Suppressive effect of coffee on lipopolysaccharide-induced hepatitis in D-galactosamine-sensitized rats

A coffee extract significantly suppressed lipopolysaccharide (LPS)-induced hepatitis in D-galactosamine-sensitized rats, as assessed by the plasma alanine and aspartate aminotransferase activities, when it was added to the diet (30 g/kg) and fed to rats for 14 days. Its effect was as strong as that of a green tea extract. The coffee extract suppressed LPS-induced hepatitis when singly force-fed (1.2 g/kg) 1.5 h prior to the injection of the drugs, whereas a decaffeinated coffee extract had no significant effect. The hepatoprotective effect of caffeine was stronger than that of theobromine. These results indicate that coffee can protect animals from LPS-induced hepatitis, and that the effect of coffee might be mainly due to caffeine.

Accelerative effect of olive oil on liver glycogen synthesis in rats subjected to water-immersion restraint stress

The effects of dietary oils on stress-induced changes in the liver glycogen metabolism of male Wistar rats at 6 weeks of age were investigated. The rats were subjected to repetitive water-immersion restraint and fed with a 20% saturated fatty acid mixture (PSC), olive oil (OLI), safflower oil (SAF), or linseed oil (LIS) diet. Stress loading decresed the body weight gain, although the food intake was hardly changed, and the weights of the liver and spleen generally declined regardless of the elapsed time after stress loading and the type of dietary oil. The adrenal weight was generally enhanced by stress in all deitary groups, and particularly tended to be greater in the OLI and PSC groups than in the other two. The plasma corticosterone concentration increased immediately after stressing (Stress-1), but approached the level of the rats with no stress (No stress) 2 h after releasing the stress load (Stress-2) in all groups. The enhancement of corticosterone level in the Stress-1 animals was large in the PSC and OLI groups, and the decline of this level in the Stress-2 animals was small in the OLI group when compared with the other groups. Although the concentrations of total cholesterol (T-CHOL) and triacylglycerol (TG) in the plasma were decreased by stress loading in all groups, these concentrations in the PSC and OLI groups were nearly always higher than in the other groups. The liver serine dehydratase (SDH) activity enhanced by stress was high in the OLI group and tended to be high in the PSC group when compared with the other groups. The contents of liver glycogen were reduced in the Stress-1 animals and extremely elevated in the Stress-2 animals of all groups, and particularly in the OLI group, the reduction in the Stress-1 animals was smaller and the enhancement in the Stress-2 animals was greater than in the other groups. These results suggest that feeding oleic acid to rats exposed to water-immersion restraint further accelerated liver glycogen synthesis through the rise in liver SDH activity due to increased corticosterone secretion when compared with the effect from linoleic and alpha-linolenic acids.

[Study of the cytotoxity against human hepatocellular carcinoma cells induced by the MAGE-1 gene modified dendritic cells]

OBJECTIVE

To genetically modify dendritic cells (DC) with a tumor associated antigen gene MAGE-1 and to observe in vitro the cytotoxic effect induced by this genetically modified DC against human hepatocellular carcinoma (HCC) cell line SMMC7721, thus giving a primary verification of the possibility of this genetically modified DC to induce specific antitumor immunity against HCC and serving as a new type of vaccine.

METHODS

The MAGE-1 gene was inserted into the retrovirus vector LXSN to construct the recombinant retrovirus LMSN. The monocyte-derived DCs were transfected by LMSN and control virus LXSN respectively as well as a third group was set up as non-transfected control. The MAGE-1 gene expression in LMSN transfected DC was identified by Western blot and the in vitro cytotoxities against SMMC7721 induced by three groups of DC were tested by MTT assay.

RESULTS

A recombinant retrovirus LMSN containing the tumor rejection antigen gene MAGE-1 was successfully constructed and the MAGE-1 gene expression in LMSN transfected human monocyte-derived DC was induced. The LMSN transfected DC could induce very high lytic activity against SMMC7721 in vitro with the lytic activity of 78.9%+/-3.6%. Nevertheless, the LXSN transfected DC and non-transfected DC only induced relatively lower lytic activity as 34.7%+/-4.3% and 3.9%+/-2.0%, respectively. The difference of the lytic activities between those three groups as statistically significant (P<0.01).

CONCLUSIONS

The MAGE-1 gene transfected DC can induce higher in vitro cytotoxicity against SMMC7721, suggesting the possibility of this genetically modified DC to induce specific antitumor activity and to serve as a new type of vaccine for HCC.

[Cloning and expression of VHB gene in D-arabitol producing yeast]

Recombinant plasmid pVgb-EX2 containing Vitreoscilla hemoglobin gene vgb and formaldehyde resistant gene SFA1 was constructed and transformed into D-arabitol producing yeast strain Saccharomyces sp. X-62. The fact that the amount of VHb in transformant cells was considerably higher than that in control cells indicated that gene vgb was expressed in transformant cells. D-arabitol productivity and yield of fermentation by transformants were improved. The most improvement of D-arabitol productivity in repeat experiments reached 27.3%. It appeared that the fermentation productivity of D-arabitol was relative to the amount of VHb in cells under experimental conditions.

Carcinoma arising in an amputation stump

We describe a 62-year-old diabetic man who presented with squamous cell carcinoma on his right thigh amputation stump 52 years after the procedure. The potential relationship of the chronic irritation by the artificial leg and the malignant transformation of the healing scar as well as optimal treatment options of scar-tissue carcinomas are reviewed.

