Presence Of Various Doses Research Articles

Synthesis of solar light driven nanorod-zinc oxide for degradation of rhodamine B, industrial effluent and contaminated river water

Surface water contamination by various dyes and pigments is a global problem caused by rapid industry, particularly textile/dyeing. Bangladesh's export-oriented textile sector has exploded in recent decades, polluting local waterways significantly. In this study, nano-ZnO were prepared using surfactant-assisted sol–gel, hydrothermal and thermal methods. SEM, XRD, reflectance spectrophotometer, EDS and adsorption tests were used to characterize the synthesized nano-ZnO. BET isotherms were used to determine the surface area, pore volume, and pore size of the as-prepared nano-ZnO. The mixed surfactant assisted-sol gel method produced nanorod-ZnO, whereas the hydrothermal and/or thermal methods yielded clusters of needles ZnO, as proven by SEM images. XRD data revealed that the synthesized nanorod-ZnO had a mainly wurtzite crystalline structure and their size was estimated using the Scherrer equation to be about 23.90 nm. EDS spectra confirmed the synthesis of pure nanorod-ZnO. Using a UV–visible reflectance spectrophotometer, the band gap energy of the as-prepared nanorod-ZnO was found to be 3.35 eV. According to BET isotherms, the BET and Langmuir surface areas were 4 and 5.4 m 2 /g, respectively. Prior to analyzing photodegradation, the RB was adsorbing in the presence of various doses of the nanorod-ZnO in the dark, but no adsorption was observed. The photocatalytic activities of the synthesized nano-ZnO were compared to TiO 2 (anatase) for the degradation of RB in an aqueous system under solar light, UV, fluorescence, and tungsten filament light irradiation. Nanorod-ZnO showed exceptional photocatalytic activity in degrading RB in an aqueous solution under solar light irradiation. The results suggest that 0.01 g/50 mL nanorod-ZnO with a solution pH of 7.8 is the best combination for complete degradation of 2.00 × 10 -5 M RB under solar light irradiation. When nano-ZnO was exposed to light, the inhibiting effect of ethanol and/or tert -butanol on the degradation of RB confirmed the formation of mostly hydroxyl free radicals. The synthesized nanorod-ZnO shown substantial photocatalytic activity in the removal of pollutants from industrial effluents and contaminated river water under solar light irradiation. A mechanism of excellent photocatalytic activity of the nanorod-ZnO is discussed.

The effects of continuous exposure to low-dose chlorine dioxide gas on the characteristics of induced pluripotent stem cells.

BackgroundRecently, various regenerative therapies have been developed based on induced pluripotent stem (iPS) cells. However, hygienic control strategies have not been established at the manufacturing facilities. We aimed to evaluate the safety and effects of continuous exposure to low-dose chlorine dioxide (ClO2) gas on cell fates, and to determine the optimum dose for safe usage of this disinfectant.MethodsWe cultured an iPS cell line in the absence or presence of various doses of ClO2 gas. We evaluated cell proliferation, cell death, the maintenance of undifferentiated state, and cell senescence.ResultsWe found that iPS cell proliferation was not affected by 0.05 or 0.1 ppmv ClO2 gas in the atmosphere. Although 0.1 ppmv ClO2 slightly affected apoptosis, it was not a significant effect. Moreover, neither at 0.05 nor 0.1 ppmv ClO2 gas significantly affected the characteristics of iPS cells.Discussion and conclusionContinuous exposure to 0.05 or 0.1 ppmv ClO2 gas did not affect the fate of iPS cells. These results may contribute to the development of new strategies for hygiene control in cell processing facilities.

A New Selective PPARγ Modulator Inhibits Triglycerides Accumulation during Murine Adipocytes' and Human Adipose-Derived Mesenchymal Stem Cells Differentiation.

