a strikingly similar genomic structure but also that the rat MOB-5 protein can bind to and signal through the human IL-24 receptors. Like human IL-24, binding of the rat MOB-5 protein to the human IL-24 receptors leads to activation of the JAK/STAT pathway, which in turn supports receptor-dependent survival and proliferation of Ba/F3 cells. Furthermore, using human colon cancer cell lines with somatic knockout of either the mutant or the wild-type k-ras allele, we demonstrate that the human IL-24 receptors also are upregulated by oncogenic ras. Taken together, these results provide strong experimental evidence that MOB-5 is indeed the rat homolog of human IL-24.

Preconcentration of Rare Earth Elements on Silica Gel Loaded with 1-Phenyl-3-methyl-4-benzoylpyrazol-5-one Prior to Their Determination by ICP-AES

A new chelating resin, silica gel loaded with 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (PMBP), was prepared and used for the preconcentration of trace amounts of rare earth elements (REEs) in water samples prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). REEs (La, Eu, Yb and Y) were quantitatively retained on the column packed with modified silica gel in the pH range 5 - 8 and separated from the matrix, and then recovered by eluting with 2.0 mol L(-1) HNO3. The adsorption capacity of modified silica gel for La, Eu, Yb and Y was 0.208, 0.249, 0.239 and 0.224 mmol g(-1), respectively. The method has been successfully applied for the determination of La, Eu, Yb and Y in geological and environmental samples with satisfactory results.

Effects of several Chinese herbal aqueous extracts on human sperm motility in vitro

The effects of six kinds of aqueous extracts of Chinese herbal medicine (Astragalus membranaceus, Acanthopanacis senticosi, Panax genseng and Ophiopogon japonicus, P. genseng and Aconitum carmichaeli, Salviae miltiorrhiae, Polyporus umbellatus polysaccharide) on sperm motility characteristics of 30 infertile male volunteers were studied in vitro with a computer-assisted sperm analysis at 15, 60 and 180 min after incubated with the drugs. The results showed that per cent viability, number of progressive motile spermatozoa, curvilinear velocity, average path velocity and amplitude of lateral head displacement were significantly enhanced by A. membranaceus (P < 0.05 or < 0.01), per cent viability, average path velocity and amplitude of lateral head displacement were significantly enhanced by A. senticosi (P < 0.05), but all the above were not affected by P. genseng and O. japonicus, P. genseng and A. carmichaeli, S. miltiorrhiae and P. umbellatus polysaccharide. It is suggested that A. membranaceus and A. senticosi can enhance the motility of human spermatozoa in vitro.

Selective separation of La3+ and lanthanum organic complexes with nanometer-sized titanium dioxide and their detection by using fluorination-assisted electrothermal vaporization ICP-AES with in-situ matrix removal

A new method for the determination of free La3+ and La organic complexes in solution using a nanometer-sized titanium dioxide as solid-phase extractant and fluorination-assisted electrothermal vaporization (FETV)-ICP-AES as sensitive detector has been developed. The effect of pH on the adsorption characteristics of La3+ and La complexes of citric acid, 2-hydroxyisobutyric acid (HIBA), and humic acid on nanometer-sized TiO2 was investigated and optimized. On the basis of the difference in volatility between fluoride of analyte (lanthanum) and the fluoride of matrix (titanium), an in-situ removal of the adsorbent matrix (TiO2) from a graphite furnace was realized. Therefore, the free La3+ and adsorbed La complexes on nanometer-sized titanium dioxide could be determined respectively by FETV-ICP-AES without any other chemical pretreatment. The proposed method was applied for the determination of free ion (La3+) and La complexes in synthetic solutions and soil extracts with satisfactory results.

