[Effect of space environment on germination and vegetation growth in Carthamus tinctorius L]

OBJECTIVE

To substantiate the effects of space condition on medicinal plants.

METHOD

The seeds of medicinal plant Carthamus tinctorius were carried on board a retrievable satellite during 3-18 July, 1994. After returing to earth, the seedling rate, state of growth and development were observed.

RESULT

The seeding rates, plant heights and branch quantities of weightless seeds and the seeds which were penetrated once and less than once by the heavy ion rays were higher than those of the seeds which were kept on earth, but these indexes of the seeds which were penetrated 2-3 times by the heavy ion rays were higher than those of the ground controlled seeds.

CONCLUSION

Weightlessness and little penetration promote the growth and development of Carthamus tinctorius, but much penetration functions the other way round.

Activation of donor-specific CTL in a tolerant recipient of cardiac allograft

Permanent graft acceptance was induced with cyclosporine A in a low responder rat strain combination PVG (RT1(c)) to DA (RT1(av1)) of cardiac transplants. Challenge (alloimmunization) with donor and third-party WF (RT1(u)) cells was performed and followed by the analysis of alloreactive cytotoxicity. The cytotoxic T lymphocytes (CTL) from recipients with permanently accepted cardiac grafts manifested cytolytic activity against third-party target cells but not against donor target cells. The findings demonstrated unresponsiveness to be donor-specific, i.e., transplant tolerance was present. This was verified by retransplantation of the DA recipient with either a second PVG heart (which was accepted) or a third-party (WF) heart (which was rejected). Restoration of donor-specific CTL after injection of exogeneous interleukin(IL)-2 concomitant with challenge showed that the donor-specific CTL were not depleted, but unable to be activated as a consequence of IL-2 deficiency. Despite donor-specific CTL activation in vivo the recipients failed to reject their established grafts, implying an ongoing presence of suppression.

Comparison of carcinoembryonic antigen promoter regions isolated from human colorectal carcinoma and normal adjacent mucosa to induce strong tumor-selective gene expression

To establish in vivo gene therapy against cancer, it is requisite to induce strong, cancer cell-selective expression of a therapeutic gene. Comparison of the promoter activity of 5' flanking regions of the carcinoembryonic antigen (CEA) gene isolated from various origins is therefore of considerable interest. The 5' flanking region of the CEA gene between -135 and +69 bp upstream from the transcriptional start site, which is recognized as the core promoter region, was isolated from CEA-producing human colorectal carcinoma (CRC), normal adjacent mucosa, CEA-producing cell lines and CEA-non-producing cell lines. No mutations were observed by single-strand conformation polymorphism in the CEA promoter regions. Subsequent sequence analysis revealed that there were no mutations in the CEA promoter regions isolated from CEA-producing CRC and normal adjacent mucosa. Furthermore, nuclear extracts prepared from CEA-producing human CRC cells could equally bind to both the CEA promoter fragments isolated from CEA-producing CRC and normal mucosa. Both CEA promoter regions could direct 5- to 20-fold higher expression of a luciferase reporter gene in CEA-producing cells than in CEA-non-producing cells. Therefore, we suggest that the use of either CEA promoter region isolated from CRC or normal mucosa is equally effective to induce strong, CEA-producing cancer-selective expression of a therapeutic gene.

Comparison of carcinoembryonic antigen promoter regions isolated from human colorectal carcinoma and normal adjacent mucosa to induce strong tumor-selective gene expression

To establish in vivo gene therapy against cancer, it is requisite to induce strong, cancer cell-selective expression of a therapeutic gene. Comparison of the promoter activity of 5' flanking regions of the carcinoembryonic antigen (CEA) gene isolated from various origins is therefore of considerable interest. The 5' flanking region of the CEA gene between -135 and +69 bp upstream from the transcriptional start site, which is recognized as the core promoter region, was isolated from CEA-producing human colorectal carcinoma (CRC), normal adjacent mucosa, CEA-producing cell lines and CEA-non-producing cell lines. No mutations were observed by single-strand conformation polymorphism in the CEA promoter regions. Subsequent sequence analysis revealed that there were no mutations in the CEA promoter regions isolated from CEA-producing CRC and normal adjacent mucosa. Furthermore, nuclear extracts prepared from CEA-producing human CRC cells could equally bind to both the CEA promoter fragments isolated from CEA-producing CRC and normal mucosa. Both CEA promoter regions could direct 5- to 20-fold higher expression of a luciferase reporter gene in CEA-producing cells than in CEA-non-producing cells. Therefore, we suggest that the use of either CEA promoter region isolated from CRC or normal mucosa is equally effective to induce strong, CEA-producing cancer-selective expression of a therapeutic gene.

Malononitrilamides 715 and 279 prolong rat cardiac allograft survival, reverse ongoing rejection, inhibit allospecific antibody production and interact positively with cyclosporin

A77 1726 is a malononitrilamide (MNA) and the active metabolite of leflunomide, which has been extensively investigated and shown to be a potent immunosuppressive drug. However, the half-life of A77 1726 is about 15-18 days in humans and leflunomide is therefore currently being developed for the treatment of autoimmune disease and not for transplantation. Search for analogues has led to the discovery of MNA 715 and 279, derivatives of A77 1726. Previous experimental experience of these compounds is still limited. The aim of the present study was to verify the efficacy of these MNAs concerning prevention and reversal of rejection, inhibition of antibody production and interaction with cyclosporin A (CsA). Heterotopic cardiac transplantation in DA to PVG rats was used. Subgroups of rats were given either CsA, MNA 715 or MNA 279 for 10 days, starting at either day 0 or day 4, or received no treatment. Titres of allospecific immunoglobulin M (IgM) and immunoglobulin G (IgG) were quantified by flow cytometry. Ten days of induction with MNA 715 or 279 produced significantly longer graft survival than in controls. Treatment from day 4 onwards, when acute rejection was established, rescued all grafts. Allospecific production of IgM or IgG was absent during MNA induction and was suppressed in animals receiving a rescue course of MNA. The transplant model was potentiated by addition of the immunomodulator quinolone-3-carboxamide (Linomide), which eliminates the effect of CsA and other immunosuppressants. The combined treatment with MNA and CsA was successful in overcoming the challenge of Linomide, demonstrating the additive effects of the two drugs. In conclusion, MNA 715 and 279 were shown to be potent immunosuppressants, preventing and reversing acute allograft rejection, inhibiting and suppressing allospecific antibody production, and the drugs interacted positively with CsA.

