Academic literature on the topic 'Bromine Physiological effect'

Abstract. Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the role of organic bromine species during desiccation is less well understood. In this study the emission of dibromomethane (CH2Br2) and bromoform (CHBr3) during exposure and desiccation of two common temperate macroalgae, Fucus vesiculosus and Ulva intestinalis, is reported. Determination of the impact exposure may have on algal physiological processes is difficult as intertidal species are adapted to desiccation and may undergo varying degrees of desiccation before their physiology is affected. For this reason we include comparisons between photosynthetic capacity (Fv/Fm) and halocarbon emissions during a desiccation time series. In addition, the role of rewetting with freshwater to simulate exposure to rain was also investigated. Our results show that an immediate flux of bromocarbons occurs upon exposure, followed by a decline in bromocarbon emissions. We suggest that this immediate bromocarbon pulse may be linked to volatilisation or emissions of existing bromocarbon stores from the algal surface rather than the production of bromocarbons as an antioxidant response.

Abstract. Exposure of intertidal macroalgae during low tide has been linked to the emission of a variety of atmospherically-important trace gases into the coastal atmosphere. In recent years, several studies have investigated the role of inorganic iodine and organoiodides as antioxidants and their emission during exposure to combat oxidative stress, yet the role of organic bromine species during desiccation is less well understood. In this study the emission of dibromomethane (CH2Br2) and bromoform (CHBr3) during exposure and desiccation of two common temperate macroalgae, Fucus vesiculosus and Ulva intestinalis, is reported. Determination of the impact exposure may have on algal physiological processes is difficult as intertidal species are adapted to desiccation and may undergo varying degrees of desiccation before their physiology is affected. For this reason we include comparisons between photosynthetic capacity (Fv / Fm) and halocarbon emissions during a desiccation time series. In addition, the role of rewetting with freshwater to simulate exposure to rain was also investigated. Our results show that an immediate flux of bromocarbons occurs upon exposure, followed by a decline in bromocarbon emissions. We suggest that this immediate bromocarbon pulse may be linked to volatilisation or emissions of existing bromocarbon stores from the algal surface rather than the production of bromocarbons as an antioxidant response.

Novel homologous series: RO-C6H4-COO-C6H3-Br-CO-CH=CH-C6H4-OC18H3 (n) (ortho bromo to –COO-) is synthesized and studied with a view to understand and establish the relation between mesomorphic properties and the molecular structure with reference to lateral substitution of bromine (-Br) at middle phenyl ring. Chalconyl homologous series consists of thirteen between (C1 to C18) homologues. Nematogenic mesomorphism commences from C5 homologue and continue up to C18 homologue in enantiotropic manner. Transition and melting points were determined by an optical polarizing microscopy (POM) equipped with a heating stage. Textures of nematic phase are threaded or schlieren. Transition curve Cr-N/I behaved in normal manner. N-I transition curve exhibited odd-even effect up to C8 homologue. It (N-I) rises and fall with negligible deviations from its normal descending tendency which appears in case of homologues C10 to C18. Thermal stability for nematic is 142.89 °C and the mesophase lengths vary minimum 8.0 °C to maximum 26.0 °C at the C7 and C8 homologue respectively. Liquid Crystal properties of present series are evaluated and compared with structurally analogous series and relative group efficiency order derived. Thus ,present series is predominantly nematogenic with absence of Smectic property. Analytical and spectral data supported moleculars of homologues.

