A visible light induced photoelectrochemical aptsensor constructed by aligned ZnO@CdTe core shell nanocable arrays/carboxylated g-C3N4 for the detection of Proprotein convertase subtilisin/kexin type 6 gene

It was reported that Proprotein convertase subtilisin/kexin type 6 (PCSK6) can promote the progression of rheumatoid arthritis to a higher aggressive status. In this work, a novel visible light induced photoelectrochemical (PEC) platform was designed to detect PCSK6 gene. ZnO@CdTe nanocable arrays/carboxylated g-C3N4 used as the PEC signal generator. Hexagonal ZnO nanorods grew on ITO electrode firstly. CdTe were then electrodeposited on the ZnO nanorods surface to enhance the photogenerated h(+)/e(-) separation efficiency. Carboxylated g-C3N4 was utilized to improve h(+)/e(-) separation efficiency and anchor the capture probes of PCSK6 gene by the covalent bonding effect. The 5' and 3' primers captured PCSK6 ssDNA by the specific recognition. The linear range was 10 pg/mL to 20.0 ng/mL with a detection limit of 2 pg/mL.

Application of Europium Multiwalled Carbon Nanotubes as Novel Luminophores in an Electrochemiluminescent Aptasensor for Thrombin Using Multiple Amplification Strategies

A novel electrochemiluminescent (ECL) aptasensor was proposed for the determination of thrombin (TB) using exonuclease-catalyzed target recycling and hybridization chain reaction (HCR) to amplify the signal. The capture probe was immobilized on an Au-GS-modified electrode through a Au-S bond. Subsequently, the hybrid between the capture probe and the complementary thrombin binding aptamer (TBA) was aimed at obtaining double-stranded DNA (dsDNA). The interaction between TB and its aptamer led to the dissociation of dsDNA because TB has a higher affinity to TBA than the complementary strands. In the presence of exonuclease, aptamer was selectively digested and TB could be released for target recycling. Extended dsDNA was formed through HCR of the capture probe and two hairpin DNA strands (NH2-DNA1 and NH2-DNA1). Then, numerous europium multiwalled carbon nanotubes (Eu-MWCNTs) could be introduced through amidation reaction between NH2-terminated DNA strands and carboxyl groups on the Eu-MWCNTs, resulting in an increased ECL signal. The multiple amplification strategies, including the amplification of analyte recycling and HCR, and high ECL efficiency of Eu-MWCNTs lead to a wide linear range (1.0×10(-12)-5.0×10(-9) mol/L) and a low detection limit (0.23 pmol/L). The method was applied to serum sample analysis with satisfactory results.

Electrochemiluminescent immune-modified electrodes based on Ag2Se@CdSe nanoneedles loaded with polypyrrole intercalated graphene for detection of CA72-4

This work described a new electrochemiluminescence (ECL) immunosensor based on polypyrrole intercalated graphene and Ag2Se@CdSe nanoneedles. The novel nanomaterial Ag2Se@CdSe, with needle-like morphology, was synthesized for the first time. The prepared Ag2Se@CdSe nanoneedles exhibited good luminous performance in the presence of K2S2O8. Polypyrrole intercalated amination graphene with high specific binding sites and excellent electrochemical performance was used as the platform for the sensor. The developed ECL immunosensor was used for the detection of CA72-4 with good linear relation in the range from 10(-4) to 20 U/mL and low detection limit of 2.1 × 10(-5) U/mL (S/N = 3). The developed ECL immunosensor with high sensitivity and spectral selectivity can be used for detection of real samples. Ag2Se@CdSe nanoneedles could be promising candidate emitter for ECL biosensors in the future.

An electrochemiluminescent immunosensor based on CdS–Fe3O4nanocomposite electrodes for the detection of Ochratoxin A

A promising electrochemiluminescent immunosensor based on CdS–Fe₃O₄nanocomposites was developed for the detection of Ochratoxin A.

A simple label-free photoelectrochemical immunosensor for highly sensitive detection of aflatoxin B1based on CdS–Fe3O4magnetic nanocomposites

A simple label-free photoelectrochemical (PEC) platform was developed based on magnetic CdS–Fe₃O₄nanocomposites and used for detection of aflatoxin B₁(AFB₁).