Green tea suppresses lipopolysaccharide-induced liver injury in d-galactosamine-sensitized rats

We conducted a series of in vivo experiments to clarify the hepatoprotective activity of green tea against lipopolysaccharide (LPS) + D-galactosamine (GalN)-induced liver injury and to elucidate the mechanism by which green tea exerts its effect in 7-wk-old male Wistar rats. Liver injury was assessed by plasma alanine aminotransferase and aspartate aminotransferase activities. Green tea extract significantly suppressed LPS + GalN-induced liver injury when added to the diet (30 or 35 g/kg) and fed to rats for 14 d or when force-fed alone (0.4-1.2 g/kg body) 1.5 h before the injection of drugs. Although all five of the fractions extracted from green tea extract with different organic solvents had significant suppressive effects, the caffeine-containing fraction exhibited the strongest effect, suggesting that the protective effect of green tea against LPS + GalN-induced liver injury is attributable mainly to caffeine. Authentic caffeine also significantly suppressed LPS + GalN-induced liver injury when added to the diet (2 g/kg) and fed to rats for 14 d. Dietary green tea suppressed LPS + GalN-induced apoptosis of liver cells, as assessed by DNA fragmentation. However, dietary green tea did not suppress LPS-induced enhancement of plasma concentration of tumor necrosis factor (TNF)-alpha, the cytokine that is thought to play a pivotal role in the pathogenesis of LPS-induced liver injury, although it significantly suppressed plasma concentrations of interleukin (IL)-1beta, IL-2, IL-4, IL-6, IL-10 and interferon (IFN)-gamma. TNF-alpha + GalN-induced liver injury and apoptosis were also suppressed by dietary green tea. In contrast, dietary caffeine significantly suppressed LPS-induced enhancement not only of plasma IL-1beta, IL-6, IL-10 and IFN-gamma concentrations, but also of TNF-alpha concentration. The results suggest that green tea might suppress LPS + GalN-induced liver injury mainly through the inhibition of TNF-alpha-induced apoptosis of hepatocytes, rather than through the suppression of TNF-alpha production, although the suppressed production of TNF-alpha may be associated with the hepatoprotective effect of caffeine.

Liver injury suppressing compounds from avocado (Persea americana)

To evaluate the protective activity of fruits against liver injury, 22 different fruits were fed to rats with liver damage caused by D-galactosamine, a powerful liver toxin. As measured by changes in the levels of plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST), avocado showed extraordinarily potent liver injury suppressing activity. Five active compounds were isolated and their structures determined. These were all fatty acid derivatives, of which three, namely, (2E,5E,12Z,15Z)-1-hydroxyheneicosa-2,5,12,15-tetraen-4-one, (2E,12Z,15Z)-1-hydroxyheneicosa-2,12,15-trien-4-one, and (5E,12Z)-2-hydroxy-4-oxoheneicosa-5,12-dien-1-yl acetate, were novel.

First staging of two laser accelerators

Staging of two laser-driven, relativistic electron accelerators has been demonstrated for the first time in a proof-of-principle experiment, whereby two distinct and serial laser accelerators acted on an electron beam in a coherently cumulative manner. Output from a CO2 laser was split into two beams to drive two inverse free electron lasers (IFEL) separated by 2.3 m. The first IFEL served to bunch the electrons into approximately 3 fs microbunches, which were rephased with the laser wave in the second IFEL. This represents a crucial step towards the development of practical laser-driven electron accelerators.

Gaf-1, a gamma -SNAP-binding protein associated with the mitochondria

The role of alpha/beta-SNAP (Soluble NSF Attachment Protein) in vesicular trafficking is well established; however, the function of the ubiquitously expressed gamma-SNAP remains unclear. To further characterize the cellular role of this enigmatic protein, a two-hybrid screen was used to identify new, gamma-SNAP-binding proteins and to uncover potentially novel functions for gamma-SNAP. One such SNAP-binding protein, termed Gaf-1 (gamma-SNAP associate factor-1) specifically binds gamma- but not alpha-SNAP. The full-length Gaf-1 (75 kDa) is ubiquitously expressed and is found stoichiometrically associated with gamma-SNAP in cellular extracts. This binding is distinct from other SNAP interactions since no alpha-SNAP or NSF coprecipitated with Gaf-1. Subcellular fractionation and immunofluorescence analysis show that Gaf-1 is peripherally associated with the outer mitochondrial membrane. Only a fraction of gamma-SNAP was mitochondrial with the balance being either cytosolic or associated with other membrane fractions. GFP-gamma-SNAP and the C-terminal domain of Gaf-1 both show a reticular distribution in HEK-293 cells. This reticular structure colocalizes with Gaf-1 and mitochondria as well as with microtubules but not with other cytoskeletal elements. These data identify a class of gamma-SNAP interactions that is distinct from other members of the SNAP family and point to a potential role for gamma-SNAP in mitochondrial dynamics.

Analysis of expressions of components in the plasminogen activator system in high- and low-metastatic human lung cancer cells

PURPOSE

To determine the expressive patterns of the components of the plasminogen activator system in human large-cell lung carcinoma strains and to analyze the effects of the patterns on tumor invasion and metastasis.

METHODS

The in vitro and in vivo invasive and metastatic potential of two human large-cell lung carcinoma strains with high (strain 95D) and low (strain 95C) metastatic potential was further confirmed by the Boyden chamber model and nude mice model. After this, the expressions of the components of the plasminogen activator system--including urokinase-type and tissue-type plasminogen activator (uPA and tPA), urokinase receptor (uPAR), and type-1 and type-2 plasminogen activator inhibitor (PAI-1 and PAI-2) in strain 95D and 95C cells--were determined by RT-PCR and immunohistochemical staining. The effects of monoclonal antibodies of uPA, uPAR, and PAI-1 on the invasive potential of strain 95D cell line were also evaluated.

RESULTS

Strain 95D cells were found to have a stronger in vitro and in vivo invasive and metastatic potential than strain 95C cells. In the former, the average number of infiltrating cells in the in vitro model in one field of vision (40055) was 73.75 +/- 7.42, while in the latter, it was 56.33 +/- 6.28 (P < 0.001). Lung metastatic loci were observed in all six nude mice inoculated with 95D cells (6/6), but not in any of the nude mice inoculated with 95C cells (0/6). The high-metastatic strain 95D cells expressed higher uPA and uPAR and lower tPA and PAI-2 than the low-metastatic strain 95C cells. The PAI-1 expressions in both 95D and 95C cells were almost the same. Monoclonal antibodies of uPA and uPAR greatly reduced the invasive potential of strain 95D cells in vitro.