[Variation of count rate of charged particle in the cabin with space position in near Earth orbit]

Two Geiger-Mueller radiation dosimeters, equipped with data recorders, were placed in the recoverable satellite launched on Oct. 20, 1996. The data recorder was used to record the count rate of proton acquired by the Geiger-Mueller dosimeter dynamically. From the obtained data, the area of high proton flux and the contour map of South Atlantic Abnormal was plotted.

[Study on quality of China made NS3 antigen]

Using anti-HCV antibody screening assay to control the quality for blood is the main measure for preventing transmission of HCV in China. This study is to evaluate the quality of NS3 antigen because of their positive rate to anti NS3 antibody in HCV infected patients and to all kinds of anti-HCV antibody detecting kits, that need NS3 antigen. We collected four China genetically engineered NS3 antigens and other two NS3 antigens came from abroad. The first step is to confirm that the antibody reactivity with coated NS3 antigen is true. The second step is to compare the quality of China made NS3 antigens with NS3 antigens abroad. The results showed that coated NS3 antigen kits have high sensitivity in identifying the positivity of sera from second generation panel, among them that were RIBA-2 indeterminate or negative. Some negative or false positive results by coated Chinese NS3 antigens indicate that manufacturer should make more efforts to ensure the best condition terms for using these antigens.

[Evaluation on the anti-hepatitis C virus enzyme-linked immunosorbent diagnostic kits]

Ten different anti-HCV ELISA kits, four manufactured from abroad (ABBOTT, Innogenetics, Murex, Monolisa) and six in China, were evaluated by China national anti-HCV panel(100 positive, 98 negative) and Boston Biomedical Inc. (BBI) anti-HCV mixted titer performance panel(23 positive and 2 negative). The detective rates in 100 China national anti-HCV positive panel were 98% by ABBOTT EIA 2.0, 96% by BHY, SKH and XWK, 95% by BBS and HHM, 97% by SCJ, and that in 23 BBI anti-HCV positive panel were 100% by ABBOTT EIA2.0, but 91% by Murex, 87% by Innogenetics and Monolisa, 74% by BHY, 87% by SKH, 83% by XWK and HHM, 70% by BBS, 91% by SCJ. The specificity for all negative panels were similar in all kits. According to the results of HCV RIBA test (Ortho HCV RIBA 2.0), the structural antigens contained in all kits were almost the same, but the antigenicity of HCV nonstructural proteins were different, in the kits made in China they were lower than that made from abroad.

Malononitrilamides 715 and 279 prevent accelerated cardiac allograft rejection synergistically with cyclosporin A in presensitized rats

A77 1726 is a malononitrilarnide (MNA) and the active metabolite of leflunomide. Leflunomide has been extensively investigated and shown to be a potent immunosuppressive drug. However, the half-life of A77 1726 is about 15-18 days in humans and the leflunomide is, therefore, currently being evaluated for the treatment of autoimmune disease and not for transplantation. The search for analogues has led to the development of MNA 715 and 279, derivatives of A77 1726. Previous limited experimental experience has shown these MNAs to prevent skin allograft and xenograft rejection and graft-versus-host disease in rodents, and to reverse ongoing allograft rejection. The aim of the present study was to verify the efficacy of these MNAs in a cardiac retransplant model of sensitized rats, concerning prevention of accelerated rejection, inhibition of antibody production and interaction with cyclosporin A (CsA). Heterotopic cardiac transplantation and retransplantation in Dark Agouti (DA) to Piebald Virol Glaxo (PVG) rats was used. Subgroups of rats were given either CsA, MNA 715, MNA 279 or combined CsA/MNA for 10 days starting either day 0 or day -1, as of regrafting or no treatment. Titres of allospecific IgM and IgG were quantitated by flow cytometry. Ten days of MNA 715 or 279 from day -1 prevented accelerated rejection of the retransplant, as did CsA. Neither treatment given from day 0 prevented rejection within 24 h. However, a combination of MNA 715 or 279 and CsA from day 0 effectively prevented accelerated regraft rejection. Production of specific alloantibodies was reduced in all immunosuppressed subgroups, IgG titres at day 7 in MNA-treated subgroups being significantly lower compared with those in the CsA-treated subgroup. In conclusion, MNA 715 and 279 were shown to be potent immunosuppressants with the capacity to prevent accelerated regraft rejection in rat cardiac transplants, most efficiently in combination with CsA, and to suppress specific alloantibody production.

[Transient and stable expression of human ApoE7 gene in NIH/3T3 cell lines]

OBJECTIVE

To investigate the expressing profile of h-apoE7 gene under the regulation of MT-I promoter in mouse cells.

METHODS

The eukaryotic expressing plasmid pME7 was constructed through cloning human apoE7 genomic DNA(6.0 kb) into pMT at the site of Bgl II/Hind III just under the control of the mouse metallothionein-I promoter. Transfection of pME7 plasmid into NIH/3T3 cell lines by Lipo-fectamine was performed.

RESULTS

The transient expression of recombinant pME7 in NIH/3T3 cells showed that the expression was not restricted to human cells; The stable expression of pME7 demonstrated that the levels of h-apoE7 mRNA was highly related to the copies of integrated h-apoE7 gene. Whereas the results of ELISA implicated that the exogenous human apoE7 gene was transcribed, processed properly, and eventually translated into functional proteins. Furthermore, heavy metal (ZnSO4) could enhance the expressing level of h-apoE7 gene in transfected cell lines. The level of human apoE7 protein arised 45%-60% while induced.

CONCLUSIONS

It was suggested that MT-I promoter could modulate the expression of recombinant h-apoE7 gene correctly. Therefore, cellular studies provided the scientific basis for establishment of h-apoE7 transgenic mouse models.

