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BACKGROUND: Work-related injuries and illness are prevalent and costly. Firefighting is especially hazardous and many firefighters sustain work-related injuries. Workplace health promotion programmes have shown positive return on investment (ROI). Little is known about how similar programmes would impact injury and cost among firefighters. AIMS: To evaluate the impact of a workplace health promotion intervention on workers' compensation (WC) claims and medical costs among Oregon fire departments participating in the PHLAME (Promoting Healthy Lifestyles: Alternative Models' Effects) health promotion programme compared with Oregon fire departments not participating in PHLAME. METHODS: Data from firefighters from four large urban fire departments in Oregon were evaluated using a retrospective quasi-experimental study design. Outcomes were (i) total annual firefighter WC claims, (ii) total annual incurred medical costs prior to and after implementation of the PHLAME firefighter worksite health promotion programme (iii) and an ROI analysis. RESULTS: Data were obtained from 1369 firefighters (mean age of 42 years, 91% white, 93% male). WC claims (P < 0.001) and medical costs (P < 0.01) were significantly lower among PHLAME fire departments compared with Oregon fire departments not participating in the programme. Fire departments participating in the PHLAME TEAM programme demonstrated a positive ROI of 4.61-1.00 (TEAM is used to indicate the 12-session peer-led health promotion programme). CONCLUSIONS: Fire department WC claims and medical costs were reduced after implementation of the PHLAME workplace health promotion programme. This is a low cost, team-based, peer-led, wellness programme that may provide a feasible, cost-effective means to reduce firefighter injury and illness rates.
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Bombeiros , Comportamentos Relacionados com a Saúde , Promoção da Saúde/métodos , Doenças Profissionais/prevenção & controle , Serviços de Saúde do Trabalhador/métodos , Traumatismos Ocupacionais/prevenção & controle , Adulto , Dieta , Exercício Físico , Feminino , Custos de Cuidados de Saúde/estatística & dados numéricos , Promoção da Saúde/economia , Humanos , Masculino , Doenças Profissionais/economia , Traumatismos Ocupacionais/economia , Avaliação de Programas e Projetos de Saúde , Estudos Retrospectivos , Comportamento de Redução do Risco , Indenização aos Trabalhadores/estatística & dados numéricos , Local de TrabalhoRESUMO
Most of adult women exhibit cellulite on the hips, buttock and thighs. Although extracellular matrix and lymphatic system disorders can increase its appearance, cellulite basically results from an excessive fat storage in the adipose tissue which exerts considerable pressure on the surrounding skin tissue and creates a dimpled irregular appearance. Caffeine, the most widely used anti-cellulite ingredient, favours fat break-down by inhibiting the phosphodiesterase enzyme and encouraging a high intracellular level of cAMP. A series of studies has shown that spermine and spermidine, two ubiquitous polyamines, encouraged fat storage and slowed fat break-down in the adipose tissue. Besides, it was shown that heparan sulfate glycosaminoglycans had a strong affinity for polyamines. To design a new cosmetic ingredient with anti-cellulite properties, we used molecular modelling to screen several ingredients with a structure similar to that of heparan sulfate glycosaminoglycans. This way, we identified sulfo-carrabiose as a potent molecule for trapping spermine and spermidine. These virtual results were first confirmed in tubo where sulfo-carrabiose was shown to dose-dependently inactivate spermine and spermidine. In vitro, adipocytes cultured with sulfo-carrabiose exhibited a significant reduction of lipogenesis and a significant increase of lipolysis. When sulfo-carrabiose was incorporated in a cosmetic formula, significant improvements were observed in thigh circumference, with better results than those obtained with caffeine after 28 days of use. Furthermore, a combination of caffeine and sulfo-carrabiose led to results significantly better than those obtained with caffeine alone. As measured by fringe projection, thigh volume was also significantly reduced after sulfo-carrabiose treatment. Finally, the appearance of cellulite assessed by clinical evaluation was also significantly reduced within 28 days.