CONCLUSIONS

These data suggest that the invasive and metastatic potential of human large-cell lung carcinoma cell lines is associated with differential expressions of the components of the plasminogen activator system and that the determination of these components may be used as a marker for judging clinically the possibility of tumor metastasis as well as the prognoses of patients.

[A study of the hereditary susceptibility of HLA-DQA1 to essential hypertension, athrothrombotic brain infarction and lacunar stroke]

OBJECTIVE

To study the types of HLA-DQA1 alleles in patients with essential hypertension (EH), athrothrombotic brain infarction (ABI) and lacunar stroke (LS) and normal control individuals and the hereditary susceptibility of HLA-DQA1 alleles to those diseases.

METHODS

The allelic typing of HLA-DQA1 was detected by PCR-SSP in 155 cases of EH, ABI and LS and 64 normal individuals.

RESULTS

The frequencies of HLA-DQA1 * 0301 in EH, ABI and LS groups were obviously higher than that in normal control group (33.6538 vs. 17.9688, 36.5884 vs. 17.9688, 33.0645 vs. 17.9688, P < 0.01). The frequencies of HLA-DQA1 * 0103 in groups of EH, ABI, LS, ABI with EH, and LS with EH were lower than that in the normal control group (6.7308 vs17.1875, RR = 0.3916, P < 0.01; 6.0976 vs. 17.1875, RR = 0.3548, P < 0.05; 6.4566 vs17.1875, RR = 0.3754, P < 0.01; 2.3809 vs17.1875, RR = 0.1385, P < 0.01; 3.5714 vs. 17.1875, RR = 0.2078, P < 0.01.

CONCLUSION

HLA-DQA1 * 0301 allele may be a correlative gene with hereditary susceptibility of EH, ABI and LS, and HLA-DQA1 * 0103 allele may be a protective gene of those diseases.

Suppressive effect of caffeine on hepatitis and apoptosis induced by tumor necrosis factor-alpha, but not by the anti-Fas antibody, in mice

Tumor necrosis factor (TNF)-alpha-induced hepatitis and apoptosis, as respectively assessed by serum enzyme activities and hepatic DNA fragmentation were effectively suppressed by a single force-feeding of caffeine (100 mg/kg) 1.5 h before injecting the drug. In contrast, caffeine had no significant effect on anti-Fas antibody-induced hepatitis and apoptosis. These results suggest that caffeine differentially affected TNF-alpha receptor- and Fas-mediated hepatitis and apoptosis.

Characterization of single-stranded DNA on chitosan-modified electrode and its application to the sequence-specific DNA detection

Single-strand DNA could bind with chitosan on a platinum electrode via forming a tight DNA-chitosan complex. The salt concentration of the ssDNA solution had an obvious effect on the surface coverage, the immobilization was remarkably reduced at high salt concentration. The sample ssDNA immobilized on the chitosan-modified electrode can hybridize efficiently with the complementary sequences and be successfully used for the sequence-specific DNA detection. The same results could be obtained using a gold or graphite electrode modified with chitosan. The stability of this electrode has been also discussed.

Suppression of lipopolysaccharide-induced liver injury by various types of tea and coffee in D-galactosamine-sensitized rats

Extracts of various types of tea and coffee significantly suppressed lipopolysaccharide (LPS)-induced liver injury, as assessed by the plasma enzyme activities, in D-galactosamine-sensitized rats when administered orally once before injecting the drugs. There was a significant negative correlation between the caffeine levels of these extracts and liver injury. Authentic caffeine also had a hepatoprotective effect. These results suggest that caffeine-containing beverages generally suppress LPS-induced liver injury according to their caffeine content.

Elliptic flow in Au+Au collisions at square root(S)NN = 130 GeV

Elliptic flow from nuclear collisions is a hadronic observable sensitive to the early stages of system evolution. We report first results on elliptic flow of charged particles at midrapidity in Au+Au collisions at square root(S)NN = 130 GeV using the STAR Time Projection Chamber at the Relativistic Heavy Ion Collider. The elliptic flow signal, v2, averaged over transverse momentum, reaches values of about 6% for relatively peripheral collisions and decreases for the more central collisions. This can be interpreted as the observation of a higher degree of thermalization than at lower collision energies. Pseudorapidity and transverse momentum dependence of elliptic flow are also presented.

[QTLs analysis of tiller angle in rice (Oryza sativa L.)]

Tiller angle is one of important characters that constitute plant type with great significance in breading. A pair of japonica/indica lines, which were significantly different in tiller angle, were used in this study. A DH population were constructed via anther culture of F1 hybrids. The tiller angles of 115 DH lines were measured. QTL analysis was conducted based on the constructed molecular linkage map. Three QTLs (qTA-9a, qTA-9b and qTA-12) were detected on chromosome 9 and 12 respectively, Their variation were 22.7%, 11.9% and 20.9% respectively and their additive effects were all negative, showing this character was controlled by genes from big tiller angle parent ZYQ8. The application of the tiller angle that was controlled by major genes and minor genes in rice breeding is also discussed.

Electrochemical detection of sequence-specific DNA using a DNA probe labeled with aminoferrocene and chitosan modified electrode immobilized with ssDNA

The electrochemical detection of sequence-specific DNA using a DNA probe labeled with aminoferrocene (AFC) is reported. Sample ssDNA was immobilized on a chitosan modified glassy carbon electrode. A sequence-known DNA with 256 bp [obtained by polymerase chain reaction (PCR)] was successfully labeled with the electro-active reagent AFC by 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide for the first time. This DNA probe labeled with AFC was applied to hybridize with a sequence-unknown DNA sample. Only the complementary sequence (cDNA) could form a double-stranded DNA (dsDNA) with the DNA probe labeled with AFC. The anodic peak currents (ipa) of the AFC bound to the dsDNA by differential pulse voltammetry were used for the determination of cDNA. The ipa of AFC was linearly related to the concentration of cDNA sequence between 1.0 x 10(-8) and 6.0 x 10(-6) mol L-1. The detection limit was 2.0 x 10(-9) mol L-1 using 3 sigma (where sigma is the standard deviation of blank solution, n = 11). The probe showed high sensitivity and selectivity.

