Home About us Contact
|
Home About us Contact | ||
|
|
||
Respective Controls (respective + control)
Selected AbstractsGenotoxicity of acrylamide and its metabolite glycidamide administered in drinking water to male and female Big Blue mice,ENVIRONMENTAL AND MOLECULAR MUTAGENESIS, Issue 1 2006Mugimane G. Manjanatha Abstract The recent discovery of acrylamide (AA), a probable human carcinogen, in a variety of fried and baked starchy foods has drawn attention to its genotoxicity and carcinogenicity. Evidence suggests that glycidamide (GA), the epoxide metabolite of AA, is responsible for the genotoxic effects of AA. To investigate the in vivo genotoxicity of AA, groups of male and female Big Blue (BB) mice were administered 0, 100, or 500 mg/l of AA or equimolar doses of GA, in drinking water, for 3,4 weeks. Micronucleated reticulocytes (MN-RETs) were assessed in peripheral blood within 24 hr of the last treatment, and lymphocyte Hprt and liver cII mutagenesis assays were conducted 21 days following the last treatment. Further, the types of cII mutations induced by AA and GA in the liver were determined by sequence analysis. The frequency of MN-RETs was increased 1.7,3.3-fold in males treated with the high doses of AA and GA (P , 0.05; control frequency = 0.28%). Both doses of AA and GA produced increased lymphocyte Hprt mutant frequencies (MFs), with the high doses producing responses 16,25-fold higher than that of the respective control (P , 0.01; control MFs = 1.5 ± 0.3 × 10,6 and 2.2 ± 0.5 × 10,6 in females and males, respectively). Also, the high doses of AA and GA produced significant 2,2.5-fold increases in liver cII MFs (P , 0.05; control MFs = 26.5 ± 3.1 × 10,6 and 28.4 ± 4.5 × 10,6). Molecular analysis of the mutants indicated that AA and GA produced similar mutation spectra and that these spectra were significantly different from that of control mutants (P , 0.001). The predominant types of mutations in the liver cII gene from AA- and GA-treated mice were G:C,T:A transversions and ,1/+1 frameshifts in a homopolymeric run of Gs. The results indicate that both AA and GA are genotoxic in mice. The MFs and types of mutations induced by AA and GA in the liver are consistent with AA exerting its genotoxicity in BB mice via metabolism to GA. Environ. Mol. Mutagen., 2006. Published 2005 Wiley-Liss, Inc. [source] Direct and indirect effects of a potential aquatic contaminant on grazer,algae interactionsENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 2 2009Michelle A. Evans-White Abstract Contaminants have direct, harmful effects across multiple ecological scales, including the individual, the community, and the ecosystem levels. Less, however, is known about how indirect effects of contaminants on consumer physiology or behavior might alter community interactions or ecosystem processes. We examined whether a potential aquatic contaminant, an ionic liquid, can indirectly alter benthic algal biomass and primary production through direct effects on herbivorous snails. Ionic liquids are nonvolatile organic salts being considered as an environmentally friendly potential replacement for volatile organic compounds in industry. In two greenhouse experiments, we factorially crossed four concentrations of 1-N-butyl-3-methylimidazolium bromide (bmimBr; experiment 1: 0 or 10 mg/L; experiment 2: 0, 1, or 100 mg/L) with the presence or absence of the snail Physa acuta in aquatic mesocosms. Experimental results were weighted by their respective control (no bmimBr or P. acuta) and combined for statistical analysis. When both bmimBr and snails were present, chlorophyll a abundance and algal biovolume were higher than would be expected if both factors acted additively. In addition, snail growth rates, relative to those of controls, declined by 41 to 101% at 10 and 100 mg/L of bmimBr. Taken together, these two results suggest that snails were less efficient grazers in the presence of bmimBr, resulting in release of algae from the grazer control. Snails stimulated periphyton primary production in the absence, but not in the presence, of bmimBr, suggesting that bmimBr also can indirectly alter ecosystem function. These findings suggest that sublethal contaminant levels can negatively impact communities and ecosystem processes via complex interactions, and they provide baseline information regarding the potential effects of an emergent industrial chemical on aquatic systems. [source] Evaluating the contribution of soil properties to modifying lead phytoavailability and phytotoxicity,ENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2006Elizabeth A. Dayton Abstract Soil properties affect Pb