Dynamic properties of individual water molecules in a hydrophobic pore lined with acyl chains: a molecular dynamics study

Recently, a certain class of synthetic molecules has been shown to form ion channels, the pore of which is lined with hydrophobic acyl chains [M. Sokabe, in: F. Oosawa, H. Hayashi, T. Yoshioka (Eds.), Transmembrane Signaling and Sensation, JSSP/VNU Science Press BV, Tokyo, 1984, p. 119; F. Hayashi, M. Sokabe, M. Takagi, K. Hayashi, U. Kishimoto, Biochim. Biophys. Acta, 510 (1978) 305; M.J. Pregel, L. Jullien, J. Canceill, L. Lacombe, J.M. Lehn, J. Chem. Soc. Perkin Trans., 2 (1995) 417; Y. Tanaka, Y. Kobuke, M. Sokabe, Angew. Chem. Int. Ed. Engl., 34 (1995) 693; M. Sokabe, Z. Qi, K. Donowaki, H. Ishida, K. Okubo, Biophys. J., 70 (1996) A201; H. Ishida, K. Donowaki, Y. Inoue, Z. Qi, M. Sokabe, Chem. Lett. (1997) p. 953]. As an initial step towards understanding the physical mechanisms of ion permeation across such a hydrophobic pore, systematic molecular dynamics simulations were performed to investigate dynamic and energetic properties of water molecules inside the pore using a dimer of alanine-N'-acylated cyclic peptide as a channel model. Dynamic energy profiles for water molecules indicated that the energy barrier at the middle region of the pore is approximately 2-3 kcal/mol higher than that in the cap water region which was defined as a vicinity region of the channel entrance. Energetics analyses demonstrated that the mutual interactions among intrapore water molecules are the major factor to give favorable interaction (negative energy contribution) for themselves. The pore, despite being lined with acyl chains, has a favorable van der Waals interaction with intrapore water molecules. These results may help to explain why water-filled channels can be formed by the hydrophobic helices in natural channels.

Effect of heparin on phosphorylation site specificity of neuronal Cdc2-like kinase

Neuronal Cdc2-like kinase (Nclk) can be stimulated by heparin in a substrate-dependent manner. While phosphorylation of tau is markedly enhanced by heparin, phosphorylation of histone H1 by Nclk is essentially unaffected. A histone H1 peptide, HS(9-18): PKTPKKAKKL, and its substitution analogues were used to examine the basis of the differential heparin effect. In the presence of heparin, the phosphorylation site specificity of Nclk is altered and only proline immediately following the phosphorylation site is still an essential substrate determinant. This change in the site specificity may adequately account for the differential heparin effect on histone H1 and tau phosphorylation.

Association of neurofilament proteins with neuronal Cdk5 activator

Cdk5 exists in brain extracts in multiple forms, one of which is a macromolecular protein complex comprising Cdk5, neuron-specific Cdk5 activator p35nck5a and other protein components (Lee, K.-Y., Rosales, J. L., Tang, D., and Wang, J.H. (1996) J. Biol. Chem. 271, 1538-1543). The yeast two-hybrid system was employed to identify p35nck5a-interacting proteins from a human brain cDNA library. One of the isolated clones encodes a fragment of glial fibrillary acidic protein, which is a glial-specific protein. Sequence alignment revealed significant homology between the p35nck5a-binding fragment of glial fibrillary acidic protein and corresponding regions in neurofilaments. The association between p35nck5a and neurofilament medium molecular weight subunit (NF-M) was confirmed by both the yeast two-hybrid assay and direct binding of the bacteria-expressed proteins. The p35nck5a binding site on NF-M was mapped to a carboxyl-terminal region of the rod domain, in close proximity to the putative Cdk5 phosphorylation sites in NF-M. A region immediately amino-terminal to the kinase-activating domain in p35nck5a is required for its binding with NF-M. In in vitro binding assays, NF-M binds both monomeric p35nck5a and the Cdk5/p35nck5a complex. The binding of NF-M has no effect on the kinase activity of Cdk5/p35nck5a.

[Effects of HE particles on medicinal plant Agastache rugosus (Fisch. et Mey.) O. Ktze]

The biological effect of HE particles on the seeds of Agastache rugosus was probed in experiments on board a retrievable satellite. The result shows that the germination rate of the seeds pierced by HE particles radiation appears rather low. The seeds hit by HE particles (piercing radiation or not) start to germinate two days earlier than those in the control group, and the first leaf emerges four to five days earlier than that in the control group. The resultant seedlings grow markedly faster. Variations take place in the nuclear types of chromosome. The yield of essential oils becomes slightly higher. No marked changes have been observed in the major chemical components of these oils.

[An analysis of radiation risk for manned space flight in low-earth orbits with medium inclination]

The radiation risk for manned space flight in the orbit with altitude <500km and inclination 40 degrees-50 degrees was analyzed. The doses of several anomalously large solar proton events (SPE) were estimated from the measured doses during the SPE where the spectral parameters were known. The result shows that the radiation risk is not serious for the mission with above orbital parameters.

Adenovirus-mediated expression of the secreted form of basic fibroblast growth factor (FGF-2) induces cellular proliferation and angiogenesis in vivo

Blood supply through collateral arteries is of critical importance in occlusive arterial diseases such as coronary atherosclerosis. Induction of angiogenic growth factor within either the narrowing arteries or jeopardized myocardium may promote angiogenesis in vivo, leading to salvage of ischemic myocardium. We constructed a replication-defective adenovirus (AdCAsFGF-2) coding for human basic fibroblast growth factor (FGF)-2 that is modified, so that its secretion will be facilitated, by tagging a signal sequence derived from FGF-4. A large quantity of FGF-2 was detected in both the cell lysate and culture medium of COS cells infected with AdCAsFGF-2, indicating that FGF-2 was secreted at least partly from the infected cells. The conditioned medium from the infected COS cells stimulated DNA synthesis in and induced cellular proliferation of arterial smooth muscle cells. These effects were eliminated by adenovirus-mediated overexpression of a dominant-negative truncated FGF-receptor type 1. Implantation of a gel of basement membrane proteins containing fibroblasts infected with AdCAsFGF-2 into the ventral subcutaneous space of mice induced extensive cellular proliferation and the formation of functional arterioles. Cells surrounding the vessels were positively immunostained with antibodies recognizing either smooth muscle-specific alpha-actin or factor VIII antigen as a marker for endothelium. These results suggest that AdCAsFGF-2 may be useful for delivering functional FGF-2 into tissues and may lead to therapeutic angiogenesis in vivo.

