Interferon gamma induces upregulation and activation of caspases 1, 3, and 8 to produce apoptosis in human erythroid progenitor cells

Interferon gamma (IFNgamma) induces apoptosis in purified human erythroid colony-forming cells (ECFC) and inhibits cell growth. Fas (APO-1; CD95) and Fas ligand (FasL) mediate apoptosis induced by IFNgamma, because Fas is significantly upregulated by IFNgamma, whereas Fas ligand is constitutively present in the ECFC and neutralization of FasL greatly reduces the apoptosis. Because conversion of caspases from their dormant proenzyme forms to active enzymes has a critical role in transducing a cascade leading to apoptosis, we performed further studies of the expression and activation of caspases in normal human and IFNgamma-treated day-6 ECFC to better understand the mechanism of IFNgamma action in producing this cell death. RNase protection assays showed that the caspase-1, -2, -6, -8, and -9 mRNAs were upregulated by IFNgamma, whereas the caspase-5 and -7 mRNAs were not increased. Western blots showed that FLICE/caspase-8 was upregulated and activated by 24 hours of incubation with IFNgamma. FADD was not similarly altered by incubation with IFNgamma. Western blots of ICE/caspase-1, which might be required for amplification of the initial FLICE activation signal, showed that pro-ICE expression significantly increased after treatment with IFNgamma for 24 hours and cleavage of pro-ICE also increased. CPP32/apopain/caspase-3, responsible for the proteolytic cleavage of poly (ADP) ribose polymerase (PARP), was also studied and treatment of ECFC with IFNgamma resulted in an increased concentration of caspase-3 by 24 hours and a clear induction of enzyme activation by 48 hours, which was identified by the appearance of its p17-kD peptide fragment. The cleavage of PARP was demonstrated by an obvious increase of the 89-kD PARP cleavage product, which was observed at almost the same time as caspase-3 activation in the IFNgamma-treated cells, whereas untreated ECFC showed little change. Peptide inhibitors of the caspase proteins, DEVD-fmk, DEVD-cho, YVAD-cho, and IETD-fmk, were incubated with the ECFC to obtain further evidence for the involvement of caspases in IFNgamma-induced apoptosis. The activation of FLICE/caspase-8 and CPP32/caspase-3 and cleavage of PARP clearly were inhibited, but the reduction of cell growth due to apoptosis, induced by IFNgamma, was only partially blocked by the presence of the inhibitors. These results indicate that IFNgamma acts on ECFC not only to upregulate Fas, but also to selectively upregulate caspases-1, -3, and -8, which are activated and produce apoptosis, whereas the concentrations of FasL and FADD are not demonstrably changed.

The theory of "expelling pathogens regardless of hard stool", a significant contribution of Wu Youke

Though there are famous theories of "assorted Qi", "membranous origin", the contribution of Wu Youke's Wen yi lun (On Warm Pestilence) of the theory of " expelling pathogens regardless of hard stool" (EPRHS) is even more important. The main points of this theory includes: it is essential to expel pathogens at an early stage, while for attacking therapy, expelling pathogens with rhubarb is essential. EPRHS elucidates the significance of expelling pathogens in attacking therapy theoretically, and elevates the efficacy clinically with profound influence in later ages. In the past 2 decades, the early application of rhubarb to elevate the therapeutic effect for the treatment of pneumonia, epidemic meningitis, and Bencephalitis even in the absence of hard constipated stool marks the significance of Wu's such theory.

[Synthesis of hirudin variant 1 (HV1) gene and primary study of expression in yeast]

OBJECTIVE

Hirudin is an extremely efficient and specific thrombin inhibitor. It is clinically used to prevent the formation of thrombus. In this research the hirudin gene was put into yeast system for expression to evaluate the feasibility of artificially synthesized gene expressed in eukaryotic system and study the factor affecting expression level.

METHODS

According to the amino acid sequence of hirudin variant 1 (HV1), the genetic code saccharomyces cerevisiae was used to design and synthesize the HV1 gene. Amplified by PCR, it was inserted into cloning vector pBS-SK(+) and sequenced. Ligation with the signal peptide gene of yeast alpha factor the correct HV1 gene was inserted into yeast expression vector pYC-DE. The recombinant plasmid was transformed into the cell of S. cerevisiae BJ1990 to carry out the primary expression experiment.

RESULTS

In cultured supernatant of screened positive clone the hirudin activity was detected to be 30 ATU/ml. The expression level was higher than HV2 in yeast and HV1 in prokaryotic system. The N terminal amino acid sequence completely matches with natural hirudin.

CONCLUSIONS

It was proved by this study that the synthesized hirudin gene had been expressed in yeast successfully. This result showed that it was a better way to carry out the expression in yeast using synthesized HV1 gene and a stronger promoter.

