Human iPSC-MSC-Derived Xenografts Modulate Immune Responses by Inhibiting the Cleavage of Caspases

Mesenchymal stem cells (MSCs) negatively modulate immune properties. Induced pluripotent stem cells (iPSCs)-derived MSCs are alternative source of MSCs. However, the effects of iPSC-MSCs on T cells phenotypes in vivo remain unclear. We established an iPSC-MSC-transplanted host versus graft reaction mouse model using subcapsular kidney injection. Th1, Th2, regulatory T cells (Treg), and Th17 phenotypes and their cytokines were investigated in vivo and in vitro. The role of caspases and the soluble factors involved in the effects of MSCs were examined. We found that iPSC-MSC grafts led to more cell survival and less infiltration of inflammatory cells in mice. iPSC-MSC transplantation inhibited T cell proliferation, decreased Th1 and Th2 phenotypes and cytokines, upregulated Th17 and Treg subsets. Moreover, iPSC-MSCs inhibited the cleavage of caspases 3 and 8 and inhibition of caspases downregulated Th1, Th2 responses and upregulated Th17, Treg responses. Soluble factors were determined using protein array and TGF-β1/2/3, IL-10, and MCP-1 were found to be highly expressed in iPSC-MSCs. The administration of the soluble factors decreased Th1/2 response, upregulated Treg response and inhibited the cleavage of caspases. Our results demonstrate that iPSC-MSCs regulate T cell responses as a result of a combined action of the above soluble factors secreted by iPSC-MSCs. These factors suppress T cell responses by inhibiting the cleavage of caspases. These data provide a novel immunomodulatory mechanism for the underlying iPSC-MSC-based immunomodulatory effects on T cell responses. Stem Cells 2017;35:1719-1732.

Effects of Inulin Supplementation in Low- or High-Fat Diets on Reproductive Performance of Sows and Antioxidant Defence Capacity in Sows and Offspring

This experiment was conducted to investigate the effects of inulin supplementation in low- or high-fat diets on both the reproductive performance of sow and the antioxidant defence capacity in sows and offspring. Sixty Landrace × Yorkshire sows were randomly allocated to four treatments with low-fat diet (L), low-fat diet containing 1.5% inulin (LI), high-fat diet (H) and high-fat diet containing 1.5% inulin (HI). Inulin-rich diets lowered the within-litter birth weight coefficient of variation (CV, p = 0.05) of piglets, increased the proportion of piglets weighing 1.0-1.5 kg at farrowing (p < 0.01), reduced the loss of body weight (BW) and backfat thickness (BF) during lactation (p < 0.05) and decreased the duration of farrowing as well as improved sow constipation (p < 0.05). Sows fed fat-rich diets gained more BW during gestation (p < 0.01), farrowed a greater number of total (+1.65 pigs, p < 0.05) and alive (+1.52 pigs p < 0.05) piglets and had a heavier (+2.06 kg, p < 0.05) litter weight at birth as well as a decreased weaning-to-oestrous interval (WEI, p < 0.01) compared with sows fed low-fat diets. However, it is worth noting that the H diet significantly decreased the serum activities of superoxide dismutase (T-SOD) and glutathione peroxidase (GSH-Px) and increased the serum malondialdehyde (MDA) levels in sows and piglets (p < 0.05). In contrast, HI diet enhanced the activities of T-SOD and GSH-Px and decreased the serum MDA concentrations (p < 0.05) in sows and piglets. In summary, the fat-rich diets fed to sows during gestation had beneficial effects on reproductive performance, but aggravated the oxidative stress in sow and piglets. Inulin-rich diets fed to sow during gestation had beneficial effects on within-litter uniformity of piglet birthweight and enhanced the antioxidant defence capacity of sows and piglets.

3D Modelling on Biodegradable Nanoparticle-Enhanced Cryoablation of Liver Tumor Based on Real Anatomical Model

BACKGROUND

Nanoparticle-enhanced freezing is of great importance for developing a conformal targeted cryoablation for liver tumor with complex shape. However, the safety and biocompatibility of nanoparticles should also be of major concerns.