bioavailability to human and ecological receptors and should be considered during ecological risk assessment of contaminated soil. We used path analysis (PA) to determine the relative contribution of soil properties (pH, organic C [OC], amorphous Fe and Al oxides [FEAL], and cation-exchange capacity [CEC]) in modifying Pb bioavailability. The response of biological endpoints (bioaccumulation and dry matter growth [DMG]) of lettuce (Lactuca sativa) grown on 21 Pb-spiked (2,000 mg/kg) soils were determined. Lettuce tissue Pb ranged from 3.22 to 233 mg/kg, and relative DMG ranged from 2.5 to 88.5% of their respective controls. Simple correlation showed strong relationships between CEC and OC (p < 0.01) and weaker relationships between pH and FEAL (p < 0.05) and Pb bioaccumulation. Results of PA suggest that soil pH increased the negative surface charge of organic matter and clay, thereby increasing CEC and decreasing Pb bioaccumulation. Also, the direct effect of OC on tissue Pb can be attributed to formation of surface Pb complexes by organic matter functional group ligands. Increased OC and/or CEC reduced Pb solubility and bioavailability in the 21 soils in the present study. The relative importance of soil properties likely will vary between studies employing different soils. Soil properties should be considered during the ecological risk assessment of metal in contaminated soils. Path analysis is useful for ecological studies involving soils with a wide range of physicochemical properties and can assist in site risk assessment of metals and remediation decisions on contaminated sites. [source] Systematic review of randomized controlled trials of pharmacological interventions to reduce ischaemia-reperfusion injury in elective liver resection with vascular occlusionHPB, Issue 1 2010Mahmoud Abu-Amara Abstract Background:, Vascular occlusion during liver resection results in ischaemia-reperfusion (IR) injury, which can lead to liver dysfunction. We performed a systematic review and meta-analysis to assess the benefits and harms of using various pharmacological agents to decrease IR injury during liver resection with vascular occlusion. Methods:, Randomized clinical trials (RCTs) evaluating pharmacological agents in liver resections conducted under vascular occlusion were identified. Two independent reviewers extracted data on population characteristics and risk of bias in the trials, and on outcomes such as postoperative morbidity, hospital stay and liver function. Results:, A total of 18 RCTs evaluating 17 different pharmacological interventions were identified. There was no significant difference in perioperative mortality, liver failure or postoperative morbidity between the intervention and control groups in any of the comparisons. A significant improvement in liver function was seen with methylprednisolone use. Hospital and intensive therapy unit stay were significantly shortened with trimetazidine and vitamin E use, respectively. Markers of liver parenchymal injury were significantly lower in the methylprednisolone, trimetazidine, dextrose and ulinastatin groups compared with their respective controls (placebo or no intervention). Discussion:, Methylprednisolone, trimetazidine, dextrose and ulinastatin may have protective roles against IR injury in liver resection. However, based on the current evidence, they cannot be recommended for routine use and their application should be restricted to RCTs. [source] Metabolic Acidosis Stimulates RANKL RNA Expression in Bone Through a Cyclo-oxygenase-Dependent Mechanism,JOURNAL OF BONE AND MINERAL RESEARCH, Issue 7 2003Kevin K Frick Abstract Metabolic acidosis inhibits osteoblastic bone formation and stimulates osteoclastic resorption. To determine whether acidosis alters expression of RNA for the osteoclastic differentiation factor RANKL, mouse calvariae were incubated in neutral or physiologically acidic media. Acidosis resulted in a significant cyclo-oxygenase-dependent increase in RANKL RNA levels, which would be expected to induce the associated increase in bone resorption. Introduction: Metabolic acidosis increases net calcium efflux from bone, initially through physicochemical mechanisms and later through predominantly cell-mediated mechanisms. Acidosis decreases osteoblastic bone formation and increases osteoclastic resorption. The growth and maturation of osteoclasts, derived from hematopoietic precursors in the monocyte/macrophage lineage, are dependent on the interplay of a number of factors. Commitment of pre-osteoclasts to osteoclasts is induced by the interaction of the osteoclastic cell-surface receptor RANK with a ligand expressed