The relationship between UV-irradiance, photoprotective compounds and DNA damage in two intertidal invertebrates with contrasting mobility characteristics

The photoprotective role of mycosporine-like amino acids (MAA) against the generation of DNA cyclobutane pyrimidine dimers (CPD) was studied in the sessile intertidal anemone Actinia tenebrosa and the mobile intertidal gastropod Diloma aethiops through 27months at a mid-latitude New Zealand location. MAA were sequestered by A. tenebrosa and D. aethiops from their diet, although maximum total MAA levels in both species were not correlated with seasonal variation in maximum ambient UV-B levels recorded at the collection site. Temporal changes in total MAA in A. tenebrosa showed a six months lag-time in their concentration regarding to the environmental UV-B levels. This lag period corresponded to an observed increase in CPD production from spring to summer; suggesting that MAA do not completely protect the anemone from UV-B during summer. For D. aethiops, total MAA concentrations did not change significantly during the study, although qualitative changes in MAA were apparent. A month lag-time in MAA concentration in D. aethiops and possibly the physical barrier that the shell confers to the animal, can explain reduced CPD levels in comparative terms with A. tenebrosa. Although MAA are used by invertebrates for photoprotection, contrasting mobility characteristics and the presence of physical adaptations can confer them important protection levels during temporal changes of UV-B at mid-latitude places of the Southern Hemisphere.

Cellular changes associated with the acclimation of the intertidal sea anemone Actinia tenebrosa to ultraviolet radiation

To assess the relative importance of long- and short-term cellular defense mechanisms in seasonally UV-R-acclimated Actinia tenebrosa (Anthozoa, Actiniidae), individuals were exposed to summer doses of PAR, UV-A, UV-B and enhanced UV-B (20%) for a period of 4 days. Mycosporine-like amino acids (MAAs) and cyclobutane pyrimidine dimer (CPD) concentrations were quantified, while oxidative damage to lipids and proteins, and the activities or levels of the antioxidant enzymes SOD, CAT, GR, GPOX and total glutathione were determined. Our results show that summer UV-R-acclimated individuals had a higher UV-R tolerance, with no significant increases in CPDs levels, than winter-acclimated sea anemones possibly due to higher MAA concentrations. Summer-acclimated individuals showed increased lipid and protein oxidation and GPOX activity only when they were exposed to UV-B at 20% above ambient UV-R levels. In contrast, winter-acclimated sea anemones showed elevated levels of oxidative damage, GPOX and SOD activities after exposure to UV-A or UV-B at ambient and elevated levels. Thus, this study indicates that long-term UV-R acclimation mechanisms such as the accumulation of MAAs could be more important than short-term increases in antioxidant defenses with respect to reducing indirect UV-R damage in intertidal sea anemones.

P38 MAPK contributes to resistance and invasiveness of HER2- overexpressing breast cancer

Intrinsic or acquired resistance to the HER2-targeted therapy trastuzumab is a clinical concern in the treatment of patients with HER2-over-expressing metastatic breast cancers. We demonstrate here that multiple models of intrinsic and acquired resistance exhibit increased phosphorylation of p38 MAPK. Kinase inhibition of p38 rescued trastuzumab sensitivity in cells with acquired resistance. In addition, knockdown of p38 increased sensitivity to trastuzumab in an intrinsically resistant cell line. We previously reported that expression of growth differentiation factor 15 (GDF15) is increased in trastuzumab-resistant HER2-overexpressing breast cancer cells. In this study, we found that exogenous GDF15 or stable overexpression of GDF15 stimulated p38 phosphorylation in HER2-positive cells, suggesting a possible mechanism by which p38 is activated in resistant cells.GDF15 stable clones showed significantly increased invasiveness, which was rescued by p38 kinase inhibition, suggesting that p38 plays a role in the pro-invasive phenotype conferred by GDF15. Importantly, immunohistochemical analysis of a breast tumor tissue array indicated a significant (p=0.0053) correlation between HER2 and phosphorylated p38 specifically in GDF15-positive tissues. Our results suggest that p38 signaling drives trastuzumab resistance and invasiveness in HER2-overexpressing breast cancer. Upstream growth factor signals that have previously been implicated in trastuzumab resistance, such as GDF15, may contribute to the increased phosphorylation of p38 found in resistant cells.