Mechanism and kinetics of low-temperature thermochemical conversion process for sewage sludge

The low-temperature thermo-chemical conversion process for sewage sludge is a prospective technology, through which the energy in the sludge can be recovered. With the help of elementary analysis of sewage sludge and its conversion products, thermal gravimetric analysis (TGA) of the sludge and GC/MS analysis of the derived oil, a study was carried out on element transfer, characteristic conversion temperature and conversion reaction mechanism of the process. The following results are obtained: 1) the predominant conversion reactions are distillation of aliphatic compounds, splitting of protein peptide bonds and group transfer; and 2) the main components involved in the conversion are aliphatic compounds and protein, with the lower reaction temperature for the former, the higher for the latter and the highest for saccharides. Based on the mechanism analyses, the simplified reaction model of the thermo-chemical conversion process for sewage sludge consists of two serial competitive reactions (producing volatile matter and char respectively). The estimated Arrhennius kinetic parameters of the reaction model based on TGA testing resultsare A1 = 4.15 x 10(6) 1/s, n1 = 2, E1 = 98 kJ/mol; A2 = 1.42 x 10(5) 1/s, n2 = 2, E2 = 85 kJ/mol; A3 = 1.01 x 10(12) 1/s, n3 = 4, E3 = 190 kJ/mol; A4 = 1.33 x 10(9) 1/s, n4 = 4, E4 = 146 kJ/mol.

Reclaimed municipal wastewater--a potential water resource in China

Due to water resource shortage and socio-economic development within twenty years, China faces serious problems of water supply and water pollution. Several criteria and suitable reclamation processes related to water reuse have been created in China, which are helpful to improve the situation of water scarcity. In the future, reclaimed municipal wastewater reuse will mainly be developed for urban and industrial use. Potential supply quantity of reclaimed water, quality of reclaimed water, and reclamation cost are favorable to potential reuses. Based on further public environmental education, on a relevant development of national and local standards for reclaimed water quality, and on an increase of sanitary rate, more and more planned reclaimed water reuse projects would be expected in China.

Immunophenotyping of lymphocyte T and B in the peripheral blood of systemic lupus erythematosus

The immunophenotyping expression levels of lymphocyte in the peripheral blood from 21 patients with active systemic lupus erythematosus (SLE) were analyzed by using the immunofluorescence labeling-flow cytometry technique to investigate the immunophenotyping expression of lymphocytes T and B in the peripheral blood of active SLE patients and its clinical value. It was showed that, compared with normal controls, the expression of CD3+, CD4+ and the ratio of CD4+/CD8+ in the peripheral blood of these patients were decreased (P < 0.01), while the expression of CD8+, CD20+ was significantly increased (P < 0.01). It was suggested that both T and B cells in patients with active SLE involved in immunoregulation, were activated. The abnormal expression of lymphocyte immunophenotyping could influence the immune reaction in SLE patients, which might be one of the important pathogenesis factors in SLE.

[Antitumor activities in vivo of interleukin-12 gene modified dendritic cells in murine models]

OBJECTIVE

To study the antitumor activities of the mIL-12 transfected and acid-eluted peptide sensitized dendritic cells (DC) in murine H22 liver cancer model.

METHODS

The murine bone marrow derived DC were transfected with the recombinant adenovirus (Ad mIL-12) containing the mIL-12 gene and control virus AdBGFP. The peptides on the surface of the murine H22 cell line were eluted with mild acid buffer and then sensitized the transfected DC. The experimental animals were immunized with the differently disposed DC and the state of tumorgenesis and tumor growth was observed.

RESULTS

The tumor growth and weight in the group immunized with mIL-12 transfected and acid-eluted peptide sensitized DC were significantly lower than those of control group (P<0.05).

CONCLUSION

The mIL-12 transfected and acid-eluted peptide sensitized DC can induce obvious antitumor activities in the murine liver cancer models and may suggest new strategies for constructing new type of DC vaccine for liver cancer.

Human glioma cell BT325 expresses a proteinase that converts human plasminogen to kringle 1-5-containing fragments

Angiostatin, a specific angiogenesis inhibitor, is an internal fragment of plasminogen, and can be generated in many systems mediated by different enzymes in vitro. The mechanism of angiostatin generation in vivo has not been well defined. Here we demonstrated that human glioma cell line BT325 can express an enzyme that can convert purified plasminogen to angiostatin-like fragments with molecular masses of 65, 60, and 58 kDa, respectively. These fragments have an identical N-terminal as KVYLS, which starts from Lys(98) of the plasminogen precusor. According to their molecular mass, the three fragments should comprise kringle domain 1 to kringle domain 5 (kringle 1-5). The proteolytic fragments obtained as above can inhibit the growth of bovine aortic endothelial (BAE) cells specifically. The proteolysis process can be completely inhibited by serine proteinase inhibitors, and partially inhibited by EDTA. The molecular weight of the peptide, which contains an enzymatic activity responsible for the proteolysis, was 13 kD determined by gel filtration and SDS-PAGE. The present data suggest that glioma cell BT325 can produce a novel proteinase to generate kringle 1-5 of plasminogen as an angiogenesis inhibitor.

Glycosidic flavonoids as rat-liver injury preventing compounds from green tea

A glycosidic flavonoids-rich fraction from green tea leaves was purified to isolate five glycosidic flavonoids, guided by the detection of a preventive effect on D-galactosamine-induced liver injury in rats. These were identified as a flavone C-glycoside (1) and trisaccharide flavonols (2-5) based on the spectroscopic analyses. These compounds suppressed the D-galactosamine-induced increase of plasma alanine aminotransferase and asparatate aminotransferase activities in rats.

Suppression of D-galactosamine-induced liver injury by mushrooms in rats

Six species of edible mushroom were found to suppress D-galactosamine-induced enhancement of plasma alanine and aspartate aminotransferase activities when powdered mushrooms were added to the diet (5%) and fed to rats for 2 wk. Grifola frondosa exhibited the most potent effect in a dose-dependent manner. A significant effect was observed only from the water-soluble low-molecular-weight fraction of G. frondosa. The results indicate that several mushrooms possess a protective effect against liver injury induced by D-galactosamine.