Understanding the molecular basis of adipogenesis is vital to identify new therapeutic targets to improve anti-obesity drugs. The adipogenic process could be a new target in the management of this disease. Our aim was to evaluate the effect of GMG-43AC, a selective peroxisome proliferator-activated receptor γ (PPARγ) modulator, during adipose differentiation of murine pre-adipocytes and human Adipose Derived Stem Cells (hADSCs). We differentiated 3T3-L1 cells and primary hADSCs in the presence of various doses of GMG-43AC and evaluated the differentiation efficiency measuring lipid accumulation, the expression of specific differentiation markers and the quantification of accumulated triglycerides. The treatment with GMG-43AC is not toxic as shown by cell viability assessments after the treatments. Our findings demonstrate the inhibition of lipid accumulation and the significant decrease in the expression of adipocyte-specific genes, such as PPARγ, FABP-4, and leptin. This effect was long lasting, as the removal of GMG-43AC from culture medium did not allow the restoration of adipogenic process. The above actions were confirmed in hADSCs exposed to adipogenic stimuli. Together, these results indicate that GMG-43AC efficiently inhibits adipocytes differentiation in murine and human cells, suggesting its possible function in the reversal of adipogenesis and modulation of lipolysis.

Assessment of changes in growth traits, oxidative stress parameters, and enzymatic and non-enzymatic antioxidant defense mechanisms in Lepidium draba plant under osmotic stress induced by polyethylene glycol.

Lepidium draba is a weed with the medicinal properties which few researches have been done on it. In this study, some traits, related to the osmotic stress, in 14-day-old L. draba sprouts that were grown 9 days in the presence of various doses of polyethylene glycol 6000 (PEG 6000) including 0, 3, 6, 9, and 12%, with different osmotic potentials (- 0.04, - 0.12, - 0.23, - 0.34, and - 0.48 MPa, respectively) were investigated. Based on our results, germination percentage besides stem and root lengths decreased with increasing the concentrations of PEG. The contents of electrolyte leakage, malondialdehyde, other aldehydes, total protein, free amino acids, total soluble carbohydrate as well as free proline increased with increasing the concentrations of PEG. Also, for the first time, our results have proven that under osmotic stress, there is an adverse relationship between hydrogen peroxide content and the activity of catalase, peroxidase, ascorbate peroxidase, and guaiacol peroxidase enzymes, such that hydrogen peroxide content decreased with induction of PEG up to 6% and after that increased, while the activity of catalase, peroxidase, ascorbate peroxidase, and guaiacol peroxidase enzymes increased up to 6% PEG and after that decreased. The expression levels of catalase, peroxidase, ascorbate peroxidase, and guaiacol peroxidase genes showed the same pattern as was seen for these enzyme activities. According to the results of this study, it can be deduced that decreasing H2O2 content cannot be the main reason for other oxidative stress parameters to decrease. In this study, P5CS and P5CR gene expression levels increased with increasing levels of PEG up to 12% which was completely similar to free proline content. Based on our results, L. draba can be considered as a semi-tolerant plant to osmotic stress.

The Mu‐Delta Opioid Receptor Heterodimer Promotes Acute and Chronic Morphine Induced Dependence/Withdrawal in Mice

Opioid drugs like morphine are the gold standard for treating acute and chronic pain, but induce detrimental side effects such as tolerance and dependence. It has been suggested that the mu‐delta opioid receptor heterodimer (MDOR) transduces some of these side effects and that heterodimer targeted drugs could be a solution to weaken these side effects. We have thus created an MDOR selective antagonist called D24M. We evaluated D24M in vitro, and found a ~100 fold selectivity for the MDOR over the monomers. Similarly, we performed hot water tail‐flick experiments in mice in the presence of various doses of D24M against CYM51010 and Deltorphin‐2 (MDOR selective agonist), and DAMGO (MOR monomer selective agonist), and found that D24M potently (A50=2–7.8 nmol) blocked MDOR activity with no activity against the MOR monomer up to 10 nmol. To test the ability of D24M to lessen acute or chronic morphine‐induced dependence and withdrawal, we established acute (4 hr) and chronic (4 day) morphine dependence models, with 1 nmol D24M or vehicle injected 5 minutes prior to naloxone precipitation of withdrawal. We found that D24M strongly reduced jumping behavior in dependent mice in both the acutely and chronically models; further confirming that the MDOR promotes withdrawal behavior, and that D24M could possibly be a promising drug candidate for opioid dependence and withdrawal. These discoveries will further determine the role of the MDOR in vivo, and provide a novel tool that could greatly impact opioid heterodimer research.This abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Glossogyne tenuifolia (Hsiang-ju) extract suppresses T cell activation by inhibiting activation of c-Jun N-terminal kinase

