Integrated approach in the assessment of skin compatibility of cosmetic formulations with green coffee oil.

OBJECTIVE: Green coffee oil (GCO) has been used in cosmetic formulations due to its emollient and anti-ageing properties. However, there are insufficient studies about its safety when applied in cosmetic formulations. METHODS: Cytotoxicity of GCO and of formulations containing 2.5-15% of GCO was evaluated by the MTT reduction assay, in human keratinocytes. Formulations containing 15% of GCO and the vehicle were applied under in use conditions in the volar forearm of human volunteers during 3 days. Transepidermal water loss, stratum corneum water content and erythema index were evaluated each 24 h using biophysical techniques. The same formulations were probed for skin tolerance through a patch test. RESULTS: Neither pure GCO nor its formulations showed cytotoxic effects in concentrations up to 100 µg mL(-1) . Transepidermal water loss values showed a slight reduction when the formulation containing GCO was applied. Stratum corneum water content and erythema index did not show significant differences, as the results observed in the first day of the study were maintained throughout 3 days. None of the volunteers display any reaction after using an occlusive patch. CONCLUSION: The results obtained in the study indicate that GCO seems to be safe for topical applications and showed good skin compatibility under the experimental conditions of the study.

Comparative assessment of the performance of two generations of Tewameter: TM210 and TM300.

The measurement of transepidermal water loss (TEWL) has been established as one of the main parameters in the assessment of skin barrier function. One of the most widely employed devices to measure TEWL is the Tewameter. Courage and Khazaka launched the TM300 in 2003 and successfully eliminated some of the limitations of the previous model. In the more recent device, the sensors inside the probe head can be pre-heated to a temperature close to that of the skin, which considerably decreases sampling time. Additionally, the new technology of the probe does not require frequent and time-consuming recalibration with different solutions. The main objective of this work was to perform a comparative assessment of the performance of the two different Tewameter models. Fifteen volunteers were used in this study, which was conducted in the mid-portion of the volar forearm. The standard measurements assessed differences in the basal values, time necessary for a stable value and coefficient of variability under normal and extreme conditions. The dynamic measurements performed were based on a plastic occlusion stress test (POST), involving the application of an occlusive patch for 24 h, after which the TEWL desorption curves were recorded. A mathematical model was adjusted to the data points using a specially modified simplex routine. Calculated parameters considered relevant to the study were t(1/2evap) (evaporation half-life) and dynamic water mass (DWM). Results show slight differences in the performance the two models, which are nevertheless statistically significant. The TM300 seems to be more sensitive to differences in TEWL and presents a much quicker measurement capacity. These results confirm a marked improvement in the more recent Tewameter model, when compared with its predecessor. The main conclusion of this work is that caution is advised when comparing results obtained with the two different models and that studies should be carried out entirely with the same device.

Assessment of induced rat mammary tumour response to chemotherapy using the apparent diffusion coefficient of tissue water as determined by diffusion-weighted 1H-NMR spectroscopy in vivo.

Chemosensitivity of N-methyl-N-nitrosourea-induced rat mammary tumours treated with 5-fluorouracil at a dose of 100 mg kg(-1) i.p. was assessed by using diffusion-weighted 1H-MRS to measure the average diffusion coefficient (ADC) of water in the tumour tissue. ADC measurements prior to any therapy correlated positively with necrotic fraction. Tumours with low initial ADC (< 0.95 x 10(9) m2 s(-1)) showed an increase in ADC 7 days after treatment, whereas tumours with a high initial ADC (> 1.2 x 10(9) m2 s(-1)) showed a decrease. All tumours decreased significantly in volume (P < 0.05) 2, 5 and 7 days after treatment. At day 7 post-treatment, tumours with a high pre-treatment ADC started to regrow. The initial ADC value, as well as changes after treatment predict tumour chemosensitivity, which could be clinically relevant.

Cognitive underpinnings of narrative attachment assessment.