Photokinetic voltammetric method for the determination of thiocyanate

Thiocyanate traces have a strong inhibitory effect on the oxidation of Neutral Red by potassium bromate under UV irradiation in diluted phosphoric acid. Neutral Red exhibits a sensitive second derivative oscillopolarographic wave at -0.6 V(vs. SCE) in diluted phosphoric acid and sodium acetate solution. The oscillopolarographic behavior of Neutral Red was selected as indicator component for its photo-activated oxidation. The photochemical reaction rate equation was determined. A detection limit of 0.3 ng mL(-1) (3sigma/k) and a linear calibration curve from 2.0-48.0 ng mL(-1) thiocyanate were obtained. The method was applied to the determination of thiocyanate in urine, saliva and serum with satisfactory results.

Purification of ethoxyquin and its two oxidation products

2,6-Dihydro-2,2,4-trimethyl-6-quinolone (QI) and 1,8'-bis(1, 2-dihydro-6-ethoxy-2,2,4-trimethylquinoline) (DM) are two oxidation products of 1,2-dihydro-6-ethoxy-2,2,4-trimethylquinoline (ethoxyquin, EQ). This paper describes several methods for the purification of technical grade EQ and for the production of pure QI and DM as standards with the purity required (>99%) for calibration of quantitative determination methods. EQ of high purity was obtained through vacuum distillation followed by a quick column chromatographic purification on silica gel. Preparative scale purity DM could be obtained through recrystallization from methanol, but QI could be purified only by a high-pressure liquid chromatographic method.

Ferrocenecarboxaldehyde labeled DNA probe for the study on DNA damage and protection

A ferrocenecarboxaldehyde (FCA) labeled DNA probe is used for the first time in the study of DNA damage and protection. The electrochemically active reagent FCA was labeled successfully on to a denatured calf-thymus DNA by 1-ethyl-3- (3-dimethyl-aminopropyl) carbodiimide (EDC). The FCA labeled DNA probe was used to hybridize with the sample DNA sequence accumulated on the surface of a graphite electrode. The anodic peaks of the FCA bound to the double-stranded DNA (dsDNA) by differential pulse voltammetry (DPV) were used for the detection of DNA damage and protection. Thiourea, sodium benzoic acid and isopropanol can decrease DNA damage by hydroxyl radicals, and their protection efficiencies are discussed.

The targeted expression of interleukin-2 in human hepatocellular carcinoma cells

To improve the safety and efficiency of human hepatocellular carcinoma (HCC) gene therapy, we explored the use of a liver-specific promoter and a tumor-specific enhancer to achieve regular IL-2 gene expression for treatment of HCC. The human alpha-fetoprotein (AFP) enhancer [E(AFP)] and the albumin promoter [P(ALB)] were amplified from human genomic DNA. We used eukaryotic expression vector pcDNA-3 for the delivery of the IL-2 gene because this plasmid is a non-transient, fast-selection expression vector. A recombinant plasmid was constructed including the selectable marker neoR gene and the human IL-2 gene derived by the E(AFP) - P(ALB). The liver-predominant expression pattern of the IL-2 gene was observed in the medium of the transfected cells. When human HCC cell lines displaying different levels of AFP and non-hepatocyte tumor cell lines were transfected with the recombinant plasmid, IL-2 was expressed highly in AFP and albumin-positive HCC cells, but low in nonhepatocyte tumor cells. Moreover, the expression level of IL-2 gene was positively proportional to the level of AFP expression in the transfected cells.

A cluster of mutations disrupt the avirulence but not the virulence function of AvrPto

avrPto in Pseudomonas syringae pv. tomato encodes an avirulence protein that triggers race-specific resistance in tomato plants carrying Pto. The AvrPto protein is secreted from P. syringae pv. tomato to plant cells through the type III secretion pathway and activates race-specific resistance by a direct interaction with the Pto protein. Here we report that avrPto enhances the virulence of P. syringae pv. tomato in a strain-dependent manner in tomato plants lacking Pto. To determine whether the virulence function can be structurally separated from the avirulence function, we examined the virulence activity of a group of AvrPto mutants that carry single amino acid substitutions and lack the avirulence activity on tomato plants. Three mutants that were clustered in the center of AvrPto exhibited virulence activity in tomato plants with or without Pto. The rest of the mutations abolished the virulence. The identification of these mutants suggested that the avirulence function of AvrPto can be structurally separated from the virulence function.

Capacity of enzymes of the euphorbiacea Aleurites montana involved in CO2-fixation, compared to plants having C3-, C4- and Crassulacean acid metabolism

Capacities of phosphoenolpyruvate carboxylase (PEP-Co), ribulose bisphosphate carboxylase (Rubisco), NADP+ malic enzyme (ME) and of malate dehydrogenase (MDH) were measured in the Euphorbiacea Aleurites montana, grown under 700 ppm CO2 for four weeks prior to enzyme extraction. For comparison Bryophyllum daigremontiana (CAM). Saccharum officinarum (C4) and Capsicum frutescens (C3) were treated in the same way. PEP-Co capacity of Aleurites was in the range of 12-, that of Capsicum approx. 26 nmol x min(-1) x mg protein(-1), without significant influence of the light period or CO2-treatment. In contrast, the activity of the enzyme from Saccharum was, depending on the duration of light, 160- respectively 96 times higher than that of the tung-oil tree. In Bryophyllum a rather low activity in the morning was increased during the day to approx. 230 nmol x min(-1) x mg protein(-1) in plants grown in the greenhouse and to approx. 115 nmol x min(-1) x mg protein(-1) in those from the growth chamber. Malate was hardly detectable in extracts of Aleurites, whereas it was high in Bryophyllum, depending on the light period. The ratio of average PEP-Co to Rub-Co capacity was high for the CAM-plant (20:1), somewhat lower for sugar cane (10:1), but almost at equality for Aleurites (0.9:1) and chilli (0.8:1). For the NADP+ malic enzyme, low capacity (20 to 28 nmol x min(-1) x mg protein(-1)) was found for Aleurites and for Capsicum, whereas it was 10 to 17 times higher in Saccharum. In Bryophyllum, the activity was up to 80 nmol x min(-1) x mg protein, dependent on light period. MDH capacity was extremely high in all plants investigated. Highest rates (10-20 micromol x min(-1) x mg protein(-1)), were obtained for Bryophyllum, followed by sugar cane and Capsicum with 5-8 micromol x min(-1) x mg protein(-1). Again, the lowest capacity was found in extracts of Aleurites with approx. 1.3 to 1.6 micromol x min(-1) x m protein(-1). Thus, in Aleurites montana no indication for C4- or Crassulacean acid metabolism was obtained. Therefore, the earlier observed very efficient uptake of CO2 cannot be explained by a high expression of the PEP-Co protein, known to occur in CAM- and C4-plants.

