bluuebunny/crossref_metadata_2025 huggingface dataset:
The distribution and status of the adder (Vipera berus L) in Scotland determined from questionnaire surveys
Authors: Reading C. J. , Buckland S. T. , McGowan G. M. , Jayasinghe G. , Gorzula S. , Balharry D.
Published: May 2007

Abstract. During 1992 two questionnaire surveys, aimed at farmers and sections of the general public, were conducted to determine the distribution and status of the adder (Vipera berus L.) in Scotland. In total, 94% of the Scottish mainland and inner isles were covered by the two surveys. The adder appears to be widespread throughout Scotland, although it is absent from much of the Central Valley, the Outer Hebrides and Northern Isles, and from much of the mountainous region between Inverness and Glasgow.

The distribution of the adder in Scotland was compared with the distributions of different habitat types defined in the ITE Land Class survey. Adders were strongly associated with areas of heterogeneous land use and negatively associated with intensively arable areas and rugged mountainous areas. Strong evidence was found to suggest that perceived adder abundance had declined during the last 10 years. Although the evidence suggesting that the distribution of adders in Scotland had changed was less strong, the results of the Farm Survey did indicate that it had contracted. The perceived change in status of the adder in Scotland during the last 10 years was compared with the observed changes in land use over the same period.
Variation of reproductive effort between parthenogenetic and sexual populations of the scorpion Tityus columbianus
Authors: Lourenĉo Wilson R. , Cuéllar Orlando , Méndez de la Cruz Fausto R.
Published: May 2007

Abstract. Geographic differences in reproductive effort were examined between sexual and parthenogenetic populations of the Colombian scorpion Tityus columbianus, from Iza (sexual) and from Mosquera (unisexual). The sexual females from Iza were significantly larger and had significantly greater relative litter mass (RLM) than the parthenogenetic ones from Mosquera. In both populations litter size increased significantly with female body size.

Litter size and RLM in the sexuals averaged 12.7 and 0.49 respectively, and in the unisexuals 8 and 0.36. We suggest that the higher values are related to greater primary productivity at the Iza site.
Investigating causality of nestedness of insular communities: selective immigrations or extinctions?
Authors: Lomolino Mark V.
Published: May 2007

Abstract. Most archipelagos are comprised of a nested set of communities, with species on depauperate islands representing proper subsets of those on richer islands. The causality for this common intra‐archipelago pattern, however, remains elusive. Here, I present a Monte Carlo approach for investigating whether nestedness results from selective extinctions, selective immigrations, or both. Results for mammal communities of three nearshore archipelagos and two montane forest archipelagos suggested that nestedness may result from both forces. Nestedness was significantly associated with area (extinctions) for all archipelagos studied, and with isolation (immigrations) for islands of Lake Huron and the American Southwest. The degree of nestedness is influenced by the degree of variations among species and islands. In addition, our ability to assess causality of nestedness is influenced by our ability to calculate biologically relevant measures of isolation, and by the potentially confounding effects of selective immigrations and extinctions on community nestedness.
Mapping forest‐cover disturbances in Papua New Guinea with AVHRR data
Authors: Estreguil Christine , Lambin Eric F.
Published: May 2007

Abstract. Land management and land‐use planning in a forested country such as Papua New Guinea, which is subject to various anthropogenic pressures, requires an accurate mapping of forest‐cover disturbances. The central hypothesis of this study was that remote sensing indicators of forest‐cover conditions can be used to measure and map the impact of long‐term forest‐cover disturbances. This was tested with single year NOAA's Advanced Very‐High Resolution Radiometer sensor (AVHRR) data at 1.1 km resolution. First, an ordinal scale of forest‐cover disturbance was defined from field observations, a set of thematic maps and high spatial resolution satellite sensor data. Secondly, we analysed the relationship between the forest‐cover disturbance scale and several biophysical indicators derived from AVHRR data at two seasons. Thirdly, a statistical analysis identified the optimal combination of biophysical indicators and observation dates to discriminate between the forest disturbance levels defined previously. A forest‐cover disturbance map was then produced over part of Papua New Guinea. Finally, a regionalization of the study area in terms of aggregate degree of disturbance was produced and the spatial patterns of forest disturbances were interpreted for each region in terms of broad processes of forest‐cover change. The overall accuracy of the forest‐cover disturbance map was 79%. Nine regions, homogeneous in regard to the distribution and spatial pattern of disturbance categories, were identified.
Recent cooling and recession of Norway spruce (Picea abies (L.) Karst.) in the forest—alpine tundra ecotone of the Swedish Scandes
Authors: Kullman Leif
Published: May 2007