Advanced oxidation treatment and photochemical fate of selected antidepressant pharmaceuticals in solutions of Suwannee River humic acid

Antidepressant pharmaceuticals have recently been detected at low concentrations in wastewater and surface water. This work reports studies of the direct and indirect photochemical fate and treatment by advanced oxidation of three antidepressant compounds (duloxetine, venlafaxine and bupropion) in solutions of humic acid in order to elucidate their behavior in the natural environment prior to reaching a water treatment facility and potentially entering a potable water supply. Humic acid solution was prepared by adding to distilled water a known amount of organic matter as a photosensitizer. All three antidepressants react very rapidly with hydroxyl radicals (·OH) and hydrated electrons (e(-)(aq)) with rate constants of ~10(8) to 10(10)M(-1)s(-1), but significantly slower with singlet oxygen ((1)ΔO(2)) (~10(3) to 10(5)M(-1)s(-1)). The steady-state concentrations of ·OH and (1)ΔO(2), in a sample of humic acid solution were measured and used with the second order rate constants to show that the hydroxyl radical was an order of magnitude more effective than the singlet oxygen in the solar-induced photochemical degradation of the antidepressants. Excited state dissolved organic matter also accounted for a substantial portion of degradation of duloxetine, decreasing its half-life by 27% under solar irradiation. Several reaction pathways and by-products arising from the photodegradation were identified using gamma-irradiation followed by LC-MS analysis.

Disposal practices for unused medications in New Zealand community pharmacies

INTRODUCTION

One of the recommended methods for households to dispose of unused medications in many countries is to return them to community pharmacies. However, such a practice will only reduce the environmental levels of pharmaceuticals if the medications are also disposed of and destroyed properly by the pharmacies.

AIM

This study reports the results of a questionnaire sent to New Zealand community pharmacists regarding disposal practices for unused or expired medications in their workplaces.

METHODS

A pre-tested, self-administered questionnaire was sent to 500 randomly selected community pharmacies from all areas of New Zealand. The participants were asked how they disposed of a variety of medications. In addition, participants were also asked about whether they knew how unused medications were destroyed if their pharmacy used a third-party contractor or distributor to dispose of them.

RESULTS

Of the 265 respondents, 80.4% and 61.1% respectively reported that solid and semi-solid medications were removed by contractors. However liquid and Class B controlled drugs were predominantly disposed of down the pharmacy sink. Over 60% of the participating pharmacists indicated that they believed the contractors incinerated the collected pharmaceutical waste, and over 90% of the participating pharmacists indicated their wish for a state-run disposal and destruction system.

DISCUSSION

Liquid medications and Class B controlled drugs, which were commonly reported to be disposed of down the sewage system, may increase the potential for environmental pollution by pharmaceuticals in New Zealand. There is a need for increased environmental awareness amongst community pharmacists in New Zealand.

Disposal practices for unused medications around the world

Pharmaceuticals have been detected throughout the environment where at least in some cases, they have been shown to have a detrimental effect. Many result from improper patient disposal of unused pharmaceuticals via environmentally-unfriendly routes, such as the sink, toilet or rubbish bin. This review surveys the current peer-reviewed literature on attitudes and practices to medicine disposal methods as reported by patients and the various medication disposal and destruction systems around the world. A literature search was carried out using the keywords 'medicines disposal', 'unused medicines', 'medicines wastage', and 'medication disposal' in the PubMed TM, ISI Web of Knowledge TM, Google Scholar TM, Medline TM, Scopus TM and International Pharmaceuticals Abstracts TM up to the end of May 2010. Twelve peer-reviewed articles with specified sample sizes were selected. The most popular methods for medication disposal were in the garbage, toilet or sink. Liquid medications were more likely to be rinsed down the sink, as opposed to solid tablets and capsules which were more likely deposited in the rubbish bin. Much confusion exists about the 'proper' way of medication disposal as many countries do not have standard medication disposal protocols. Furthermore, some pharmacies around the world refused to accept unused medications or discouraged the practice. Patients with knowledge about the impact of pharmaceuticals in the environment were more likely to return medications for proper disposal and destruction. It is concluded that it is of paramount importance that a formalized protocol for patient disposal and destruction of pharmaceuticals be implemented around the world.