Genetic basis of resistance and studies on cross-resistance in a population of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

The genetic basis of abamectin resistance was studied in a strain of the diamondback moth, Plutella xylostella (L), following laboratory selection of a field population collected at Xuanhua, Hebei Province, China. Data from the testing of F1 progeny from reciprocal crosses between abamectin-resistant and abamectin-susceptible strains indicated that resistance might be autosomal and incompletely recessive with a degree of dominance of -0.13. Chi-squared analyses from the response of a backcross of crossed F1 progeny and the resistant strain and F2 progeny were highly significant, suggesting that the resistance was probably controlled by more than one gene. The results of cross-resistance studies showed that there was little cross-resistance between abamectin and four pyrethroid insecticides (deltamethrin, beta-cypermethrin, fenvalerate and bifenthrin) and no cross-resistance between abamectin and the acylureas chlorfluazuron or flufenoxuron.

ICP-AES detection of ultratrace aluminum(III) and chromium(III) ions with a microcolumn preconcentration system using dynamically immobilized 8-hydroxyquinoline on TiO2 nanoparticles

Titanium dioxide nanoparticle dynamically loaded with 8-hydroxyquinoline (nanometer TiO2-Oxine) was used as a solid-phase extractant for the preconcentration of trace amounts of aluminum(III) and chromium(III) prior to their determination by inductively coupled plasma atomic emission spectrometry (ICP-AES). The optimal conditions for preparing nanometer TiO2-Oxine were obtained. Also, the separation/preconcentration conditions of analytes, including the effects of the pH, the sample flow rate and the volume, the elution solution and the interfering ions on the recovery of the analytes were investigated. At pH 6.0, the adsorption capacity of nanometer TiO2-Oxine was found to be 5.23 mg g(-1) and 9.58 mg g(-1) for Al(III) and Cr(III), respectively. An enrichment factor of 50 was achieved by this method, and the detection limits (3sigma) for Al(III) and Cr(III) were 1.96 and 0.32 microg L(-1) respectively. The proposed method was applied for the determination of trace Al(III) and Cr(III) in biological samples and lake water with satisfactory results.

Sequential pathological and immunologic analysis of percutaneous microwave coagulation therapy of hepatocellular carcinoma

PURPOSE

To evaluate sequential pathologic and immunologic changes and their prognostic significance after percutaneous microwave coagulation therapy (PMCT) of hepatocellular carcinoma (HCC).

METHODS

Eighty-nine nodules in 82 consecutive patients were studied. The 89 nodules were divided into two groups: a treatment group, with 82 primary nodules (average dimension was 3.4 +/- 1.2 cm) in 82 patients, and a control group, of seven nodules (average dimension was 1.4 +/- 0.6 cm) in seven patients. The criteria for a nodule's inclusion in the control group was that the nodule was one of two nodules in the same patient and that the two nodules were located in different liver lobes. This guarantees that while one nodule is treated by PMCT, the distant one will not be directly affected by the microwave thermal field. The control group nodules were treated after the study was completed. Specimens were taken with ultrasound-guided liver biopsy from the treated nodule and the control nodule, pre- and post-PMCT. Infiltration by T-lymphocytes, B-lymphocytes, NK cells and macrophages in the tumour tissue were observed immunohistochemically using a panel of monoclonal antibodies against CD3, CD45RO, CD20, CD56 and CD68. The extent of immune cell infiltration was compared both before and after PMCT, as well as between the treated and control nodules. The relationship between the prognosis and the extent of immunocyte infiltration was analysed.

RESULTS

The patients were followed for 2-26 months (mean 14.6 +/- 6.3) post-treatment. The recurrence rates at 1 and 2 years were 20.4% and 28.1% within the liver in treatment group, respectively. The survival rates at 1 and 2 years were 92.5% and 75.3% for the treatment group. T-cells, NK cells and macrophages increased significantly in both treated and untreated nodules after PMCT, albeit less markedly within untreated nodules when compared to the treated ones. There is a statistically significant correlation between survival outcome and the extent of immunocyte infiltration.

CONCLUSIONS

For inoperable HCC patients, PMCT is one of the treatment choices shown to be effective. Apart from its tissue coagulation effect, an increased systemic immune response directed against the tumour may also play an important role in improved survival.