Abstract. Repeated crown condition surveys, 1974–94, of subalpine clonal groups of Norway spruce (Picea abies (L.) Karst.) were carried out in the Swedish Scandes. Complementary analyses concerned radial and vertical growth, sexual regeneration and range limit responses of other plant species. Significant defoliation of spruce progressed linearly over the period of study, reaching cumulative values of about 85%. It is inferred that defoliation was preconditioned by decreasing radial growth since the thermal climax in 1937 and was proximately initiated by the extremely cold winter of 1965/66 and paralleled by consistently declining radial growth and staggering vertical increase. It appears that severe and prolonged ground freezing invoked winter desiccation (xylem cavitation), extensive needle loss and reduced radial growth. Hypothetically, from circumstantial evidence, these processes are interrelated in a positive feedback system, implying increasing sensitivity to climatic stress and decreasing ability to take advantage of positive climatic anomalies. Thus, the total demise of the supranival stems is cautiously predicted, by linear regression of the 20‐yr defoliation pattern, to be less than a decade ahead. The recession of P. abies, clearly relevant in a landscape perspective, conforms with analogous responses of Pinus sylvestris L. and Betula pubescens Ehrh. ssp. tortuosa (Ledeb.) Nyman and a significant altitudinal range‐limit retraction of certain silvine field‐layer species. The structural development examined in this study concurs with long‐term climate cooling and cold events and strongly contrasts with simulations of the performance of this system in response to a putative enhanced‘greenhouse’effect.
Therapy outcome in patients with chronic hepatitis C: role of therapy supervision by expert hepatologists
Authors: Sagir A. , Heintges T. , Akyazi Z. , Oette M. , Erhardt A. , Häussinger D.
Published: May 2007

Summary.  Previous large multicentre trials reported sustained virological response (SVR) rates of 45–80% in chronically infected hepatitis C virus (HCV) patients. However, it is unclear whether such a treatment success is also achieved in daily routine and to what extent it depends on expert hepatological supervision. This was retrospectively analysed in patients presenting at our outpatient department during May 1997 and March 2004 and receiving at least one treatment dose. A total of 302 treatment‐naive HCV patients [72% genotypes 1 or 4 (n = 215), 25% genotypes 2/3 (n = 78) and 3% undetermined genotype (n = 9)] were included in the analysis. Out of these, 196 patients consulted an expert hepatologist at least once every 3 months during treatment [regular visitors (RV)], whereas in 106 patients treatment was performed and supervised by a general practitioner (irregular visitors). Both patient groups did not differ in their baseline characteristics. However, the virological response rates at the end of treatment (ETR; 146/196, 74%vs 51/106, 48%, P < 0.001) and 6 months thereafter (SVR; 129/196, 66%vs 36/106, 34%, P < 0.001) were significantly higher in RV. In patients treated with pegylated‐interferon (PEG‐IFN)/ribavirin, this difference was statistically highly significant (P < 0.001) for HCV genotypes 1 and 4 (treated patients: SVR: 62/101, 61%vs 14/51, 27%, P < 0.001), but not for genotypes 2/3. SVR rates were also significantly better in RV with advanced liver damage [SVR 69% (22/32) vs 25% (5/20), P = 0.004]. In regular and irregular visitors treatment was discontinued in 7% (14/196) and 15% (16/106) respectively (P = 0.015). Patients with unfavourable genotypes 1 and 4 or with advanced liver damage benefit from HCV therapy supervision by a specialist, probably because of less frequent treatment interruptions or dose reductions.
Tracing hepatitis C and Delta viruses to estimate their contribution in HCC rates in Mongolia
Authors: Kurbanov F. , Tanaka Y. , Elkady A. , Oyunsuren T. , Mizokami M.
Published: May 2007

Abstract.  An estimated incidence of hepatocellular carcinoma (HCC) in Mongolia is currently one of the highest in the world. According to previous reports, the sero‐prevalence of hepatitis B (HBV) and hepatitis C (HCV) viruses in general population of the country is very high (HBV, 10% and HCV, 15%, respectively). Moreover, the majority (75–100%) of the HBV‐infected individuals have co‐infection with hepatitis Delta virus (HDV). Despite reported observations that HBV + HDV/HCV co‐infection have significantly stronger association with HCC when compared with HCV‐monoinfection, the later is still frequently observed among Mongolian HCC patients (39%). In this study, an approach based on principles of population genetics and mathematical epidemiology was used to trace an epidemic history of HCV and HDV. In agreement with the sero‐epidemiological and social‐historical background of the country, the results have demonstrated that the viruses had different epidemic dynamics in Mongolia; HCV was characterized by earlier epidemic expansion, whereas HDV spread with approximately 50 years lag. This may explain the comparable contribution of the HCV‐monoinfection and HBV + HDV co‐infection in current HCC rate despite different levels of risk of carcinogenesis. Used approach is useful in evaluation of current and prospective disease burden.
The impact of hepatitis C virus infection on survival in dialysis patients: meta‐analysis of observational studies
Authors: Fabrizi F. , Takkouche B. , Lunghi G. , Dixit V. , Messa P. , Martin P.
Published: May 2007

Summary.  The impact of hepatitis C virus (HCV) infection on mortality of patients receiving regular dialysis remains unclear. The assessment of the natural history of HCV in dialysis population is difficult because of the low progression of HCV‐related liver disease over time and the reduced life expectancy in patients with end‐stage renal disease. The aim of the study was to conduct a systematic review of the published medical literature concerning the impact of HCV infection on the survival of patients undergoing maintenance dialysis. The relative risk of mortality was regarded as the most reliable outcome end‐point. Study‐specific relative risks were weighted by the inverse of their variance to obtain fixed‐ and random‐effects pooled estimates for mortality with HCV across the published studies. We identified seven studies involving 11 589 unique patients on maintenance dialysis; two (29%) were case–control studies. Pooling of study results demonstrated that presence of anti‐HCV antibody was an independent and significant risk factor for death in patients on maintenance dialysis. The summary estimate for adjusted relative risk (aRR) (all‐cause mortality) was 1.34 with a 95% confidence interval (CI) of 1.13–1.59. Heterogeneity statistics, Ri = 0.48 (P‐value by Q‐test = 0.13). In a sensitivity analysis including only (n = 5) cohort studies, the pooled aRR was 1.38 (95% CI, 1.20–1.59); heterogeneity statistics Ri = 0.46. As a cause of death, hepatocellular carcinoma and liver cirrhosis were significantly more frequent among anti‐HCV‐positive than ‐negative dialysis patients. Our meta‐analysis indicates that anti‐HCV‐positive patients on dialysis have an increased risk of mortality compared with HCV‐negative patients. The excess risk of death in HCV‐positive patients may be at least partially attributed to chronic liver disease with its attendant complications.
Inferring local adaptation fromQST–FSTcomparisons: neutral genetic and quantitative trait variation in European populations of great snipe
Authors: SÆTHER S. A. , FISKE P. , KÅLÅS J. A. , KURESOO A. , LUIGUJÕE L. , PIERTNEY S. B. , SAHLMAN T. , HÖGLUND J.
Published: May 2007