A biomimetic mussel-inspired photoelectrochemical biosensing chip for the sensitive detection of CD146

A universal biomimetic mussel-inspired photoelectrochemical biosensing chip was constructed by a polydopamine coating strategy.

Advances in non-peptidomimetic HIV protease inhibitors

HIV protease plays a crucial role in the viral life cycle. It can cleave a series of heptamers in the viral Gag and GagPol precursor proteins to generate mature infectious virus particles. Successful inhibition of the protease will prevent this maturation step and hence block the spreading of HIV. However, the rapid emergence of drug resistance makes it urgent to develop new HIV protease inhibitors to combat the global disease. Besides, poor oral bioavailability, unacceptable side effects, high treatment cost and pill burden also trouble the application of HIV protease inhibitors. In such situations, non-peptidomimetic HIV protease inhibitors have drawn an increasing interest as a potential therapeutic option due to their small molecular weight, favorable bioavailability, high stability in vivo, low resistance and cost of production. In this review, we present the recent advances in non-peptidomimetic HIV protease inhibitors. Their design strategies, biological activities, resistance profiles, as well as clinical application will also be discussed.

Mapping shape quantitative trait loci using a radius-centroid-contour model

As the consequence of complex interactions between different parts of an organ, shape can be used as a predictor of structural-functional relationships implicated in changing environments. Despite such importance, however, it is no surprise that little is known about the genetic detail involved in shape variation, because no approach is currently available for mapping quantitative trait loci (QTLs) that control shape. Here, we address this problem by developing a statistical model that integrates the principle of shape analysis into a mixture-model-based likelihood formulated for QTL mapping. One state-of-the-art approach for shape analysis is to identify and analyze the polar coordinates of anatomical landmarks on a shape measured in terms of radii from the centroid to the contour at regular intervals. A procrustes analysis is used to align shapes to filter out position, scale and rotation effects on shape variation. To the end, the accurate and quantitative representation of a shape is produced with aligned radius-centroid-contour (RCC) curves, that is, a function of radial angle at the centroid. The high dimensionality of the RCC data, crucial for a comprehensive description of the geometric feature of a shape, is reduced by principal component (PC) analysis, and the resulting PC axes are treated as phenotypic traits, allowing specific QTLs for global and local shape variability to be mapped, respectively. The usefulness and utilization of the new model for shape mapping in practice are validated by analyzing a mapping data collected from a natural population of poplar, Populus szechuanica var tibetica, and identifying several QTLs for leaf shape in this species. The model provides a powerful tool to compute which genes determine biological shape in plants, animals and humans.

Effects of degradable MG-ND-ZN-ZR alloy on osteoblastic cell function

This study aimed to investigate the effects of a novel patented Mg-3Nd-0.2Zn-0.4Zr (weight %, JDBM) alloy on osteoblastic cell function, as these cells play an important role in bone repair and remodeling. The associated effects of the JDBM alloy on osteoblastic cell function involving cell adhesion, cell proliferation, and mineralization were investigated using scanning electron microscopy (SEM), MTT assay and ambramycin staining, respectively. At the same time, the in vitro degradation behavior of the JDBM alloy in cell culture medium was evaluated by the weight-loss method and SEM. Pure magnesium was used as control. The results showed that osteoblastic cells cultured on JDBM alloy samples manifested better cell adhesion, improved cell proliferation and increased mineralization ability, compared with cells seeded on pure magnesium samples. Our data indicate that the JDBM alloy has excellent bioactivity, improving the cell function of osteoblastic cells seeded on it.

Assessing the potential of candidate DNA barcodes for identifying non-flowering seed plants