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Tecido Adiposo/efeitos dos fármacos , Carragenina/farmacologia , Cosméticos/farmacologia , Adipócitos/efeitos dos fármacos , Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Adulto , Processos de Crescimento Celular/efeitos dos fármacos , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Espermidina/antagonistas & inibidores , Espermidina/metabolismo , Espermina/antagonistas & inibidores , Espermina/metabolismo , Coxa da Perna/fisiologia , Adulto JovemRESUMO
In the skin, heparin, heparan sulphate and heparan sulphate proteoglycans control the storage and release of growth factors and protect them from early degradation. We developed a cosmetic active ingredient containing Hibiscus Abelmoschus seed extract (trade name Linefactor) that can maintain the FGF-2 content in the skin by mimicking the protective effect of heparan sulphate proteoglycans. By preventing the natural degradation of FGF-2, Hibiscus Abelmoschus seed extract maintains the bioavailability of this growth factor for its target cells, i.e. skin fibroblasts. Our in vitro evaluations showed that this ingredient exhibited heparan sulphate-like properties and dose-dependently protected FGF-2 from thermal degradation. We could also show that, in turn, the protected FGF-2 could stimulate the synthesis of sulphated GAGs, the natural protective molecules for FGF-2, thus providing a double protection. Finally, the in vitro results were confirmed in vivo thanks to a clinical study in which skin biomechanical properties and reduction in wrinkles were assessed.
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Fator 2 de Crescimento de Fibroblastos/metabolismo , Hibiscus/química , Extratos Vegetais/farmacologia , Envelhecimento da Pele/efeitos dos fármacos , Pele/efeitos dos fármacos , Adulto , Proliferação de Células/efeitos dos fármacos , Elasticidade , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Proteoglicanas de Heparan Sulfato/metabolismo , Humanos , Pessoa de Meia-Idade , Sementes/química , Pele/citologia , Pele/metabolismo , Propriedades de SuperfícieRESUMO
Growing evidence suggests a distinction between water intake necessary for maintaining a euhydrated state, and water intake considered to be adequate from a perspective of long-term health. Previously, we have proposed that maintaining a 24-h urine osmolality (UOsm) of ⩽500 mOsm/kg is a desirable target for urine concentration to ensure sufficient urinary output to reduce renal health risk and circulating vasopressin. In clinical practice and field monitoring, the measurement of UOsm is not practical. In this analysis, we calculate criterion values for urine-specific gravity (USG) and urine color (UCol), two measures which have broad applicability in clinical and field settings. A receiver operating characteristic curve analysis performed on 817 urine samples demonstrates that a USG ⩾1.013 detects UOsm>500 mOsm/kg with very high accuracy (AUC 0.984), whereas a subject-assessed UCol⩾4 offers high sensitivity and moderate specificity (AUC 0.831) for detecting UOsm >500 m Osm/kg.
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Ingestão de Líquidos , Estado de Hidratação do Organismo/fisiologia , Gravidade Específica , Urinálise/estatística & dados numéricos , Urina/química , Adulto , Cor/normas , Feminino , Voluntários Saudáveis , Humanos , Masculino , Curva ROC , Valores de Referência , Sensibilidade e Especificidade , Adulto JovemRESUMO
We describe the use of unique microcapsules that may be degraded by the actions of bacteria. These microcapsules are approximately 35 mum in diameter, are composed of natural protein, and may be filled with a variety of actives. We describe the use of antimicrobial actives such as farnesol and methylparaben to demonstrate that their release by the degradative actions of axillary bacteria such as Corynebacterium minutissimum, C. urealyticum, and Staphylococcus epidermidis leads to their demise. These microcapsules may be used in consumer products such as deodorants and antiperpirants that may, under actual use conditions, control malodor.