BackgroundGlossogyne tenuifolia (GT) (Hsiang-ju) is a Chinese herbal medicine previously exhibited an anti-inflammatory activity. This study aimed to investigate the effect of GT ethanol extract (GTE) on T cell-mediated adaptive immunity.MethodsHuman peripheral blood mononuclear cells (PBMCs) and Jurkat T cells were activated by phytohemagglutinin in the presence of various doses (3.13–50 μg/mL) of GTE. The effect of GTE on T cell activation was examined by a proliferation assay of activated PBMCs and the level of the activation marker CD69 on the surface of activated Jurkat T cells. Apoptosis was determined by propidium iodide staining in hypotonic solution. Signaling pathway molecules were assessed by western blotting.ResultsGlossogyne tenuifolia ethanol extract was demonstrated to inhibit T cell activation, not only in the proliferation of human PBMCs at the concentrations of 12.5, 25 and 50 μg/mL (P = 0.0118, 0.0030 and 0.0021) but also in the CD69 expression in Jurkat cells, which was not due to the cytotoxicity of GTE. The presence of GTE did not change the activity of nuclear factor kappa-light-chain-enhancer of activated B cells or extracellular signal-regulated kinase upon T cell activation. In addition, GTE significantly reduced activation of c-Jun N-terminal kinase (JNK) (P = 0.0167) and p38 (P = 0.0278). Furthermore, decreased JNK activation mediated the preventive effect of GTE on T cell activation-induced cell death (AICD).ConclusionGlossogyne tenuifolia ethanol extract inhibited T cell activation of Jurkat cells and freshly prepared human PBMCs due to suppression of JNK activity. Furthermore, GTE inhibited AICD by blocking prolonged JNK phosphorylation in activated T cells. Taken together, the anti-inflammatory effects exerted by GTE were mediated via suppression of JNK phosphorylation in T cell activation.

THE EFFECTS OF NITROGLYCERIN ON THE PROLIFERATIVE AND MIGRATORY POTENTIAL OF PERIPHERAL BLOOD MONONUCLEAR CELLS

Aim. To study the effects of nitroglycerin on proliferative and migratory activity of mononuclear cells and endothelial progenitor cells in patients with chronic heart failure. Materials and methods. Proliferative potential of peripheral blood mononuclear cells in donors and patients were studied in MTT-test in the presence of 50 and 100 mg/ml nitroglycerin. Proliferation and migration of endothelial progenitor cells in patients were evaluated by changes in the cell impedance in real-time in the presence of various doses of nitroglycerin. Results. It is shown that nitroglycerin reduces in vitro both spontaneous and Concanavalin A stimulated proliferative activity of mononuclear cells in patients with chronic heart failure. Peripheral blood mononuclear cells in patients with chronic heart failure, obtained after procedure of mobilization by granulocyte colony-stimulating factor respond to nitroglycerin dose of 50 mg/ml with the increased proliferative activity, and with the suppressed proliferative activity to nitroglycerin dose of 100 mg/ml. Mononuclear cells of healthy donors respond to 50 mg/ml of nitroglycerin with the activation of proliferative capacity, but at a dose of 100 mg/ml spontaneous proliferative activity of mononuclear cells inhibit. It is also shown that the presence of nitroglycerin in medium dose in stimulating test leads to the inhibition of mononuclear cells proliferation from healthy donors. It is shown the stimulating effect of nitroglycerin on proliferative and migration potential of endothelial progenitor cells. Conclusion. Multidirectional and dose-dependent effects of nitroglycerin to the various types of human cells in vitro were observed.