This study was conducted to investigate the ameliorative effect of lactic acid bacteria Lactobacillus casei and Lactobacillus acidophilus against Potassium bromate (25, 50) mg / kg toxicity by some physiological indicators in 35 of female rats after 21 days. The animals were divided into 7 groups within each group 5 animals weighted 140 – 155 g. The results showed a significant decrease (P<0.05) in value of Red blood cells (RBC), hemoglobin (Hb), White blood cells (WBC), Lymphocyte (LYM) and Platelets (PLT), While increasing the values of Granules (GRN). Also found that the addition of Potassium bromate Potassium bromate led to increase in cholesterol, triglyceride (TG), Low Density Lipoprotein (LDL) and blood glucose, while decreased the values of High Density Lipoprotein (HDL) for rats groups with increasing the concentration of Potassium bromate compared with control group. The addition of two types of lactic acid bacteria L. casei and L. acidophilus with Potassium bromate showed a positive effect to reducing the negative effect of Potassium bromate on blood and lipid profile parameters compared with the control group and Potassium bromate group. It is concluded that the lactic acid bacteria has protective effects and reduces the effects that Potassium bromate.

Recent studies suggest that proinsulin-connecting peptide (C-peptide) may exhibit characteristics of a hormone and show physiological functions in various tissues. This study was aimed to determine whether C-peptide could be involved in the regulation of lipolysis, adiponectin release, and function of mesenchymal stem cells (MSCs) in adipose tissue. Human subcutaneous adipose tissue was cultured in the presence of C-peptide. The level of lipolysis was determined by glycerol measurement in the conditioned media. Effect of C-peptide on adiponectin secretion was evaluated in differentiated adipocytes. The adipogenic and osteogenic abilities of adipose MSCs were evaluated using oil red and alizarin red staining, respectively. The tetrazolium bromide test was conducted for evaluating the effect of C-peptide on MSCs proliferation. C-peptide induced a significant decrease in basal lipolysis at concentrations of 8 and 16 nM (p < 0.05). It had no significant effects on isoproterenol-stimulated lipolysis, adiponectin secretion, and adipogenic or osteogenic differentiation of MSCs. At a concentration of 4 nM, this peptide significantly increased the proliferative capability of MSCs (p < 0.05). These results suggest that C-peptide has some physiological effects in human subcutaneous adipose tissue and contributes to the regulation of basal lipolysis and pool of MSCs.

The corrosion behaviour of cationic surfactants, namely: cetyl trimethyl ammonium bromide (CTAB) and dodecyl trimethyl ammonium bromide (DTAB), have been used as corrosion inhibitors for carbon steel in well water. Protection efficiencies of the studied surfactants were depended on the hydrophobic chain length and concentration of the surfactants. The results shows that the order of protection efficiency is CTAB > DTAB. Tafel curves showed these surfactants are acting as an anodic inhibitors. Nyquist curves revealed that a protective film is formed on the metal surface. FTIR spectra suggest that the tested surfactants protective film consists of Fe2+-CTAB, Fe2+-DTAB and Zn(OH)2. Protection efficiency values and synergism parameters obtained weight loss; potentiodynamic polarization and electrochemical impedance spectroscopy are consistent.

AbstractThe effect of ionic strength on DNA condensation by cationic liposomes prepared as a mixture of ethane-1,2-diylbis(dodecyl-dimethylammonium bromide) (C2GS12) and dioleoylphosphatidylcholine (DOPC) was studied using fluorescence spectroscopy. The DNA condensation followed by changes in emission intensity of ethidium bromide shows a strong dependence on the ionic strength of the solution. At physiologically relevant ionic strength (0.15 mol/l NaCl), the amount of DNA condensed between lipid bilayers is approximately 40% lower compared to 0.005 mol/l NaCl. The structure of formed complexes was studied using small angle X-ray diffraction (SAXD). DNA–C2GS12–DOPC complexes form a condensed lamellar phase organisation, which is partially disrupted by the increase of ionic strength. Both the lamellar repeat distance and DNA–DNA distance show dependence on C2GS12/DOPC molar ratio, temperature and also on ionic strength. We found that the method of preparation significantly affects both the quality of organisation and the structural parameters of complexes as discussed in the paper.