Leukocyte adhesion and microvessel permeability

To investigate the direct effect of leukocyte adherence to microvessel walls on microvessel permeability, we developed a method to measure changes in hydraulic conductivity (L(p)) before and after leukocyte adhesion in individually perfused venular microvessels in frog mesentery. In 19 microvessels that were initially free of leukocyte sticking or rolling along the vessel wall, control L(p) was measured first with Ringer-albumin perfusate. Blood flow was then restored in each vessel with a reduced flow rate in the range of 30-116 microm/s to facilitate leukocyte adhesion. Each vessel was recannulated in 45 min. The mean number of leukocytes adhering to the vessel wall was 237 +/- 22 leukocytes/mm(2). At the same time, L(p) increased to 4.7 +/- 0.5 times the control value. Superfusion of isoproterenol (10 microM) after leukocyte adhesion brought the increased L(p) back to 1.1 +/- 0.2 times the control in 5-10 min (n = 9). Superfusing isoproterenol before leukocyte adhesion prevented the increase in L(p) (n = 6). However, the number of leukocytes adhering to the vessel wall was not significantly affected. These results demonstrated that leukocyte adhesion caused an increase in microvessel permeability that could be prevented or restored by increasing cAMP levels in endothelial cells using isoproterenol. Thus cAMP-dependent mechanisms that regulate inflammatory agent-induced increases in permeability also modulate leukocyte adhesion-induced increases in permeability but act independently of mechanisms that regulate leukocyte adhesion to the microvessel wall. Application of ketotifen, a mast cell stabilizer, and desferrioxamine mesylate, an iron-chelating reagent, attenuated the increase in L(p) induced by leukocyte adhesion, suggesting the involvement of oxidants and the activation of mast cells in leukocyte adhesion-induced permeability increase. Furthermore, with the use of an in vivo silver stain technique, the locations of the adherent leukocytes on the microvessel wall were identified quantitatively in intact microvessels.

Dominant role of cAMP in regulation of microvessel permeability

We reported previously that increasing cAMP levels in endothelial cells attenuated ATP-induced increases in hydraulic conductivity (L(p)), and that the activation of cGMP-dependent pathways was a necessary step to increase L(p) in response to inflammatory mediators. The aim of the present study was to evaluate the role of basal levels of cAMP in microvessel permeability under resting conditions and to evaluate the cross talk between cAMP- and cGMP-dependent signaling mechanisms in regulation of microvessel permeability under stimulated conditions, using individually perfused microvessels from frog and rat mesenteries. We found that reducing cAMP levels by inhibition of adenylate cyclase or inhibiting cAMP-dependent protein kinase through the use of H-89 increased basal L(p) in both frog and rat mesenteric venular microvessels. We also found that 8-bromocAMP (8-BrcAMP, 0.2 and 2 mM) was sufficient to attenuate or abolish the increases in L(p) due to exposure of frog mesenteric venular microvessels to 8-BrcGMP (2 mM) and ATP (10 microM). Similarly, in rat mesenteric venular microvessels, application of 8-BrcAMP (2 mM) abolished the increases in L(p) due to exposure to 8-BrcGMP alone (2 mM) or with the combination of bradykinin (1 nM). In addition, application of erythro-9-(2-hydroxy-3-nonyl)adenine, an inhibitor of cGMP-stimulated phosphodiesterase, significantly attenuated both 8-BrcGMP- and bradykinin-induced increases in L(p). These results demonstrate that basal levels of cAMP are critical to maintaining normal permeability under resting conditions, and that increased levels of cAMP are capable of overcoming the activation of cGMP-dependent pathways, therefore preventing increases in microvessel permeability. The balance between endothelial concentrations of these two opposing cyclic nucleotides controls microvessel permeability, and cAMP levels play a dominant role.

[The expression and localization of wild-type p53-GFP fused gene on human high-metastasis hepatocellular carcinoma cell line]

OBJECTIVE

To study the normal expression and location of wt-p53 protein on human high-metastasis hepatocellular carcinoma (HCC) cell line.

METHODS

According to the sequence of human wild-type p53, the mp53 cDNA in which stopped codon TGA was mutated to TGG, was amplified by PCR, ligated to EGFP gene, of pEGFP-N1. The recombinant plasmid was transfected into MHCC97, in which p53 gene was mutated. The expression of human p53 protein was observed by fluorescence microscopy.

RESULTS

There was a p53 mutation on 249 codon in human high-metastasis hepatocellular carcinoma cell line MHCC97, but no mutation in low-metastasis HCC cells LD20. The two genes of wt-p53 and GFP were fused in codon frame by DNA sequencing. The fluorescence microscopy showed that fluorescence light was spread in all of MHCC97 cells transfected with pEGFP-N1, but fluorescence light was focused on the nucleus of MHCC97 cells transfected with pEGFP-53.

CONCLUSION

The p53 mutation on 249 codon may be related to the character of metastasis of HCC cells. The human wild-type p53-GFP fusion protein is expressed in MHCC97 cell line and located in cell nucleus, which is similar to the expression of wt-p53 protein.