[Hepatitis B virus DNA detection by means of polymerase chain reaction in patients with chronic hepatitis and hepatocellular carcinoma]

HBV immunological detection and HBV DNA detection by polymerse chain reaction (PCR) or molecular hybridization with 32P labeled probe were done in 61 patients with chronic hepatitis (CH) and 47 patients with hepatocellular carcinoma (HCC) to investigate the relationship between HBV replication and serum markers. The HBV DNA was detected in 90.50% of CH patients and 50.00% of HCC patients with HBsAg, HBeAg and anti-HBc positive; in 45.40% of CH patients and 7.14% of HCC patients with HBsAg, anti-HBe and anti-HBc positive; in 60.00% of CH patients and 40.00% of HCC patients with HBsAg and negative HBeAg, anti-HBe positive; in 20.00% of CH patients and 22.22% of HCC patients with HBsAg negative and anti-HBe or anti-HBe or anti-HBs positive; in 0 of CH or HCC patients lack of HBV serum markers. Our data suggested that the most active HBV replication was correlated to the presence of both HBsAg and HBeAg, there were some extent of HBV replication in CH or HCC patients with positive HBsAg, the inhibition of HBV replication was related to anti-HBe, the less active HBV replication was seen in HCC patients when compared with CH patients.

Single dose anti-CD4 monoclonal antibody for induction of tolerance to cardiac allograft in high- and low-responder rat strain combinations

Repeated administration of monoclonal antibodies (mAb) directed against the CD4 lymphocyte receptor may induce specific, long-lasting unresponsiveness to fully MHC-mismatched cardiac allografts in rats without additional immunosuppression. We assessed the effect of a single dose of murine anti-rat depleting anti-CD4 mAb (OX-38) on allograft survival in high- and low-responder rat strain combinations. Isogenic strains of DA (RT1av1), PVG (RT1c), AUG (RT1c), and WF (RT1u) rats were used. Recipients in antibody treated groups were given one dose of 5 mg/kg OX-38 mAb on the day of transplant, a dose which was shown to effectively deplete (or block) circulating CD4+ T cells. Other groups were treated for 10 days with cyclosporin A (CsA) and/or Linomide, a novel immunomodulator, which is the first compound able to fully eliminate the effect of CsA in the rat cardiac allograft model. The DA strain was identified as a low-responder to the allogeneic haplotype RT1c (PVG or AUG), but not to RT1u (WF), and developed true tolerance following RT1c grafting and OX-38 or low-dose CsA (5 mg/kg) induction, as verified by the response to retransplantation of a graft from the same donor strain or a third-party challenge. PVG recipients of DA grafts were characterized by high response and only modest (OX-38; median 9.5 days) or moderate (CsA; 23.5 days) prolongation of graft survival. Contrasting graft survival results were obtained in the low-responder combination, either very early rejection (at 10 days) or permanent graft survival (> 100 days). Linomide challenge affected CsA treatment in the high-responder combination but not tolerance induction in the low-responder combination, or the effect of OX-38. It was concluded that in rat heart transplantation a single-dose anti-CD4 mAb therapy may induce permanent donor-specific unresponsiveness in a low-responder strain combination, and that anti-CD4 mAb seems to be unique among immunosuppressive agents while being resistent to challenge by Linomide.

[Simultaneous coronary artery bypass grafting with other cardiovascular surgical procedures]

To improve the effect and reduce the mortality of the simultaneous coronary artery bypass grafting (CABG) with other cardiovascular surgical procedures, from Nov, 1984 to July, 1996, 51 patients underwent such operation. Among them 45 patients had valvular heart diseases, 4 postinfarction ventricular septal defect and ventricular aneurysm, and 1 myxoma of left atrium and abdominal aortal aneurysm. The operative mortality was 5.85% (3/51), and 3 patients died. Cardiovascular surgical patients of over 50 years or with angina pectorsi and ECG confirmed myocardiac ischemia should undergo coronary angiography routinely. If main coronary artery branches stenosis occupied over 50%, CABG must be performed. During the operation revasculariztion should be made as full as possible to enhance myocardiac protection and reduce the ascending aortic cross-clamping time.

[Herbological study of 4 Chinese herbs in Ardisia and "yiedihong"]

Herbological study are given to the original plants of "Zijinniu", "Pingdimu", "Xiaoqing", "Duanjiaosanlang" and "Yiedihong" recorded in the herbal books. The research shows that they are not the same plant with different names. Also, "Yiedihong" doesn't belong to Ardisia.

Double mutagenesis of a positive charge cluster in the ligand-binding site of the ferric enterobactin receptor, FepA

Siderophores and colicins enter bacterial cells through TonB-dependent outer membrane proteins. Using site-directed substitution mutagenesis, we studied ligand recognition by a prototypic Escherichia coli siderophore receptor, FepA, that binds the iron chelate ferric enterobactin and colicins B and D. These genetic experiments identified a common binding site for two of the three ligands, containing multiple positive charges, within cell surface residues of FepA. Elimination of single residues in this region did not impair the adsorption or transport of ferric enterobactin, but double mutagenesis in the charge cluster identified amino acids (Arg-286 and Arg-316) that participate in siderophore binding and function in FepA-mediated killing by colicins B and D. Ferric enterobactin binding, furthermore, prevented covalent modification of FepA within this domain by either a fluorescent probe or an arginine-specific reagent, corroborating the involvement of this site in ligand recognition. These results identify, for the first time, residues in a TonB-dependent outer membrane protein that participate in ligand binding. They also explain the competition between ferric enterobactin and the colicins on the bacterial cell surface: all three ligands interact with the same arginine residues within FepA during their penetration through the outer membrane.

Activation of alloreactive natural killer cells is resistant to cyclosporine

BACKGROUND

We have previously shown that cytotoxic T lymphocytes (CTL) with alloreactivity were induced when Wistar Furth (WF; RT1u) rats were immunized with allogeneic Brown Norway (BN; RT1n) cells. In contrast, when BN rats were immunized with WF cells, the allospecific response was confined to alloreactive natural killer (NK) cells, and no CTL activity was observed. In this study, the effect of cyclosporine (CsA) on the activation of alloreactive NK cells in vivo was analyzed.

METHODS

Distinct peritoneal effector cells from rats immunized with allogenic cells with or without concomitant CsA and/or interleukin (IL) 2 treatment were tested for specific cytolytic activity. Furthermore, the presumptive role of NK cells in rejection immunity was addressed in a cardiac graft model.