OBJECTIVE

This study is to investigate the enhanced cryoablation mediated by the MgO nanoparticles which are nontoxic, biodegradable, and have few side-effects on the human body.

MATERIALS AND METHODS

A three-dimensional numerical model has been developed based on a real geometrical anatomical structure to characterize such nanocryosurgical freezing of liver tumor. The evolutions of temperature field and ablation volume were investigated subject to different concentrations and scopes of the loaded nanoparticles, respectively. Additionally, the results of different probe numbers were also taken into consideration.

RESULTS

It was found that the lesion growth was evidently affected by the configurations of both the nanoparticles and cryoprobes. Both ablation and frozen regions were enlarged with the increase of the loading ratio and scope of MgO nanoparticles. It was worth mentioning that thermal-physiological behavior of the adjacent large blood vessels also played an important role in affecting the target temperature field distribution.

CONCLUSION

The present study established a feasible way for verisimilarly simulating the physiological manifestation of human liver in the process of nano-freezing modality, which would provide a valuable guidance for future clinical practice of conformal nano-cryoablation on liver tumor.

Effects of Dietary Supplementation of β-hydroxy-β-methylbutyrate on Sow Performance and mRNA Expression of Myogenic Markers in Skeletal Muscle of Neonatal Piglets

The effects of dietary β-hydroxy-β-methylbutyrate (HMB) supplementation during gestation on reproductive performance of sows and the mRNA expression of myogenic markers in skeletal muscle of neonatal pigs were determined. At day 35 of gestation, a total of 20 sows (Landrace × Yorkshire, at third parity) were randomly assigned to two groups, with each group receiving either a basal diet or the same diet supplemented with 4 g/day β-hydroxy-β-methylbutyrate calcium (HMB-Ca) until parturition. At parturition, the total and live litter size were not markedly different between treatments, however, the sows fed HMB diet had a decreased rate of stillborn piglets compared with the sows fed the control (CON) diets (p < 0.05). In addition, piglets from the sows fed HMB diet tended to have an increased birth weight (p = 0.08), and a reduced rate of low birth weight piglets (p = 0.05) compared with piglets from the CON sows. Nevertheless, lower feed intake during lactation was observed in the sows fed the HMB diet compared with those on the CON diet (p < 0.01). The relative weights of the longissimus dorsi (LD) and semitendinosus (ST) muscle were higher (p < 0.05) in neonatal pigs from the HMB than the CON sows. Furthermore, maternal HMB treatment increased the mRNA levels of the myogenic genes, including muscle regulatory factor-4 (MRF4, p < 0.05), myogenic differentiation factor (MyoD) and insulin-like growth factor-1 (IGF-1, p < 0.01). In conclusion, dietary HMB supplementation to sows at 4 g/day from day 35 of gestation to term significantly improves pregnancy outcomes and increases the expression of myogenic genes in skeletal muscle of neonatal piglets, but reduces feed intake of sows during lactation.

Relationship between eNOS gene polymorphism and cerebral infarction of young and middle-aged Chinese Han population

PURPOSE

To discuss the relationship between the acute cerebral infarction of differently aged population and the variable number tandem repeat polymorphism of endothelial nitric oxide synthase (eNOS) gene.

METHODS

The genotypes of 129 acute cerebral infarction patients and 100 healthy control subjects were determined by PCR and polyacrylamide gel electrophoresis (PAGE).

RESULTS

In the patient group, the frequency of allelic gene a was higher than that in the control group (13.56 % vs 3 %, p < 0.01), and the frequencies of the patients followed the descending order from young through middle-aged to elderly (42.31 % vs 17.2 % vs 5.8 %). The frequencies of the young, middle-aged and elderly population in the control group differed significantly (5.55 % vs 2.94 % vs 2.63 %), and those of the young and middle-aged population in the two groups also differed statistically significantly.