In plants, matK and rbcL have been selected as core barcodes by the Consortium for the Barcode of Life (CBOL) Plant Working Group (PWG), and ITS/ITS2 and psbA-trnH were suggested as supplementary loci. Yet, research on DNA barcoding of non-flowering seed plants has been less extensive, and the evaluation of DNA barcodes in this division has been limited thus far. Here, we evaluated seven markers (psbA-trnH, matK, rbcL, rpoB, rpoC1, ITS and ITS2) from non-flowering seed plants. The usefulness of each region was assessed using four criteria: the success rate of PCR amplification, the differential intra- and inter-specific divergences, the DNA barcoding gap and the ability to discriminate species. Among the seven loci tested, ITS2 produced the best results in the barcoding of non-flowering seed plants. In addition, we compared the abilities of the five most-recommended markers (psbA-trnH, matK, rbcL, ITS and ITS2) to identify additional species using a large database of gymnosperms from GenBank. ITS2 remained effective for species identification in a wide range of non-flowering seed plants: for the 1531 samples from 608 species of 80 diverse genera, ITS2 correctly authenticated 66% of them at the species level. In conclusion, the ITS2 region can serve as a useful barcode to discriminate non-flowering seed plants, and this study will contribute valuable information for the barcoding of plant species.

Comparison of micafungin and voriconazole in the treatment of invasive fungal infections in kidney transplant recipients

WHAT IS KNOWN AND OBJECTIVE

Invasive fungal infections are a major threat to renal transplant recipients. Micafungin and voriconazole are two useful antifungal agents for treating such infections. Our objective is to evaluate the comparative efficacy and safety of micafungin and voriconazole in the initial treatment of such infections.

METHODS

In this prospective, multicentre, open-labelled, randomized, controlled trial, renal transplant recipients with invasive fungal infections were assigned to receive either micafungin or voriconazole. The enrolled subjects received a kidney transplant between March 2008 and March 2010 at one of the two transplant centres in Henan Province, China. The efficacy and adverse effects of the two treatments were compared.

RESULTS AND DISCUSSION

The clinical trial enrolled 65 patients, of whom 31 were treated with micafungin, and 34 with voriconazole. The rates of microbiological evidence of infection in the micafungin and voriconazole groups were 64.5% and 70.5%, respectively, whereas the rates of Candida as the major cultured fungus were 80.0% and 75.0%, respectively. Complicated bacterial infection rates in the two treatment groups were 38.7% and 32.4%, respectively, whereas complicated CMV viral infection occurred at a rate of 19.2% and 23.5%, respectively. Fungal infection within one to 3 months after transplant was 83.6% (26/31) and 85.3% (29/34) in the micafungin and voriconazole groups, respectively. There was no significant difference between the two groups in terms of efficacy, survival beyond 10 days and discontinuation of treatment because of lack of efficacy (P > 0.05). Mortality rates in the micafungin and voriconazole groups were 9.7% (3/31) and 12.1% (4/33), respectively. Rates of adverse effects in the two groups were 41.9% and 51.6% (P > 0.05), respectively.

WHAT IS NEW AND CONCLUSIONS

This is the first comparison of micafungin and voriconazole in renal transplant patients. Our study shows that the effectiveness of micafungin was similar to that of voriconazole in such patients.

Xanthohumol, a prenylated chalcone derived from hops, suppresses cancer cell invasion through inhibiting the expression of CXCR4 chemokine receptor

Cancer metastasis is the main cause of death (90%), and only recently we have gained some insight into the mechanisms by which metastatic cells arise from primary tumors and target to specific organs. Cysteine X Cysteine (CXC) chemokine receptor 4 (CXCR4), initially linked with leukocyte trafficking, is overexpressed in various tumors and mediates homing of tumor cells to distant sites expressing its cognate ligand CXCL12. Therefore, identification of CXCR4 inhibitors has great potential to abrogate tumor metastasis. In this study, we demonstrated that xanthohumol (XN), a prenylflavonoid derived from the female flowers of the hops plant (Humulus lupulus. L), suppressed CXCR4 expression in various cancer cell types in a concentration- and time-dependent manner. Both proteasome and lysosomal inhibitors had no effect to prevent the XN-induced downregulation of CXCR4, suggesting that the inhibitory effect of XN was not due to proteolytic degradation but occurred at the transcriptional level. Electrophoretic mobility shift assay and chromatin immunoprecipitation assay further confirmed that XN could block endogenous activation of nuclear factor kappa B, a key transcription factor regulates the expression of CXCR4 in cancer cells. Consistent with the above molecular basis, XN abolished cell invasion induced by CXCL12 in both breast and colon cancer cells. Interestingly, although co-exist in hops, XN is the only isoform that exhibited the inhibitory effect on the expression of CXCR4 compared with other isomers, isoxanthohumol and 8-prenylnaringenin. Together, our results suggested that XN, as a novel inhibitor of CXCR4, could be a promising therapeutic agent contributed to cancer treatment.