RESULTS

The results showed that doses of CsA that completely inhibited the activation of alloreactive CTL, only marginally affected the activation of alloreactive NK cells. We also showed that CsA treatment failed to prolong graft survival in BN recipients of WF hearts. Treatment of BN rats with CsA/IL-2 during immunization with allogeneic WF cells resulted in concomitant induction of alloreactive NK cells and alloreactive CTL.

CONCLUSIONS

We have demonstrated that CsA failed to suppress the activation of alloreactive NK cells. Consequently, the cardiac graft survival in the donor-recipient combination known to activate alloreactive NK cells was not significantly prolonged by CsA treatment, emphasizing the involvement of NK cells as effectors in organ rejection. Furthermore, the parallel emergence of alloreactive NK cells and CTL only in the presence of CsA/IL-2 indicated that CsA interfered with alloreactive NK cell-associated suppression of CTL activated by allogeneic tissue.

Mycophenolate mofetil, azathioprine and cyclophosphamide enhanced efficacy combined with cyclosporine in rat cardiac transplantation

Anti-proliferative drugs have been used for immunosuppression since the introduction of clinical transplantation. Most transplant centres include azathioprine (Aza) and cyclosporine (CyA) in their standard regimens, despite several controlled studies having failed to confirm the benefit of this combination. Aza is still the most commonly used anti-proliferative drug, although no major differences in immunosuppressive or toxic effects have been shown between Aza and cyclophosphamide (Cph). Cph as an adjunct to CyA has never been tested in a randomized study. Recently, mycophenolate mofetil (MMF) has been developed as the most selective inhibitor of T- and B-cell proliferation and promoted as an adjunct to CyA treatment. In the present study, the additive or synergistic effects of these three anti-proliferative agents in combined treatment with CyA have been investigated using a rat cardiac transplantation model in which the immunomodulator linomide (Lin) was included as a potentiator of rejection. As single drug treatment, CyA, Cph and MMF, but not Aza, exerted a beneficial effect on graft survival. This prolongation of graft survival was abrogated when any one drug was administered together with Lin. The addition of MMF, Aza or Cph to CyA plus Lin treatment improved the graft survival significantly, thus demonstrating each of the anti-proliferative drugs to exert additive or synergistic effects in conjunction with cyclosporine. MMF seemed to be the most effective and least toxic of the drugs tested.

[Efficacy of dihydroartemisinin in treatment of 37 malaria cases]

Dihydroartemisinin is an efficacious derivative of artemisinin which can be taken orally in treatment of malaria with less side reactions. Thirty-seven cases with malaria were treated with this drug in Beijing and in Ruili City, Yunnan Province. Out of them, 25 cases suffered from falciparum malaria with an average parasitemia of 73,218/microliter and 12 from vivax malaria with an average parasitemia of 4,950/microliter. The dosage was 60 mg daily or 2 mg/kg for paediatric patients for 7 successive days with the first dose doubled. All the patients were clinically cured after treatment. Fever subsided 22-72 hours after the beginning of treatment in falciparum malaria patients with an average fever clearance time of 36.24 +/- 15.30 hours and their parasite clearance time was 24-72 hours with an average parasite clearance time of 44.80 +/- 19.09 hours. One of them had recrudescence 19 days after the disappearance of parasites, hence the recrudescence rate of falciparum malaria was 4.8%. Five early cerebral cases in this series were completely cured after the treatment. All the 12 cases with vivax malaria were also clinically cured after treatment, but 1 case had relapse 35 days after treatment. This patient was completely cured with another course of dihydroartemisinin combined with primaquine. All patients tolerated well the oral administration of dihydroartemisinin and no significant side reactions were seen.

Complete regression of established murine hepatocellular carcinoma by in vivo tumor necrosis factor alpha gene transfer

BACKGROUND & AIMS

Although tumor necrosis factor (TNF)-alpha possesses a potent antitumor activity, systemic administration of TNF-alpha causes severe side effects. To circumvent this, the efficacy of tumor cell-targeted TNF-alpha gene therapy was investigated.

METHODS

Murine hepatocellular carcinoma (HCC) cells were infected with MNSM-Alb e/p-TNF-alpha retroviruses carrying the murine TNF-alpha gene under the transcriptional control of the murine albumin gene promoter, and antitumor effects induced by TNF-alpha gene transfer were examined in vitro and in vivo.

RESULTS

Although MNSM-Alb e/p-TNF-alpha retrovirally infected HCC cells showed the same in vitro cell growth as parental HCC cells, they lost their tumorigenicity when implanted in syngeneic mice and induced tumor immunity against parental HCCs. The retrovirally infected HCC cells also significantly inhibited the tumorigenicity of previously implanted parental HCCs. Furthermore, intratumoral administration of MNSM-Alb e/p-TNF-alpha retroviruses showed the antitumor effect against established HCCs, resulting in significantly prolonged survival periods. Most importantly, intratumoral implantation of MNSM-Alb e/p-TNF-alpha retroviral-producing cells completely abrogated established HCCs in mice.

CONCLUSIONS

These results indicate the potential efficacy of transferring the TNF-alpha gene via retroviral vectors directly into tumors for gene therapy against HCCs.

[Experimental study on free grafting of fat particles]

Forty-eight rats were used to study the change in fat tissue after grafting. In the experimental group, the fat tissue to be grafted was treated with insulin. Evaluation was made by graft measurement, ink injection, light microscopic and electronic microscopic observations. The results showed that the volume of the grafted fat decreased obviously and there was no significant difference between the experimental and the control groups in the change of volume of the grafted fat tissue. At the early stage of grafting, the grafted fat showed ischemia. The adipocytes released lipid and dedifferentiated to preadipocytes. After revascularization, the preadipocytes began to absorb lipid and became mature adipocytes. The structure of the grafted fat was almost normal at 6 months after grafting. The formation of the cytoskeletal filament, found by ultrastructural study, was closely related with the synthesis of lipid.