CONCLUSION

The ab genotype of eNOS 4th intron is correlated with the acute cerebral infarction of young and middle-aged Chinese Han population that may involve allelic gene a as an independent risk factor (Tab. 3, Fig. 3, Ref. 13).

Identification of CYP2C19 inhibitors from phytochemicals using the recombinant human enzyme model

The aim of the present study was to develop the recombinant insect cell-expressed protein as an in vitro model for inhibitors screening for human cytochrome P450 2C19 (CYP2C19), and to use the model to investigate the inhibition effect of three phytochemicals on CYP2C19 in vitro. Omeprazole was applied as the probe substrate. The estimated inhibitory constant (K(i)) of ticlopidine and fluvoxamine were 0.64 +/- 0.025 microM and 0.29 +/- 0.090 microM, respectively. After co-incubation with ticlopidine or fluvoxamine, the mean omeprazole Michaelis-Menten constant (K(m)) increased from 4.99 +/- 0.22 microM to 16.25 +/- 1.22 microM or 19.20 +/- 1.73 microM, respectively, while omeprazole's mean V(max) did not vary much. Both ticlopidine and fluvoxamine were competitive inhibitors of CYP2C19. The IC50 of three phytochemicals, isoalantolactone, curcumol and schisandrin A was determined as 38.91 microM, 121.0 microM and 86.41 microM, and the K(i) as 5.02 +/- 1.04 microM, 35.84 +/- 8.95 microM, and 4.46 +/- 0.017 microM, respectively. The in vitro model for inhibitor screening established using recombinant CYP2C19 could be used to assess the inhibition potential of drug candidates. Isoalantolactone and schisandrin A are potent inhibitors of CYP2C19, while curcumol is a moderate potent inhibitor of CYP2C19.

Construction and application of double-transfected cells expressing the human transporter P-glycoprotein and cytochrome P450 3A4

Intestinal P-glycoprotein (P-gp) and cytochrome P450 (CYP) enzymes are known to influence oral bioavailabilities of drugs. Recombinant plasmids pcDNA3.1/Hypgro/CYP3A4 were transfected into MDCK and MDCK-MDR1 cells to construct the single-transfected cell line MDCK-CYP3A4 and double-transfected cell line MDCK-MDR1/CYP3A4. The expression of CYP3A4 in the double-transfected cell line was determined by Western blot and its activity was detected by the metabolism assays of three substrates of CYP3A4, which were 7-benzyloxy-4-trifluoro-methylcoumarin (BFC), testosterone and midazolam. In addition, the selection of monoclones with high CYP3A4 activities in the single-tranfected cell line was performed by the P450 Glo CYP3A4 assay. Through MTT assay, the interaction between P-gp and CYP3A4 was preliminarily determined based on the changes of IC50 values. The results showed that paclitaxel detoxified in the single-transfected MDCK-MDR1 cell because of P-gp efflux. And it was also less toxic in the single-transfected CYP3A4 cell line due to the metabolism by CYP3A4. In the double-transfected MDCK-MDR1/CYP3A4 cell line, the toxicity decreased dramatically because of the interplay between P-gp and CYP3A4. Therefore, the cell model could be applied to study the toxicity and detoxification of chemicals due to the metabolism by CYP3A4 and the efflux through P-gp.