In vivo seizure induction and affinity studies of domoic acid and isodomoic acids-D, -E and -F

Domoic acid and its isomers are produced via algal blooms and are found in high concentrations in shellfish. Here, we assessed the acute seizurogenic potencies of isomers-D, -E and -F and their binding affinities at heterogeneous populations of KA receptors from rat cerebrum. In addition, binding affinities of all six isomers (Iso-A through -F) were assessed at AMPA receptors. Radioligand displacement studies indicated that the seizurogenic potency of Iso-F (E-configuration) closely correlates with its affinities at both KA and AMPA receptors, whereas isomers-D (Z) and -E (E), which exhibit distinctly lower seizurogenic potencies, are quite weak displacers. Previously observed functional potencies for isomers-A, -B and -C (Sawant et al., 2008) correlated with AMPA receptor affinities observed here. Taken together, these findings call into question previous structure-activity rules. Significantly, in our hands, Iso-D was ten-fold less potent than Iso-F. To further explain observed links between structural conformation and functional potency, molecular modeling was employed. Modeling results closely matched the rank order of potency and binding data observed. We further assessed the efficacy of isomers-D, -E and -F as pharmacological preconditioning agents. Acute preconditioning with low-dose Iso-D, -E or -F, before high-dose DA failed to impart behavioural tolerance. This study has shed new light on structural conformations affecting non-NMDA ionotropic glutamate receptor binding and functional potency, and provides a foundation for future work in areas of AMPA and KA receptor modeling.

Disposal practices for unused medications in New Zealand

BACKGROUND

There is an enhanced international awareness that the improper disposal of unwanted and unused medications may have a detrimental effect on the environment.

OBJECTIVES

The aim of this study was to determine the proportion of unused medications in New Zealand that are not returned to a pharmacy for disposal and are instead disposed of via land fill or water systems. In addition, this study intended to identify why these medications were unused or unwanted.

DESIGN

An online survey was placed on the New Zealand National Poisons Centre website for a period of three months during 2008. This consisted of a series of questions with predefined answer sets and asked about collection of medications, why there may be unused medications, storage of medications and disposal of medications.

RESULTS

This survey was completed by 452 individuals. 62% of respondents currently had unwanted medications in their house. The most common reason for people to have leftover medication was 'medical condition improved or resolved' (n=307). Depending on formulation type, between 13-24% of unused medications were returned to pharmacies with tablets and capsules being most likely to be returned and liquids most likely to be added to water systems.

CONCLUSIONS

A significant percentage of unwanted medications are disposed of via routes that have the potential to adversely affect the environment. Reducing excess medications and wastage as well as education of appropriate disposal techniques may minimize their potential impact on the environment.

Photochemically induced changes in dissolved organic matter identified by ultrahigh resolution fourier transform ion cyclotron resonance mass spectrometry

Sunlight-induced molecular changes have been observed in two samples of dissolved organic matter (DOM) collected in the Cape Fear River system, North Carolina, USA. The molecular composition of a water sample collected in the Black River (sample B210, salinity 0) and another water sample collected within the Cape Fear River estuary (sample M61, salinity 13.7) were analyzed using an ultrahigh resolution 9.4 Tesla (T) electrospray ionization Fourier transform ion cyclotron resonance mass spectrometer. Additionally, the Ultraviolet/Visible (UV/vis) absorbance as well as the excitation emission matrix (EEM) fluorescence spectra were determined to identify changes in the optical properties associated with photochemical reactions of the chromophoric DOM (CDOM). The molecular formulas forthe Cape Fear River Estuary (M61) sample before the irradiation experiments indicated the presence of highly aromatic compounds which were not present in the unirradiated Black River sample (B210). These aromatic compounds, with oxygen-subtracted double bond equivalents (DBE-O) values greater than nine, are more photoreactive and readily photodegraded relative to saturated compounds. Compounds with DBE-O values below nine are less photoreactive. The UV/vis absorbance and EEM fluorescence results supported this different photodegradation behavior, suggesting that the photoreactivity of CDOM is highly dependent on the molecular composition of the CDOM.

Free-radical-induced oxidative and reductive degradation of N,N'-diethyl-m-toluamide (DEET): Kinetic studies and degradation pathway

N,N'-Diethyl-m-toluamide (DEET) is widely used as an insect repellent and has therefore been detected as a contaminant in numerous waste and surface waters. In this study we have determined the absolute reaction rate constants of DEET with the hydroxyl radical and the hydrated electron in aqueous solution as (4.95+/-0.18)x10(9) and (1.34+/-0.04)x10(9) M(-1) s(-1), respectively, using pulse radiation. To provide additional information on the radicals formed upon oxidation, transient spectra were measured from 1 to 150 micros, with transient decay rates determined from the time-dependence of the maximum absorption at 330 nm. These data suggest simple decay of the initially formed radical to stable products. Radical-based destruction mechanisms for destruction of DEET are proposed based on the LC-MS determination of the stable compounds produced by 60Co gamma-irradiation of DEET solutions. These data will be useful in evaluating potential advanced oxidation/reduction processes for the control of DEET and understanding its fate and transport in surface water where analogous radical chemistry is operative.