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Several products are known to inhibit the biosynthesis of ceramides and glucosylceramides, but very few stimulate this process. We studied the influence of a hydrolysate of potato proteins (Lipidessence) in vitro on the sphingolipid metabolism of normal human epidermal keratinocytes. By measuring growth with the thymidine uptake assay, it was seen that Lipidessence, added in the culture medium up to an 8% concentration, did not change significantly the proliferation rate of keratinocytes, but beyond this concentration a progressive dose-dependent inhibition of growth was noticeable. Following incubation of cells with the product at 5% and 10% concentrations for 2 days, the lipids were extracted. The different lipid classes were separated by fractionation on columns of aminopropyl silica gel and analyzed by high-performance thin-layer chromatography. When keratinocytes were cultivated in the presence of Lipidessence, the biosynthesis of cholesterol, phosphatidylcholine, phosphatidylserine and gangliosides was stimulated, and a major increase was noticeable in the biosynthesis of free fatty acids, free ceramides, glucosylceramide and sphingomyelin. Radioactive [(14)C]-serine was used as a precursor of sphingoid bases to study sphingolipid biosynthesis. After migration of lipid fractions on thin-layer plates, autoradiography showed that free ceramides and glucosylceramide were labeled, thus suggesting that de novo biosynthesis was accounting for the increased cellular content in sphingolipids.
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BACKGROUND/OBJECTIVES: Urinary biomarkers of hydration (urine osmolality, UOsm; urine specific gravity, USG) follow circadian variations. For individuals, researchers and health-care professionals, there is value in identifying time frames during which spot values of UOsm and USG are representative of 24-h values in healthy young adults. SUBJECTS/METHODS: Eighty-two free-living adults (22.3±2.9 years, 22.2±1.5 kg/m(2)) collected individual urine voids over a 24-h period. UOsm and USG were measured on each void and on the pooled 24-h sample. To determine the time of day when a spot sample was likely to be equivalent to the 24-h value, daytime voids were binned by time and equivalence was tested for each 2-h window. Equivalence was a priori defined as being within 100 mOsm/kg (UOsm) and within 0.003 units (USG) of 24-h values. RESULTS: For both UOsm and USG, voids between 1400 and 2000 hours produced values that were equivalent to the 24-h sample, whereas earlier voids tended to overestimate 24-h UOsm and USG. For windows 1401-1600 hours, 1601-1800 hours and 1801-2000 hours, the mean difference (95% confidence interval) between spot and 24-h UOsm (mOsm/kg) was -25 (-72; 22), 28 (-35; 92) and 12 (-41; 66), respectively, whereas for USG the difference was 0.0014 (-0.0028; -0.0001), 0.0001 (-0.0017; 0.0019) and 0.0005 (-0.0018; 0.0009), respectively. CONCLUSIONS: In free-living healthy French adults, 24-h urine concentration can be approximated from a mid- to late-afternoon spot urine sample. This finding suggests that an afternoon sample may be an accurate and practical tool for hydration monitoring, useful to individuals and health-care practitioners.
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Ritmo Circadiano/fisiologia , Estado de Hidratação do Organismo/fisiologia , Coleta de Urina/estatística & dados numéricos , Urina/fisiologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Concentração Osmolar , Gravidade Específica , Fatores de Tempo , Coleta de Urina/métodos , Adulto JovemRESUMO
The consequences of implanting an automatic cardioverter defibrillator (ICD) on vehicle driving in France are poorly known. This retrospective study examined the behaviour at the wheel of ICD recipients who were recommended to abstain from driving for 3 to 6 months after device implantation. The study population included 98 patients (mean age = 59.5 +/- 14.8 years) followed for a mean of 24. +/- 23.9 months, who underwent ICD implant for ventricular tachycardia (65% of patients ventricular fibrillation (15%), syncope (8%), as part of a research protocol of myocardial cell transplantation 6%, or for primary prevention (5%). The underlying heart disease was ischemic in 59% of patients dilated cardiomyopathy in 11%,hypertrophic cardiomyopathy in 8%, valvular in 6%. Brugada syndrome in 4%, right ventricular arrhythmogenic cardiomyopathy in 2%, and miscellaneous disorders in 9% of patients. Five patients died without post mortem interrogation of the ICD. Only 28% of drivers remembered, and 13% observed, the recommended driving limitations. However, 45% (the oldest) claimed to drive prudently. During follow-up, 47% of patients received an ICD shock. Their mean it ventricular ejection fraction was 34 +/- 14%, versus 43 +/- 18% in patients who received no ICD therapy (p = 0.015). Syncope occurred in 16% who received ICD shocks. Shocks were delivered during driving in 6 patients, without consequent accident. Despite their non-observance of recommended driving limitations. ICD recipients suffered few traffic accidents. Legislation in France should reproduce the guidelines issued by European professional societies and enacted by the British laws.