Bioavailability of cyclosporine in rats after intragastric administration: a comparative study of the L2-phase and two other lipid-based vehicles

The purpose of this study was to evaluate formulations based on surface active dietary lipids only as oral vehicles for cyclosporine. The absolute bioavailability of cyclosporine from two new lipid vehicles was determined in rats after intragastric administration and compared to that of Sandimmun oral solution, which contains non-ionic surface active substances in addition to dietary lipids. In the new vehicles, cyclosporine was dissolved in two different mixtures of glycerides from long-chained fatty acids. One mixture forms an L2-phase, an oil with very low interfacial tension towards water, and was administered both as the oily L2-phase and as a predispersed emulsion formulation. The other mixture forms a liquid crystalline phase and was administered only as an aqueous dispersion. The mean bioavailability of cyclosporine from Sandimmun was 8% while it was 34% from the L2-phase, 38% from the predispersed L2-phase and 27% from the dispersed liquid crystalline phase. The coefficients of variation in area under the blood concentration curve after administration of the two formulations based on the L2-phase were quite low (31% for the L2-phase and 24% for the predispersed L2-phase) and comparable to that after intravenous administration (24%), while the dispersed liquid crystalline phase gave a higher variability (91%), comparable to that of Sandimmun oral solution (101%). The low variabilities found with the two L2-phase vehicles suggest that this formulation is "self-emulsifying' in the gastrointestinal tract. Since the L2-phase is based on dietary lipids only, it is expected to be well tolerated and could prove to be a good vehicle for long-term clinical use of oral cyclosporine.

Construction of retroviral vectors to induce strong hepatoma cell-specific expression of cytokine genes

Continuing advances in molecular biology have provided tools for a promising approach to the treatment of cancer. Among the various strategies of gene therapy for cancer, many are aimed at killing tumour cells indirectly by the induction or reinforcement of a host immune response by gene transduction of various cytokines, major histocompatibility complex or immune accessory molecules. In the present study, we selected the tumour necrosis factor-alpha, interleukin-2 and interleukin-3 genes as potential cytokine genes to induce antitumour effects. We constructed retroviral vectors carrying these cytokine genes under the control of the murine albumin enhancer and promoter and retrovirally transduced these genes into hepatoma and non-hepatoma cell lines. Strong expression of the cytokine genes was induced in transduced hepatoma cells, while no evident expression was detected in transduced non-hepatoma cells. These results demonstrate the hepatoma-specific expression of cytokine genes and imply the feasibility of in vivo gene transfer into hepatomas without affecting any other tissues. Furthermore, these cytokine genes were expressed much more intensively when they were derived from the albumin enhancer and promoter than when derived from the simian virus 40 early region promoter. These results indicate that transcriptional regulatory sequences specific for the target tissues could be preferable to viral promoters for the gene therapy of cancer.

Moderate additive immunosuppressive effect of thalidomide combined with cyclosporin A in rat cardiac transplantation

Thalidomide is an immunomodulating agent shown to prolong graft survival in experimental skin, renal, cardiac and bone marrow transplantation. The main purpose of the present study was to investigate the possible additive effect of combining thalidomide with cyclosporin A (CyA). Members of our group have previously created a basis for such studies by demonstrating the ability of Linomide to abolish the effect of CyA. The additional effect of combined treatment with a second drug is thereby more readily evaluated, compared with using subtherapeutic dose levels to induce early rejection. Cardiac grafting was performed in three rat strain combinations (BN to WF, DA to Lew, and BN to Lew). Rats were given no treatment, or thalidomide, CyA and/or Linomide in single, double or triple drug therapy. Except for a consistent beneficial effect of CyA as single drug treatment, graft survival varied depending on the rat strain combination used. In the DA to Lew combination, the expected effects of Linomide were seen, and thalidomide was shown to prolong graft survival significantly (P = 0.004) when added to CyA and Linomide. However, there was no effect of thalidomide when given alone. In WF recipients of BN hearts, thalidomide tended to prolong graft survival (P = 0.07), and surprisingly Linomide manifested a marked immunosuppressive effect (P = 0.0002) and did not counteract the effect of CyA. When transplanting BN grafts to Lew recipients, Linomide reduced significantly but did not abolish completely the effect of CyA. Neither Linomide nor thalidomide had any beneficial impact on graft survival on their own. To sum up, thalidomide was shown to have a minimal or moderate immunosuppressive effect additive to that of CyA. The effects of the two immunomodulating drugs, thalidomide and Linomide, varied depending on the rat strain combination used, and were similar with respect to prolongation of graft survival when used as single drug treatment in BN to WF grafting, a fact which may indicate them to have a similar mechanism of action, both having been shown to exert similar effects on levels of tumour necrosis factor alpha.

[Relationship between particle fluence and dose in cabin of recoverable satellite]

Radiation doses in the cabin of the recoverable satellite measured by GJ-III personal dosimeters and LiF thermoluminescent dosimeters were presented. The relationship between the particle fluence calculated from instrument display and the measured doses was studied. It shows that the particle fluence can be directly calculated from the measured dose with a transformation coefficient which is not obviously affected by shielding around the measuring site. The estimated average energy of the particles in the cabin is on the level of Galactic cosmic radiation.

Determination of the steady state tissue distribution of midazolam in the rat

The aim of this study was to determine the steady state tissue:blood (Kb), tissue:plasma (Kp), and tissue:plasma water (Ku) partition coefficients of midazolam in all major organs and tissues in the rat, after development of a gas chromatographic assay. The Kp in 12 tissues ranged between 1.3 (in muscle) and 9.0 (in fat). Ku ranged correspondingly between 16 and 115.

Neuronal Cdc2-like kinase: from cell cycle to neuronal function

Neuronal Cdc2-like kinase, Nclk, is a heterodimer of cyclin-dependent protein kinase 5 (Cdk5) and a 25-kDa essential regulatory subunit that is derived from a 35-kDa brain- and neuron-specific protein. This protein is called neuronal Cdk5 activator, p25/35nck5a. Nclk is one of the best characterized Cdc2 family kinases whose primary function is not cell cycle related. It has been suggested that this protein kinase plays important roles in neurocytoskeleton dynamics and its loss of regulation has been implicated in Alzheimer pathology. As a member of the Cdc2-like kinase family, Nclk shares many common properties with other members of the Cdc2-like kinase family. It also possesses unique characteristics that may be related to its distinct and noncell cycle related functions. The regulatory and functional properties of Nclk are reviewed in this communication.