Effects of Tetracycline Son Soil Enzyme Activities in an Alluvial Soil

Aims: To study the effect of various doses of tetracycline (TC), oxytetracycline (OTC) and chlortetracycline (CTC) on the enzymatic (DHA, acid phosphatase, alkaline phosphatase, urease and catalase) activity in sewage amended and un-amended alluvial soil. Methodology: A laboratory incubation study was conducted during 2012-2013 on an Aligarh farm alluvial soil. The enzymatic activity was studied in presence of various doses of three tetracycline antibiotics in soil; soil amended with sewage sludge; and mixture of sewage sludge and tetracyclines at different time intervals [(0 (4h), 7, 14, 21, 35, 56, 70,91d]. Results: Activity of all the studied enzymes was significantly inhibited for up to 14-21 days of incubation (14 d for DHA and acid phosphatase, 21 d for alkaline phosphatase, urease and catalase) and thereafter inhibition got weaker. The activity of all the studied enzymes decreased with increase in the doses of tetracyclines. Higher enzymatic activity was observed in sewage sludge amended soil than in the un-amended soil. Tetracyclines in presence of sewage sludge were found to have no appreciable effect on enzymatic activities. Conclusions: Dehydrogenase, acid and alkaline phosphatase, urease and catalase activity in tetracycline free soil was superior to soil containing antibiotics in the period of 2-3 weeks of incubation. The inhibition of soil enzyme activity was directly proportional to tetracycline concentration. In presence of sewage sludge, the studied enzymes activity initially increased up to Original Research Article Bansal; BJMMR, 5(8): 1007-1016, 2015; Article no.BJMMR.2015.111 1008 3 weeks and decreased thereafter. In presence of sewage sludge and antibiotics, the activity of enzymes remains almost unchanged. The activity of studied enzymes in soil was positively correlated to soil organic content.

Development of tomato plants growing on nutrient solution containing ammonium salts in the presence of various doses of potassium

In all the experiments the best development of tomato plants was observed when nutrient solutions containing 1/3 of full doses of potassium were applied (i.e. when the N : K ratio = 0.84). On the other hand, the poorest development of plants was observed in combinations with 1/100 of the full potassium dose. Tenfold doses of potassium added to the nutrient solution de-pressed markedly plant growth, particularly at pH 7.6. The supply of potassium in the nutrient solution was correlated with the nitrogen, potassium and calcium amounts absorbed by the plants.

Changes in cell cycle, apoptosis and necrosis following the establishment of a 125I brachytherapy model in the spinal cord in Banna mini-pigs

Brachytherapy is regarded as the most effective method in the treatment of metastatic spinal tumors since little damage is caused to surrounding healthy tissue. However, this method may cause radiation myelopathy if an overdose occurs. In the present study, we established a Banna mini-pig (125)I spinal cord implantation model to provide a tool for the study of how to reduce these types of side effects. Cell cycle alteration, apoptosis and necrosis of spinal cord neurons in the presence of various doses and durations of (125)I brachytherapy were also investigated. The pigs were randomly divided into four groups, A, B, C and D. In group A, four (125)I seeds (total radioactivity, 4.0 mCi) were implanted into the dura mater of the spinal canal at the level of T13. In groups B and C, eight (125)I sources (total radioactivity, 8.0 mCi) were inserted at the same location. Groups A and C were raised for up to 8 months and group B for only 2 months. Neurons from the swine spinal cord at the T13 level were collected and cell cycle analysis was performed. Apoptosis and necrosis were tested by a terminal deoxynucleotidyl transferase dUTP nick end-labeling (TUNEL) assay. The Banna mini-pig brachytherapy model was successfully established. Radiation myelopathy was closely associated with radiation dose and duration, more neurons were blocked in the G2 and S phases as dose and time increased, and an increase in apoptosis and necrosis was detected. Ratios of apoptosis and necrosis were reduced as lower doses and shorter durations of radiation were applied. Our results demonstrate that the Banna mini-pig is an ideal animal to study (125)I brachytherapy. Low-dose and short-term brachytherapy may effectively decrease apoptosis and necrosis in spinal cord cells in Banna mini-pigs.