Isolation of the Aspergillus nidulans sudD gene and its human homologue

We have been studying the heat-sensitive bimD6 mutation of Aspergillus nidulans. At a restrictive temperature, the chromosomes of bimD6 mutant strains fail to attach properly to the spindle microtubules, and the mutant also displays a high rate of chromosome loss. We previously cloned the sudA gene, an extragenic suppressor of the heat-sensitive bimD6 mutation and showed that it coded for a DA-box or SMC protein. SMC proteins have been demonstrated to function in chromosome condensation, segregation and global gene regulation. We have now cloned the sudD gene, another of the extragenic suppressor genes of the bimD6 mutation. The predicted SUDD protein is the founding member of a widely expressed protein family. Similar proteins are found in sequence databases for Saccharomyces cerevisiae, Caenorhabditis elegans, mammals and four species of archaebacteria. We have also cloned and sequenced a human cDNA that encodes the human homologue of SUDD and mapped the gene to 18q11.2. The predicted SUDD proteins from A. nidulans, Homo sapiens and S. cerevisiae all share a variety of features. The predicted proteins are approximately 60000Da in mass and have a serine-plus-threonine content of about 11%. The evolutionary conservation of the proteins suggests an ancient origin and conserved function for these proteins.

[Peak shape distribution rule of high performance liquid chromatography in the end of column under linear and nonideal conditions]

The central moments of chromatographic elution curve are important parameters for describing the column efficiency and chromatographic peak shape. According to the equation of chromatographic dynamics, we can get the second central moment and the third central moment of elution curve of HPLC under linear nonideal conditions. In our work, we investigated the relationships between second central moment, third central moment, coefficient of skewness of components distribution in the end of column and chromatographic column parameters, operation conditions, such as diameter of packing particle, desorption constant, diffusion coefficient in mobile phase, linear velocity of mobile phase, effect of extra column and so on. By means of computer, we discovered that there are no significant differences the second central moment, third central moment and coefficient of skewness for different components with different distribution coefficients. In the column end, therefore, different components have similar peak shape if there exist no obvious extra column effects. The column extra effect which stems from joint line and/or dead volume of detector is an important factor, causing column efficiency lower and peak shape tailing.

[Rapid and simple detection of Ki-ras gene mutations in pancreatic adenocarcinoma by PCR-SSP]

In order to judge whether Ki-ras gene mutations are present and their mutation styles, three kinds of special sequence primers (SSP) for polymerase chain reaction with regard to the mutant styles (CGT, GTT and GAT) at codon 12 were used to study the mutations in frozen tissues of pancreatic adenocarcinoma. The amplification products were studied with conventional electrophoresis using acrylamide gels and stained with ethidium bromide to detect the mutations.

RESULTS

In 23 of 25 frozen pancreatic adenocarcinoma specimens, Ki-ras genes with mutations at codon 12 were found; 2 mutant styles were found in 8 of the 23 samples; no mutations were found in 11 normal pancreatic tissues, 12 benign pancreatic disease tissues and 3 bile duct carcinoma tissues. This method is rapid, convenient, specific as well as sensitive. We conclude that this may become a valuable diagnostic modality for pancreatic carcinoma and for differentiating benign pancreatic diseases from carcinoma.

[Expressing poliovirus (type I) and hepatitis A virus antigens by recombinant vaccinia virus]

A recombinant vaccinia virus expressing PV-I and HAV antigens was constructed. Dot blot and Southern blot confirmed that the recombinant virus genome contained PV-I cDNA and HAV cDNA chimeric fragment. The result of IF indicated that PV-I antigen and HAV antigen were successfully expressed in the mammalian cells infected with the recombinant virus. The expressed PV-I and HAV antigen showed one band which had both PV-I and HAV antigenicities in Western blot. The band was about 120,000(MW). When guinea pigs were immunized with the recombinant virus, PV-I and HAV neutralizing antibodies were induced. The result indicated that the recombinant virus constructed here had bi-valence of PV-I and HAV antigen as well as PV-I and HAV immunogenecities.

Distinct regulatory roles of lymphocyte costimulatory pathways on T helper type-2 mediated autoimmune disease

We assessed the role of CD40-CD40L, cytotoxic T lymphocyte (CTL)A4/CD28-B7s, and CD2-CD48/CD58 lymphocyte costimulatory pathways in the development of mercury chloride (HgCl2)-induced autoimmune disease in mice, which is believed to be mediated by T helper (Th) subset Th2. Inhibition of CD40-CD40-L and CTLA4/CD28-B7s interactions by anti-CD40-L antibody and soluble CTLA4-immunoglobulin (Ig) fusion protein, respectively, abrogated the autoimmune disease without affecting interleukin 4 (IL-4) production, showing the importance of physical contact between T and B lymphocytes in the Th2-mediated process. In contrast, two anti-CD2 antibodies that have been shown to induce immunosuppression of Th1-mediated events exacerbated the autoantibody response and augmented IgG1, IgE, and IL-4 production, transforming a mild mesangial glomerulopathy into a severe systemic immune complex disease. These observations demonstrate that manipulation of lymphocyte accessory counterreceptor interactions may affect the course of Th2-associated autoimmune disease and suggest that signals resulting from CD2 engagement play an essential role in the regulation of the Th1-Th2 effector equilibrium.