[The application of inductively coupled plasma atomic emission spectrometry/mass spectrometry in the trace elements and speciation analysis of traditional Chinese Medicine]

A review on the content and speciation analysis of trace element in traditional chinese medicine (TCM) by ICP-AES/MS was presented. The study is mainly focused on the following subjects: sample digestion techniques; determination and speciation analysis of trace elements. The development trend of this area in the near future is briefly introduced. 58 references are cited. The results show that the microwave digestion techniques is a idea pretreatment method of sample for tradition chinese medicine; ICP-AES/MS and all kinds of hyphenated techniques for atomic optical/mass spectrometry/chromatography are very useful for the determination and speciation analysis of trace elements in TCM.

Differential display analysis of gene expression in mammals: a p53 story

Differential display is used worldwide as a method to identify changes in gene expression and to discover novel genes that are involved in important biological pathways. The principle of differential display is the systematic amplification of the 3' termini of messenger RNAs by using anchored oligo-dT primers in combination with upstream arbitrary primers. The separation of the polymerase chain reaction products by gel electrophoresis and their direct comparison allows the identification of differentially regulated genes. Recently, fluorescent differential display was established as the first nonradioactive differential display system with equivalent sensitivity to originally 33P isotopic labeling method. Because of its simplicity, sensitivity, reproducibility and automation, which increase the throughput and accuracy, differential display has become one of the most widely used gene-screening methods in biomedical research involving mammals. This chapter provides a glimpse of the application of differential display in search of target genes of the p53 tumor suppressor gene.

Differential display technology: a general guide

The 10 years since the invention of differential display technology (DD) has produced a massive amount of literature detailing problems and improvements to the technique, successful gene expression studies and studies done using genes found through the use of DD. In this review we summarise the results of 10 years of research that has focussed on improving DD and discuss how some of the problems associated with DD can be resolved or minimised. In addition to discussing DD, we address issues related to other differential gene expression analysis techniques and try to illustrate how these techniques can be used to complement one's use of DD. This review also serves as an introduction to the taxa-specific DD review articles that are found in this issue.

[Construction of a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma tissue]

OBJECTIVE

To construct a subtracted cDNA library of differentially expressed genes in human normal liver tissue and primary hepatocellular carcinoma (HCC) tissue.

METHODS

Using the suppression subtractive hybridization (SSH), a novel technique has been described recently. cDNA fragments of missing or low expressing tumor suppressor genes in HCC tissue were isolated using paracancerous normal liver tissue and HCC tissue as targets. Then these cDNA fragments were directly inserted into T/A cloning vector to set up the subtractive library. Amplification of the library was carried out with transformation of E.coli by high voltage electroperforation. One hundred positive bacteria clones were randomly picked and identified using enzyme restriction method.

RESULTS

The amplified library contained more than 4,000 positive bacteria clones. Random analysis of 100 clones with enzyme restriction method showed that all clones contained 200-600 bp inserts.

CONCLUSIONS

A subtracted cDNA library of differentially expressed genes in human normal liver tissue and HCC tissue is constructed successfully with SSH and T/A cloning techniques. The library is efficient and lays solid foundation for screening and cloning new and specific missing or low expressing tumor suppressor genes of HCC.

[Isolation and identification of neural precursor cells from human embryonic cortical tissue]

OBJECTIVE

To isolate neural precursor cells from human embryonic cortical tissue of 20 weeks and identify their proliferation capacity as well as differentiating potential.

METHODS

Human fetuses of about 20 weeks from spontaneous abortion were adopted. A serum-free medium containing basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF) was used to make the neural precursor cell divide continuously in the culture. The proliferating ability of these cells was tested with BrdU. Growth factors were removed so as to induce differentiation of the precursor cells. The cell cycle of the cells in the neurosphere was analysed using flow cytometry.

RESULTS

Cells from human embryonic cortical tissue could be maintained and propagated in the presence of growth factors. Neurospheres generated continually and the cells in the sphere could incorporate into BrdU. Upon differentiation, the precursor cells gave rise to mature neurons, astrocytes and oligodendrocytes. They retained their multilineage potential over repeated passages. The cell cycle analysis indicated that the cells proliferated actively.

CONCLUSION

Cells that able to self-renew and differentiate into mature cells in culture cam be isolated from human embryonic tissues. They are verified to be neural precursor cells.