Abstract LB-166: Characterization of a novel class of carbazole based radiation sensitizers

Abstract Technological advances in radiation therapy have greatly improved our ability to deliver a precise dose of radiation to a defined volumetric target with high accuracy. However, local recurrence of cancer, especially that in the previously irradiated area continues to be a significant cause of morbidity and mortality in patients who initially receive radiation therapy. It has been known for some time that certain agents, mostly chemotherapeutic drugs, are capable of enhancing the effects of radiation when given in conjunction with radiation therapy. Concurrent use of these agents (including cis-platinum and 5-fluorouracil, to name a few) with radiation has been shown to result in improved disease control in a wide variety of cancers. Even though these agents are highly beneficial to many patients who receive them, their use is often limited due to their inherent toxicities as well as their ability to enhance radiation induced normal tissue reactions. Previously, we have reported that quinacrine, an old antimalarial drug known to induce p53 activity and suppress NF-κB activity in cells, are capable of radiation sensitization in vitro. Since that time, we have been studying a group of compounds we named Curaxins for its radiation sensitizing qualities. Curaxins are carbazole compounds that were selected for their ability to induce p53 activity and reduce NF-κB activity in a variety of human cancer cell lines. These compounds are known to have much higher potency than quinacrine. Though they were originally developed as single-agent anticancer agents, our recent investigations have shown that many of these Curaxins are also very potent radiation sentizers in vitro and in vivo. We have recently completed a preliminary screen of our existing Curaxins for their ability to enhance cytotoxicity of ionizing radiation, utilizing B16 murine melanoma cell line as our model system. Clonogenic survival assays were peformed in presence of various doses of Curaxins ranging from 2 nM to 200 nM. Of twelve Curaxins screened for this purpose, nine were found to be very potent sensitizers at either 2 nM and/or 20 nM. We also studied the effect of two of the Curaxins for their radiosensitizing activities in vivo, using a B16 lung metastasis model in C57BL/6 mice. Combination of Curaxins to thoracic irradiation resulted in greater tumor control (indicated by reduced lung weight) and longer mean survival compred to irradiation alone or Curaxins alone. It is notable that in vitro radiosensitization by these two Curaxins occurs at concentrations not known to cause p53 induction in B16 cells, suggesting that this effect may not be entirely dependent on the p53 pathway. We are currently in the process of further characterizing the radiosensitizing qualities of the remaining seven radiosensitizing Curaxins both in vitro and in vivo. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-166.

The Triterpenoid CDDO-Me Delays Murine Acute Graft-versus-Host Disease with the Preservation of Graft-versus-Tumor Effects after Allogeneic Bone Marrow Transplantation

The occurrence of acute graft-versus-host disease (aGVHD) and tumor relapse represent the two major obstacles impeding the efficacy of allogeneic bone marrow transplantation (BMT) in cancer. We have previously shown that the synthetic triterpenoid 2-cyano-3, 12-dioxooleana-1, 9-dien-28-oic acid (CDDO) can inhibit murine early aGVHD, but antitumor effects were not assessed. In the current study, we found that a new derivative of CDDO, CDDO-Me, had an increased ability to inhibit allogeneic T cell responses and induce cell death of alloreactive T cells in vitro. Administration of CDDO-Me to mice following allogeneic BMT resulted in significant and increased protection from lethal aGVHD compared to CDDO. This correlated with reduced TNF-alpha production, reduced donor T cell proliferation, and decreased adhesion molecule (alpha(4)beta(7) integrin) expression on the donor T cells. CDDO-Me was also superior to CDDO in inhibiting leukemia growth in vitro. When CDDO-Me was administered following an allogeneic BMT to leukemia-bearing mice, significant increases in survival were observed. These findings suggest that CDDO-Me is superior to CDDO in delaying aGVHD, while preserving or possibly even augmenting GVT effects.