We applied a phenotypicQST(PST) vs.FSTapproach to study spatial variation in selection among great snipe (Gallinago media) populations in two regions of northern Europe. Morphological divergence between regions was high despite low differentiation in selectively neutral genetic markers, whereas populations within regions showed very little neutral divergence and trait differentiation.QST > FSTwas robust against altering assumptions about the additive genetic proportions of variance components. The homogenizing effect of gene flow (or a short time available for neutral divergence) has apparently been effectively counterbalanced by differential natural selection, although one trait showed some evidence of being under uniform stabilizing selection. Neutral markers can hence be misleading for identifying evolutionary significant units, and adopting thePST–FSTapproach might therefore be valuable when common garden experiments is not an option. We discuss the statistical difficulties of documenting uniform selection as opposed to divergent selection, and the need for estimating measurement error. Instead of only comparing overallQSTandFSTvalues, we advocate the use of partial matrix permutation tests to analyse pairwiseQSTdifferences among populations, while statistically controlling for neutral differentiation.
Nonadditive effects of group membership can lead to additive group phenotypes for anti‐predator behaviour of guppies,Poecilia reticulata
Authors: BLEAKLEY B. H. , PARKER D. J. , BRODIE E. D.
Published: May 2007

Nonadditive effects of group membership are generated when individuals respond differently to the same social environment and may alter predictions about how behavioural evolution will occur. Despite this importance, the relationship between an individual's behaviour in two different social contexts and how reciprocal interactions among individuals within groups influence group behaviour are poorly understood. Guppy anti‐predator behaviour can be used to explore how individuals behaviourally respond to changes in social context. Individuals from two strains were tested for response to a model predator alone and in groups to evaluate how individuals alter their behaviour in response to social context and how group phenotype relates to individual behaviour. Nonadditive effects of group membership were detected for a number of behaviours, revealing that the effect of being in a group differed among individuals. These nonadditive effects, however, yielded an additive group phenotype. That is, the average behaviour of the group was equal to the average of its parts, for all behaviours in both strains. Such an additive group phenotype may have resulted because all individuals within a group respond to the specific social environment provided by the other members of their group.
Involvement of Plasma Progesterone, Oestradiol‐17β and Cortisol in Ovulatory Response to Gonadotropin‐releasing Hormone in Dairy Cows with Cystic Follicles
Authors: Isobe N , Yamada K , Yoshimura Y
Published: May 2007

Contents The aim of the present study was to examine the plasma concentrations of progesterone, oestradiol‐17β and cortisol in the cows with cystic follicle and to examine its relationship with the ovulatory response to gonadotropin‐releasing hormone (GnRH). Eighty‐five post‐partum Holstein–Friesian cows with cystic follicles regardless of the presence of corpus luteum were studied. Follicular size, presence of corpus luteum and occurrence of ovulation were checked by palpation per rectum. Blood collection and palpation per rectum were conducted on days 0, 7 and 14. Gonadotropin‐releasing hormone was administered at day 7. Plasma concentrations of progesterone, oestradiol‐17β and cortisol were determined. Progesterone concentrations of <3.2, 3.2–4.8 and >4.8 nmol/l were defined as low, intermediate and high, respectively. Sixty‐three (74.1%) of 85 cows showed low (<3.2 nmol/l =1 ng/ml) progesterone concentrations on day 0. Only 40 (47.1%) of them showed low–low pattern of progesterone at days 0 and 7. In 27 (31.8%) of them, progesterone concentration had increased by day 14. Of 22 cows having high progesterone concentration (≥4.8 nmol/l) on day 0, corpus luteum was not detected in 18 cows (21.2%). Only in 10 cows, cystic follicle disappeared after GnRH administration. However, only one of 27 cows in which progesterone pattern was low–low–high at days 0, 7 and 14 experienced ovulation of the cystic follicle. Significantly lower oestradiol‐17β concentration was found on day 7 in cows showing a low–low–low pattern than a low–low–high pattern of progesterone (43.0 ± 4.6 vs 55.8 ± 2.8 pmol/l, p < 0.05). There was no significant difference in cortisol concentration on any days (days 0, 7 and 14) between cows showing a low–low–low and low–low–high pattern of progesterone. These results suggest that approximately one‐fifth of cows diagnosed to have ovarian cysts possess luteal cysts and that a high oestradiol‐17β concentration at the time of GnRH administration is involved in the subsequent ovulation of the follicle, although ovulated follicle may not be cystic.
Effects of Body Condition and Protein Supplementation on LH Secretion and Luteal Function in Sheep
Authors: Meza‐Herrera CA , Ross T , Hallford D , Hawkins D , Gonzalez‐Bulnes A
Published: May 2007