by osteoblasts, RANKL. The RANK/RANKL interaction not only initiates a differentiation cascade that culminates in mature bone-resorbing osteoclasts but also increases osteoclastic resorptive capacity and survival. Methods: To test the hypothesis that metabolic acidosis increases expression of RANKL, we cultured neonatal mouse calvariae in acidic (initial medium pH ,7.1 and [HCO3,] ,11 mM) or neutral (initial medium pH ,7.5 and [HCO3,] ,25 mM) medium for 24 and 48 h. We determined the relative expression of RANKL RNA by reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitated the expression by Northern analysis. Results: In this model of metabolic acidosis, there was significantly increased expression of RANKL RNA at both 24 (2-fold) and 48 h (5-fold) compared with respective controls. Net calcium efflux from bone was also increased in acidic medium compared with control medium. At 48 h, net calcium efflux correlated directly with RANKL expression (r = 0.77, n = 15, p < 0.001). Inhibition of prostaglandin synthesis with indomethacin blocked the acid-induced increase in RANKL RNA as well as the increased calcium efflux. Conclusions: Metabolic acidosis induces osteoblastic prostaglandin synthesis, followed by autocrine or paracrine induction of RANKL. This increase in RANKL would be expected to augment osteoclastic bone resorption and help explain the increase in cell-mediated net calcium efflux. [source] Germination Conditions Affect Physicochemical Properties of Germinated Brown Rice FlourJOURNAL OF FOOD SCIENCE, Issue 9 2009Phantipha Charoenthaikij ABSTRACT:, Germinated brown rice has been reported to be nutritious due to increased free gamma-aminobutyric acid (GABA). The physicochemical properties of brown rice (BR) and glutinous brown rice (GNBR) after germination as affected by different steeping times (24, 36, 48, and 72 h depending on the rice variety) and pHs of steeping water (3, 5, 7, and as-is) were determined and compared to those of the nongerminated one (control). As the steeping time increased or pH of steeping water decreased, germinated brown rice flours (GBRF) from both BR and GNBR had greater reducing sugar, free GABA and ,-amylase activity; while the total starch and viscosity were lower than their respective controls. GBRFs from both BR and GNBR prepared after 24-h steeping time at pH 3 contained a high content of free GABA at 32.70 and 30.69 mg/100 g flour, respectively. The peak viscosity of GBRF obtained from both BR and GNBR (7.42 to 228.22 and 4.42 to 58.67 RVU, respectively) was significantly lower than that of their controls (255.46 and 190.17 RVU, respectively). The principal component analysis indicated that the important variables for discriminating among GBRFs, explained by the first 2 components at 89.82% of total explained variance, were the pasting profiles, ,-amylase activity, and free GABA. [source] Polyethylene cross-linking by two different methods reduces acetabular liner wear in a hip joint wear simulatorJOURNAL OF ORTHOPAEDIC RESEARCH, Issue 5 2003Darryl D. D'Lima Advances in cross-linking have led to the development of wear resistant ultrahigh molecular weight polyethylene for total joint replacement. This study compared wear reduction by two different cross-linking methods as measured in a hip wear simulator. One highly cross-linked polyethylene was treated with 7.5 Mrad gamma irradiation with post-irradiation annealing and a sterilization dose of 2.5 Mrad (10 Gamma), while the other used 9.5 Mrad warm irradiation with 10 MeV electron-beam (9.5 EB). Liners of the same design, made from nominally cross-linked (gamma sterilized) polyethylene were also tested. Gravimetric wear analysis was performed every 500,000 cycles for 5,000,000 cycles. After correcting for weight gain due to water absorption, the nominally cross-linked liners demonstrated mean wear rates of 15.7 (±1.7) and 12.5 (±1.0) mg/million cycles. Both highly cross-linked polyethylene liners demonstrated significantly less wear than their respective controls (with mean wear rates of 1.5 (±1.2) and ,1.4 (±1.5) mg/million cycles). The 9.5 EB liners gained weight presumably due to increased fluid absorption, in addition to that measured in loaded,soaked control implants. Any wear occurring was therefore assumed to have been more than offset by weight gain. Highly cross-linked polyethylene was significantly more wear resistant than non- or nominally cross-linked polyethylene. The differences in wear rates between the two highly cross-linked polyethylene designs (9.5 EB or 10 Gamma) are probably too small to be clinically significant. © 2003 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved. [source] Inhibition