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Condução de Veículo , Desfibriladores Implantáveis , Acidentes de Trânsito , Idoso , Feminino , França , Humanos , Masculino , Pessoa de Meia-Idade , Política Pública , Estudos Retrospectivos , Síncope/terapia , Taquicardia Ventricular/terapia , Fibrilação Ventricular/terapiaRESUMO
The electrocardiographic appearances and the significance of right bundle branch block were described at the beginning of the 20th century. Typical appearances include prolongation > 0.12 s of the QRS complex, RR' or rR' or Rr' appearances in V1 and widened S waves in the leads exploring the left ventricle (SI, aVL, V5 and V6). A delay in the appearance of the intrinsic deflection > 0.08 s may also be observed in the right precordial leads and negative T waves with ST depression may be seen in V1 and sometimes in V2. Left axis deviation of the QRS complex greater than - 45 degrees suggests associated left anterior hemiblock. Right axis deviation beyond + 120 degrees is equivocal. The principal differential ECG diagnosis is the Brugada syndrome, a familial arrhythmogenic autosomal dominant cardiomyopathy of variable penetration. This diagnosis is suggested when ECG abnormalities are observed in patients with a personal or family history of sudden death. Right bundle branch block only seems to have haemodynamic consequences in cardiac failure with associated asynchrony of the left ventricle or in certain cases of right ventricular dilatation encountered in congenital heart disease. The prognosis of right bundle branch block in the absence of underlying cardiac disease is good but it may be poor in other cases, particularly coronary artery disease. Moreover, the prognosis of right bundle branch block to complete atrioventricular block is rare in the absence of associated cardiac disease.
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Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/fisiopatologia , Eletrocardiografia , Bloqueio de Ramo/mortalidade , Diagnóstico Diferencial , Humanos , PrognósticoRESUMO
Aerobatics is an aerial sport which has many physiological constraints, principally cardiovascular, with a risk if not adapted of sudden mid-air incapacity which could jeopardise aviation safety, and thus justifies the selection and surveillance of pilots. The aeronautical constraints during flight are multiple, related to the environment traversed, how the aircraft functions and its movements. Those which cause accelerations (+G in particular) pose the problem of haemodynamic tolerance because they can induce loss of consciousness due to cerebral hypoxia. Tolerance of acceleration varies among individuals; it can be improved with training, certain protective manoeuvres, and is reduced by hypoxia, certain medications, dehydration and heat. Moreover, in aerobatics certain tricks require manoeuvres which reduce this tolerance to +G accelerations. This is the "push-pull" effect (_G acceleration immediately followed by +G acceleration). This leads to a risk of sudden loss of consciousness with a load factor much lower than that which the pilot knows he is capable of tolerating. Besides the haemodynamic effects, the existence of an actual acceleration cardiomyopathy has been suggested but has not been proven in man. Finally, while changes in cardiac rhythm during accelerations are usual and relate to changes in vaso-sympathetic balance, ventricular and supra-ventricular rhythm disturbances are rare and are related to the intensity and duration of the acceleration.
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Medicina Aeroespacial , Cardiomiopatias/etiologia , Hipergravidade/efeitos adversos , Esportes , Aeronaves , Desidratação , Hemodinâmica , Humanos , Hipóxia , Fenômenos Físicos , Física , Fatores de RiscoRESUMO
Normal human skin controls the intrusion of microorganisms by the production of peptide antibiotics such as defensins. The aim of our study was to develop a culture model of normal human keratinocytes for optimal beta-defensin mRNA detection which allows the screening of molecules able to stimulate hBD2 and hBD3 without inducing pro-inflammatory cytokines. A keratinocyte culture model in 96-well plates, in high calcium medium (1.7 mm) allowed to analyze hBD2 and hBD3 mRNA expression in basal condition and after cell stimulation by products from diverse vegetal extracts. The release of IL-8 and the chemokine MIP-3alpha was also evaluated in cell supernatants by ELISA. Among the 184 extracts tested, 75 showed a stimulatory effect on beta-defensin expression: 40 on hBD2, 26 on hBD3 and nine on both defensins. Fifteen of these substances which also induced the release of pro-inflammatory cytokines were eliminated. Among the other substances, four were selected and were analyzed in a dose-dependent study (n = 4) by real-time quantitative RT-PCR and completed by a measure of MIP-3alpha, IL-8 and IL-1alpha levels. These data underline the important necessity of screening result controls by a quantitative method reproduced at least three times. This new method of intensive screening allowed us to exhibit vegetal extracts that were able to stimulate epidermal beta-defensin expression without inducing an up-secretion of pro-inflammatory cytokines.