Free radical destruction of beta-blockers in aqueous solution

Many pharmaceutical compounds and metabolites are currently found in surface and ground waters which indicates their ineffective removal by conventional water treatment technologies. Advanced oxidation/reduction processes (AO/ RPs) are alternatives to traditional water treatment, which utilize free radical reactions to directly degrade chemical contaminants. This study reports the absolute rate constants for reaction of three beta-blockers (atenolol, metoprolol, and propranolol) with the two major AO/RP radicals; the hydroxyl radical (*OH) and hydrated electron ((e-)aq). The bimolecular reaction rate constants for *OH are (7.05 +/- 0.27) x 10(9), (8.39 +/- 0.06) x 10(9), and (1.07 +/- 0.02) x 10(10), and for (e-)aq they are (5.91 +/- 0.21) x 10(8), (1.73 +/- 0.03) x 10(8), and (1.26 +/- 0.02) x 10(10), respectively. Transient spectra were observed for the intermediate radicals produced by hydroxyl radical reactions. In addition, preliminary degradation mechanisms and major products were elucidated using 60Co gamma-irradiation and LC-MS. These data are required for both evaluating the potential use of AO/RPs for the destruction of these compounds and for studies of their fate and transport in surface waters where radical chemistry may be important in assessing their lifetime.

Flow injection analysis of H2O2 in natural waters using acridinium ester chemiluminescence: method development and optimization using a kinetic model

Chemiluminescence (CL) of acridinium esters (AE) has found widespread use in analytical chemistry. Using the mechanism of the reaction of H2O2 with 10-methyl-9-(p-formylphenyl)acridinium carboxylate trifluoromethanesulfonate and a modified flow injection system, the reaction rates of each step in the mechanism were evaluated and used in a kinetic model to optimize the analysis of H2O2. Operational parameters for a flow injection analysis system (reagent pH, flow rate, sample volume, PMT settings) were optimized using the kinetic model. The system is most sensitive to reaction pH due to competition between AE hydrolysis and CL. The optimized system was used to determine H2O2 concentrations in natural waters, including rain, freshwater, and seawater. The lower limit of detection varied in natural waters, from 352 pM in open ocean seawater (mean, 779 pM +/- 15.0%, RSD) to 58.1 nM in rain (mean, 6,340 nM +/- 0.92%, RSD). The analysis is specific for H2O2 and is therefore of potential interest for atmospheric chemistry applications where organoperoxides have been reported in the presence of H2O2.

Sources of heavy metals and polycyclic aromatic hydrocarbons in urban stormwater runoff

Polycyclic aromatic hydrocarbons (PAHs) and heavy metals were measured in road debris collecting in urban areas and in the suspended sediment (SS) component of runoff from two stormwater catchments in Dunedin, New Zealand. Levels in the road debris ranged from 119-527 microg/g for lead, 50-464 microg/g for copper, 241-1 325 microg/g for zinc and 1.20-11.6 microg/g for sigma16PAH. The SS from the largely rural catchment (20% urban) had similar concentrations to the road debris, indicating that this urban material was the main source of the contaminants measured in the stormwater. Similar PAH fingerprint profiles and isomer ratios indicative of dominant pyrogenic (combustion) sources were also found in these two groups of materials. The SS from the 100% urban catchment contained 2- to 6-fold higher concentrations of metals and 10-fold greater levels of sigma16PAH. The higher levels of lead and copper were probably a result of industrial land uses in this catchment, while the additional zinc was linked to an abundance of zinc-galvanised roofing iron in the catchment's residential suburbs. The PAH profiles and isomer ratios were different for this urban catchment and suggested that a disused gasworks was contributing PAHs to the stormwater runoff.