of localized thrombosis in P2Y1 -deficient mice and rodents treated with MRS2179, a P2Y1 receptor antagonistJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 6 2003N. Lenain Summary., Previous studies in experimental models revealed a role for the P2Y1 platelet ADP receptor in systemic vascular thromboembolism models. In the present work, we used models of localized arterial and venous thrombosis to assess the role of the P2Y1 receptor in these processes. Arterial thrombosis was induced in one mesenteric arteriole of a mouse using FeCl3, while venous thrombosis was studied in a Wessler model adapted to rats. P2Y1 -deficient mice and mice treated with the P2Y1 antagonist MRS2179 displayed significantly less arterial thrombosis than their respective controls. Combination of P2Y1 deficiency with P2Y12 inhibition led to a significant additive effect. Venous thrombosis was slightly but significantly inhibited in MRS2179-treated rats. These results demonstrate a role for the P2Y1 receptor in both arterial and venous thrombosis, further establishing this receptor as a potential target for antithrombotic drugs. [source] Immunohistochemical localization of angiotensin II receptor types 1 and 2 in the mesenteric artery from spontaneously hypertensive ratsMICROSCOPY RESEARCH AND TECHNIQUE, Issue 8 2007Carmen Diniz Abstract Angiotensin II plays a crucial role in the control of blood pressure, acting at AT1 or AT2 receptors, and can act as a potent vasoconstrictor of the peripheral vasculature inducing hypertrophy, hyperplasia, or both, in resistance arteries. The aim of the present study was to investigate whether the pattern of distribution of angiotensin AT1 and AT2 receptors on mesenteric artery sections differs in spontaneously hypertensive rats (SHR) versus their respective controls (Wistar,Kyoto [WKY] rats). Immunohistochemistry using anti-AT1 or anti-AT2 antibodies was performed on perfused-fixed/paraffin-embedded mesenteric arteries from SHR and WKY rats. 3,3,-Diaminobenzidine tetrahydrochloride (DAB; activated by hydrogen peroxide) staining revealed distinct AT1 and AT2 labeling of all artery layers (adventitia, media and intima) from WKY rats, whereas in SHR an abundant AT1 labeling was found in both intima and adventitia and a sparser labeling in the media. There was a vast reduction of AT2 labeling throughout all layers. These results suggest a crucial role for AT2 receptors in the pathogenesis of hypertension. Microsc. Res. Tech., 2007. © 2007 Wiley-Liss, Inc. [source] Overexpression of cyclin D2 is associated with increased in vivo invasiveness of human squamous carcinoma cellsMOLECULAR CARCINOGENESIS, Issue 3 2002Shao Chen Liu Abstract Overexpression of cyclin D2 was studied in 10 human squamous cell carcinoma lines, to establish whether this gene plays a role in tumor progression. We found that those cell lines that overexpressed cyclin D2 (CCND2) had the most invasive in vivo behavior. The invasive ability of the cell lines was determined by evaluating the penetration of carcinoma cells into the tracheal wall in an in vivo assay with de-epithelialized tracheas transplanted into the subcutaneous tissue of nude mice. From five cell lines that exhibited low invasive ability, we selected two that had very little CCND2 expression (SCC9 and SCC15), to evaluate whether CCND2 gene transfer would increase the invasive behavior. After confirming the successful transfer of CCND2 by Northern, Western, and kinase-activity assays, we assessed the in vivo invasive behavior of the CCND2 -transfected cells and their respective vector alone,transfected controls. The cell lines containing the transferred CCND2 gene had a significantly higher invasive ability than respective controls. This was accompanied by a moderate increase in gelatinase activity. In addition, the in vitro proliferative abilities, under normal culture conditions, of the parental CCND2 - transfected and vector alone,transfected cells were found to be similar, as was the in vivo labeling index of Ki-67 in the tracheal transplants. These results indicated that the overexpression of CCND2 in squamous cell carcinoma lines modulates cell proliferation after induced quiescence and also has a powerful enhancing effect on in vivo aggressive growth behavior. © 2002 Wiley-Liss, Inc. [source] Insect herbivores and their frass affect Quercus rubra leaf quality and initial stages of subsequent litter decompositionOIKOS, Issue 1 2008Christopher J. Frost Defoliation-induced changes in plant foliage are ubiquitous, though factors mediating induction and the extent of their influence on ecosystem processes