Comparison of catalytical activity and stereoselectivity between the recombinant human cytochrome P450 2D6.1 and 2D6.10

Polymorphisms of the cytochrome P450 2D6 (CYP2D6) gene play a major role in pharmacokinetic variability in human, while CYP2D6*10 is an important subtype in Asian people. In this study, the co-expression enzyme of human recombinant CYPOR, CYPb5 and CYP2D6.1 or CYP2D6.10 with the Bac-to-Bac system in baculovirus-infected insect cells was used to study the catalytical activity to imipramine metabolism and stereoselective metabolism of propranolol. The metabolites of imipramine were identified of hydroxyl imipramine and desipramine by LC-MS/MS. There are some differences between CYP2D6.1 and CYP2D6.10 activity. The kinetics parameters K(m), V(max), and CL(int) are 11.77 +/- 0.91 micromol/L, 0.4235 +/- 0.05 nmol/nmol CYP2D6.1/min and 3.60 x 10(-5) ml/min/nmol CYP2D6.1 (n = 3) for CYP2D6.1, respectively, and 9.05 +/- 0.87 micromol/L, 0.42 +/- 0.03 nmol/nmol CYP2D6.10/min, and 4.60 x 10(-5) ml/min/nmol CYP2D6.10 (n = 3) for CYP2D6.10. For propranolol, two metabolites were identified to be hydroxyl and N-desisopropylation propranolol by LC-MS/MS. When the substrate concentration was 0.20 micromol/L, CYP2D6.1 and CYP2D6.10 exhibited significant stereoseletivity. Furthermore, enantioselective formation has been detected. Both of CYP2D6.1 and CYP2D6.10 produced more hydroxyl propranolol from the R-(+)-isomer than from the S-(-)-isomer while there was no obvious difference for N-desisopropylation propranolol production between R-(+)- and S-(-)- isomer. In summary, there is a somewhat different catalytical activity and stereoselectivity between the human recombinant CYP2D6.1 and CYP2D6.10. The data we got will be helpful in preclinical research and clinical use of CYP2D6 substrates.

Generation of transgenic chicks using an oviduct-specific expression system

We successfully replaced the ovalbumin gene of a magnum region in chickens with a human plasminogen activator. We constructed pL-eGFP, pL-tPAGFP and pL-2.8OVtPAGFP vectors and cultured 293FT chicken embryo fibroblasts, chicken primordial germ cells, Hela C127 cells, and oviduct epithelial cells. All vectors were expressed in the transfected cells, except pL-2.8OVtPAGFP vector, which was only expressed in oviduct epithelial cells. A lentivirus with pL-2.8OVtPAGFP was injected in fertilized eggs; 11 chicks hatched in the G₀ generation, four of them carried the tPAGFP. Two cockerels from the G₀ generation were crossed with four wild-type hens. Three chicks in G₁ carried the tPAGFP. We concluded that by using an oviduct-specific vector for transfection, human recombinant plasminogen activator protein can be expressed in the oviducts of laying hens. This character is inherited and can be reproduced with a need for repeated transfection.

Development and operation of research-scale III-V nanowire growth reactors

III-V nanowires are useful platforms for studying the electronic and mechanical properties of materials at the nanometer scale. However, the costs associated with commercial nanowire growth reactors are prohibitive for most research groups. We developed hot-wall and cold-wall metal organic vapor phase epitaxy reactors for the growth of InAs nanowires, which both use the same gas handling system. The hot-wall reactor is based on an inexpensive quartz tube furnace and yields InAs nanowires for a narrow range of operating conditions. Improvement of crystal quality and an increase in growth run to growth run reproducibility are obtained using a homebuilt UHV cold-wall reactor with a base pressure of 2x10(-9) Torr. A load lock on the UHV reactor prevents the growth chamber from being exposed to atmospheric conditions during sample transfers. Nanowires grown in the cold-wall system have a low defect density, as determined using transmission electron microscopy, and exhibit field effect gating with mobilities approaching 16,000 cm(2)/(V s).

Recombinant human growth hormone improves survival and protects against acute lung injury in murine Staphylococcus aureus sepsis

OBJECTIVE

To investigate whether recombinant human growth hormone (rhGH) reduces mortality and protects against Staphylococcus aureus sepsis-induced acute lung injury.