Contents

In ruminants, nutrition is one of the exogenous inputs affecting reproductive function at different levels of the hypothalamic–hypophyseal–gonadal axis. However, the exact mechanisms or even the identification of the signalling metabolic compounds by which nutrition affects reproductive function still need further clarification. The role of static body condition (BC) and its interaction with a short‐term protein supplementation (PL), on secretion of metabolic hormones [growth hormone (GH), insulin and insulin‐like growth factor‐1 (IGF‐1)], as well as on secretion of LH and progesterone (P4) was evaluated in sheep. Twenty‐four Rambouillet ewes divided into two groups, with lower (LBC) and higher body condition (HBC), were randomly assigned within BC to one of two PL levels: low (LPL, 24% of crude protein; 14 g/animal/day), and high (HPL, 44% of crude protein; 30 g/animal/day). The secretion of GH, insulin, IGF‐1 and LH was evaluated on day 10 of the oestrous cycle; appearance and timing of oestrous behaviour were previously detected using rams. Progesterone secretion was evaluated on day 13 of the same cycle. No differences were found (p > 0.05) between PL groups on serum GH concentrations during the sampling period (overall mean of 4.0 ± 0.3 ng/ml), but a trend for lower values in HBC sheep was found (3.6 ± 0.4 vs 4.4 ± 0.4 ng/ml, p = 0.06). A BC effect was observed (p < 0.05) on serum IGF‐1 level, with higher values in HBC sheep (p < 0.05). Neither BC nor PL affected (p > 0.05) secretion of LH and the number of corpora lutea, nor serum P4 and insulin concentrations. Results indicate a predominance of the static component of nutrition on sheep metabolic hormone responses, GH and IGF‐1, with no effect of short‐term PL on secretion of pituitary and ovarian hormones as well as luteal number and activity.
Controlled release of dehydroacetic acid sodium salt for the stability improvement of cosmetic formulations*
Authors: GAZZANIGA A. , SANGALLI M.E. , GIORDANO F. , CONTE U. , SEMENZATO A. , BETTERO A.
Published: May 2007

Synopsis

The kinetics of decomposition of the sodium salt of dehydroacetic acid (DHA.Na) in presence of formaldehyde and formaldehyde donors was investigated. The possibility of preparing systems capable of providing the cosmetic preparation with increasing amounts of DHA.Na corresponding to portions interacted with formaldehyde was explored. Data relevant to matrices prepared from ethylcellulose and polyethylene by casting and moulding process, respectively, are reported and discussed. Experimental data demonstrate the possibility of preparing polymeric systems able to control in terms of rate and duration the relase of DHA.Na, according to time and concentration needs of a typical cosmetic formulation.
Influence of the polar phase in the formulation of cosmetics
Authors: COMELLES F. , CAELLES J. , PASCUAL A. , LEAL J. SÁNCHEZ
Published: May 2007

Synopsis

Frequently, the incoporation of the polar phase, as a second step in the formulation of a cosmetic, is considered as a simple dilution process. This work shows the influence of the polar phase on the final formulation, according to its constitution as well as the method of incorporation. Modelling the system through a regular tetrahedron suggests alternative ways to the usual method of incorporation (direct titration with a polar phase with a given composition), based on selective incorporation of the polar ingredients (double titration procedures). Depending on the constitution of the polar phase, it is possible to obtain different kinds of formulations (gel, liquids, …), and, depending on the different possibilities of incorporation of the polar ingredients, identical compositions can be formulated in terms of percentage of their components, but showing different rheological characteristics, allowing an adaptation to the required specific needs of formulation.
Stability of vitamin A palmitate in cosmetic emulsions: influence of physical parameters
Authors: SEMENZATO A. , BAÙ A. , DALL'AGLIO C. , NICOLINI M. , BETTERO A. , CALLIARI I.
Published: May 2007

Synopsis

The aim of this work was to verify if a close relationship exists between the physical stability of an emulsion and the chemical stability of vitamin A palmitate included in it. Oil‐in‐water cosmetic emulsions with high viscoelastic properties were prepared, and their rheological behaviour was investigated in oscillatory conditions. The stability of each sample was verified in high‐temperature stress conditions: periodical checks of physical parameters and chromatographic analysis of vitamin A were performed during storage. Results show that the chemical stability of vitamin A palmitate strictly depends on the physical stability of the formulation and in particular on the presence of a coherent gel‐like structure in the external phase of the emulsion.
Evaluation expérimentale de l'hydratation et du pouvoir occlusif in vivo et in vitro d'excipients lipophiles et de leurs émulsions phase huile continue
Authors: MARTI‐MESTRES G. , PASSET J. , MAILLOLS H. , SAM V. VAN , GUILHOU J.J. , MESTRES J.P. , GUILLOT B.
Published: May 2007