Induction of insulin resistance by malathion: Evidence for disrupted islets cells metabolism and mitochondrial dysfunction

Hyperglycemia is observed with exposure to organophosphorus (OP) pesticides. The aim of this study was to investigate the effects of malathion on secretion of insulin from rat pancreatic islets in vitro and in vivo. Malathion was administered through food for 4 weeks at concentrations of 100, 200, and 400 ppm. For in vivo experiment, at the end of treatment, blood sample was obtained and plasma was separated. For in vitro experiment, the treated rats were anesthetized and underwent a laparatomy. The common bile duct was cannulated and the pancreas distended by injecting of cold collagenase V using peristaltic infusion pump. Islets were then hand picked under a stereomicroscope and cultured in the presence of various doses of glucose and KCl. Malathion at doses of 200 and 400 ppm increased plasma glucose and insulin concentrations and lowered activity of erythrocyte acetylcholinesterase. The isolated islets from pretreated animals with malathion 200 and 400 ppm showed lower glucose-stimulated insulin secretion while no change was observed in the presence of KCl. Light microscopic examination revealed that malathion causes patchy degenerative changes in pancreatic islets. Combination of in vivo and in vitro findings suggests that malathion induces a kind of insulin resistance that cannot overwhelm hyperglycemia. This action of malathion is mediated through disruption of islets mitochondrial function.

EFFECTS OF ANTIOXIDANTS ON TERT-BUTYL HYDROPEROXIDE CELL KILLING IN MACROPHAGE (RAW 264.7) CELLS.

The aim of this study was to examine the protective effects of a variety of antioxidants, including alpha-tocopherol (vitamin E), ascorbic acid, and selenium, in an in vitro model of alcohol-mediated free radical generation in the liver, one of the major organs affected by chronic alcohol abuse. Hepatic macrophage cells (RAW 264.7 cells) were cultured to confluence in 24-well plates. A dose-response curve of tBH (tert-butyl hydroperoxide) killing in the presence or absence of ethanol (EtOH) was determined. Cell killing was evaluated by determining cell leakage of lactate dehydrogenase. Cells were then exposed to a tBH dose that killed 50% of the cells in the presence of various doses of each of the potential antioxidants: ascorbic acid, alpha-tocopherol, or selenium. Alpha-tocopherol acted as an antioxidant by decreasing tBH cell killing in a dose-dependent manner. Selenium at a relatively high dose (10 μmol had no effect on tBH killing. However, at 50 μmol, it enhanced tBH cell killing, thereby acting as a pro-oxidant. Ascorbic acid at low doses protected the cells from tBH cell killing, but at doses higher than 500 μmol, it enhanced cell killing, thereby acting as a pro-oxidant. Our results indicate that protection from free radical damage depends on the dose of alpha-tocopherol, ascorbic acid, or selenium. An antioxidant regimen can be developed to minimize free radical generation due to ethanol metabolism that will significantly reduce the subsequent damage to the liver caused by alcohol abuse.

Genistein and other isoflavones found in soybeans inhibit estrogen metabolism in salmonid fish

The study was conducted to test the hypothesis that genistein, an isoflavone found in high concentrations in soybeans, inhibits hepatic and renal estrogen metabolism in salmonid fish. Liver and kidney tissues of rainbow trout ( Oncorhyncus mykiss), Atlantic salmon ( Salmo salar), and lake trout ( Salvelinus namaycush) were incubated in vitro with radiolabelled estradiol-17β (E2) in the presence of various doses of genistein. The cultures were extracted to remove unmetabolized E2 and neutral E2 metabolites, and the production of water-soluble (conjugated) E2 metabolites was quantified by liquid scintillation counting. High doses (1 and 10 μM) of genistein inhibited E2 metabolism in the liver and kidney of Atlantic salmon and rainbow trout, and in the liver of lake trout. At 1 μM, daidzein, glycitein, and a mix of genistein/daidzein/glycitein at a ratio typically found in soybeans (1.3:1:0.2), all inhibited estrogen metabolism in the liver of rainbow trout, but had no effect on the kidney. The results suggest that the inhibition of hepatic and renal E2 metabolism may be, at least in part, a mechanism mediating the estrogenic effects of isoflavones in salmonid fish.