METHODS

The bacteria-positive rate of blood smears and bacteria colony counts in bacteria plate culture, TNFalpha and IL-10 plasma levels, lung injury score, expression of intercellular adhesion molecule-1 (ICAM-1) as well as activation of nuclear factor-kappa B (NF-kappaB) in the lungs were determined 6, 12 and 24 h after 140 KM mice were injected with physiologic saline (i.p. group C, n = 20); S. aureus E311122 (1.75 x 10(12) cfu/L, 40 ml/kg, i.p. group S, n = 60); or S. aureus (as group S) with a subsequent treatment of rhGH (1.0 U kg(-1) day(-1)), i.m. group T, n = 60). The cumulative survival rate of an additional 15 mice from each group was followed for 7 days post S. aureus injection.

RESULTS

rhGH treatment significantly increased IL-10 plasma levels and the 7-day cumulative survival rate, whereas the bacteria-positive rate of blood smears, bacteria colony counts in bacteria plate cultures, lung injury score, ICAM-1 and NF-kappaB expression in the lungs were significantly reduced. In addition, rhGH treatment significantly suppressed the S. aureus sepsis-induced elevation of TNFalpha plasma levels.

CONCLUSIONS

These results indicate an ability of rhGH to prevent S. aureus sepsis-induced acute lung injury in mice, which may be attributed to attenuation of increased plasma TNFalpha levels, and elevated IL-10 plasma levels as well as reduced ICAM-1 expression and inhibited NF-kappaB activity in the lungs.

Effect of processing parameters on the formation of spherical multinuclear microcapsules encapsulating peppermint oil by coacervation

The gelatin/gum arabic multinuclear microcapsules encapsulating peppermint oil were prepared by coacervation. The effect of various processing parameters, including the core/wall ratio, wall material concentration, pH value, as well as stirring speed on the morphology, particle size distribution, yield and loading was investigated. When the wall material concentration or the core/wall ratio increased, the morphology of multinuclear microcapsules changed from spherical to irregular and the average particle size increased, the optimal wall material concentration and the core/wall ratio were 1% and 2:1, respectively. The multinuclear spherical microcapsules with desired mean particle size can be manufactured by modulating the pH value and stirring speed. The ideal preparation conditions were pH 3.7 at 400 rpm of stirring speed. The yield of multinuclear microcapsules encapsulating peppermint oil by coacervation was approximately 90% and the processing parameters had very slight influence on the yield. When transglutaminase was used as the cross-linker instead of formaldehyde, morphology, mean particle size, yield and loading remained the same as that hardening with formaldehyde, but the particle size distribution became narrower.

Thermal nociception in adult Drosophila: behavioral characterization and the role of the painless gene

Nociception, warning of injury that should be avoided, serves an important protective function in animals. In this study, we show that adult Drosophila avoids noxious heat by a jump response. To quantitatively analyze this nociceptive behavior, we developed two assays. In the CO2 laser beam assay, flies exhibit this behavior when a laser beam heats their abdomens. The consistency of the jump latency in this assay meets an important criterion for a good nociceptive assay. In the hot plate assay, flies jump quickly to escape from a hot copper plate (>45 degrees C). Our results demonstrate that, as in mammals, the latency of the jump response is inversely related to stimulus intensity, and innoxious thermosensation does not elicit this nociceptive behavior. To explore the genetic mechanisms of nociception, we examined several mutants in both assays. Abnormal nociceptive behavior of a mutant, painless, indicates that painless, a gene essential for nociception in Drosophila larvae, is also required for thermal nociception in adult flies. painless is expressed in certain neurons of the peripheral nervous system and thoracic ganglia, as well as in the definite brain structures, the mushroom bodies. However, chemical or genetic insults to the mushroom bodies do not influence the nociceptive behavior, suggesting that different painless-expressing neurons play diverse roles in thermal nociception. Additionally, no-bridge(KS49), a mutant that has a structural defect in the protocerebral bridge, shows defective response to noxious heat. Thus, our results validate adult Drosophila as a useful model to study the genetic mechanisms of thermal nociception.