Insulin is a cytokine which promotes cell growth. Recently, a few published reports on insulin in different cell lines support the antiapoptotic effect of insulin. But the reports fail to explain the role of insulin in modulating glutamate-mediated neuronal cell death through excitotoxicity. Thus, we examined the neuroprotective effect of insulin on glutamate-induced toxicity on differentiated SH-SY5Y neuronal cells. Changes in cell viability were measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTT) based assay, while apoptotic damage was detected by acridine orange/ethidium bromide and Hoechst staining. Intracellular reactive oxygen species (ROS) accumulation and morphological alterations were also measured. Treatment with glutamate induced apoptosis, elevated ROS levels and caused damage to neurons. Insulin was able to attenuate the glutamate-induced excitotoxic damage to neuronal cells.

Cell apoptosis or programmed cell death is a physiological phenomenon during the development of the body; however, under certain pathological conditions, insufficient, or excessive apoptosis can cause tissue damage and physiological dysfunction. This study investigated the inhibition of oxidized low-density lipoprotein (oxLDL)-induced macrophage apoptosis in mice with coronary heart disease by regulating the target Fasassociated protein with death domain (FADD) gene. We used Western blotting to measure the effect of oxLDL on mouse macrophages and observe the effects of adding simvastatin, 3-methyladenine (3-MA), self-blocking, and other drugs. The results indicated that the target FADD gene played an important role in inhibiting lactate dehydrogenase release by 13%, in the process of oxLDL-induced lipid aggregation in macrophages. The EC50 observed by dual acridine orange/ethidium bromide fluorescence-staining accounts for the proportion of FADD being reduced by 32%, indicating that the target FADD gene exhibited a significant inhibitory effect on oxLDL-induced macrophage apoptosis in coronary heart disease. This study used a novel chitosan-lipid nanoparticle as a gene carrier to significantly improve efficacy. Therefore, targeting the FADD gene using novel chitosan-lipid nanoparticles to deliver siRNA could be a potential clinical treatment in coronary heart disease.

Assessment of a significant number of water samples across South Africa by Casey and Meyer over a number of years, revealed that high concentrations (30- 32 mg/L) of bromine (Br) occur naturally within groundwater in South Africa, hence a potentially hazardous chemical constituent (PHCC). Br, the only liquid non-metallic element, is ubiquitous and an abundant trace element, but it has not been conclusively shown to perform essential functions in plants, micro organisms or animals (NRC, 2005). The recommended limit (maximum limit for no risk) for Br in drinking water was set at 1 mg/L by Kempster et al. (1980); Casey and Meyer (2001) recommend the relevant safety guideline for Br to be 0.01 mg/L. The aim of this project was to establish the effect of Br and iodine (I) in drinking water on the physiological parameters of broilers. This will contribute to verifying and refining water quality guidelines. The effect of six treatments administered as sodium bromide (NaBr) and potassium iodide (KI): 0 mg Br/L and 0 mg I/L; 1 mg Br/L; 1mg Br/L and 0.7 mg I/L; 0.7 mg I/L; 3 mg Br/L; 3 mg Br/L and 0.7 mg I/L, in the drinking water of 540 mixed Ross broiler chickens was investigated. The trial ran over a 42-day growth period from Day 1 post-hatching where mortalities, water and feed intakes were recorded daily. Chickens were weighed weekly and slaughtered at 4 and 6 weeks of age. Blood samples were taken before slaughter and free T3 and T4 hormone levels were quantified. Thyroid gland, liver and kidney samples were analysed for Br and I quantity. The different treatments of Br, irrespective of I, significantly decreased water intake (P=0.0232) and feed intake (P=0.0035) over the 42 days. The overall interaction of Br and I had no significant effect on water (P=0.0928) and feed (P=0.9593) intakes thus I did have an effective ameliorating effect on Br. FCR, weight gain and mortalities were not significantly affected by Br intake. This was also found for free T3 and T4 hormone levels. Br had an overall effect on the thyroid gland (P=0.0457), liver (P=0.0025) and kidney (P=0.0032) with accumulation of the PHCC within these three organs. It was apparent that 1 and 3 mg Br/L water administered to broilers or ingestion rates of 1.59 and 4.44 mg Br/L per bird per day, over a production period of 42 days did affect the production parameters of the birds sub-clinically. Another derivation to refine the water quality guidelines was that the administration of 0.7 mg I/L water or ingestion rates of 1.1 mg I/L per bird per day did alleviate the severe detrimental effect of the high PHCC. The 3 mg Br/L guideline is thus not too restrictive. Further research exposing the animals for a longer time period (exceeding 42 days) and exposing mature animals (producing nutritional products for human consumption) to these treatments would assist in quantifying these results.
Dissertation (MSc(Agric))--University of Pretoria, 2011.
Animal and Wildlife Sciences
unrestricted