Spatial and temporal variations in trace metal concentrations in the cockle, Austrovenus stutchburyi from Otago, New Zealand

This is the first comprehensive study of sources of variation in metal concentrations within the whole tissues of a shallow burrowing, filter-feeding intertidal clam, Austrovenus stutchburyi. Samples were collected from 12 sites in April, August, November and February in 1993-1994 in the vicinity of Otago Harbour and Peninsula, New Zealand. Total tissue trace metal concentrations (microg g(-1) dry weight) were measured in individual animals for the essential metals : Mn, Cu, Zn, Ni and the non-essential Cr using trace-metal clean acid-digestion and ICP-OAES techniques. Average metal concentrations were 3-60 microg g(-1) for Cu, 40-118 microg g(-1) for Zn, 2-12 microg g(-1) for Mn, 5-35 microg g(-1) for Ni and 1-44 microg g(-1) for Cr. These levels decreased with body weight and differed amongst sites except for Cr in February (mid-summer). Highest concentrations occurred at sites close to a city (Dunedin) and within the central harbour region although the Cu, Zn, Ni and Cr concentrations did not correlate with the environmental gradient or season. At one coastal site, samples of both the blue mussel Mytilus galloprovincialis and cockles gave similar trends in trace metal levels. These results suggest that the cockle could be a useful trace metal biomonitor within NZ estuaries.

Reduction in functional potency of the neurotoxin domoic acid in the presence of cadmium and zinc ions

The tricarboxylic neurotoxin domoic acid (DA) binds trace metals such as iron and copper. In vitro brain slice recording (area CA1 of rat hippocampal slices) was used to assess changes in DA potency in the presence of cadmium and zinc. Cadmium or zinc alone had little or no effect on CA1 responses. DA alone produced hyperexcitability and, with prolonged administration, a robust suppression of CA1 responses. Coadministration of DA with either 2 or 4μM Cd(2+) produced significant reductions in the potency of DA; less striking effects were seen in the presence of 4μM Zn(2+). These findings suggest that interactions of Cd(2+) and Zn(2+) with DA result in the formation of trace metal-neurotoxin complexes which are either unavailable for binding to ionotropic glutamate receptors, or bind without producing full agonist activity.

The use of carbon and nitrogen isotope ratios to identify landfill leachate contamination: Green Island Landfill, Dunedin, New Zealand

A study was undertaken to determine whether the isotopic ratios of C and N could be used to uniquely identify municipal solid waste landfill leachate as a source of contamination in the Kaikorai Estuary, Dunedin, New Zealand. Leachate samples were taken from the adjacent Green Island Landfill (GILF), and surface water samples were collected over an 8-month period from the stream and estuary, upstream and downstream of the landfill. Samples were analysed for delta(13)C-dissolved inorganic carbon (DIC), delta(15)N-NO(3)(-), delta(15)N-NH(4)(+), and particulate organic matter (POM) delta(13)C and delta(15)N. Plant material collected along the Kaikorai Stream was analysed for POM delta(13)C and delta(15)N. Leachate was found to have a distinct isotopic signature characterised by a highly enriched delta(13)C-DIC (as much as 16.11+/-0.23 per thousand ) and highly enriched delta(15)N-NH(4)(+) (as much as 27.42+/-0.90 per thousand ). Evidence of leachate contamination was found in the isotopic signatures of downstream delta(13)C-DIC, delta(15)N-NH(4)(+), and delta(13)C and delta(15)N of plant material POM. Other potential sources of enriched delta(13)C-DIC and delta(15)N-NH(4)(+) present in the study area, such as estuarine waters and livestock effluent, were eliminated on the basis of their isotopic characteristics.

X-Ray Crystal Structure Determination of Some Sodium Anthraquinone Sulfonate Derivatives

The crystal structures of sodium 9,10-dioxo-9,10-dihydroanthracene-2-sulfonate hydrate (1) and sodium 9,10-dioxo-9,10-dihydroanthracene-1,5-disulfonate trihydrate (2) have been determined by single-crystal X-ray diffraction at 253 K and refined to R 0.03 for (1) (1535 reflections) and R 0.04 for (2) (1409 reflections). Crystals of (1) are monoclinic, P21, a 17.395(5), b 6.625(2), c 5.537(1)Ǻ, β 91.87(2)°, Z 2, and those of (2) are orthorhombic, Pnma, a 11.332(4), b 20.048(5), c 7.634(3)Ǻ, Z 4. The results of molecular mechanics calculations on these two molecules were in general agreement with those determined by X-ray methods. The effect of sulfonate substitution in the 1-position compared with that in the 2-position include a small lengthening of the C-S bond and a displacement of the sulfur and quinone oxygen atoms to opposite sides of the plane of the substituted aromatic ring. However, these differences do not appear to be of sufficient magnitude to account for the much greater differences in the electrochemical and photochemical behaviour of these two classes of anthraquinone sulfonate derivatives.