Suppressive Activity of Fexofenadine Hydrochloride on Thymus- and Activation-Regulated Chemokine Production from Human Peripheral Blood Leukocytes in Response to Antigenic Stimulation in vitro

Background: Thymus- and activation-regulated chemokine (TARC) is accepted as being an important molecule in the development and maintenance of allergic diseases. However, there is little information about the influence of antiallergic agents on TARC production after allergen challenge. The aim of this study is to examine the influence of fexofenadine hydrochloride (FEX), an H₁-receptor antagonist, on TARC production from human peripheral blood leukocytes (PBL) using an in vitro cell culture technique. Methods: PBL prepared from donors with pollinosis were cultured with either Japanese cedar pollen allergen, Cry j 1, or interleukin (IL)-4 in the presence of various doses of FEX for 6 days. Levels of TARC and the T cell cytokines IL-4 and interferon (IFN)-γ in culture supernatants were examined by ELISA. Results: FEX did not affect PBL proliferation induced by Cry j 1 stimulation, even when 500 ng/ml of the agent, twice the therapeutic blood levels, was added to cell cultures as assessed by measuring ³H-thymidine incorporation into DNA. On the other hand, FEX at 250 ng/ml (but not 125 ng/ml), similar to therapeutic blood levels, significantly inhibited the ability of PBL to produce IL-4 (but not IFN-γ), which was enhanced by Cry j 1 stimulation. FEX at concentrations of more than 250 ng/ml also exerted a suppressive effect on TARC production from PBL in response to Cry j 1 and IL-4 stimulation in vitro. Conclusion: This inhibitory action of FEX may be partially responsible for the attenuating effect of the agent on allergic diseases.

Studies with Synthetic Peptides of 80 kDa Human Sperm Antigen (80 kDa HSA)

The 80 kDa human sperm antigen (HSA) is a sperm-specific and conserved antigen, capable of inducing immunological infertility. Partial N-terminal amino acid sequences of 80 kDa HSA (Peptide NT) and its peptides obtained by digestion with endoproteinase Lys-C (peptides 1-4) and endoproteinase Glu-C (peptides 5-6) did not show any sequence homology with reported known proteins deposited in the Gen-Bank. These sequenced peptides were synthesized and conjugated to key hole limpet haemocyanin (KLH) and evaluated for its antifertility effects. The present communication describes the characterization of these peptides and their antibodies. Peptides NT, 1, 2, 3 and 4 were synthesized and conjugated to KLH. Antibodies to KLH conjugated peptides were raised in rabbits by active immunization and the antibody titer was determined by enzyme-linked immunosorbent assay (ELISA) using sperm extract coated wells. The binding specificity of the synthetic peptides or purified 80 kDa HSA to their antibodies was assessed in the presence of various doses of respective synthetic peptides or 80 kDa HSA. The binding specificity was further confirmed by Western blot analysis. Antipeptide antibodies were also checked for sperm agglutinating activity, in-vitro. Active immunization of rabbits elicited significant antibody titers against the synthetic peptides, except for peptide 3. Antipeptide antibodies specifically recognized the native protein in an ELISA and induced in-vitro agglutination of human, rat and monkey sperm. In addition, Western blot analysis showed that these antipeptide antibodies specifically bind to the 80 kDa HSA band of the sperm extract. Synthetic peptides of 80 kDa HSA are immunogenic and antibodies raised against these peptides recognize the native protein detected by ELISA, Western blot analysis. In addition, they possess sperm agglutinating activity. These findings suggest that they are promising candidates in the development of immunocontraceptives.

