Whitening effect of alpha-bisabolol in Asian women subjects

SYNOPSIS

Although skin pigmentation, which results from the production and distribution of melanin in the epidermis, is the major physiological defence against solar irradiation, hyperpigmentation is a common and distressing problem caused by various inflammatory skin disorders, such as eczema, allergic contact dermatitis and irritant contact dermatitis. We evaluated the effects of a preparation containing alpha-bisabolol on pigmented skin of a group of subjects. The effectiveness of the active compound, alpha-bisabolol, in a base-cream preparation for the treatment of pigmented skin was tested on 28 female subjects as follows: the cream was applied once a day to the back for 8 weeks. These same women also applied a vehicle control cream to the pigmented skin. The results were evaluated by clinical and biophysical test methods. After 8 weeks of treatment of the alpha-bisabolol-containing cream, there was significant lightening effect in the pigmented skin for the majority of the subjects who tested the cream.

Effects of biomaterials for Lab-on-a-chip production on cell growth and expression of differentiated functions of leukemic cell lines

The rapid increase of the applications for Lab-on-a-chip devices has attracted the interest of researchers and engineers on standard process of the electronics industry for low production costs and large scale development, necessary for disposable applications. The printed circuit board technology could be used for this purpose, in particular for the wide range of materials available. In this paper, assays on biocompatibility of materials used for Lab-on-a-chip fabrication has been carried out using two tumor cell lines growing in suspension, the human chronic myelogenous leukemia K562 cell line, able to undergo erythroid differentiation when cultured with chemical inducers, and the lymphoblastoid cell line (LCL), extensively used for screening of cytotoxic T-lymphocytes (CTLs). We have demonstrated that some materials strongly inhibit cell proliferation of both the two cell lines to an extent higher that 70-75%, but only after a prolonged exposure of 3-6 days (Copper, Gold over Nickel, Aramid fiber filled epoxy uncured, b-stage epoxy die attach film, Tesa 4985 adhesive tape, Pyralux uncured, Copper + 1-octodecanethiol). However, when experiments were performed with short incubation time (1 h), only Aramid fiber filled epoxy uncured was cytotoxic. Variation of the results concerning the other materials was appreciable when the experiments performed on two cell lines were compared together. Furthermore, the effects of the materials on erythroid differentiation and CTL-mediated LCL lysis confirmed, in most of the cases, the data obtained in cytotoxic and antiproliferative tests.

Promotion of stem cell proliferation by vegetable peptone

OBJECTIVES

Technical limitations and evolution of therapeutic applications for cell culture-derived products have accelerated elimination of animal-derived constituents from such products to minimize inadvertent introduction of microbial contaminants, such as fungi, bacteria or viruses. The study described here was conducted to investigate the proliferative effect of vegetable peptone on adult stem cells in the absence of serum, and its possible mechanisms of action.

MATERIALS AND METHODS

Cell viability and proliferation were determined using the MTT assay and Click-iT EdU flow cytometry, respectively. In addition, changes in expression of cytokine genes were analysed using MILLIPLEX human cytokine enzyme-linked immunosorbent assay kit.

RESULTS

Viability of cord blood-derived mesenchymal stem cells (CB-MSC) and adipose tissue-derived stem cells (ADSC) increased significantly when treated with the peptone. In addition, median value of the group treated with peptone shifted to the right when compared to the untreated control group. Furthermore, quantitative analysis of the cytokines revealed that production of vascular endothelial growth factor (VEGF), transforming growth factor-beta1 (TGF-beta1), and interleukin-6 (IL-6) increased significantly in response to treatment with our vegetable peptone in both CB-MSCs and ADSCs.

CONCLUSIONS

Our findings revealed that the vegetable peptone promotes proliferation of CB-MSCs and ADSCs. In addition, results of this study suggest that induction of stem cell proliferation by vegetable peptone is likely to be related to its induction of VEGF, TGF-beta1, and IL-6 expression.

Expression of EGFR, VEGF, and K-ras mutation as predictors for response of cetuximab in colorectal cancer patients

e15147

Background: Cetuximab has been effective in metastatic colorectal cancer (CRC) patients. EGFR is involved in CRC through its downstream signaling pathways, including RAS and MAKP pathway and angiogenesis. We evaluated the predictive value of EGFR and VEGF expressions and K-ras mutation status in colorectal cancer patients treated with cetuximab in combination with chemotherapy Methods: Our study included 29 CRC patients treated with cetuximab in combination with chemotherapy (20 patients with FOLFIRI and 5 patients with FOLFOX, and 4 patients with monotherapy). Paraffin blocked tumor tissues were analyzed for EGFR and VEGF expression using quantitative real time PCR and K-ras mutation status (codons 12 and 13) using direct sequencing. Results: 12 patients (43%) had a partial response (PR) and 6 patients (21%) with stable disease (SD) and 11 patients (38%) with progressive disease (PD). EGFR expression was not correlated with the response of cetuximab (p=0.60) The median EGFR expression level was 0.30 x 10-3 in PR and 0.25 x 10-3 in SD and 0.26 x 10-3 in PD. High VEGF expression was associated with the response of cetuximab (p=0.03). The mean VEGF expression level was 4.3 x 10-3 in PR and 1.64 x 10-3 in SD and 1.72 x 10-3 in PD. A K-ras mutation was present in 45 % (13/29) and did not significantly correlated with non-response of cetuximab (p=0.05). A K-ras mutation was detected 33% (4/12) in PR and 33% (2/6) in SD and 70 % (7/10) in PD. Conclusions: VEGF expression in tumor may be a potential predictor for the response of cetuximab. But EGFR expression and K-ras mutation status is not significantly correlated with clinical outcome of cetuximab. And a K-ras mutation is found in the response group.