The overall objective of this research was to elucidate the horticultural, pathological, physiological and molecular factors impacting melon varieties (scion) grafted onto M. cannonballus resistant melon and squash rootstocks. Specific objectives were- to compare the performance of resistant melon germplasm (grafted and non-grafted) when exposed to M. cannoballus in the Lower Rio Grande valley and the Wintergarden, Texas, and in the Arava valley, Israel; to address inter-species relationships between a Monosporascus resistant melon rootstock and susceptible melon scions in terms of fruit-set, fruit quality and yield; to study the factors which determine the compatibility between the rootstock and the scion in melon; to compare the responses of graft unions of differing compatibilities under disease stress, high temperatures, deficit irrigation, and salinity stress; and to investigate the effect of rootstock on stress related gene expression in the scion. Some revisions were- to include watermelon in the Texas investigations since it is much more economically important to the state, and also to evaluate additional vine decline pathogens Didymella bryoniae and Macrophomina phaseolina. Current strategies for managing vine decline rely heavily on soil fumigation with methyl bromide, but restrictions on its use have increased the need for alternative management strategies. Grafting of commercial melon varieties onto resistant rootstocks with vigorous root systems is an alternative to methyl bromide for Monosporascus root rot/vine decline (MRR/VD) management in melon production. Extensive selection and breeding has already produced potential melon rootstock lines with vigorous root systems and disease resistance. Melons can also be grafted onto Cucurbita spp., providing nonspecific but efficient protection from a wide range of soil-borne diseases and against some abiotic stresses, but compatibility between the scion and the rootstock can be problematic. During the first year experiments to evaluate resistance to the vine decline pathogens Monosporascus cannonballus, Didymella bryoniae, and Macrophomina phaseolina in melon and squash rootstocks proved the efficacy of these grafted plants in improving yield and quality. Sugars and fruit size were better in grafted versus non-grafted plants in both Texas and Israel. Two melons (1207 and 124104) and one pumpkin, Tetsukabuto, were identified as the best candidate rootstocks in Texas field trials, while in Israel, the pumpkin rootstock RS59 performed best. Additionally, three hybrid melon rootstocks demonstrated excellent resistance to both M. cannonballus and D. bryoniae in inoculated tests, suggesting that further screening for fruit quality and yield should be conducted. Experiments with ABA in Uvalde demonstrated a significant increase in drought stress tolerance and concurrent reduction in transplant shock due to reduced transpiration for ‘Caravelle’ plants. In Israel, auxin was implicated in reducing root development and contributing to increased hydrogen peroxide, which may explain incompatibility reactions with some squash rootstocks. However, trellised plants responded favorably to auxin (NAA) application at the time of fruit development. Gene expression analyses in Israel identified several cDNAs which may code for phloem related proteins, cyclins or other factors which impact the graft compatibility. Manipulation of these genes by transformation or traditional breeding may lead to improved rootstock cultivars. Commercial applications of the new melon rootstocks as well as the ABA and TIBA growth regulators have potential to improve the success of grafted melons in both Israel and Texas. The disease resistance, fruit quality and yield data generated by the field trials will help producers in both locations to decide what rootstock/scion combinations will be best.