Une étude a été réalisée sur trois émulsions eau dans huile et leurs phases grasses respectives, vaseline, huile de paraffine et huile d'amande douce, en vue de comparer leurs propriétés occlusives et par voie de conséquence leur influence sur l'hydratation cutanée. Une méthode in vitro utilisant des cellules de type ‘Patel’a permis dans un premier temps de classer les différentes émulsions et leurs phases grasses‐en fonction de leur perméabilitéà la vapeur d'eau, ce qui conduit par ordre croissant de degré d'occlusion à: huile d'amande douce, huile de paraffine et vaseline. Pour les études in vivo chez l'homme, l'influence de l'application des mêmes substances sur la perte insensible d'eau (PIE) et l'hydratation cutanée a été mesurée avec un évaporimètre et un cornéomètre. Les différentes phases grasses, utilisées pures, augmentent l'hydratation par effet occlusif, ce phénomène étant objectivé par les mesures de PIE. Par contre pour les émulsions correspondantes, il semblerait que l'augmentation de l'hydratation ne fasse pas intervenir de mécanisme occlusif.
Synthesis of quaternary ammonium bromides of 5‐[4‐(ω‐dialkylaminoalkoxy)phenyl‐methylene]‐1, 3, 3‐trimethyl‐2‐oxabicyclo [2.2.2]octan‐6‐ones as potential UV sunscreens
Authors: MARIANI E. , SCHENONE P. , BARGAGNA A. , LONGOBARDI M. , DORATO S.
Published: May 2007

Synopsis

Materials and methods for the synthesis of eight quaternary ammonium bromides of 5‐[4‐(ω‐dialkylaminoalkoxy)phenylmethylene]‐1,3,‐trimethyl‐2‐oxabicyclo[2.2.2]octan‐6‐ones are illustrated. They were routinely prepared starting from cineole aminoethers by reaction with primary alkyl bromides and their physico‐chemical data are reported. These substances have been tested for UV filtering and/or microbiological activity. The substances have their UV absorption maxima at 315–322 nm. Tests on antimicrobial activity were performed using benzalkonium chloride as reference standard. All quaternary ammonium bromides were totally inactive against Escherichia coli (Gram —) and partially active on Staphylococcus aureus (Gram +). These preliminary findings seem to indicate that these new quaternary ammonium bromides could be considered as potential UV sunscreens.
Measurement of diffusional parameters in membranes using ATR‐FTIR spectroscopy
Authors: WATKINSON A.C. , HADGRAFT J. , WALTERS K.A. , BRAIN K.R.
Published: May 2007

The use of ATR‐FTIR spectroscopy for the assessment of synthetic and biological membrane permeability is described. Measurement of the diffusion coefficient of acetonitrile in a polydimethylsiloxane membrane showed the method to be of reasonable reproducibility. It has been demonstrated that the concurrent measurement of both solvent and solute permeability is feasible and that the deconvolution of the diffusion and partition coefficients of these species is theoretically possible. Where the diffusing species changed the nature of the membrane a correcting normalization routine was performed by assessing the state of the membrane as a function of time. The use of this method for the routine investigation of membrane permeation phenomena has great potential for the future.
Fruit acid extracts, a fresh approach to skin renewal
Authors: SCHOLZ D. , BROOKS G.J. , PARISH D.F. , BURMEISTER F.
Published: May 2007

Synopsis

Alpha‐hydroxy acids are a common class of naturally occurring chemicals that have become increasingly popular for cosmetic use. Currently alpha‐hydroxy acids from both natural and synthetic sources are being used in skincare products. From lactic acid to complex natural blends, several different approaches have been adopted for the use of alpha‐hydroxy acids. This paper reviews the history of alpha‐hydroxy acids use in cosmetics and gives new data showing the increased rate of cell renewal by topical application.
Evaluation of predictable irritative power of surfactant mixtures by human fibroblast culture and its correlation to physico‐chemical parameters
Authors: RIGANO L. , CAVALLETTI T. , BENETTI S. , TRANIELLO S.
Published: May 2007

The predictable toxic effects of some surfactants, their blends and some preserving agents on human fibroblast cultures were investigated with in vitro tests, with the aim of finding a possible correlation between the biologic evaluations and some physical characteristics of detergent solutions. Lactate dehydrogenase release into the medium was used as a marker of the plasma membrane integrity, while the amount of 3H‐radiolabelled proteins in the fibroblasts was measured in order to assess the cell biosynthetic machinery function. Disodium‐alkyl‐semi‐sulphosuccinate induced membrane damage in the lactate dehydrogenase test and decreased the protein synthesis, with an EC 50 around 1mm, while sodium lauryl ether sulphate had an EC 50 at about 100 μm, indicating that this compound is ten‐fold more toxic, when measured by this method. An ethoxylated glyceride, on the contrary, was completely harmless on the plasma membrane and, surprisingly, activated fibroblast protein synthesis in a dose‐response way up to two‐fold. Mixtures of the three surfactants evidenced the protective effect of the non‐ionic against the cellular functionality damage. Parabens do not influence this type of evaluation, while some influence was shown by the formaldehyde releaser 2‐bromo‐2‐nitro‐propandiol at the highest concentration. The comparison between critical micellar concentration measures of the different surfactants and their in vitro detected irritative power shows, for the two anionics, that in vitro toxicity is proportionally bound to the amount of micelles even if the structural differences between the two types of molecules are reflected into different damage values, while the non‐ionic compound shows a not defined CMC and a very low toxicity profile. Blends of anionics with the non‐ionic show an increased CMC and a reduced toxicity profile. Toxicity evaluations of complex finished foaming formulations, carried out with human fibroblast cultures evaluation show that a relationship between micelles amount and cell toxicity seems to exist, mainly when multiple surfactants blends are tested.
Headspace analysis study of evaporation rate of perfume ingredients applied onto skin
Authors: VUILLEUMIER C. , FLAMENT I. , SAUVEGRAIN P.
Published: May 2007