On-line coupling of subcritical water extraction with high-performance liquid chromatography via solid-phase trapping

Although ambient water is very polar and cannot dissolve many organic species, water at elevated temperatures behaves like a polar organic solvent. Thus, subcritical water has been proven to be an effective extraction fluid for several classes of organic compounds. While solvent trapping was used to collect the extracted analytes in most of previous subcritical water extractions, sorbent trapping has also been developed for subcritical water extraction. In this study, an on-line system for subcritical water extraction and high-performance liquid chromatography (HPLC) was built and tested. A sorbent trap was used as the interface between subcritical water extraction and HPLC. Several shut-off valves have been utilized to switch the system from one mode to another (e.g., from the extraction mode to HPLC mode). The coupling technique of subcritical water extraction and HPLC eliminates the liquid-liquid extraction used in solvent trapping subcritical water extraction and provides higher sensitivity. Compared to the off-line system reported in an earlier work, the operation of this on-line system is even easier. Some peak broadening occurred after the coupling the water extraction with HPLC for the analytes studied. The performance of this on-line system was evaluated by the extraction and determination of caffeine, nitrotoluenes, polychlorinated biphenyls, chlorophenols and anilines.

Seeds of Trichosanthes kirilowii, an energy-rich diet

The kernels of Trichosanthes kirilowii seeds contain a green oil which makes up for 62% of their dry matter. This oil consists up to 95% of triglycerides, 2% of glycolipids, 1.3% of phospholipids and 1.8% of chlorophylls. As fatty acid components the triglycerides, glycolipids and phospholipids contain the unsaturated fatty acids linoleic and oleic acid and the saturated palmitic acid. In the triglycerides 19% of the C18:3 acid occur with the configuration delta9 cis, delta11 trans, delta13 cis. This acid is called trichosanic acid and is absent in glycolipids and phospholipids which contain instead another C18:3 fatty acid, which has conjugated double bounds and occurs with an amount of 21% and 3%, respectively. Typically, these oil seeds contain in addition up to 30% of their dry matter proteins and up to 2.5% mono- and oligosaccharides. The monosaccharides consist of rhamnose, galactose and glucose and the oligosaccharides represent a mixture of tri- and tetrasaccharides.

[Application of microsatellite markers for the seed purity examination of a hybrid rice, Gangyou-22]

For seed commercialization of hybrid rice it is necessary to examine the purity of its seeds before field-production, because the seed purity is closely related to their heterosis performance and yield increase. In this research, 160 microsatellite markers were used for PCR amplification of rice seedling DNAs of Gangyou-22, which is a major hybrid rice in China, and its parents, Gang46A(CMS line) and CDR22(restorer line). A microsatellite marker, RM168, was screened out for its ability to produce polymorphic bands specific to each of the two parents but different from other 22 restorer lines and 9 cultivars. This provides an accurate and efficient method to examine the purity of a hybrid rice at an earlier time. Amplification of DNAs extracted from seeds and application of two microsatellite markers in one PCR system can further simplify the procedure and improve the accuracy of the seed purity examination.

[Effects of different loading exercises on endogenous sex hormones and their metabolites]

Small loading and strengthening exercises were performed by 22 athletes(11 males and 11 females). The levels of serum hormones and their urinary metabolites were detected. The results showed that the serum levels of testosterone(T), free testosterone(FT) and 17-OH-progesterone(17-OHP) in male athletes exhibited no conspicuous changes. The excretion of their urinary androsteroids was significantly increased after exercises(P < 0.05), but significantly decreased in the recovery period(P < 0.05). After small loading exercises, their serum levels of T and FT revealed no obvious changes except those of 17-OHP which evidently increased in female athletes(P < 0.05); whereas the excretion of their urinary steroid hormones declined promptly after the exercises and in the recovery period (all P < 0.05). After strengthening exercises, the serum levels of T, FT and 17-OHP decreased distinctly in female athletes (all P < 0.05), the excretion of their urinary steroid hormones raised clearly after training and in the recovery period(P < 0.05). Therefore, it is suggested that the secretion and metabolism of sex hormones in the organism are influenced by the loading quality of sports during training, and sexual difference exists simultaneously.

Spectroscopic studies of copper(II) and iron(II) complexes of adriamycin

The complexes of adriamycin (ADM) with Cu(II) and Fe(II) have been studied by visible absorption, circular dichroism (CD) and fluorescence spectra, respectively. In Tris buffer at pH 7.0, either metal ions forms a single species with adriamycin: Cu(ADM)2 or Fe(ADM)3. Interaction of these two complexes with various biological molecules has been examined. It is shown that some amino acids, glutathione and albumin are able to remove the Cu(II) ion from Cu(II)-ADM complex, releasing the free drug. However, Fe(II)-ADM keeps in an undissociated form under the same conditions. The possibility of Fe(II) ADM as a new alternative drug has been discussed.

Catalytic determination of ultra trace amounts of tellurium by 2.5-order differential oscillopolarography

A highly sensitive and selective catalytic method with 2.5-order differential oscillopolarographic detection is described for the determination of tellurium, based on its activation effect on the slow Pd(II)-catalyzed reaction of sodium hypophosphite and methyl red in hydrochloric acid medium at 100 degrees C. Methyl red exhibited a sensitive 2.5-order differential polarographic wave at -0.35 V (vs. SCE) in the supporting electrolyte of pH 5.0 acetate buffer solution and was chosen as the indicating component for the indirect determination of tellurium. A calibration curve of tellurium in the range of 0.02-2.0 ng mL(-1) was obtained by the fixed-time procedure. The detection limit was 0.007 ng mL(-1). Possible interferences by co-existing substances were examined. The new method has been used to analyze trace tellurium in organs of white mice with satisfactory results. RSD was 0.54% to 2.10%, recovery 98.4% to 95.7%. The mechanism is also discussed.