Antigen presentation by Peyer's patch cells can induce both Th1- and Th2-type responses depending on antigen dosage, but a different cytokine response pattern from that of spleen cells.

The Th1 and Th2 preference induced by cells from the Peyer's patch (PP) and spleen (SPL) with various doses of an antigen was examined. The same splenic T cell receptor-transgenic CD4+ T cells were first incubated with PP or SPL cells in the presence of various doses of an antigen, and the cytokine response was observed after secondary stimulation. A Th2-type pattern was only obtained for primary stimulation at 10 microM of the antigen with PP cells, whereas a Th1 pattern was induced at both higher and lower concentrations. SPL cells in the presence of 0.1 to 1 microM of the antigen induced the secretion of Th2-type cytokines. Ten and 100 microM of the antigen plus SPL cells did not induce the release of a large quantity of cytokines. PP cells induced a different cytokine pattern at the antigen concentration that induced a similar level of T cell proliferation with SPL cells. Our findings suggest that the antigen-dose dependent development of Th1/Th2 cells is differentially modulated by the antigen-presentation function of cells in PP and SPL.

RESPONSE OF A LOCAL AND SOME EXOTIC MUNGBEAN VARIETIES TO BIO- AND MINERAL FERTILIZATION

A pot trial was carried out in the greenhouse of the National Research Centre during the summer season of 1999 to investigate the combined impact of Bradyrhizobium sp. (vigna) and Azotobacter vinelandii in the presence of various doses of chemical fertilizers, i.e. 25%, 50% and 100% of the recommended dose of NPK, on nodulation, growth parameters, seed yield and its components, and seed contents of protein, phosphorus and potassium of a local (Kawmy-1) and three exotic (VC-4, VC-9 and King) varieties of mungbean. The results indicated that there were no significant differences between the different varieties for nodule number per plant, while significant variations were obtained between both varieties and biofertilization treatments. The plants of the Kawmy-1 variety gave the shortest period of growth, the highest number of pods per plant and the highest values of harvest index and seed protein content. The King variety had the longest period of growth and the highest values for number of branches, seed yield, biological yield, seed index and seed phosphorus content. The inclusion of Azotobacter vinelandii significantly augmented various tested parameters, with the exception of seed yield, biological yield and potassium content, in comparison with Bradyrhizobium. Insignificant differences were found owing to the interaction between varieties, various levels of mineral fertilizers and types of biofertilizers with the exception of harvest index and seed phosphorus content.

N-methyl-D-aspartate receptor antagonists are less effective in blocking long-term potentiation at apical than basal dendrites in hippocampal CA1 of awake rats

Long-term potentiation (LTP) of field excitatory postsynaptic potentials (fEPSPs) at the apical or basal dendrites of CA1 pyramidal cells was induced by stimulation with a 1-s train of 200-Hz pulses in awake rats, with or without the presence of various doses of an N-methyl-D-aspartate (NMDA) receptor antagonist. Apical LTP was blocked by an intracerebroventricular (i.c.v.) dose of 40 microg D-2-amino-5-phosphonopentanoic acid (D-AP5) or 20 mg/kg i.p. D-2-amino-4-methyl-5-phosphono-3-pentanoic acid (CGP-40116), whereas basal LTP was blocked by half the dose of D-AP5 or CGP-40116. The noncompetitive antagonist MK-801 (< or =1 mg/kg i.p.) had no significant effect on apical LTP. Apical LTP was not blocked by i.c.v. nifedipine. The effect of an NMDA receptor antagonist alone on apical and basal fEPSPs was also evaluated, to assess the net effect of the NMDA receptor antagonist in blocking LTP. MK-801 (0.5-1 mg/kg i.p.) or CGP-40116 (10-20 mg/kg i.p.) but not D-AP5 suppressed apical fEPSPs for several hours and confounded the expression of apical LTP during this time. We concluded that hippocampal LTP at different synapses has different sensitivity to NMDA receptor antagonists and that a general blockade of hippocampal NMDA receptor functions cannot be inferred by a single hippocampal LTP measure.