such as leaf litter decomposition are poorly understood. Soil nitrogen (N) availability, which can be affected by insect herbivore frass (feces), influences phytochemical induction. We conducted experiments to test the hypotheses that insect frass deposition would (1) reduce phytochemical induction following herbivory and (2) increase the decomposition and nutrient release of the subsequent leaf litter. During the 2002 growing season, 80 Quercus rubra saplings were subjected to a factorial experiment with herbivore and frass manipulations. Leaf samples were collected throughout the growing season to measure the effects of frass deposition on phytochemical induction. In live foliage, herbivore damage increased tannin concentrations early, reduced foliar N concentrations throughout the growing season, and lowered lignin concentrations in the late season. Frass deposition apparently reduced leaf lignin concentrations, but otherwise did not influence leaf chemistry. Following natural senescence, litter samples from the treatment groups were decomposed in replicated litterbags for 18 months at the Coweeta Hydrologic Laboratory, NC. In the dead litter samples, initial tannin concentrations were lower in the herbivore damage group and higher in the frass addition group relative to their respective controls. Tannin and N release rates in the first nine months of decomposition were also affected by both damage and frass. However, decomposition rates did not differ among treatment groups. Thus, nutrient dynamics important for some ecosystem processes may be independent from the physical loss of litter mass. Overall, while lingering effects of damage and even frass deposition can therefore carry over and affect ecosystem processes during decomposition, their effects appear short lived relative to abiotic forces that tend to homogenize the decomposition process. [source] Influence of high-pressure processing on selected polymeric materials and on the migration of a pressure-transmitting fluidPACKAGING TECHNOLOGY AND SCIENCE, Issue 5 2002A. Schauwecker Abstract This study investigated the migration of 1,2-propanediol (PG) through selected food packaging films exposed to high-pressure processing (HPP). Pouches made from these materials were filled with 95% ethanol as a food-simulating liquid. These packages were then processed using a pilot-scale high-pressure food processor at 400, 600 and 827,MPa and 30, 50 and 75°C for 10,min. Controls were processed at similar temperatures and times, but at atmospheric pressure. To investigate any structural changes to these films during HPP, water was used as the food simulant at temperatures of 30, 75, 85, 90 and 95°C and at pressures of 200, 400, 690 and 827,MPa. No detectable PG migration into the polyester/nylon/aluminium (Al) polypropylene (PP) meal-ready-to eat (MRE)-type pouches was observed. PG migration into the nylon/ethylene vinyl alcohol (EVOH)/PE (EVOH) pouches was similar at 30, 50 and 75°C after 10,min under atmospheric pressure. However, PG migration into the EVOH pouches significantly decreased when treated with high pressure at 30, 50 and 75°C. At 75 and 50°C, the PG migration was significantly higher than the amounts detected at 30°C. Visible signs of delamination between the polypropylene (PP) and aluminum (Al) layers were observed in the MRE pouches processed at ,200,MPa and 90°C for 10,min. This delamination appeared to occur between the PP and Al layers. The differential scanning calorimetric analyses and Fourier transform infrared (FTIR) spectra were similar for the high-pressure treated pouches when compared to their respective controls. This indicated that there were no HPP-induced molecular changes to the treated pouches. Results from this study should be useful to HPP users for predicting PG migration trends and in deciding the selection of appropriate packaging materials for use under similar processing conditions. Copyright © 2002 John Wiley & Sons, Ltd. [source] Protective immunization of calves against Ostertagia ostertagi using fourth stage larval extractsPARASITE IMMUNOLOGY, Issue 9-10 2010A. M. HALLIDAY Summary ConA lectin was used to isolate glycoproteins from detergent extracts of fourth stage Ostertagia ostertagi larvae. This preparation contained proteins additional to those observed in a similar fraction prepared from adult O. ostertagi. Two vaccine trials were conducted with this preparation, and sub-fractions thereof, in groups of 6,8 worm-free calves. All groups were challenged with 50 000 O. ostertagi larvae 1 week after the final immunization, and protection was assessed by comparing the egg and worm counts of the