[A multiparametric monitoring network system based on windows operation system]

This paper introduces the general structure and implementary method both in hardware and software of a monitoring network system, which is developed for monitoring physiological multi-parameter under Windows operation system and based on personal computer. The parameters monitored by the system include Electrocardiogram (ECG), Noninvasive Blood Pressure (NIBP), Oxygen Saturation (SpO2), Respiration (RESP) and Body Temperature. Monitoring data can be shared by internal hospital network. The system has the advantages of easy operation and flexible structure. It is a new kind of hospital monitoring equipment.

Measurement of acoustic dispersion using both transmitted and reflected pulses

Traditional broadband transmission method for measuring acoustic dispersion requires the measurements of the sound speed in water, the thickness of the specimen, and the phase spectra of two transmitted ultrasound pulses. When the sound speed in the specimen is significantly different from that in water, the overall uncertainty of the dispersion measurement is generally dominated by the uncertainty of the thickness measurement. In this paper, a new water immersion method for measuring dispersion is proposed which eliminates the need for thickness measurement and the associated uncertainty. In addition to recording the two transmitted pulses, the new method requires recording two reflected pulses, one from the front surface and one from the back surface of the specimen. The phase velocity as well as the thickness of the specimen can be determined from the phase spectra of the four pulses. Theoretical analysis and experimental results from three specimens demonstrate the advantages of this new method.

Role of alpha-SNAP in promoting efficient neurotransmission at the crayfish neuromuscular junction

In this manuscript, we address the role of the soluble N-ethylmaleimide sensitive factor attachment protein (alpha-SNAP) in synaptic transmission at the neuromuscular junction of the crayfish opener muscle. Immunochemical methods confirm the presence of alpha-SNAP in these preparations and show that it is concentrated in the synaptic areas. Microinjection and electrophysiological studies show that alpha-SNAP causes an increase in neurotransmitter release yet does not significantly affect the kinetics. More specific quantal analysis, using focal, macropatch, synaptic current recordings, shows that alpha-SNAP increases transmitter release by increasing the probability of exocytosis but not the number of potential release sites. These data demonstrate that the role of alpha-SNAP is to increase the efficiency of neurotransmission by increasing the probability that a stimulus will result in neurotransmitter release. What this suggests is that alpha-SNAP is critical for the formation and maintenance of a "ready release" pool of synaptic vesicles.

MAGE-1 and related MAGE gene expression may be associated with hepatocellular carcinoma

PURPOSE

The possibility of tumor rejection antigen, encoded by the MAGE-1 gene, being a target for immunotherapy in hepatocellular carcinoma (HCC) patients and the cloning of the full-length cDNA of this gene for subsequent studies were explored with the aim of discovering new immunotherapeutic strategies for HCC.

METHODS

Expression of the MAGE-1 gene in HCC specimens and HCC cell lines was examined by the reverse transcription/polymerase chain reaction (RT-PCR) with a pair of specific primers, which gave a 421-bp fragment. Another pair of primers were then used to amplify the full-length MAGE-1 cDNA by the same method. The PCR products were then digested by restriction endonucleases and inserted into the plasmid PUC19. After primary selection of the recombinants by endonuclease digestion, the sequences of the inserted gene fragments were confirmed by DNA sequence analysis.

RESULTS

In 45 HCC patients, MAGE-1 mRNA was expressed in 27 tumor tissues (60%) and 5 paratumor tissues (11.1%). All the four HCC cell lines positively expressed the MAGE-1 gene. Owing to the high homology of the MAGE gene family, we obtained three clones of different MAGE genes using the same pair of cloning primers. The three clones were confirmed to be a full-length MAGE-1 gene, a 750-bp fragment of the MAGE-3 gene and a fragment highly homologous to MAGE-6 and MAGE-12 but not identical to any known MAGE genes.

CONCLUSION

The high expression frequency of MAGE-1 gene in HCC suggests the possibility of using it as a target for immunotherapy in HCC patients. Some MAGE genes other than MAGE-1 may also be expressed in HCC together with an unknown MAGE gene that might introduce new targets for immune attacks. The three gene clones obtained in this study can be used in further investigations and especially in the development of new liver cancer vaccines.

Allele frequencies of eight STRs in Japanese and Chinese

Allele frequencies for the eight STR loci Hum-CSF1P0, F13A01, F13B, FES/FPS, LPL, TH01, TPOX and VWA were investigated in Japanese and Chinese populations. No significant deviations from Hardy-Weinberg equilibrium could be found for all loci. In the Japanese population VWA, CSF1PO, TH01, FES/FPS and TPOX were found to be useful for forensic applications and in the Chinese population, VWA, CSF1PO, TH01 and TPOX were found to be useful. Allele distributions were similar between both populations except for FES/FPS.

Chlorpromazine inhibits hepatocyte apoptosis caused by withdrawal of phenobarbital in mice

AIM

To study the inhibitory effect of chlorpromazine (Chl), verapamil, and aspirin on hepatocyte apoptosis induced by the cessation of phenobarbital (Phe) treatment in mice.

METHODS

Liver DNA content, ratio of liver weight/body weight, DNA fragmentation, DNA electrophoresis, the end-labeling test (TUNEL), and the morphologic changes of liver cells as indices of liver mass and hepatocyte apoptosis were applied to investigate (1) the kinetic process of hepatocyte proliferation induced by Phe 75 mg.kg-1 i.p. and the regression of hyperplastic liver caused by withdrawal of Phe in mice, (2) the effect of Chl 25 mg.kg-1, verapamil 50 mg.kg-1 or aspirin 60 mg.kg-1 i.p. on mouse hepatocyte apoptosis, and (3) the time course of effects of Chl on the regression of liver size and DNA fragmentation content after withdrawal of Phe.

RESULTS

The process of hepatocyte proliferation and regression induced by administration and withdrawal of Phe in mice consisted of 4 phases: proliferation, plateau, rapid regression, and slow regression phases. In the rapid regression phase, the typic changes of hepatocyte apoptosis were found, which was prevented in early period by the Ca(2+)-calmodulin antagonist Chl, but not by verapamil or aspirin.

CONCLUSION

The Ca(2+)-calmodulin played an important role in the hepatocyte apoptosis caused by withdrawal of Phe.