Complementary deoxyribonucleic acid cloning of avian G0/G1 switch gene 2, and its expression and association with production traits in chicken

As a member of the G0/G1 switch genes, G0/G1 switch gene 2 (G0S2) is related to many regulatory processes in the human and mouse. For example, it interacts directly with adipose triglyceride lipase to active its triglyceride hydrolysis activities. In this study, G0S2 gene cDNA of the chicken (522 bp), zebra finch (420 bp), sparrow (417 bp), pigeon (417 bp), and Bengalese finch (416 bp) were cloned, and each of them was encoded as a protein of 99 amino acids. The expression of G0S2 mRNA was determined by real-time reverse-transcription PCR analysis in 20 tested tissues of 21- and 91-d-old chickens. The highest mRNA level was found in abdominal fat and subcutaneous fat in both stages. Considerable G0S2 mRNA was also observed in chicken heart and muscle tissues. Expression of the chicken G0S2 gene varied at different stages and sexes. The abundance of G0S2 mRNA on d 21 was far higher than that on d 91. The abundance in female chickens was higher than that in males at both stages. In the coding region, we found 4 SNP, among which only G197A led to a change in the amino acids (Arg66Gln); the rest were synonymous substitutions. Association analysis showed that both G102A and G255A were significantly associated with head width (P < 0.05) and were highly significantly associated with leg muscle color (P < 0.01). The G102A was significantly associated with shank diameter at 63 d (P < 0.05). The SNP G197A was significantly associated with shank diameter at 49 d; CP content of leg muscle; total weights of the heart, liver, gizzard, and glandular stomach; and small intestine length (P < 0.05). In conclusion, much higher G0S2 mRNA was detected in both male and female chickens at 21 d of age than at 91 d of age, and 3 SNP (G102A, G197, and G255A) were associated with chicken production traits.

ERIC-PCR-based strain-specific detection of phenol-degrading bacteria in activated sludge of wastewater treatment systems

AIMS

To evaluate the use of Enterobacterial Repetitive Intergenic Consensus PCR (ERIC-PCR)-derived probes and primers to specifically detect bacterial strains in an activated sludge microbial community.

METHODS AND RESULTS

ERIC-PCR was performed on two phenol-degrading bacterial strains, Arthrobacter nicotianae P1-7 and Klebsiella sp. P8-14. Their amplicons were DIG labelled for use as probes and then hybridized with ERIC-PCR fingerprints. The results showed the distinct band patterns for both bacterial strains. Strain-specific PCR primers were designed based on the sequences of ERIC-PCR bands. The DNA of each of these strains was successfully detected from its mixture with activated sludge DNA, either by using their respective ERIC-PCR-based probes for hybridization or by using species-specific primers for amplification, with higher sensitivity by latter method.

CONCLUSIONS

Two phenol-degrading bacterial strains were identified from a mixture of activated sludge by using ERIC-PCR-based methods.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study demonstrated that the bacteria, which have important functions in complex wastewater treatment microbial communities, could be specifically detected by using ERIC-PCR fingerprint-based hybridization or amplification.

Diffractive grating structure for coherent light source production

A diffractive structure of cavities is designed to produce resonances at very high frequencies. This type of cavity structure may be useful for producing controllable coherent synchrotron radiation by microbunching the particle beam.

Potential of a novel polysaccharide preparation (GLPP) from Anhui-grown Ganoderma lucidum in tumor treatment and immunostimulation