Thalidomide prolonged graft survival in a rat cardiac transplant model but had no inhibitory effect on lymphocyte function in vitro

The effects of thalidomide on in vitro interleukin 2 (IL-2) production and thymidine uptake by human peripheral blood lymphocytes or rat splenocytes were investigated. Phytohaemagglutinin-stimulated human lymphocytes were incubated in the presence of thalidomide added at culture initiation. No immunosuppressive effect of thalidomide was observed in these experiments. Primary human mixed lymphocyte cultures treated with thalidomide for 6 days were also unaffected. A microsomal rabbit liver homogenate was prepared for metabolizing thalidomide. Stimulated lymphocytes secreted significantly more IL-2 in the presence of microsomal-treated thalidomide than did controls. The effect of thalidomide was then studied either as single therapy or in combination with cyclosporin A (CyA) in a rat allograft cardiac transplantation model. In addition, T cell subsets were analysed by flow cytometry in untransplanted rats treated with thalidomide. Treatment was given as induction therapy from the day of transplantation until day 9. Graft survival in rats treated with thalidomide was significantly prolonged compared to the untreated group. No difference in graft survival was detected between rats treated with thalidomide or CyA only. Graft survival was found to be slightly prolonged in rats given thalidomide and CyA in combination compared to rats treated with CyA alone. In untransplanted rats given thalidomide a decrease of CD4 positive T cells was detected on days 3 and 5. The T helper/cytotoxic-suppressor cell ratio was significantly diminished but, after 1 week of treatment, values for T cell subsets had almost returned to baseline levels. No inhibitory effect was obtained when phytohaemagglutinin-stimulated rat splenocytes were cultured with metabolized thalidomide. In summary, the ability of thalidomide to improve allograft survival in a solid organ transplant model was verified. The occurrence of thalidomide-induced changes in T cell subset ratios was demonstrated. In in vitro studies, however, there was no decrease but an increase in IL-2 production, and no change in thymidine uptake. The mechanism responsible for the immunosuppressive effect of thalidomide remains to be elucidated.

Pharmacotherapeutic effects of toki-shakuyaku-san on leukorrhagia in young women

Toki-shakuyaku-san is a traditional Chinese herbal prescriptions that is composed of 6 herbal plants, i.e., peony root, atractylodes lancea rhizome, alisma rhizome, hoelen, cnidium rhizome and Japanese angelica root. Administration with Toki-shakuyaku-san normalized irregular menstrual cycle, healed cervical pseudo-erosion and reduced leukorrhagia in young women who had insufficient luteal function.

Protein phosphatase 2A is the major enzyme in brain that dephosphorylates tau protein phosphorylated by proline-directed protein kinases or cyclic AMP-dependent protein kinase

The paired helical filament (PHF), which makes up the major fibrous component of the neurofibrillary lesions of Alzheimer's disease, is composed of hyperphosphorylated and abnormally phosphorylated microtubule-associated protein tau. Previous studies have identified serine and threonine residues phosphorylated in PHF-tau and have shown that tau can be phosphorylated at several of these sites by proline-directed protein kinases and cyclic AMP-dependent protein kinase. Here we have investigated which protein phosphatase activities can dephosphorylate recombinant tau phosphorylated with mitogen-activated protein kinase, glycogen synthase kinase-3 beta, neuronal cdc2-like kinase, or cyclic AMP-dependent protein kinase. We show that protein phosphatase 2A is by far the major protein phosphatase activity in brain that dephosphorylates tau phosphorylated in this manner.

On the use of microbend fiber optic mode strippers and scramblers: cautionary note

Microbend mode strippers/scramblers are commonly assumed to remove higher order modes uniformly. In fact, they only remove higher order modes propagating in the plane of the microbends, resulting in an elliptical output pattern from a circular fiber.

[Photodynamic effect of HPD on DNA functions]

After treatment of the DNA by HPD and light the number of transformants of the M13mp8 DNA obviously decreased during the period of transforming the treated DNA into E coli. Meanwhile some of the mutation sequences appeared in the DNA which recovered from the DNA/HPD/Light transformant. It showed that the wrong replication happened because of the mutated template. Also the in vitro run-off transcription of IL-2R alpha gene was affected by HPD and light. It means that the DNA functions are influenced by the photodynamic effects.

Synthesis and application of hepatitis E virus peptides to diagnosis

Based on computer analysis of hydrophobicity and prediction of secondary structures for the full-length putative proteins encoded by open reading frame-1 (ORF-1), ORF-2 and ORF-3 of hepatitis E virus (HEV), we selected antigenic regions with hydrophilicity, beta-turn, and beta-sheet, and synthesized 7 peptides of possible epitope-containing regions of the polypeptide encoded by all 3 ORFs of HEV genomic RNA by Merrifield's method of solid-phase synthesis. The synthetic peptides were screened and identified by solid-phase enzyme-linked immunosorbent assay (ELISA). Three of the peptides (EH174 from ORF-1, EH286 from ORF-2 and EH362 from ORF-3) showed antigenic activity and possible application for the development of anti-HEV test kits (the peptide-based ELISA). The laboratory experiments and clinical trials showed that the kits, using a set of 3 synthetic HEV peptides as coating antigens, were of high specificity and exhibited good reproducibility. The small-scale seroepidemiological survey indicated high seroprevalence (14.3%) of anti-HEV in Tibetan populations. Additionally, the results also demonstrated good agreement with clinical findings, suggesting that the test kits will be of major use for immunodiagnosis and seroepidemiological surveys of HEV infection.

Regulatory properties of neuronal cdc2-like kinase

Neuronal cdc2-like kinase, nclk, is a heterodimer of cyclin dependent protein kinase 5, cdk5, and a 25 kDa subunit derived from a novel, neuron-specific, 35 kDa protein: p35. The characterization and regulation of nclk will be summarized in this minireview. The activity of nclk appears to be governed by highly complex regulatory mechanisms including protein-protein interaction, protein phosphorylation and isoforms. The histone H1 kinase activity of nclk is absolutely dependent of the interaction between the 25 kDa subunit and the catalytic subunit, cdk5. In addition, nclk interacts with other cellular proteins to form macromolecular complexes. The kinase activity of nclk is inhibited in vitro by the phosphorylation reactions of a weel-like protein tyrosine kinase and a protein serine/threonine kinase from bovine thymus. Northern blot analysis has revealed the existence of two populations of p35 mRNA of 2 and 4 kb. A novel cDNA encoding a p35 homologous protein has been obtained from a human hippocampus library.