Enhanced dissipation of phenanthrene and pyrene in spiked soils by combined plants cultivation

Polycyclic aromatic hydrocarbons (PAHs), a class of POPs, are widely distributed in the environment. Phytoremediation has long been recognized as a cost-effective method for removal of PAHs pollutants from soil. This study was conducted to investigate the capability of three plant species separately and their combination to promote the degradation of phenanthrene and pyrene in soil. The performance of three plant species, maize, ryegrass and white clover for phenanthrene and pyrene removal was also compared. The result showed that the presence of vegetation significantly enhances the dissipation of phenanthrene and pyrene in the soil environment. This effect was especially marked with maize. At the end of 60 days treatment, phenanthrene and pyrene concentrations in treated soils declined from an initial 52.52 mg kg-1 and 58.19 mg kg-1 to 4.15 mg kg-1 and 6.77 mg kg-1, respectively, indicating that phenanthrene and pyrene was successfully removed by maize. Around 92.10% of phenanthrene and 88.36% of pyrene were removed from soils planted with maize. Within approximately two months experimental period, the dissipation extent showed that the 4-ring pyrene was more recalcitrant than 3-ring phenanthrene. Although the extents did not differ significantly among three tested species, the rates of degradation were different. The maize treatment had the highest rate of contaminant removal after two months, followed by white clover and annual ryegrass. As compare to single plant cultivation, combined plants cultivation significantly enhanced the destruction rate and extent of phenanthrene and pyrene in soils. Around 98.22% of phenanthrene and 95.81% of pyrene were removed from soils planted with maize and ryegrass. This research indicates the potential for phenanthrene and pyrene mineralization in combined plants cultivation, which may be especially useful for phytoremediation of soils contaminated with PAHs.

Enhancement of the superconducting transition temperature of MgB2 by a strain-induced bond-stretching mode softening

We report a systematic increase of the superconducting transition temperature T(c) with a biaxial tensile strain in MgB2 films to well beyond the bulk value. The tensile strain increases with the MgB2 film thickness, caused primarily by the coalescence of initially nucleated discrete islands (the Volmer-Weber growth mode.) The T(c) increase was observed in epitaxial films on SiC and sapphire substrates, although the T(c) values were different for the two substrates due to different lattice parameters and thermal expansion coefficients. We identified, by first-principles calculations, the underlying mechanism for the T(c) increase to be the softening of the bond-stretching E(2g) phonon mode, and we confirmed this conclusion by Raman scattering measurements. The result suggests that the E(2g) phonon softening is a possible avenue to achieve even higher T(c) in MgB2-related material systems.

Oral administration of type II collagen suppresses pro-inflammatory mediator production by synoviocytes in rats with adjuvant arthritis

The objective of this study was to investigate the effect of the oral administration of type II collagen (CII) on pro-inflammatory mediator production by synoviocytes in rats with adjuvant arthritis (AA). Sprague-Dawley rats were fed with bovine CII either before immunization with Complete Freund's adjuvant (CFA) or after initiation of arthritis. Hind paw secondary swelling was measured and synoviocytes were harvested. Sera from portal vein of oral tolerized rats were collected and in vitro synoviocytes culture or synoviocytes-Peyer's Patches (PP) cells coculture system were developed. Interleukin (IL)-1 activity was measured by a mouse thymocyte activation assayed by MTT dye reduction and tumour necrosis factor (TNF) activity was measured by an L929 cytotoxicity bioassay. Nitric oxide (NO) and malondialdehyde (MDA) levels were measured by biochemical methods. We found that feeding with CII (5, 50 and 500 micro g/kg) for 7 days before immunization significantly suppressed hind paw secondary swelling measured at day 16, 20, 24 and 28 (all P < 0.01) and pro-inflammatory mediator (IL-1, TNF, NO and MDA) production by synoviocytes (all P < 0.01) in rats with AA. Feeding with CII (5, 50 and 500 micro g/kg) for 7 days after initiation of arthritis had a similar effect. CII (1, 10, 100 micro g/ml) had no effect on IL-1 and TNF production by synoviocytes in vitro, but CII 10 micro g/ml suppressed IL-1 and TNF production by synoviocytes-PP cells coculture system (P < 0.01), which was antagonized by anti-TGF-beta antibody (10 micro g/ml) (P < 0.01). Portal serum (1 : 10) from oral tolerized rats suppressed IL-1 and TNF production by synoviocytes (P < 0.01), which was also antagonized by anti-TGF-beta antibody (10 micro g/ml) (P < 0.01). We conclude that oral administration of CII had prophylactic and therapeutic effects on AA and over-production of IL-1, TNF, NO and MDA by synoviocytes was suppressed. Bystander active suppression may be the main mechanism of oral CII in the suppression of synoviocyte function.