Glutathione-S-Transferase M1 null genotype in autoimmune hepatitis

Autoimmune hepatitis is associated with genes located in the major histocompatibility complex. The search for genes at other loci that may play a role in disease susceptibility and/or severity is an area of active investigation in autoimmune liver diseases. Genes for glutathione-S-transferases, enzymes that are widely distributed and collectively metabolize carcinogens, pollutants, drugs, and a broad spectrum of harmful, foreign compounds have been associated with liver disease. The objective of this study was to search for a relationship between the glutathione-S-transferase Ml null genotype and autoimmune hepatitis using polymerase chain reaction analysis. The findings indicate that the frequency of the null genotype is not increased in patients with autoimmune hepatitis when compared to control subjects. These results coupled with similar ones in primary biliary cirrhosis do not support a role for this mutation in autoimmune liver disease.

Detection of an mRNA polymorphism by differential display

Differential Display (DD) technology was utilized to compare programs of gene expression in primary cultures of human skin fibroblasts from normal volunteers and patients diagnosed with melancholic depression. Polymorphic transcripts of a single gene differing by one tandem repeat sequence of four nucleotides (TGAT) in the 3' noncoding region were detected.

[Functional assessment of infiltrating immunocytes in patients with primary hepatocellular carcinoma after percutaneous microwave coagulation therapy]

OBJECTIVE

To assess the function local immune cells in patients with primary hepatocellular carcinoma (HCC) after percutaneous microwave coagulation therapy (PMCT).

METHODS

Thirty-eight patients with histologically proved primary HCC underwent ultrasound guided PMCT. Specimens were taken from the lesion site before and 17 days after PMCT respectively using 18-guage core needle through US-guide biopsy, embedded in paraffin, and stained by immunohistochemistry. The panel of monoclonal antibodies of CD3, CD56, CD68 and Fas-L were used to detect the CD3+, CD56+, CD68+ cells and T lymphocyte Fas-ligand. The positive cells were detected under light microscopy. Their diameter and area and the Fas-L expression rate of T lymphocytes and changes of secondary lysosomes in macrophages were measured by computer.

RESULTS

Before PMCT, only a few infiltrating immunocytes were seen in the tumor specimens; the diameter of most CD3+ and CD56+ cells was less than 10 microns and the diameter of CD68+ cells was less than 18 microns. The amount and volume of CD3+, CD56+, and CD68+ cells significantly increased after PMCT (t = 3.48, P = 0.025 for CD3+ cells, t = -4.76, P = 0.000 for CD56+ cells, and t = -2.46, P = 0.028 for CD68+ cells). The percentage of CD3+ and CD56+ cells with the largest diameter > 10 microns increased from 10.4% and 20.1% respectively before PMCT to 24.9% and 30.2% respectively after PMCT. The percentage of CD68+ cells with the largest diameter > 18 microns increased from 10.2% before PMCT to 33.4% after PMCT. The Fas-l expression rate of T lymphocytes increased from 7.2% to 20.1% (t = -19.12, P = 0.000). The secondary lysosomes and cellular debris within microphages and the cellular organs in T lymphocytes significantly increased.

CONCLUSION

The function of intratumaral infiltrating immunocytes is significantly enhanced after PMCT.

[Relationship between proteoglycans and apoE on the HepG2 cell surface]

OBJECTIVE

To characterize the associations and functions of apoE with the HepG2 cell surface through the study of the relationship between proteoglycans and apoE on HepG2 cell surface.

METHODS

The specific binding of 7C9, a monoclonal antibody against the N-terminal domain of apoE was employed to demonstrate the effects of glycosaminoglycans, heparinase, chondroitinase, xyloside, and chlorate on the apoE of HepG2 cell surface.