Growing evidence indicates the potential of developing novel polysaccharide-based adjuvant for tumor therapy from edible mushrooms, including Ganoderma lucidum. In the present study, a novel polysaccharide preparation (GLPP) was isolated from the fruiting body of G. lucidum grown in Anhui, China, and characterized for its physicochemical properties. GLPP had an average molecular weight of 6600 and a specific optical rotation of +25.6 degrees , contained 10.6% protein, and had a molar ratio of 0.9:15:1 for mannose, glucose, and galactose, respectively. GLPP was also investigated and compared with PSP (polysaccharopeptide preparation), a commercial antitumor and immunostimulating agent, for its antitumor and immunostimulation capacity, and potential in reducing the toxic effects induced by cyclophosphamide (Cy) treatment and Cobalt-60 ((60)Co) radiation in mice. GLPP at levels of 100 and 300 mg/kg body weight (BW)/d significantly inhibited the growth of inoculated S(180), Heps, and EAC tumor cells in mice. GLPP at a dose of 300 mg/kg BW/d showed stronger growth inhibition against all 3 tested tumor cells than PSP at 1 g/kg BW/d. GLPP also dose-dependently increased phagocytic index, phagocytic coefficient, and 50% hemolysin value in the EAC tumor-bearing mice, indicating its potential immunostimulating property. In addition, GLPP at 300 mg/kg BW/d was comparable to PSP at 1000 mg/kg BW/d in preventing the decrease of thymus index, spleen index, white blood cells, and bone marrow karyote numbers induced by Cy treatment and (60)Co radiation. These data demonstrated the potential utilization of GLPP as an adjuvant to conventional treatments of cancers and its use for cancer prevention.

Reverse transcriptase activity in patients with primary biliary cirrhosis and other autoimmune liver disorders

BACKGROUND

Patients with biliary disease make retroviral antibodies and the Human Betaretrovirus has been characterized in patients with primary biliary cirrhosis.

AIM

To screen patients with autoimmune liver disease for evidence of retroviral infection.

METHODS

Real-time reverse transcriptase polymerase chain reaction was used to detect Human Betaretrovirus, and a reverse transcriptase assay to measure reverse transcriptase activity in plasma.

RESULTS

Using reverse transcriptase polymerase chain reaction, 24% of primary biliary cirrhosis samples were positive for Human Betaretrovirus when compared to 13% with autoimmune hepatitis, 5% of other liver diseases and 3% of the non-liver disease control subjects. Reverse transcriptase activity was found in 73% of patients with autoimmune hepatitis, 42% with primary biliary cirrhosis, 22% of liver patients without viral or autoimmune disease and 7% of subjects without liver disease. In patients with autoimmune liver disease, detection of reverse transcriptase activity was related to higher ALT levels, whereas others stabilized on immunosuppressive therapy either preliver or postliver transplantation were less likely to be reverse transcriptase-positive.

CONCLUSIONS

Most patients with autoimmune hepatitis have detectable reverse transcriptase activity. Investigations will be required to assess whether this represents the expression of endogenous retroviruses and retrotransposable elements in inflamed tissue, or signifies the presence of exogenous retroviral infection.

Chronic endothelin-A receptor antagonism is as protective as angiotensin converting enzyme inhibition against cardiac dysfunction in diabetic rats

BACKGROUND AND PURPOSE

Diabetes mellitus is associated with a specific cardiomyopathy. We compared the cardioprotective effects of an endothelin-A receptor blocker (ET(A)-RB) with those of an angiotensin-converting enzyme inhibitor (ACE-I) in rats with streptozotocin (STZ)-induced diabetes.

EXPERIMENTAL APPROACH

Diabetic rats were left untreated or received either the ET(A)-RB atrasentan or the ACE-I ramipril (each 3 mg kg(-1) per day) orally for 8 weeks. Isolated isovolumic heart function was studied during normoxia and in response to ischaemia-reperfusion. Cardiac fibrosis, tissue oxidative stress and tissue nitric oxide synthase (NOS) activity were determined.

KEY RESULTS

Basal left ventricular systolic contractility was lower in diabetic compared to nondiabetic hearts and ET(A)-RB or ACE-I treatment significantly antagonised the decline. Following 15 min of no-flow ischaemia, reperfusion systolic function was depressed and left-ventricular end-diastolic pressure (LVEDP) was elevated in diabetic hearts. ET(A)-RB or ACE-I treatment significantly improved recovery of reperfusion systolic and diastolic function, without differences between groups. Hydroxyproline (an index of tissue fibrosis) and malondialdehyde (a measure of tissue oxidative stress) were elevated at the end of reperfusion in diabetic, compared to nondiabetic hearts. Either treatment reduced hydroxyproline and malondialdehyde to control level. Constitutive NOS activity was similar in nondiabetic and diabetic hearts and unaffected by ET(A)-RB or ACE-I treatment.