Functional analysis of iceA1, a CATG-recognizing restriction endonuclease gene in Helicobacter pylori

iceA1 in Helicobacter pylori is a homolog of nlaIIIR, which encodes the CATG-specific restriction endonuclease NlaIII in Neisseria lactamica. Analysis of iceA1 sequences from 49 H.pylori strains shows that a full-length NlaIII-like ORF is present in 10 strains, including CH4, but in other strains, including strain 60190, the ORFs are truncated due to a variety of mutations. Our goal was to determine whether iceA1 can encode a NlaIII-like endonuclease. Overexpression in Escherichia coli of iceA1 from CH4, but not from 60190, yielded NlaIII-like activity, indicating that the full-length iceA1 is a functional endonuclease gene. Repair of the iceA1 frameshift mutation in strain 60190 and its expression in E.coli yielded functional NlaIII-like activity. We conclude that iceA1 in CH4 is a functional restriction endonuclease gene, while iceA1 in 60190 is not, due to a frameshift mutation, but that its repair restores its restriction endonuclease activity.

Reversible structural transition in epitaxial manganite film

A reversible structural transition of an epitaxial La(2/3)Sr(1/3)MnO3 film deposited on a LaAlO3 substrate has been investigated by means of in situ high-resolution transmission electron microscopy and electron diffraction, combined with image and diffraction calculations. We observe that the crystallographic symmetry of the film can be lowered via electron beam irradiation, leading to a rhombohedral-monoclinic transition. This transition can be attributed to the cooperating effect of the mismatch stress and the irradiation-induced thermal stress.

The protective effects of melatonin from oxidative damage induced by amyloid beta-peptide 25-35 in middle-aged rats

This work investigated the ability of melatonin to prevent oxidative damage in brain tissue induced by injection of beta-amyloid peptide 25-35 (Abeta25-35) in middle-aged rats. The Morris water maze was used to evaluate the cognitive function of the rats. Thiobarbituric acid-reactive substances and antioxidative enzymes (superoxide dismutase and glutathione peroxidase) activities were measured. It was found that injection of (Abeta25-35) (20 microg) into the rat hippocampus caused an increase in the latency (the time to find the platform), the total swimming distance to the platform, and the starting angles in (Abeta25-35)-treated rats. Furthermore, a significant rise in lipid peroxidation and decrease in antioxidative enzyme activities in brain tissue were found. Melatonin (0.1, 1, and 10 mg/kg, i.g. x 10 days) improved the spatial resolution of amnesic rats in the Morris water maze test. Meanwhile, melatonin antagonized the lipid peroxidation in both the mitochondria (P < 0.01) at the doses of 0.1, 1.0, and 10 mg/kg and in the cytoplasm at the doses of 0.1 and 1.0 mg/kg. Also in the amnesic rats, melatonin (0.1, 1.0, and 10 mg/kg. i.g. x 10 days) stimulated the antioxidative enzyme activities. The results show that melatonin effectively reduced lipid peroxidation and enhanced the antioxidative enzyme activities in Abeta(25-35)-treated rats, which may contribute to the improvement of rats' learning and memory impaired by Abeta(25-35).