The use of 2,2,6,6-tetramethyl-4-maleimido-piperidin-1-oxyl in electron paramagnetic resonance spin label studies of drug interactions with erythrocyte membranes

The electron spin resonance (EPR) spectrum of erythrocyte membranes labeled with 2,2,6,6-tetra-methyl-4-maleimido-piperidin-1-oxyl (MAL-6) indicates both weakly and strongly immobilized labeling sites. Changes in the ratio of the membrane's low field spectral peaks (W/S) have often been used to monitor drug-erythrocyte interactions. We have investigated a number of experimental factors that may influence this ratio even in the absence of drug. Instrumental settings on the EPR spectrometer had no obvious effect. As the weight ratio of label/protein decreased, the W/S ratio increased. Similarly an increase in labeling time and temperature lead to an increase in the ratio. The ratio also increased with time after labeling; this change was most marked in samples kept at 37 degrees C, but was insignificant in samples kept at 4 degrees C. Increasing the viscosity of the sample with low-molecular-weight substances such as sucrose or glycerol, but not with those with high molecular weight such as dextran and PVP, caused a reduction in the ratio. Increasing the pH and changing the buffer concentrations also lead to a small increase in W/S. These results suggest that it is very important that all of these factors be kept constant and at some optimal value if reliable and consistent results are to be obtained using this method to monitor drug-erythrocyte interactions.

Paramagnetic organometallic molecules. XIV. Ion-pair and steric effects in dissociative electron transfer reactions of metal cluster carbonyl radical anions

An investigation of electron attachment reactions of cluster metal carbonyls is presented. In general, alkyl and organometallic halides react rapidly with metal carbonyl cluster radical anions at ambient temperatures to give the neutral cluster molecule. Halide ion and alkyl or organometallic radicals are also produced, which indicate that these are dissociative electron attachment reactions analogous to those of organic radical anions. The rate of dissociative electron attachment in reactions of PhCCo3(CO)9- was found to depend on the R-X bond energy, the size of the alkyl group and the nature of the counter-ion. In particular, (Ph3P)2N+ retarded some electron transfer reactions to the extent that the bimolecular decay of PhCCo3(CO)9- effectively competed with the electron transfer process in determining the reaction path.

Paramagnetic organometallic molecules. XV. Electron attachment reactions of metal carbonyls

A number of polynuclear metal carbonyl complexes can be used as substrates for electron attachment reactions induced by the photoionization of N,N,N',N'-tetramethyl-p-phenylenediamine. Theproducts of such reactions are derived from metal carbonyl radicals produced by cleavage of the metal-metal bonds.

ESR measurements on the effects of ethanol on the lipid and protein conformation in biological membranes

The effects of ethanol on the conformation of proteins or fluidity of lipids was studied in human erythrocyte ghosts and rat brain synaptosomal membranes. A maleimide nitroxide probe (MAL-6) was coupled to membrane protein, or 5-doxylstearic (5NS) was dissolved in the membrane lipid, and the electron spin resonance (ESR) spectra were recorded in the presence of increasing ethanol concentrations and at different temperatures from 4 degrees to 37 degrees. The lipid probe at all temperatures studied showed an increase in fluidity in the membrane lipid when ethanol was added in concentration over 20 mM. The protein probe however required a high concentration of ethanol (200 mM) to produce an increase in the rigidity of the protein conformation of 4 degrees in both erythrocyte and synaptosomal membranes. A decrease in protein rigidity was observed at high ethanol concentrations at 37 degrees only in the erythrocytes. Thus an effect of ethanol on the conformation of membrane protein was observed using MAL-6 only at high ethanol concentrations and depended on the membrane used and the temperature of measurement.

13C coupling in the E.S.R. spectrum of the pyrene anion in tetrahydrofuran

Examination of the e.s.r, spectrum of pyrene anion in tetrahydrofuran under conditions of high resolution has yielded the 13C hyperfine coupling parameters for five of the six carbon positions. The parameters agree well with those calculated by molecular orbital methods. No evidence of ion pair formation was found under the conditions used in these experiments.

E.P.R. studies of the anions of some peri-alkylnaphthalenes

The hyperfine coupling constants for the radical anions of 2,3-dihydro- phenalene (perinaphthane) and 7,8,9,l0-tetrahydrocyclohepta[de]naphthalene have been determined from analysis of the electron spin resonance spectra in solution. The results are compared with data from other mono- and di-peri- substituted naphthalenes. A simple H�ckel molecular orbital treatment is used to describe the inductive effect of the aliphatic substituent.