immunized groups with their respective controls. Immunization with the ConA-binding antigen or its sub-fractions induced high titre serum antibody responses. In the first trial, the cumulative egg count of the group immunized with unfractionated antigen was 60% lower than the corresponding control value, and worm counts were 47% lower. In the second trial, the cumulative egg counts of the vaccinated groups ranged from 70% to 85% lower than the corresponding controls, with worm counts up to 64% lower. It was concluded that detergent-soluble, ConA-binding extracts prepared from O. ostertagi fourth stage larvae contained protective immunogens that were as effective as the best antigens published for O. ostertagi to date. [source] Effects of fertilization on understorey vegetation in a Norwegian Pinus sylvestris forestAPPLIED VEGETATION SCIENCE, Issue 2 2002Astrid Skrindo Abstract. Boreal coniferous forests have been impacted by long distance airborne pollutant deposition for most of the 20th century. Changes in forest understorey vegetation attributable to N-deposition have been observed in southern Sweden, but not so far in southern Norway. We recorded the quantity of all species of vascular plants, bryophytes and lichens in 144 plots in a fertilization experiment in a 35-yr old Pinus sylvestris forest in Aust Agder County, southernNorway initiated 6 yr before our study. Each plot represented a combination of three levels of nitrogen, two levels of magnesium and two levels of phosphorus addition. Effects of fertilization on species quantity were tested by Kruskal-Wallis one-way analysis by ranks. For vascular plants, only small and hardly significant differences were found between treatments and control. Significant negative effects of N-fertilization were found on both mosses and lichens. To some extent, these effects could be attributed to direct effects of application of the fertilizer, but were more likely to be due to a negative feedback response to the faster growth of pine trees in fertilized stands, reducing throughfall precipitation and increasing litter fall. Significant differences between Mg- and P-fertilized sites and respective controls were found for too few species to be likely to represent an overall trend. [source] Decreased expression of heparin-binding epidermal growth factor,like growth factor as a newly identified pathogenic mechanism of antiphospholipid-mediated defective placentationARTHRITIS & RHEUMATISM, Issue 5 2010N. Di Simone Objective Heparin-binding epidermal growth factor,like growth factor (HB-EGF) plays a role in blastocyst implantation and is down-regulated in preeclampsia and in hypertensive pregnancy disorders associated with defective extravillous trophoblast invasion. Defective placentation and severe preeclampsia are also features of the antiphospholipid syndrome (APS). The purpose of this study was to investigate whether abnormal HB-EGF expression plays a pathogenic role in antiphospholipid antibody (aPL),mediated defective placentation. Methods HB-EGF expression in placental tissue was evaluated by Western blotting and messenger RNA analysis in normal and APS placentae. Polyclonal IgG fractions or monoclonal ,2 -glycoprotein I,dependent aPL and their respective controls were investigated for the following 4 features: their binding to human trophoblast monolayers, as determined by cell enzyme-linked immunosorbent assay (ELISA); their effect on HB-EGF expression by Western blotting in trophoblast cell extracts as well as by ELISA as a protein secreted in the culture supernatants; their inhibitory effect on in vitro trophoblast invasiveness, as evaluated by Matrigel assay; and their inhibitory effect on matrix metalloproteinase (MMP) levels, as measured by gelatin zymography. Experiments were also performed in the presence of serial concentrations of heparin or recombinant HB-EGF. Results Placental APS tissue displayed reduced expression of HB-EGF. Polyclonal and monoclonal aPL bound to trophoblast monolayers and significantly reduced the in vitro synthesis and secretion of HB-EGF. Heparin inhibited aPL binding and restored HB-EGF expression in a dose-dependent manner. Addition of recombinant HB-EGF reduced the in vitro aPL-induced inhibition of Matrigel invasiveness as well as MMP-2 levels. Conclusion These preliminary findings suggest that the reduction of aPL-mediated HB-EGF represents an additional mechanism that is responsible for the defective placentation associated with APS and that heparin protects from aPL-induced damage by inhibiting antibody binding. [source] Acceleration of germination and early growth of wheat and bean seedlings grown