[Effects of leflunomide on immunological liver injury]

AIM

To study the effect of leflunomide (Lef) on immunological liver injury in mice.

METHODS

Immunological liver injury was induced by tail vein injection of BCG + LPS (BCG 2.5 mg, 1 d, LPS 10 micrograms, 10 d). The ALT, AST, NO level in plasma and MDA, GSHpx in liver homogenate were assayed by spectroscopy. The serum content of TNF-alpha was determined by ELISA. IL-1, IL-2 and ConA-induced splenocyte proliferation response were determined by methods of 3H-infiltrated cell proliferation.

RESULTS

Immunological liver injury induced by BCG + LPS was successfully duplicated. Lef (4, 12, 36 mg.kg-1) was found to significantly decrease the serum transaminase (ALT, AST) activity and MDA content in liver homogenate, and improved reduced GSHpx level of liver homogenate. Furthermore, Lef (4, 12, 36 mg.kg-1) significantly reduced TNF-alpha and NO level in serum, and IL-1 production by PM psi. Moreover, the decreased IL-2 production and ConA-induced splenocyte proliferation response were further inhibited.

CONCLUSION

Lef showed significant protective action on immunological liver injury in mice.

Improvement of melatonin to the learning and memory impairment induced by amyloid beta-peptide 25 - 35 in elder rats

AIM

To investigate improvement of melatonin on learning and memory impairment induced by amyloid beta-peptide 25 - 35 (Abeta25-35) in elder rats.

METHODS

Step-down type passive avoidance test, shuttle-box test, and Morris water maze were used together to determine effects of Abeta25-35 and melatonin on learning and memory. Pathological changes were observed by HE, Congo red, and Ag staining.

RESULTS

The elder rats were injected bilaterally Abeta25-35 20 microg into the hippocampus to induce learning and memory dysfunction. Melatonin administration (0.1, 1, and 10 mg/kg, ig x 8 d) to the Abeta25-35-treated rats prolonged the latency, shortened the total stimulating time, and decreased the number of errors in the step-down test. Shuttle-box test showed that melatonin improved amnesic rats' performance at the same doses. Melatonin (0.1, 1, and 10 mg/kg ), giving for 10 d, could enhance the spatial resolution of amnesic rats in Morris water maze test. Also in Abeta25-35-treated group, a decrease in the number of neurons in cortex and hippocampus, a massive glial reaction, and neurophilic phenomenon were detected by HE staining; the positive vascular amyloidosis by Congo red and fibrils by Ag staining were observed. Melatonin (0.1 and 1 mg/kg)could inhibit above pathological changes in Abeta25-35 group.

CONCLUSION

Melatonin improved the impaired learning and memory induced by Abeta25-35 in elder rats.

[Reclamation of the plant regeneration efficiency of Brassica campestris subsp. chinensis var.Parachinensis]

This investigation has developed an efficient and fast method for plant regeneration from petiole of cotyledon explants of Brassica campestris L. subsp. chinensis Makino var. parachinensis Tsen et Lee. A medium was designed for B. campestris subsp. chinensis var. parachinensis to obtain the high frequency of shoot regeneration, which contained BAP 2 mg/L, NAA 0.75-1.0 mgL and 7.5 mg/L AgNO3 solution to the half of NH4+ concentration's MS basic medium. 60 mL/L coconut milk were added to all of media. In this method, frequency of shoot regeneration of "youqing caixin" reached as high as 91.2% and the number of shoots per explant reached as high as 4.7 plants. The result showed that there was a positive correlation between frequency of shoot regeneration and number of shoots per explant. The little shoots could be observed five days after inoculation and were formed directly. The inducing rate of roots of the shoots reached as high as 100% and the rate of viability of transferred mature plant reached higher than 95%. The regeneration period from petiole with cotyledon to a seedling was shorten to about 49 days. Factors influencing in vitro explant regeneration were studied.