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UNLABELLED: Multislice computed tomography (MSCT) is a non-invasive and validated technique to detect coronary stenoses. Some questions remain about its accuracy to detect coronary stenoses (CS), especially for asymptomatic patients (P) when a prior stress test isn't conclusive. METHODS: MSCT was performed among 45 asymptomatic men (mean age: 58,3 +/- 16), with a high ten year risk of fatal cardiovascular disease (SCORE 2003 data for low-risk regions of Europe), without any previous coronary history and with previous non conclusive exercise testing. When significant (> 50%) CS was suspected at MSCT, an angiocoronarography (AC) was done. RESULTS: Eighteen MSCT were normal, unsignificant CS (< 50%) were detected on 14 MSCT and significant coronary stenoses (SCS) for 13 P. Among this 13 P, 19 SCS were identified: 2 SCS of left main coronary artery (CA), 9 of the left descending CA, 6 of the right CA and 2 of the left circumflex CA. 13 CS were confirmed at AC. Finally, because of critical angiographic lesions +/- ischemia at nuclear tomoscintigraphy (NT), 9 P had coronary revascularization (7 catheter based, 2 surgical bypass), 4 P had medical treatment. DISCUSSION: Benefits of this preliminary study are obvious: 9 coronary revascularization/45 P. However, the place of MSCT for the screening of CS is uncertain, but may be usefull as a complement for the screening of coronary arterial disease.
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Estenose Coronária/diagnóstico , Tomografia Computadorizada por Raios X/métodos , Idoso , Idoso de 80 Anos ou mais , Angiografia Coronária , Estenose Coronária/terapia , Teste de Esforço , Humanos , Masculino , Pessoa de Meia-Idade , Revascularização Miocárdica , Fatores de RiscoRESUMO
INTRODUCTION: The association of vasoplegic shock and myocardial infarction in a patient under iloprost treatment for critical ischemia of the lower limbs has not previously been reported. OBSERVATION: A 56 year-old man suffering from type 2 diabetes, hypertension and dyslipidemia developed critical ischemia of the right leg and was treated with iloprost. On the 19th day of infusion, he developed a vasoplegic shock with myocardial infarction. The shock resolved and he recovered from the infarction. DISCUSSION: This case report indicates the need for reinforced blood pressure and electrocardiographic monitoring in diabetes patients treated with iloprost.
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Iloprosta/efeitos adversos , Isquemia/tratamento farmacológico , Perna (Membro)/irrigação sanguínea , Infarto do Miocárdio/induzido quimicamente , Choque Cardiogênico/induzido quimicamente , Vasodilatadores/efeitos adversos , Diabetes Mellitus Tipo 2/complicações , Seguimentos , Humanos , Iloprosta/administração & dosagem , Masculino , Pessoa de Meia-Idade , Fatores de Tempo , Vasodilatadores/administração & dosagemRESUMO
In France, approximately 3000 people are repatriated every year, either in a civil situation by insurers. Repatriation also concerns French army soldiers. The literature is scarce on the topic of venous thromboembolic risk and its prevention during repatriation for medical reasons, a common situation. Most studies have focused on the association between venous thrombosis and travel, a relationship recognized more than 60 years ago but still subject to debate. Examining the degree of venous thromboembolic risk during repatriation for medical reasons must take into account several parameters, related to the patient, to comorbid conditions and to repatriation modalities. Appropriate prevention must be determined on an individual basis.