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[Risk of nanoparticles?]

Nanotechnology is an "emerging industry" and becomes more widely used. As a result human exposure to nanoparticles is inevitable. Exposure to nanoparticles can affect the upper aerodigestive tract, before particles reach lung, stomach and intestine. The effects of this passage depend on particle size, particle concentration, the kind of the particle and the duration of contact. Only few in-vitro-investigations about effects of the exposition of nanoparticles on the mucous cells of oral cavity, nose and nasal sinuses exist. In-vitro-analysis with cells of nasal mucous membrane exposed to nanoparticles showed a release of mediators involved in inflammation and allergy development. Cytotoxic and genotoxic effects could be found for several nanoparticles (e.g. carbon nanotubes) in vitro. Due to different size, structure, chemical and physical properties nanoparticles can not be summarized in a homogenous group; quite the contrary risk evaluation of nanoparticles must be carried out case-related. Today toxicological risks can not be evaluated sufficiently. Biological interactions and tissue permeability of manufactured nanoparticles is a major issue for further investigations. In this report the use and health effects of nanoparticles are overviewed.

Highly birefringent terahertz polarization maintaining plastic photonic crystal fibers

Guided-wave propagation of sub-ps terahertz (THz) pulses in a highly birefringent plastic photonic crystal fiber was studied by using a THz time domain spectroscopy technique. The plastic photonic crystal fiber was fabricated by using high density polyethylene tubes and solid filaments. The fabricated THz plastic photonic crystal fibers exhibit an extremely large birefringence of ~ 2.1 x 10(-2), which is almost one order of magnitude larger than that of previously reported photonic crystal fibers.

Mechanisms of melanogenesis inhibition by 2,5-dimethyl-4-hydroxy-3(2H)-furanone

BACKGROUND

Increased production and accumulation of melanin is characteristic of a large number of skin diseases, including acquired hyperpigmentation such as melasma, postinflammatory melanoderma and solar lentigo. Thus, there is a increasing need for the development of depigmenting agents.

OBJECTIVES

To evaluate the depigmenting capacity of 2,5-dimethyl-4-hydroxy-3(2H)-furanone (DMHF) and to elucidate the mechanisms by which it inhibits alpha-melanocyte-stimulating hormone (alpha-MSH)-induced melanogenesis in B16 melanoma cells in vitro.

METHODS

Several experiments were performed in B16 melanoma cells. We studied melanin content, tyrosinase activity and cAMP production, and performed cAMP response element (CRE) luciferase reporter assay and Western blots for proteins involved in melanogenesis.

RESULTS

The melanin content and tyrosinase activity induced by alpha-MSH were inhibited significantly by DMHF. To clarify the mechanism of the depigmenting property of DMHF, we examined the involvement of DMHF in cAMP signalling induced by alpha-MSH. In CRE luciferase reporter assay, CRE reporter activation induced by alpha-MSH was inhibited by DMHF. Additionally, although DMHF did not inhibit cAMP production by alpha-MSH, both CRE binding protein (CREB) phosphorylation and the reduction of glycogen synthase kinase-3beta phosphorylation by alpha-MSH were blocked by DMHF. These data suggest that DMHF inhibits the downstream step of cAMP production induced by alpha-MSH, consequently inhibiting melanogenesis. This suggestion was further confirmed by the fact that the increased production levels of microphthalmia-associated transcription factor, tyrosinase and tyrosinase-related protein-1 induced by alpha-MSH were all reduced by DMHF in B16 melanoma cells.

CONCLUSIONS

Our study shows that DMHF inhibits alpha-MSH-induced melanogenesis by suppressing CREB phosphorylation, which is induced by protein kinase A, and suggests that DMHF may be an effective inhibitor of hyperpigmentation.

Mechanical properties and structure of particle coated interfaces: influence of particle size and bidisperse 2D suspensions

We report surface pressure-area (Pi-A) isotherms of bidisperse mixtures of anionic polystyrene latex particles at a water/n-decane interface as well as optical photographs of the interface for various compressions and mixture ratios. In the case of mixtures of 3 and 5 mum particles, we observe crystalline layers at high or low concentration ratios, where the "impurity" particles concentrate at the grain boundaries of the crystalline structure. At intermediate ratios, the layers become highly disordered. However, in both cases, we show that the shape of the isotherms remains unchanged. In the case of the mixtures of 9 mum particles with either 3 or 5 mum particles, the smaller particles aggregate around the larger particles through capillary interaction resulting in the formation of large fractal aggregates. At high compression, these layers contain holes that seem very compressible. As a result, the surface pressure isotherms show a smaller surface pressure jump than for other mixtures.