Reconstitution of neuronal Cdc2-like kinase from bacteria-expressed Cdk5 and an active fragment of the brain-specific activator. Kinase activation in the absence of Cdk5 phosphorylation

Neuronal Cdc2-like kinase is a heterodimer of Cdk5 and a 25-kDa subunit which is derived from a brain-specific 35-kDa novel protein, p35 (Lew, J., Huang, Q.-Q., Qi, Z., Winkfein, R. J., Aebersold, R., Hunt, T., and Wang, J. H. (1994) Nature 371, 423-426). Three truncated forms of p35 including the one corresponding to the 25-kDa subunit of the kinase have been expressed in Escherichia coli and shown to activate a bacteria-expressed Cdk5 with equal efficacy. The shortest truncated form of p35, p21, spanning amino acid residues 88 to 291, has been used to reconstitute active Cdk5 kinase and to characterize the activation reaction. The purified kinase displays similar specific enzyme activity and similar phosphorylation site specificity as the neuronal Cdc2-like kinase purified from bovine brain. Bovine brain extract contains Cdk5 uncomplexed with p35 or p25 which has also been found to be activated by p21 or p25. The results substantiate the previous suggestion that p35 is a specific Cdk5 activator. Several observations suggest that, unlike other well characterized Cdc2-like kinases whose activities depend on the phosphorylation of the catalytic subunits at a specific site by a distinct kinase, the reconstituted Cdk5/p21 does not depend on the phosphorylation of Cdk5 for activity. The reconstitution of the highly active Cdk5 kinase was achieved without requiring any other kinase in the reconstitution reaction. The possibility of autophosphorylation of Cdk5 on the putative activation site has been ruled out as no phosphorylation occurred on Cdk5 during the enzyme reaction. The rate and extent of the kinase reconstitution were not significantly affected by Mg2+ ATP.

Structure, function, and regulation of neuronal Cdc2-like protein kinase

We have identified and purified from bovine brain a novel protein kinase which catalyzes in vitro phosphorylation of neurofilament proteins NF-H and NF-M and tau proteins at sites implicating the enzyme in the regulation of neurocytoskeleton dynamics and in Alzheimer pathology. The protein kinase displays a phosphorylation site specificity similar or identical to the cell cycle regulatory kinase, cdc2 kinase. The purified kinase is a heterodimer of a cdc2-like catalytic subunit, called cdk5, and a 25 kDa regulatory subunit. The regulatory subunit is essential for kinase activity, and it is derived from a 35 kDa protein, p35 by proteolysis. Northern blot analysis of tissue distribution indicates that cdk5 is widely distributed but especially rich in brain, whereas p35 expression is only found in brain. The protein kinase is therefore termed neuronal cdc2-like kinase. The neuron-specificity of the enzyme appears to be conferred by the regulatory subunit. During cell division, cdc2 kinase is regulated by complex phosphorylation mechanisms involving a network of specific protein kinases. Some of these kinases or their homologs have been found in mammalian brains and they may be involved in the regulation of neuronal cdc2-like kinase.

[The DNA damage by photodynamic effects of hematoporphyrin derivatives (HPD)]

Photodynamic effects of HPD has been used for cancer therapy (PDT) successfuly. The biological mechanism of the PDT was studied by using DNA as a target in this work. After treatment of phage M13 DNA with HPD + light the molecule of the DNA kept intact in TE buffer. But the smear bands by puting DNA in 0.1 mol/L NaOH at 90 degrees C and separating with electrophoresis denoted the degradation of DNA at the alkali-labile sites of phosphodiester bond in which the groups of the bases were photooxydized. The primer extension experiment showed the aggregation of DNA template by photooxydation. The DNA sequencing results showed that some of the wrong sequences appeared both at the site of A,G,C,T bases. The mouse Ehrlich ascetes carcinoma cell DNA was treated as above then degraded by Bgl II and BamH I respectively. It was found that the restriction fragments became larger than the controls. It also meant the alteration of the bases of DNA by the photooxydation. So the four bases of A,G,C,T of DNA were altered by photodynamic effects of HPD.

Femtosecond vacuum-ultraviolet pulse measurement by field-ionization dynamics

Three techniques are demonstrated for measuring femtosecond pulses from the deep vacuum ultraviolet to the visible based on the ionization dynamics of optical-field-ionized plasmas. A probe pulse propagates through a plasma generated by an intense femtosecond KrF excimer laser pump pulse. Ionization-induced defocussing or collisional absorption yield a cross-correlation measurement of the probe pulse. Ionization-induced spectral blue shifting of the probe can give an upper limit for the probe pulse duration.

A brain-specific activator of cyclin-dependent kinase 5

Phosphorylation of the neurofilament proteins of high and medium relative molecular mass, as well as of the Alzheimer's tau protein, is thought to be catalysed by a protein kinase with Cdc2-like substrate specificity. We have purified a novel Cdc2-like kinase from bovine brain capable of phosphorylating both the neurofilament proteins and tau. The purified enzyme is a heterodimer of cyclin-dependent kinase 5 (Cdk5) and a novel regulatory subunit, p25 (ref. 8). When overexpressed and purified from Escherichia coli, p25 can activate Cdk5 in vitro. Unlike Cdk5, which is ubiquitously expressed in human tissue, the p25 transcript is expressed only in brain. A full-length complementary DNA clone showed that p25 is a truncated form of a larger protein precursor, p35, which seems to be the predominant form of the protein in crude brain extract. Cdk5/p35 is the first example of a Cdc2-like kinase with neuronal function.

Clone Q379 immunoscreened from a Chinese HCV cDNA lambda gt11 library

A Chinese HCV cDNA clone, designated as Q379, 379 nucleotides in length, was selected by recombinant immunoscreening from a random-primed Chinese HCV lambda gt11 library. DNA sequencing demonstrated that Q379 situated from positions 7314 to 7695 at NS5 region corresponded with the American prototype HCV nucleotide sequence. The homologies of Q379 with the equivalent sequences of the prototype were found to be 72.8% in nucleotides and 73.8% in amino acids, respectively. Hydrophobicity profile shows that Q379-encoded polypeptide (126 amino acid residues) contains two hydrophilic areas. This Chinese HCV clone would be valuable in basic and clinical studies of Chinese HCV infection.