CONCLUSIONS AND IMPLICATIONS

These results suggest that in experimental type 1 diabetes ET(A)-RB is as effective as an ACE-I in ameliorating myocardial functions during normoxia and ischaemia-reperfusion. Combining the two treatments neither afforded additive effects, nor diminished any protection effect seen with either drug.

Low energy electron storage ring with tunable compaction factor

A low energy electron storage ring is designed to have many desirable properties, such as varying momentum compaction factor, damping partition numbers, favorable betatron tunes for multiturn accumulations, and excellent dynamic aperture. This storage ring can be used for debunching rf linac beams in one turn, for compression of linac pulses, and more importantly for a compact photon source based on inverse Compton scattering of laser beams.

Elicitation of Both CD4+ and CD8+ T-Cell-Mediated Specific Immune Responses to HCA587 Protein by Autologous Dendritic Cells

We recently cloned a new member of cancer/testis antigen named HCA587, which was highly expressed in human hepatocellular carcinoma (HCC) tissues. To investigate it as a potential tumour-specific target for immunotherapy, the immunogenicity of this protein, especially the ability to induce specific cellular immune responses, was evaluated in the present study. As dendritic cells (DC) are the most potent antigen-presenting cells, DC-based vaccination has recently shown marked promise for the treatment of human malignancies by immunological intervention. Here, we demonstrate that autologous DC loaded with HCA587 protein could induce specific T-cell responses in healthy individuals by in vitro stimulations. Enzyme-linked immunospot analysis for interferon-gamma (IFN-gamma) secretion demonstrated HCA587-specific CD8(+) T cells in the antigen-stimulated peripheral blood lymphocytes, and the analysis of CD4(+) T cells by proliferation assay also showed antigen-specific reactivities in normal donors. Two-colour flow cytometric analysis of surface markers and intracellular cytokine expression demonstrated that HCA587-specific cytotoxic T lymphocytes exhibited a heterogeneous CD8(+)/CD56(+) expression, and a striking T-helper 1 cytokine bias (IFN-gamma(high)/IL-4(low)) was observed for both CD4(+) and CD8(+) HCA587-specific lymphocyte populations. We conclude that HCA587 is a potent immunogen that can induce CD4(+) and CD8(+) T-cell-mediated specific immune responses, and these findings propose HCA587 as a good candidate for the development of a therapeutic protein-based DC tumour vaccine for the treatment of HCC patients.

Effect of La3+ on the activities of antioxidant enzymes in wheat seedlings under lead stress in solution culture

In order to improve the plant ability to resist lead stress, effect of 0.05 mg/l La(NO3)3 on the activities of catalase (CAT), superoxide dismutase (SOD), the level of malondialdehyde (MDA) in wheat seedlings under lead stress was studied. The effect of La3+ on plant growth, chlorophyll content in wheat seedlings after adding 0, 50, 100 mg/l Pb(NO3)3 to the nutrient solution for 12 days was observed. The plants were grown in nutrient solution in a strictly controlled climate growth room. Effects of La3+ (with La treatment) compared with check groups was evidently observed. The activities of SOD and CAT in root were enhanced 0.45-1.69 times and 33.20-77.77% respectively and MDA content was reduced 11.05-27.49% in root after treatments from the second day till the end of the experiment. The activities of SOD and CAT was found to be increased slightly (P < 0.05) and MDA content decreased in shoot and root of wheat seedlings by La3+ under lead stress within five days after treatments compared with Pbl and Pb2 groups. It was assumed that antioxidant enzymes was found to be increased by La(NO3)3, the antioxidant potential of the wheat seedlings to resist lead stress enhanced. It is suggested that La3+ could be used to resist lead stress at the beginning under stress while the stress was not so serious.

[Application of the IFN-gamma ELISPOT assay for monitoring CD8(+) T cell response to specific antigen from hepatocellular carcinoma patients]

OBJECTIVE

To study the specific CD8(+) T cell response to HLA-A2 binding peptide Flu p58-66 from HLA-A2-positive hepatocellular carcinoma patients and healthy donors.