under various magnetic field and osmotic conditionsBIOELECTROMAGNETICS, Issue 2 2010Turgay Cakmak Abstract Magnetic field (MF) can have different effects on plant metabolism depending on its application style, intensity, and environmental conditions. This study reports the effects of different intensities of static MF (4 or 7,mT) on seed germination and seedling growth of bean or wheat seeds in different media having 0, 2, 6, and 10 atmosphere (atm) osmotic pressure prepared with sucrose or salt. The germination percentages of the treated seeds were compared with untreated seeds germinated in different osmotic pressure during 7 days of incubation. The application of both MFs promoted the germination ratios of bean and wheat seeds, regardless of increasing osmotic pressure of sucrose or salt. Growth data measured on the 7th day showed that the treated plants grew faster than control. After 7 days of incubation, the mean length of treated seedlings was statistically higher than control plants in all the media. The greatest germination and growth rates in both plants were from the test groups exposed to 7,mT MF. Strikingly, effects of static MF on germination and growth increased positively with increasing osmotic pressure or salt stress compared to their respective controls. On the other hand, MF application caused an increase in dry biomass accumulation of root and shoots of both seedlings; however, this effect was found statistically important in all the conditions for wheat but not for bean, in general. Bioelectromagnetics 31:120,129, 2010. © 2009 Wiley-Liss, Inc. [source] The effects of dietary flaxseed on the Fischer 344 rat.CELL BIOCHEMISTRY AND FUNCTION, Issue 6 2005Abstract The hepatotoxic effect of carbon tetrachloride (CCl4) administered by gavage at 0.25,ml CCl4 (1:1 in olive oil) per 100,g body weight was examined 24,h later in regular chow fed (RC) and 10% flax chow fed (FC) male and female Fischer 344 rats. CCl4 -treated RC rats were subdued, lethargic and unkempt. CCl4 -treated FC rats were much less affected. CCl4 treatment resulted in loss of weight in RC and FC rats. In males, the weight loss was 6.7% body mass in RC rats compared to 5.6% body mass in FC rats. In females, the weight loss was 7.5% body mass in both RC and FC rats. While CCl4 treatment increased the level of the liver injury marker plasma alanine aminotransferase (ALT) in RC rats, this CCl4 effect was significantly attenuated in FC rats. In male rats, the ALT increase was 435-fold in RC rats and 119-fold in FC rats, over that of their respective controls. In female rats, the ALT increase was 454-fold in RC rats and 381-fold in FC rats, over that of their respective controls. These results provide evidence that flax consumption protects the liver against injury and that the extent of the protection is sex dependent. CCl4 had no effect on the plasma level of ,-glutamyltranspeptidase (,GT) in RC and FC rats supporting the contention that plasma ,GT is not a useful marker for acute liver injury which is seen in this model. The activity of ,GT was increased in the livers of FC rats compared to RC rats: 2.7-fold in males and 1.5-fold in females. In RC rats, the activity of liver ,GT was decreased by CCl4 treatment: 70% in the male and 25% in the female. However, this CCl4 effect was reversed or abolished by flax consumption. Compared to RC rats: in male FC rats, CCl4 actually increased the activity of liver ,GT 1.28-fold; while in female FC rats, the depressing effect of CCl4 treatment was abolished. The flax-induced preservation of ,GT in the liver in response to injury may be involved in the observed hepatoprotection through generation of GSH. In RC male rats, CCl4 treatment effected a 25% reduction in plasma glucose levels. There was no decrease in CCl4 -treated FC male rats. In female rats, CCl4 treatment effected a 21% decrease in plasma glucose levels in both RC and FC rats. In conclusion, multiple parameters for acute CCl4 -induced injury were attenuated in the FC compared to the RC rat. That flaxseed consumption conferred greater protection against liver injury in the male than in the female suggests an involvement of the estrogenic lignan component of flaxseed. We discuss the possibility that this hepatoprotection is through a flax lignan-induced increase in reduced glutathione related to a flax effect on the activity of liver ,GT in the resting state and the maintenance of its activity in response to injury. Copyright © 2005 John Wiley & Sons, Ltd. [source] 1,,25-Dihydroxyvitamin D3 inhibits rat liver ultrastructural changes and the development of ,-glutamyltranspeptidase-positive foci in