Synopsis

Diffusion of perfume ingredients from skin or hair is measured using an original method based on dynamic headspace technology. This has been used for pure odorants, fine fragrances, as well as for perfumed cosmetic applications such as soaps, creams or shampoos, in order to characterize diffusion processes and air/skin or air/hair partitioning. Accordingly, a special collection system, applied on the inner face of the forearm, has been developed, allowing the adsorption of diffusing organic vapours from skin onto Tenax (poly‐diphenyl phenylene oxide) with a controlled air flow rate. A simple model composition containing eleven volatile synthetic odorants was prepared in an alcoholic matrix and the solution was applied onto the skin. The diffusion rate of the different components was measured by determining the concentration of each in the gas phase versus time. Conversely, the same experiment was effected by the application of an alcoholic solution of each individual component. In this manner, the relative diffusion from skin of the components alone or mixed was compared using the same experimental technique. The effect of a musky component was also tested. Both compositions (with and without musk) were then applied in a soap base. Thus, following a rigorous protocol, the forearm was washed with the perfumed soap and rinsed with water before collection of the headspace. The results show the different diffusion rates of the individual odorants. In particular, components evaporate slower from the skin when they have been applied from a soap bar compared to when they have been applied from alcoholic solution. We also present results describing the characterization of skin types using a panel comprised of 80 people (40 females and 40 males); amount of sebum, hydration and pH were systematically measured on different parts of the face, the neck as well as the outer and inner faces of the forearm. The panelists were then classified into different sub‐groups taking into account these parameters. It should be noted that the foregoing results were obtained on an ‘average’skin type.
Reduction of nitrosamines in cosmetic products
Authors: CHALLIS B.C. , TREW D.F. , GUTHRIE W.G. , ROPER D.V.
Published: May 2007

From initial rate studies of morpholine nitrosation in aqueous media by nitrite ion in the presence of formaldehyde at pH 5–7 and 25°C, four potential pathways are revealed for the concurrent formation of nitrosamine contaminants in cosmetic and toiletry products. Three of the pathways involve conventional electrophilic nitrosation by XNO reagents of both neutral amine and N‐hydroxymethylamine compounds obtained by prior reaction with formaldehyde. The fourth pathway involves a nucleophilic reaction by nitrite ion with the iminium ion derived from N‐hydroxymethylamine. For morpholine, reaction via XNO reagents is substantial at pH 5 only, whereas the iminium ion pathway is pre‐eminent at pH 7. The concurrent formation of nitrosamines by mechanistically different pathways implies that combinations of nitrosation inhibitors are necessary to minimize contamination of cosmetic and toiletry products. For these different pathways, novel inhibitory compounds are described which fulfil the usual acceptance criteria for cosmetic and toiletry materials. The efficacy of these compounds is assessed against N‐nitrosomorpholine formation in the presence of formaldehyde. These include erythorbate, ascorbate, pentanedione and pyranone compounds for the XNO pathways (pH 6) and neutral organic and inorganic salts for the iminium ion pathways (pH 7). Preliminary results for both a bath gel and a cream‐base formulation deliberately adulterated with morpholine, diethanolamine, nitrite and a preservative which releases low levels of formaldehyde on decomposition show better than 90% inhibition of nitrosamines by selected pairs of inhibitor compounds on storage at 40°C over several months. This novel technology is the subject of a worldwide patent application.
Synthesis of 2‐N‐oleoylamino‐octadecane‐1,3‐diol: a new ceramide highly effective for the treatment of skin and hair
Authors: PHILIPPE M. , GARSON J.C. , GILARD P. , HOCQUAUX M. , HUSSLER G. , LEROY F. , MAHIEU C. , SEMERIA D. , VANLERBERGHE G.
Published: May 2007

Synopsis

2‐N‐Oleoylamino‐octadecane‐1,3‐diol is a new synthetic ceramide. The process enables a four‐step preparation of 2‐amino‐octadecane‐1,3‐diol (D,L‐erythro/threo) and a five‐step synthesis of 2‐N‐oleoylamino‐octadecane‐1,3‐diol (D,L‐erythro/threo). The latter compound is related to ceramide 2 according to the classification of Downing. This route of synthesis is rapid, reproducible and uses low‐cost starting materials. The new ceramide was analysed as follows: 1H, 13C, 15N NMR spectra afforded an unambiguous characterization of the structure; additionally, these three methods identified the threo and erythro isomers. 1H and 13C NMR permitted the measurement of the threo/erythro ratio (26.6/73.4 and 25.5/74.5, respectively). Chemical ionization mass spectrometry confirmed the expected mass of the pseudo‐molecular ion (m/z= 566.5: [M + H]+) as well as the presence of different chain lengths other than the oleic moiety due to the fatty acid composition of the technical grade oleic acid used for the synthesis. Capillary gas chromatography measured the threo/erythro ratio (23.5/76.5) which agrees with the 1H and 13C NMR data. Moreover, this method afforded the relative distribution of the different N‐acylated chains. The properties of the new synthetic ceramide for the treatment of skin and hair were mainly assessed by two in vitro methods. The first measured the flux of water through lipid‐extracted stratum corneum. The described ceramide showed high efficacy in decreasing water loss. The second recorded the friction coefficient of different types of hair: virgin, permanent‐waved, and bleached. Treatment by the ceramide led to a strong decrease in this coefficient. This was particularly observed on unrinsed hair. These findings suggest two potential fields of application and beneficial contribution for the new ceramide: repairing the barrier to transepidermal water loss, and improving the surface properties of hair.