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Turismo Médico , Viagem , Tromboembolia Venosa/epidemiologia , Anticoagulantes/uso terapêutico , França , Humanos , Metanálise como Assunto , Militares , Guias de Prática Clínica como Assunto , Licença Médica , Trombofilia/complicações , Tromboflebite/epidemiologia , Tromboflebite/prevenção & controle , Tromboembolia Venosa/etiologia , Tromboembolia Venosa/prevenção & controleRESUMO
Since 1984, we have utilized a metabolic device in which activity and food intake are measured at 10-second intervals, in relation to the respiratory exchanges in the rat (indirect calorimetry). To solve the problem of quantifying precisely the metabolic cost of activity, we have developed models of the diffusion of the cells' respiratory exchanges in the rat and in the metabolic chamber until they reached the gas analyzers. The predictions of these models have been used to feed a process of numerical filtering that computed an estimation of the energy cost of activity, and an estimation of the value of the part of the total metabolism that was not due to the cost of the muscular contractions. This later component of metabolism has been named background metabolism to be clearly distinguished from the true resting metabolism measured during resting periods. In this paper, two models of diffusion of the cell's respiratory exchanges are described, and examples of the computation of the background metabolism by the process of Kalman filtering are shown.
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Algoritmos , Metabolismo Basal/fisiologia , Calorimetria Indireta/métodos , Metabolismo Energético/fisiologia , Sistemas On-Line , Animais , Modelos Estatísticos , Contração Muscular , Ratos , Projetos de PesquisaRESUMO
Nano-emulsions consist of fine oil-in-water dispersions, having droplets covering the size range of 100-600 nm. In the present work, nano-emulsions were prepared using the spontaneous emulsification mechanism which occurs when an organic phase and an aqueous phase are mixed. The organic phase is an homogeneous solution of oil, lipophilic surfactant and water-miscible solvent, the aqueous phase consists on hydrophilic surfactant and water. An experimental study of nano-emulsion process optimisation based on the required size distribution was performed in relation with the type of oil, surfactant and the water-miscible solvent. The results showed that the composition of the initial organic phase was of great importance for the spontaneous emulsification process, and so, for the physico-chemical properties of the obtained emulsions. First, oil viscosity and HLB surfactants were changed, alpha-tocopherol, the most viscous oil, gave the smallest droplets size (171 +/- 2 nm), HLB required for the resulting oil-in-water emulsion was superior to 8. Second, the effect of water-solvent miscibility on the emulsification process was studied by decreasing acetone proportion in the organic phase. The solvent-acetone proportion leading to a fine nano-emulsion was fixed at 15/85% (v/v) with EtAc-acetone and 30/70% (v/v) with MEK-acetone mixture. To strength the choice of solvents, physical characteristics were compared, in particular, the auto-inflammation temperature and the flash point. This phase of emulsion optimisation represents an important step in the process of polymeric nanocapsules preparation using nanoprecipitation or interfacial polycondensation combined with spontaneous emulsification technique.
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Emulsões/química , Nanoestruturas/química , Óleos/química , Solventes/química , Tensoativos/química , Química Farmacêutica , Tamanho da PartículaRESUMO
Polyurethane polymers and poly(ether urethane) copolymers were chosen as drug carriers for alpha-tocopherol. This active ingredient is widely used as a strong antioxidant in many medical and cosmetic applications, but is rapidly degraded, because of its light, heat and oxygen sensitivity. Polyurethane and poly(ether urethane)-based nanocapsules were synthesized by interfacial reaction between two monomers. Interfacial polycondensation combined with spontaneous emulsification is a new technique for nanoparticles formation. Nanocapsules were characterized by studying particle size (150-500 nm), pH, yield of encapsulation and morphologies. Polyurethanes (PUR) were obtained from the condensation of diisocyanate (isophorone diisocyanate: IPDI) and polyol: 1,2-ethanediol (EG), 1,4-butanediol (BD), 1,6-hexanediol (HD). Poly(ether urethane) copolymers were obtained by replacing diols by polyethylene glycol oligomers (PEG) M(w) 200, 300, 400 and 600. Molecular weights of di- and polyols have a considerable influence on nanocapsules characteristics cited above. The increase of molecular weight of polyols tends to increase the mean size of nanocapsules from (232+/-3)nm using EG to (615+/-39)nm using PEG 600, and led to the apparition of a population of agglomerate particles. We also noted that the yield of encapsulation increases with the increase of polyol length (from 85.6 to 92.2% w/w). Microscopic observations confirmed particle size analysis, but cannot predict the membrane structure owing the small size of the particles.