RESULTS

Growth of cells in beta-D-xyloside decreased cell surface apoE by 45% with a concomitant increase in apoE secretion (4.3-fold), underlining the importance of glycosaminoglycan association of apo E. Incubations with heparinase (3 U/ml) and heparin (1 mg/ml) decreased apoE by 25.0% and 30.5% respectively indicating association through cell surface haparin sulfate proteoglycans. Incubations with chondroitinase ABC (1.5 U/ml) reduced cell surface apoE by 40.0%. Chondroitin sulfate A and chondroitin sulfate B reduced cell surface apoE by 23.6% and 15.3% respectively while incubations with chondrointin sulfate C not effective. Decreasing the levels of cell surface apoE with haparin or chondrointin sulfates A and B increased the subsequent binding of LDL to the HepG2 cell surface.

CONCLUSIONS

ApoE associates with the cell surface mainly through chondrointin sulfate proteoglycans and to a lesser extent through heparan sulfate proteoglycans, decreased levels of cell surface apoE increase the binding of LDL to the cell surface.

[Characterization of macrophage cell (THP-1) surface apoE and it's role in metabolism of cell lipids]

OBJECTIVE

To study the characterization of THP-1 cell surface apoE in order to learn the further role of macrophage in development of atherosclerosis.

METHODS

Using monoclonal antibodies (7C9,3H1) against apoE to analyze the effects of AcLDL, heparin, chondroitinase, and Liposyn II on the apoE of THP-1 cell surface.

RESULTS

Cholesterol (AcLDL) loaded cell demonstrated reduced binding of 125I-7C9 to the cell surface by 19% at 4 degrees C, but if the THP-1 cell incubated at 37 degrees C for 2 hours after the removal of AcLDL there was a increase (25%) in 7C9 bound to loaded cells when compared to the 4 degrees C controls; prior loading with AcLDL also increased the secretion of apoE to the extracellular medium in a time-dependent manner; heparinase or chondroitinase ABC did not reduce the surface apoE associated with unloaded cells; the apoE on the surface of loaded macrophage was only marginally affected (9.3%) by incubation with heparinase but was efficiently reduced (50%) by incubation with chondroitinase ABC; Liposyn II dramatically increased the binding of apoA1 to the cell surface (1.5-1.8 fold), the Liposyn II mediated increased binding of apoA1 was antagonized by pre-incubation of THP-1 cells with 3H1 indicating that it was an apoE-dependent process.

CONCLUSIONS

Cell surface apoE of THP-1 macrophage relates to the process of cholesterol loading of macrophage cells and lipid mediated binding of apoA1 to the cell surface. It may affect the process of atherosclerosis development.

[Effect of mm-LDL on NF-kB activation in endothelial cell]

OBJECTIVE

To investigate the signal transduction pathway of NF-kB activated by minimally modified low density lipoprotein (mm-LDL) in endothelial cells and the effect of NF-kB on platelet derived growth factor b (PDGFb) mRNA expression.

METHODS

mm-LDL was prepared through iron oxidation by dialyzing the native LDL against FeSO4 in PBS. Endothelial cells were incubated in a medium containing mm-LDL, TNF, and IL-1 respectively and electrophoretic mobility shift assay (EMSA) was displayed to check on the activation of NF-kB. Luciferase reporter gene was analysed to investigate the effect of nuclear factor inducing kinase (NIK), inhibitor of NF-kB kinase alpha (IKK alpha) and inhibitor of NF-kB kinase beta (IKK beta) on NF-kB activation. In addition, endothelial cells were transfected using PDGFb promoter-luciferase for reporter gene analysis or transfected with mut-NIK for slot blot analysis to study the effect of NF-kB on PDGFb mRNA expression.

RESULTS

mm-LDL was able to activate NF-kB in endothelial cells. mut-NIK and mut-IKK beta inhibited luciferase activity induced by mm-LDL. mm-LDL could also enhance luciferase activity controlled by upstream sequence of PDGFb promoter which contains element interacting with NF-kB. Result of slot blot showed inhibition of PDGFb mRNA expression by mut-NIK in the endothelial cells stimulated by mm-LDL.

CONCLUSION

mm-LDL may activate NF-kB through NIK-IKK beta pathway and promote PDGFb mRNA expression in endothelial cells.