Synthèse du 2‐N‐oleoylamino‐octadécane‐1,3‐diol: nouveau céramide à haut potentiel dans le soin de la peau et du cheveu.
Studies in vivo by electron spin resonance of free radical mechanisms implicated in UV‐induced skin photocarcinogenesis
Authors: VALAVANIDIS A. , RALLIS M. , PAPAIOANNOU G. , XENOS K. , KATSAROU A.
Published: May 2007

Synopsis

Solar ultraviolet radiation (UVR) is implicated in many types of skin damage, such as photodermatoses, photoageing, erythema, pigmentation, skin cancer etc. Free radicals and reactive oxygen species are considered to play an important role in cutaneous photocarcinogenesis. But skin is endowed with photoprotective agents, namely melanins and antioxidant enzymatic and non‐enzymatic mechanisms. In this study we describe the in vivo electron spin resonance (ESR) signals of melanins after UVR exposure, using skin specimens of various types of mice, which were taken from different parts of their bodies. The ESR signals were used as a model for testing the antioxidant properties of butylated hydroxyanisole, tocopherol acetate, and octyl p‐methoxycinnamate with butyl methoxy dibenzoyl methane and superoxide dismutase (SOD). Additional UVB radiation was applied to the skin samples in situ (in the cavity of the ESR spectrometer). Suppression of ESR signals of melanins was observed in all cases.

Etudes in vivo par resonance paramagnetique electronique, après exposition au rayonnement UV, des méchanismes radicalans impliqués a la photocarcinogénèse cutanée
Water retention of treated stratum corneum measured by a coupling method: thermal desorption‐mass spectrometry
Authors: GOURNAY A. , NAVARRO R. , MATHIEU J. , RIVIERE M.
Published: May 2007

Synopsis

A thermal desorption autosampler coupled to a mass spectrometer has been used to measure the in vitro water retention of human stratum corneum as a function of treatment applied. Samples were treated with ingredients possessing good hygroscopic properties which are used in the formulation of moisturizing creams. After being treated, stratum corneum samples were dried and rehydrated and then analysed. The paper describes the method used to quantify their hygroscopic capacity in terms of the percentage of water retained. Ten humectants were examined, of which urea, glycerine, ammonium lactate and a new salt of an α‐hydroxy acid were found to have the highest activities. This method can also be used to quantify the water retention capacity of various types of pathological skin such as ichthyosis and psoriasis.
Influence du protocole opératoire sur les caractéristiques d'une émulsion L/H réalisée avec des surfactifs polymériques non ioniques
Authors: NIELLOUD F. , LAGET J.P. , FORTUNE R. , MARTI‐MESTRES G. , MAILLOLS H.
Published: May 2007

Synopsis

The mode of operation has an effect on the properties of emulsions. We have studied the influence of the method of preparation (temperature, stirring rate, time of phase introduction and method of cooling) on the rheological properties of an oil in water emulsion. The importance of factors is classified with the help of two‐level full and fractional factorial designs. The most significant factor is the mode of cooling, a progressive cooling produces an increase of viscosity and the influence of the other studied factors is insignificant. Sudden cooling entails a lowering of the viscosity and a diminution of the stability, and shows the influence of the rate of mixing and the temperature of manufacture.
Alternative methods: Hen's egg chorioallantoic membrane and in vitro cytotoxicity – a complementary approach
Authors: BOUE‐GRABOT M. , BERNARDIN G. , CHAUMOND S. , PINON J.F.
Published: May 2007

Synopsis

The ocular irritation potential of 107 cosmetics and toiletries was compared using the rabbit's eye Draize test (IOMA), a cytotoxicity in vitro method (CFIO), and the hen's egg chorioallantoic membrane test (HET‐CAM). There was a good correlation between both alternative methods and the Draize test. Non‐correlating results were observed in 12 cases with the HET‐CAM method (six false positives, two false negatives, four technical failures) and in 14 cases with the CFIO method (ten false positives, four false negatives). However, all clearly irritant products were detected. False negatives were only found in products whose ocular irritation index lay close to the boundary (IOMA = 15) between the slightly and the moderately irritant products. None of the products was falsely found to be negative by both alternative methods. Therefore, the risk of underestimating the ocular irritation potential was avoided. The coupling of these two methods seemed to be of interest as an alternative approach to the assessment of the potential for ocular irritation of cosmetics and toiletries.
A screening procedure for total N‐nitroso contaminants in personal care products: results of collaborative studies undertaken by a CTPA Working Group
Authors: CHALLIS B.C. , COLLING J. , CROMIE D.D.O. , GUTHRIE W.G. , POLLOCK J.R.A. , TAYLOR P. , TELLING G.M. , WALLACE L.
Published: May 2007

Synopsis

A modified procedure for the determination of total N‐nitroso compounds in personal care products was evaluated in collaborative studies organized through the UK Cosmetic Toiletry and Perfumery Association (CTPA). The method offers a true ‘totals’determination in that a solution of the whole sample is analysed. Samples are dissolved/suspended in water or aqueous THF, and nitrite/nitrite ester interferences are removed by prior treatment with sulphamic acid. The treated test solution is denitrosated in a single reaction with HBr/acetic acid, in refluxing n‐propyl acetate, and ‘total’N‐nitroso compounds are determined in a chemiluminescence reaction of the released nitric oxide with ozone. The use of a propyl acetate denitrosation solvent and of higher concentrations of HBr have improved both the sensitivity (routine limit of determination at 10 μgkg‐1) and water tolerance of the method. The method was shown to recover N‐nitrosamines quantitatively, and to be sufficiently repeatable and reproducible to be used as a screening technique for N‐nitroso compounds in personal care products.
Some simple theoretical considerations on the bending stiffness of human hair
Authors: SWIFT J.A.
Published: May 2007

