Nuclease Activity of Human Interleukin-10

The nuclease activity of human interleukin-10, an immunosuppressive cytokine, was predicted on the basis of structural homology between the 97–105 sequence of human interleukin-10 and the DNA/RNA-hydrolyzing fragment of the endogenous differentiation factor for the HL-60 line of human promyelocyte leukemia cells. The human recombinant interleukin-10 was shown to cleave all forms of plasmid DNA. The role of interleukin-10 in the apoptosis induction in monocytic cells was hypothesized.     

Effect of chitooligosaccharides on peroxidase isoenzyme composition in wheat calli cocultured with bunt causal agent

Effects of chitooligosaccharides (COS) on the activity of peroxidase and its isoenzyme composition were investigated in cocultures of wheat calli (Triticum aestivum L.) with common bunt fungal pathogen (Tilletia caries (DC) Tul.). COS elevated the activity of readily soluble form of peroxidase: at concentrations of 0.01 and 1 mg/l, peroxidases with isoelectric points (pI) of about 3.5 and 9.8 and at concentration of 100 mg/l—those with pI of 4.3–5.2 were activated. It was shown that treatment with COS boosted the resistance of wheat calli to T. caries, inducing the accumulation in the cell wall of pathogen-specific isoperoxidases, especially its anionic isoform with pI ∼ 3.5. The ultimate indicator of defense responses is quick lignification of cultured cell walls under the effect of COS in the contamination area.     

Effects of salicylic and jasmonic acids on the components of pro/antioxidant system in potato plants infected with late blight

The effects of salicylic acid (SA) and jasmonic acid (JA) on plant defense responses were studied with aseptic potato (Solanum tuberosum L.) plantlets infected with Phytophthora infestans (Mont.) de Bary. Plant treatment with 10⁻⁶ M SA or 10⁻⁷ M JA induced plant resistance; the mixture of these acids was most efficient. After treatment with these compounds, phenolic compounds were accumulated and peroxidase was activated in the sites of pathogen localization, and this might be the reason of resistance enhancement. In addition, more H₂O₂ was accumulated in infected plants treated with JA or its mixture with SA but not in plants treated with SA alone. It might occur because of observed inhibition of catalase and activation of isoperoxidase with the isoelectric point (pI) of ∼9.3, which manifests an affinity for the pathogen cell wall. The data obtained allow us to recommend the application of these compounds for potato plant protection against late blight.     

A comparison of BoviPure and Percoll on bull sperm separation protocols for IVF

In the present study, we have examined the effect of density gradient preparations BoviPure and Percoll on bull sperm separation and the in vitro fertilization (IVF) and culture (IVC) results. Frozen/thawed semen from five simmental bulls were pooled. Sperm quality parameters such as sperm motility, concentration, membrane activity (HOS assay), membrane integrity (SYBR-14/PI assay) and acrosomal status (EthD-1/FITC-PSA assay) were evaluated before and after sperm processing for IVF using BoviPure and Percoll density gradient separations. The results of the evaluated parameters before sperm processing were: motility 50%, concentration 82.33x10(6)spz/mL, membrane activity 39.05%, membrane integrity 42.97% and the acrosomal status 46.90% of the live spermatozoa with intact acrosomes. After sperm processing with BoviPure and Percoll the motility was 66.67 and 64.17%, the concentration was 25.50x10(6) and 27.67x10(6)spz/mL, the membrane activity was 53.78 and 56.58%, the membrane integrity was 70.85 and 68.76% of and the acrosomal status was 74.16 and 67.46% of the live spermatozoa with intact acrosomes, respectively. Percentages were referred to the total number of spermatozoa. There were significant differences (P<0.05) between the evaluated parameters before and after sperm processing for both separation protocols. We found no significant differences (P>0.05) regarding sperm evaluation parameters between the protocols. A total of 492 oocytes were matured and fertilized in vitro and cultured in SOFaaBSA in six replicates. The cleavage (D2) and blastocysts (D7) rate were significantly higher (P<0.05) for the BoviPure group compared to the Percoll group: 75.80 and 28.21%; 61.58 and 20.83%, respectively. However, the number of hatched blastocysts (D10) did not differ significantly between sperm separation protocols (P>0.05). Our results indicate that both protocols gave suitable sperm for IVF. This finding and the similarity between those two density gradient preparations suggests that BoviPure is a good alternative for sperm separation in bovine IVF.     