METHODS

The CD8(+) T cells were separated with immunobeads from PBMC of HCC patients and healthy donors, respectively. The irradiated autologous CD8(-) PBMC or isolated dendritic cells were loaded with influenza matrix peptide as APC. After 7 days' culture, the frequency of effector cells to secrete IFN-gamma in response to Flu p58-66 was detected in ELISPOT assay.

RESULTS

With CD8(-) PBMC as APC, the frequency of effector cells to secrete IFN-gamma in response to Flu peptide was 22 +/- 9/well in HCC patients (n = 8) and 59 +/- 27/well in healthy donors (n = 12) when the effector cells were 5 x 10(4)/well (P < 0.01). To compare the antigen-presenting capacity of APC derived from 5 healthy donors, DC was better than CD8(-) PBMC.

CONCLUSION

Although the frequency of specific effector CTL to secrete IFN-gamma in response to Flu p58 - 66 was lower in HCC patients than in healthy individuals, the majority of HCC patients have the cellular immunity specific to antigen peptides.

[Effect of lead stress on the activity of antioxidant enzymes in wheat seedling]

The changes of the antioxidant enzyme activity, such as superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) were researched through nutrient solution culture. The results showed that the activity of SOD in shoot and root were significantly enhanced under lead stress. The activity of CAT in root was also improved, but the degree was not bigger than that of SOD activity. However, the MDA content in shoot and root was significantly higher than that of check group, it suggested that the membrane system were damaged by lead stress. The experiments also revealed that the shoot of wheat seedling was influenced by lead stress greatly stronger than that of root.

[Detection of DNA crosslinks with comet assay]

A simple and rapid method for the detection of DNA cross-links was explored. DNA cross-links was induced by formaldehyde (FA) in TK6 cells. Hydrogen peroxide was used as a standard DNA breakage agent. Two protocols on detecting DNA cross-links with comet assay were tested and compared. The results showed that with increasing FA, the length of DNA migration caused by H2O2 was decreased. When the level of FA was 1000 mumol/L, no any tailed cell could be observed, the migration of DNA was inhibited completely even H2O2 was used. The detection of DNA cross-link could be tested by both protocols. However, when the DNA cross-link agent (FA) was added to the cells before the treatment with DNA breakage agent (H2O2), the result of the scheme was much better than that in the opposite order. The former scheme was much easy to be manipulated, with no influence from DNA repair and had better dose-response relationship in the detection of DNA cross-links. The comet assay is indeed a sensitive, convenient and rapid method for the detection of DNA cross-link.

Identification of a potential HIV-induced source of bystander-mediated apoptosis in T cells: upregulation of trail in primary human macrophages by HIV-1 tat

The induction of apoptosis in T cells by bystander cells has been repeatedly implicated as a mechanism contributing to the T cell depletion seen in HIV infection. It has been shown that apoptosis could be induced in T cells from asymptomatic HIV-infected individuals in a Fas-independent, TNF-related apoptosis-inducing ligand (TRAIL)-dependent manner if the cells were pretreated with anti-CD3. It has also been shown that T cells from HIV-infected patients were even more sensitive to TRAIL induction of apoptosis than they were to Fas induction. Recently, it has been reported that in an HIV-1 SCID-Hu model, the vast majority of the T cell apoptosis is not associated with p24 and is therefore produced by bystander effects. Furthermore, few apoptotic cells were associated with neighboring cells which were positive for either Fas ligand or TNF. However, most of the apoptotic cells were associated with TRAIL-positive cells. The nature of these TRAIL-positive cells was undetermined. Here, we report that HIV infection of primary human macrophages switches on abundant TRAIL production both at the RNA and protein levels. Furthermore, more macrophages produce TRAIL than are infected by HIV, indicating that a bystander mechanism may, at least in part, upregulate TRAIL. Exogenously supplied HIV-1 Tat protein upregulates TRAIL production by primary human macrophages to an extent indistinguishable from infection. The results suggest a model in which HIV-1-infected cells produce extracellular Tat protein, which in turn upregulates TRAIL in macrophages which then can induce apoptosis in bystander T cells.