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Portadores de Fármacos/química , Poliuretanos/química , Administração Tópica , Antioxidantes/administração & dosagem , Antioxidantes/química , Cápsulas , Portadores de Fármacos/síntese química , Emulsões , Concentração de Íons de Hidrogênio , Peso Molecular , Nanotecnologia , Tamanho da Partícula , Poliuretanos/síntese química , Solventes , Tensoativos/química , alfa-Tocoferol/administração & dosagem , alfa-Tocoferol/químicaRESUMO
Fighting skin ageing is one of the major targets of cosmetology research. However, traditional approaches to skin ageing using stimulation of basal keratinocyte proliferation and fibroblastic neosynthesis appear today to be incomplete, particularly considering changes occurring at the dermal-epidermal junction (DEJ) during the course of ageing. Unfortunately, the lack of in vitro model limits the exploration process of the phenomena of DEJ ageing, and particularly the evaluation of the changes of key components, that are laminin-5, types IV and VII collagens. The aim of this work was to provide an in vitro model of reconstructed skin, base for new dosage and identification methods for qualitative and quantitative analysis of the key components of DEJ. Reverse transcriptase-polymerase chain reaction (RT-PCR) and quantitative RT-PCR were successfully applied to this model to analyse mRNA of laminin-5, types IV and VII collagens and their variation in 'young' and 'mature' reconstructed skin model. Finally, this model was used to test the activity of ingredients for cosmetic application, in order to modulate the expression of the major components of DEJ. To conclude, we demonstrated that this in vitro model of reconstructed young and mature skin provides a useful tool to get into the biology of the DEJ, key structure of the skin, and specifically into its dynamic changes during the ageing process.
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To show the benefits of retinol encapsulation in cosmetic industry, we compared the diffusion of two different retinol preparations through skin:oil-in-water (o/w) emulsions of retinol, also called 'free retinol', and suspension of Cylasphere including retinol, also called 'encapsulated retinol'. Two methods were used: Franz cell elucidated retinol release and storage in a hairless mouse skin according to time for the two types of preparations. The dosage of retinol by high performance liquid chromatography (HPLC) showed that encapsulated retinol was maintained into the skin for a longer time than free retinol. Raman microspectrometry measurements established a spectral image of the skin and determined the localization of retinol. Maps were collected according to time. They detailed the shifts of free and encapsulated retinol in the epidermis of a human biopsy. Spheres were smaller than droplets and they moved two times faster at this level of the skin.
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Most of the slimming products already developed for cosmetic applications did not result from strategies that integrate whole lipolysis-regulating mechanisms. We thus focused our attention on a more complete integration of these mechanisms and we developed slimming liposomes (SLC) containing two micro-circulation activators, i.e., esculoside and Centella asiatica extracts, one phosphodiesterase inhibitor, i.e., caffeine, and one fatty acid-beta oxidation activator, i.e., L-carnitine. The validity of our approach was assessed through (a) in vitro tests demonstrating that SLC induced a dramatic increase in the cyclic adenosine monophosphate (cAMP) content in human adipocytes, with a subsequent rise in the nonesterified fatty acids (NEFA) content of human adipocyte incubation medium, and (b) in vivo studies showing that SLC could provide an actual potent slimming effect on human volunteers. Moreover, we give here, through binding experiments, the unambiguous demonstration that SLC is able to antagonize the alpha(2)-adrenergic receptor that is known to reduce intracellular AMPc content and, subsequently, to down-regulate lipolysis. This alpha(2)-adrenergic antagonism has never been reported for any component of SLC, and this work is the first demonstration of the alpha(2)-adrenergic antagonism of such a combination of active liposome compounds.