Computer-aided dynamic simulation of microwave-induced thermal distribution in coagulation of liver cancer

To develop a method of dynamic three-dimensional (3-D) simulation of thermal distribution in ultrasound-guided microwave coagulation therapy of liver cancer and to verify its accuracy. The specific absorption rate (SAR) values were established by measuring the temperature in equivalent phantom tests. Those values were different under different power output condition. Dynamic 3-D temperature distributions were reconstructed with a finite-element model. Testing and rectification were performed through animal experiments and clinical trials, respectively. The temperature curves in the experiments corresponded well with simulated ones in vitro--91.4% and 88.9% using single and double electrodes, respectively. The measured coagulated boundary and simulated temperature boundary had a good correspondence in 85.7% of the specimens. In both in vivo experiments and clinical trials, blood perfusion influenced the rise in temperature significantly. Temperature curves between the simulations and actual measured results showed good correspondence--67.8% (19/28) in the patients with hepatocellular carcinoma. Distance between electrodes and combined thermal distributions were both optimized with computer-aided simulation during simultaneous two-electrode coagulation. The results demonstrated that computer-aided simulation of microwave thermal distribution is an accurate and reliable method which provides a theoretical and technical basis for controlling coagulated tissue volume and placement of the electrodes during microwave coagulation therapy of liver cancer.

[Kinetic study on photocatalytic degradation of p-chlorobenzoate at different light intensities]

Kinetics of photocatalytic degradation were investigated at different light intensities using para-chlorobenzoate as a model pollutant. It was experimentally found that the Langmuir-Hinshelwood model could satisfactorily describe all the kinetic processes. However, the two crucial parameters involved in the L-H model were dependent of the incident light intensity. With elevated light intensity, the rate constant, kr, increased whereas the apparent adsorption constant, Ks, decreased. Grossly, both kr and Ks-1 were correlated with the light intensity in a power law. The experimental discovery implies that the photonic efficiency would be much deteriorated with increased radiation intensity although the reaction rate can be enhanced. Applying mild light intensity might be one of the critical strategies in photocatalytic reactor design to improve the photonic efficiency.

Differential display analysis of gene expression altered by ras oncogene

The goal of the signal transduction pathways, such as those controlled by Ras, is in large part to ensure highly stringent regulation of the target genes in the nucleus, which are collectively responsible for the signal output, or phenotypes, of the cell. Understanding of the Ras effect ultimately requires the identification of these downstream target genes. Reverse genetic approaches would trace back the pathways by which they are regulated by Ras. While newer methods such as DNA microarray are emerging, differential display has allowed the identification of a greater number of differentially expressed genes than have been cloned by all the other methods combined, based on Medline search. Much of this success has been attributed to its simplicity (RT-PCR and DNA-sequencing gel) and versatility (compare more than two RNAs for both up- and downregulated genes). It has become obvious that finding the genes by either differential display or DNA microarray is only the first step toward the understanding of biological problems under investigation. It is hoped that finding the right genes through careful experimental designs, such as outlined here, will narrow down the number of relevant genes and increase the odds for solving the puzzles of nature, such as ras.

High glucose concentrations induce oxidative damage to mitochondrial DNA in explanted vascular smooth muscle cells

Oxidative stress is considered to be one of the mechanisms leading to atherosclerosis. It occurs in response to injury or to altered metabolic state. Alterations in cell growth (proliferation or apoptosis) can also contribute to the pathogenesis of atherosclerosis and is influenced by oxidative stress. Smooth muscle cells (SMC) from aortic explants of JCR:LA-cp homozygous cp/cp corpulent rats who are genetically predisposed to develop atherosclerosis exhibit increased SMC proliferation, which can be attenuated by exercise and food restriction. This study was conducted to characterize the effects fo oxidative stress and high glucose media on cell growth and its relationship to mitochondrial DNA integrity and gene expression in explanted aortic SMC from corpulent and lean JCR:LA-cp rats. The results show that SMC from the cp/cp rat appear to be resistant to oxidant-induced cell death and that they accumulate mitochondrial DNA mutations, probably as a result of a reduction in apoptosis. These data suggest that susceptibility to age- and glucose-related atherosclerosis may be related to alterations in redox signaling.