Acute stress increases permeability of the blood-brain-barrier through activation of brain mast cells

Disruption of the blood-brain-barrier (BBB) is important in the pathophysiology of various inflammatory conditions of the central nervous system (CNS), such as multiple sclerosis (MS), in which breakdown of the BBB precedes any clinical or pathological findings. There is some evidence that relapsing-remitting MS attacks may be correlated with certain types of acute stressful episodes. Stress typically activates the hypothalamic-pituitary-adrenal (HPA) axis through the release of corticotropin releasing hormone (CRH), leading to production of glucocorticoids that down regulate immune responses. However, acute stress also has pro-inflammatory effects that appear to be mediated through activation of mast cells. Here we show that acute stress by immobilization increased permeability of rat BBB to intravenous 99Technetium gluceptate (99Tc). This effect was statistically significant in the diencephalon and the cerebellum, while it was absent in the cerebral cortex where there are not mast cells. Immobilization stress also induced activation of mast cells in diencephalon, the site where most mast cells are found in the rat brain. Both BBB permeability and mast cell activation were inhibited by the 'mast cell stabilizer' disodium cromoglycate (cromolyn). These results expand the pathophysiology of mast cells and implicate them in CNS disorders, that may possibly be induced or exacerbated by stress.

Expression of the MAGE-1 gene in human hepatocellular carcinomas

OBJECTIVE

To further investigate the expression of MAGE-1 gene in hepatocellular carcinoma (HCC).

METHODS

The tumors and adjacent liver tissue from 45 HCC patients and liver tissue from 28 non-HCC patients (16 with liver cirrhosis and 12 with normal liver) were characterized by RT-PCR. A 421 bp PCR product from a cDNA fragment spanning exons 1, 2 and 3 was sequenced. The HLA type was assayed by standard ELISA in 43 HCC patients.

RESULTS

Thirty-two of 45 tumor tissues from HCC patients expressed MAGE-1 mRNA (71.1%). In contrast, MAGE-1 mRNA was not detected in adjacent tissues. Three were found to have point mutations at 3 identical sites resulting in the substitution of two amino acid residues. The most frequent HLA types in 43 HCC patients were: HLA-A2, 53.5%; A11, 25.6%; A24, 20.9%; A33, 20.9%; HLA-B13, 28.3% and B35, 23.2%. Expression of HLA-A33 (20.9%) was higher in HCC patients than that predicted in the normal Chinese population (8.8%). There was no discemable correlation between MAGE-1 expression and alpha-FP level, tumor size and hepatitis B or C virus infection. The identification of peptides which are restricted by haploptypes other than A1 should increase the opportunity for peptide based immunotherapy.

CONCLUSIONS

This study shows that MAGE-1 mRNA is highly expressed in HCC tumor tissue in Chinese patients. Previously unreported point mutations in the MAGE-1 gene are described and may also provide additional opportunities for immunotherapy.

[Lifetable of cotton bollworm under different control condition]

The lifetables of 3rd and 4th generation of cotton bollworm Helicoverpa armigera Hubner were established by action factors under four different control conditions. The results showed that under natural control, the egg parasitic rates of 3rd and 4th cotton bollworm were 4.39% and 1.19%, the predatory rates were 21.11% and 15.80%, and the larvae parasitic rates were 19.34% and 16.20% respectively. The indexes of population trend were only 0.0032 and 0.0014 respectively, after using selective pesticides IKI and Bt to control cotton bollworm. Though the index of population trend decreased to 48.66% and 61.67% after contantly praying chemical pesticides, the number of predators also decreased to 23.48% and 41.26% respectively. Transgenic Bt cotton could inhibit the population increase of cotton bollworm, but had no effect on predators. The parasitic rates of 3rd and 4th cotton bollworm on Transgenic Bt cotton were 51.14% and 0% respectively, as compared to control.

[Arthropod diversity in leafy vegetable field and sampling technology]

Two sampling units (plant and quadrat) and two sampling methods (random and fixed) were adopted to compare the variation degree of the diversity of arthropod communities in different chinese cabbage fields. The results show that a lower variation degree was found when the random sampling method was adopted with quadrat (0.11 m2) as sampling unit at seedling stage and with plant as sampling unit from growing to mature stage. The community diversity was relatively steady, when the critical number of samples was more than 12 quatrats (0.11 m2) at seedling stage, 30 plants in growing period, and 20 plants at mature stage. The optimum sampling unit, sampling method and sampling number of arthropod diversity in leafy vegetable field were also determined.