Synopsis

Factors affecting the cantilever bending of human hair have been investigated by theoretical structural mechanics in which the hair was treated as if it was of isotropic structure and internal mechanical property. Despite the simplicity of the model it is a valuable one for assessing the major geometric factors affecting a hair's bending behaviour in relation to perceptions of coarseness and fineness. Simple equations have been used for predicting relative bending stiffness between hairs of different racial types using published fibre cross‐sectional information and these accord with existing perceptions of behaviour. Strikingly it is the hair's minor elliptic diameter which has a dominant effect upon bending resistance and it is shown that the hair's cuticle could be making a very high proportional contribution. It is shown that triangular hairs of the uncombable hair syndrome will be stiffer than normal elliptical hairs of the same cross‐sectional area and that this goes some way to explaining the condition.
Seasonal influences on stratum corneum ceramide 1 fatty acids and the influence of topical essential fatty acids
Authors: CONTI A. , ROGERS J. , VERDEJO† P. , HARDING C. R. , RAWLINGS A. V.
Published: May 2007

Synopsis

Ceramide 1 is the main repository of stratum corneum linoleic acid, and changes in the levels of ceramide 1 linoleate are associated with cutaneous abnormalities: essential fatty acid deficiency, atopic dermatitis and acne. We have previously reported seasonal variation in stratum corneum lipids where lipids, particularly ceramides, are very much reduced in winter which probably influences the appearance of skin xerosis in this season. However, investigations into the seasonal variation in ceramide 1 fatty acid levels and the effects of topical essential fatty acids on the composition of these lipid species have not been conducted in healthy subjects. We determined the composition of stratum corneum ceramide 1 esterified fatty acids in leg skin from Caucasian women in winter and summer and also investigated the effects of topical triglycerides rich in linoleic acid on stratum corneum ceramide 1 fatty acid levels in winter. A dramatic seasonal variation was observed. Whereas decreased levels of linoleic acid and some saturated fatty acids (C‐15 and C‐24) were observed in the winter months, increased levels of oleic acid were found. Nevertheless, it was possible to normalize the levels of stratum corneum ceramide 1 linoleate following topical application of formulations containing linoleic acid‐rich triglycerides for 4 weeks. The reduction in ceramide 1 linoleate may lead to impaired stratum corneum function and increased susceptibility to skin xerosis in winter. However, by using formulations containing linoleic acid esters it is possible to correct these changes and possibly improve barrier resilience.
Consequences for sun protection factors when solar simulator spectra deviate from the spectrum of the sun
Authors: UHLMANN B. , MANN T. , GERS‐BARLAG H. , ALERT D. , SAUERMANN G.
Published: May 2007

Synopsis

The sun protection factor (SPF) of two products, one with an expected SPF of 4 and another with an expected SPF of 15 were determined, using two solar simulators: Multiport Solar UV Simulator (xenon, Solar Light, Philadelphia, PA, USA), and Supersun 5000 (metal halide, Mutzhas, Munich, Germany). The mean SPFs using the Multiport were: 4.8 for the low SPF product and 19.4 for the high SPF one. The results using the Supersun were lower: 2.6 for the low SPF product and 7.2 for the high SPF one. Relative emission spectra of the two sources were recorded using a fluorescence spectrophotometer in bioluminescence mode. Efficacy spectra were calculated and compared with the corresponding spectrum of natural sunlight. It was evident that the spectral power of the xenon source is too high in the UVB, leading to overestimation of SPFs, whereas the Supersun irradiator emits too much in the UVA, resulting in too low SPFs. Heat effects and photodegradation of UV filters are discussed as further possible reasons for the discrepancies between the experimentally determined SPFs. Our results confirm a recent publication about theoretical SPFs, calculated with emission spectra of a xenon source and spectra of the sun at different elevation angles, where the authors provide evidence that in natural sunlight the contribution of UVA to total UV radiation is twice as high as in a xenon source. This may contribute to an understanding of why sunscreens tested according to the FDA method (xenon sources) often yield higher SPFs than those obtained from European testing procedures.
Survey of micro‐organisms associated with spoilage of cosmetic creams manufactured in South Africa
Authors: ANELICH L.E. , KORSTEN L.
Published: May 2007

Synopsis

Two studies were conducted to determine the predominant micro‐organisms found in spoiled cosmetic creams manufactured in South Africa. The products evaluated included facial creams and hand and body lotions. Spoiled cosmetic creams were obtained from different manufacturers and analysed microbiologically for the presence of bacteria, yeasts and moulds. The frequency and relative density (percentage) of micro‐organisms isolated from naturally spoiled creams were calculated. Pseudomonas aeruginosa and Enterobacter gergoviae were the most predominant bacteria, whilst Candida parapsilosis and Aspergillus flavus were the most predominant yeast and mould, respectively. Of all the samples examined, approximately two‐thirds (69%) were due to microbial spoilage. This study highlighted the importance of adopting suitable quality control guidelines for the local cosmetics industry, similar to those currently used by international cosmetics manufacturers.