diethylnitrosamine-initiated and streptozotocin-induced diabetes-promoted hepatocarcinogenesisCELL BIOCHEMISTRY AND FUNCTION, Issue 3 2002Barun Kanti Saha Abstract In the present study, the chemopreventive effect of the active metabolite of vitamin D, 1,,25-dihydroxyvitamin D3 (VD3), against chemically-induced and diabetes-promoted rat liver carcinogenesis was investigated. Hepatocarcinogenesis was initiated with a single intraperitoneal (i.p.) injection of diethylnitrosamine (DEN) (125 mg kg,1 body weight) at week 4 followed by promotion with streptozotocin (STZ) (65 mg kg,1 body weight with a single i.p. injection) at week 7. With this basic experimental regimen, the effect of VD3 (0.3 ,g (0.1 ml),1 propylene glycol per os twice a week) was investigated with effect from 4 weeks prior to the exposure of DEN. The results showed that VD3 supplementation throughout the experimental period reduced the incidence, total number and multiplicity and altered the size of visible persistent nodules (PNs) in DEN- or DEN,+,STZ-treated rats as compared with their respective controls. In these two groups, it also caused a significant decrease in the number (p,<,0.002 and 0.001 respectively) and focal area (p,<,0.05) of ,-glutamyltranspeptidase (GGT)-positive hepatic foci. Moreover, continuous supplementation of VD3 exhibits a protective effect in maintaining the normal cellular architecture of the hepatocytes in DEN- or DEN,+,STZ-treated rats. Our results thus strongly suggest that VD3 is very effective in the inhibition of DEN-initiated and STZ-induced diabetes-promoted rat liver carcinogenesis. Copyright © 2002 John Wiley & Sons, Ltd. [source] Overexpression of cysteine proteinase 2 in Entamoeba histolytica or Entamoeba dispar increases amoeba-induced monolayer destruction in vitro but does not augment amoebic liver abscess formation in gerbilsCELLULAR MICROBIOLOGY, Issue 1 2001A. Hellberg To study the role of cysteine proteinases in the pathogenicity of Entamoeba histolytica, we have attempted to overexpress the three main cysteine proteinases (EhCP1, EhCP2, EhCP5) of this parasite in trophozoites of E. histolytica as well as in non-pathogenic Entamoeba dispar by episomal transfection. Although each of the corresponding coding sequences were cloned in identical expression plasmids, we were unable to overexpress EhCP1 and EhCP5, respectively, but could substantially induce expression of EhCP2 in both amoeba species by sevenfold, leading to a threefold increase in total cysteine proteinase activity. Overexpression of EhCP2 did not influence expression of other cysteine proteinases and could be attributed to an increase of a single 35 kDa activity band in substrate gel electrophoresis. In contrast to previous findings, which indicated that amoeba cysteine proteinases are involved in erythrophagocytosis and liver abscess formation, cells overexpressing EhCP2 showed no difference in erythrophagocytosis or liver abscess formation compared with respective controls. However, overexpression of EhCP2 in both amoeba species resulted in a marked increase of in vitro monolayer destruction. [source] The role of docosahexaenoic acid on visual evoked potentials in one kidney-one clip hypertensionACTA OPHTHALMOLOGICA, Issue 4 2006Gulay Hacioglu Abstract. Purpose:, To investigate the effects of polyunsaturated fatty acid (PUFA) docosahexaenoic acid (DHA) on visual evoked potentials (VEPs) in a one kidney-one clip (1K-1C) hypertension model in rats. Methods:, Five experimental groups were formed: a control group, a sham group, a group supplemented with DHA, a 1K-1C group, and a 1K-1C + DHA group. The DHA groups were treated for 60 days. In the 1K-1C groups, the right kidney was removed and a silver clip with a 0.2-mm gap was placed on the left renal artery. Results:, The DHA-supplemented rats had lower blood pressure than their respective controls (p < 0.01). The increased brain and retina thiobarbituric acid reactive substances (TBARS) levels in hypertensive rats were abolished by DHA administration. The brain nitrite levels were lower in the DHA, 1K-1C and 1K-1C + DHA groups compared with the control group (p < 0.01), and the retina nitrite level was higher in the 1K-1C + DHA group compared with the DHA and 1K-1C groups (p < 0.01). There was an improvement of P2, N2 and P3 components following DHA supplementation in 1K-1C hypertensive rats compared with the 1K-1C group. Conclusion:, The present study suggests that DHA supplementation has the potential to prevent VEP changes caused by an experimental model of hypertension. This state might be related to the lipid peroxidation lowering effect of DHA. [source] | ||||||||||||||||