Red sensitivity of dichromated cellulose triacetate as a holographic recording material

The red sensitivity of dichromated cellulose triacetate holographic recording material without any dye sensitization is reported. We suggest that the sensitivity is due to the absorption at 590 nm of the intermediate Cr(V) formed in the reducing process of chromium from Cr(VI) to Cr(III). In the experiment, the real-time transmission gratings are recorded with 632.8-nm irradiation from a He-Ne laser.

[Studies of purification, inactivity and immunogenicity of antigenically chimeric poliovirus]

Purified viruses were inactivated with 1:4000 formalin at 37 degrees C for 12d. Before and after inactivation, XF414 with anti-PV-1 and anti-PV-2, XF3 with anti-PV-1 and anti-PV-3 were observed by immunoelectron microscopy and the results were positive. Neutralization inhibition test and D-Ag unit detection were conducted, and the results were as follow: XF414 had type 1 D-Ag 15971 units/ml and type 2 D-Ag 15644 units/ml; XF3 had type 1 D-Ag 13314 units/ml and type 3 D-Ag 15971 units/ml. When rabbits were immunized with XF414 and XF3, they produced bivalent antiserum; i.e. anti-PV-1 and anti-PV-2 induced by XF414 and anti-PV-1 and anti-PV-3 induced by XF3.

[Mouse neurovirulence of antigenic chimeras (type I/II) of polioviruses]

The mouse-adapted Lansing strain of poliovirus type 2 PV-2(L) induces fatal poliomyelitis in mice after intracerebral inoculation, while mice inoculated with Mahoney strain of poliovirus type 1 PV-1(M) show no signs of disease. Previous work had indicated that both the 5' non-translated region of the viral genome and the viral capsid protein, neutralization antigenic site I (N-Ag1), were involved in mouse neurovirulence. In order to further explore the role of N-Ag1 in mouse neurovirulence, antigenic chimeras of two poliovirus strains, XF414 and XF324, were constructed. In the two strains, ten amino acids (in XF414) or 16 amino acids (in XF324) in antigenic site I in Vp1 of PV-I (M) were replaced with a PV-2(L)-specific sequences using a mutagenesis cartridge. Mouse neurovirulence tests indicated that mice cerebral inoculated with XF414 and XF324 developed poliomyelitis leading to paralysis or death. The viruses possessing antigenicity of the inoculating viruses were isolated from cerebral tissues of the paralyzed mice. The results demonstrated that N-Ag1 is an important determinant of poliovirus host range, and may be involved in attachment and penetration of poliovirus (in)to cells of the mouse central nervous system.

Studies on the immunogenicities of intertypic chimeric polioviruses

To study the relationship between structure and antigenicity, two hybrid viruses, XF414 and XF3, were constructed. In XF414, N-Agl of PV1 was replaced by N-Agl of PV2; while in XF3, N-Ag1 of PV1 was replaced by N-Ag1 of PV3. In this study, XF414 and XF3 were cultured on a large scale in primary monkey kidney cells. The viruses were concentrated with PEG, purified with chloroform and Sepharose 2B and inactivated with formaldehyde. Their bivalent antigenicity was confirmed by neutralization inhibition test, immunoelectron microscopy, and rabbit immunization. It was also shown that both XF414 and XF3 can elicit bivalent neutralizing antibodies and that the bivalent antigenicities are not destroyed by formaldehyde inactivation. Such a study can provide a basis for the development of multivalent picornavirus vaccines.

Reliability and validity of a Chinese computerized diagnostic instrument

This paper reports on the development and testing of a new Chinese diagnostic instrument--the Adult Diagnostic Interview Schedule-Present (ADIS-P). This instrument uses a selection of items adapted from DIS and SADS. It is administered within approximately 25 min by a trained clinician using a small portable computer that provides an immediate diagnosis. The instrument was tested on 1,331 patients from six large mental hospitals across the country. The concurrent validity was good: compared to the concensus diagnosis of two senior clinicians (who were blinded to the ADIS-P result), the overall diagnostic accuracy was 83% and the weighted Kappa value was 0.60. The 1 month test-retest reliability was satisfactory (weighted Kappa = 0.55). We conclude that ADIS-P is a convenient, reliable and valid diagnostic instrument.