Plant resistance inductors and active forms of oxygen. III. The influence of bisol 2 and baitan on morphogenesis and defense response of wheat non-morphogenic callus cells infected with smut agent

A study was made of the influence of bisol 2 and baitan compounds on morphogenesis and defence response of wheat calluse cells infected with bunt agent in associated with oxalate oxidase activation. After introduction of bisol and baitan into cultivation medium, dense area with meristema zones, germs of shoots and rhizoids appeared on non-morphogenic calluses, which correlated with enzyme activation. Parenchyma-like cells, generating hydrogen peroxide, were seen in the site of pathogen penetration under infestation, but were never revealed in control. Generation of hydrogen peroxide in the site of infection was accompanied with an increased oxalate oxidase activity in the cytoplasmic fraction, and with suppression of this activity in a fraction bound to the cell wall. Both compounds induced oxalate oxidase activity under combined cultivation of wheat calluses with bunt agent.     

Neuroprotective effect of the hexapeptide HLDF-6 on neurons of rat hippocampus on the model of Alzheimer's disease in vivo and in vitro

The neuroprotective effect of Thr-Gly-Glu-Asn-His-Arg hexapeptide (HLDF-6), a biologically active fragment of the differentiation factor of human leukemia cells (HLDF), was demonstrated on models of Alzheimer's disease in vivo and in vitro. The syndromes of this pathology were induced in male rats by administration of the peptide corresponding to the 25-35 sequence of beta-amyloid peptide (25-35) and ibotenic acid into the hippocampus. HLDF-6 prevented loss of long-term memory and decrease in the orientation-investigation activity of these animals and significantly decreased the number of pyknotic neurons in the CA1 area of the hippocampus. This peptide also exerts a protective effect in vitro on the primary cultures of neurons of the hippocampus and cerebellum of rats under conditions of the beta-amyloid toxicity. An increase in the dihydrotestosterone (DHT) content was demonstrated in the blood plasma of rats with the syndrome of Alzheimer's disease and in the medium of the culture of hippocampus neurons in the presence of the Abeta(25-35) peptide. HLDF-6 inhibited this increase in both cases. A probable mechanism of the neuroprotective effect of HLDF-6 was suggested as being connected to its possible effect on both the biosynthesis and the metabolism of sex steroid hormones.     

Assay and inhibition of diacylglycerol lipase activity

A series of N-formyl-α-amino acid esters of β-lactone derivatives structurally related to tetrahydrolipstatin (THL) and O-3841 were synthesized that inhibit human and murine diacylglycerol lipase (DAGL) activities. New ether lipid reporter compounds were developed for an in vitro assay to efficiently screen inhibitors of 1,2-diacyl-sn-glycerol hydrolysis and related lipase activities using fluorescence resonance energy transfer (FRET). A standardized thin layer chromatography (TLC) radioassay of diacylglycerol lipase activity utilizing the labeled endogenous substrate [1″-(14)C]1-stearoyl-2-arachidonoyl-sn-glycerol with phosphorimaging detection was used to quantify inhibition by following formation of the initial product [1″-(14)C]2-arachidonoylglycerol and further hydrolysis under the assay conditions to [1-(14)C]arachidonic acid.     

Functional state of the thyroid gland in sheep at a remote period after single administration of Sr-90, Pu-239 and their mixture

Five years after single intravenous injection of a mixture of 239Pu and 90Sr to semifine-wool sheep (7.4 kBq/kg + 185 kBq/kg) the iodine-fixing and hormone secreting functions of the thyroid gland were inhibited; where 90Sr alone was injected in the above dose inhibited was the hormone-secreting function only. Since 239Pu alone did not cause such alterations, the observed remote effect was attributed to the effect of the incorporated 90Sr.