Traditional story completion methods used to examine attachment representations in childhood draw heavily on socially significant content and clinical judgment. Using these methods with 37-month-olds, Bretherton, Ridgeway, and Cassidy (1990) found that attachment security scored from story completions were related to a wide range of secure base, personality, intellectual, and family variables. We examined story completions from 24 of Bretherton et al. 's (1990) subjects who had also produced story completions at 54 months, but scored passage length (idea units) and scriptedness. Results captured much of the attachment-related variance associated with the traditional scoring, but had better discriminant validity vis-à-vis general developmental level. These results indicate that analysis of cognitive variables underlying conventional scoring can advance understanding of attachment representations and their relations to the organization and content of attachment-related narratives.

An assessment of artefacts in localized and non-localized 31P MRS studies of phosphate metabolites and pH in rat tumours.

UA hepatomas, GH3 prolactinomas and N-methyl-N-nitrosourea-induced mammary tumours, which were subcutaneously grown in rats, have been studied by 31P MRS using non-localized pulse-acquire, image selected in vivo spectroscopy (ISIS) and one-dimensional chemical shift imaging (1-D CSI) techniques. Comparisons have been made with measurements from acid extracts of these tumour types and surrounding tissues (i.e., muscle and skin). Since muscle containing high concentrations of phosphocreatine (PCr) is often found adjacent to the tumour, we have compared the ratio of the PCr to gamma-NTP peaks in the spectra with the same ratio calculated from the acid extract data, and have used deviations between the two sets of data to assess the discrimination of the MRS localization technique to signals from the tissue surrounding the tumour. Extract data showed an average NTP content of 1.25 mumol/g wet wt for all three tumour types. PCr (at 0.42 mumol/g wet wt), was significant only in the GH3 prolactinoma whereas it was negligible in the other tumour types (< 0.1 mumol/g wet wt). There was good agreement between the ISIS PCr/gamma-NTP ratio and the extract data for all tumours. However, the 1-D CSI data showed an unexpectedly large contamination of the tumour spectrum with PCr signals from the skin which was shown by subsequent phantom experiments to be due to the curved geometry of tumour and skin rather than Fourier bleed. In pH measurements by MRS it was found that biological variability was greater than the effects of artefacts (due to either the chemical shift artefact in the ISIS technique or partial volume effects) in the localization technique. An average pH of 7.2 was observed for all tumours. By initially comparing data from different localization schemes with that from chemical extracts potential sources of error have been highlighted and show that phantom studies alone are not sufficient to fully assess the accuracy of localized MRS data.

An assessment of 31P MRS as a method of measuring pH in rat tumours.

The contribution of extracellular components to the measurement of pHMRS of a variety of rat tumours (nitrosomethyl urea induced mammary tumours, GH3 prolactinomas, Hepatoma 9618a, UA hepatomas and Walker sarcomas) has been assessed. Acid extractable P(i) was between 2.6 and 12.5 mumol/G wet wt depending on tumour type, and of this 53 +/- 4.8% (mean +/- SEM) was MRS-visible. The P(i) content of tumour exudate was 2-3 mM, of interstitial fluid (sampled from a micropore chamber incorporated within a tumour) 1.7 mM, and of blood plasma 1.95 mM. The mean extracellular volumes of the tumours, measured by distribution of 3H2O and [14C]inulin, were 49-55% depending on tumour type and were at least twice that found in normal liver. Calculations suggested that for most tumours with an extracellular volume not exceeding 55%, at least 65% of the P(i)(MRS) signal was derived from intracellular P(i), and thus that pH(MRS) is a measure of pHi. For each tumour type, pHMRS was measured both in 'pulse-acquire' mode at 1.9 T which may include signals from surrounding tissue, and in localized mode at 4.7 T where the signal came uniquely from tumour tissue. The steady state pHMRS was either neutral or on the alkaline side of neutrality (pH range 7.04-7.37). Raised lactate content and decreased buffering capacity (compared to normal tissues) accompanied these neutral to alkaline pH values.(ABSTRACT TRUNCATED AT 250 WORDS)