Percutaneous absorption of sunscreen agents from liquid paraffin: Self-association of octyl salicylate and effects on skin flux

This study provides an investigation of the availability of octyl salicylate (OS), a common sunscreen agent, from liquid paraffin and the effect of OS on skin permeability. A model membrane system to isolate the vehicle effect from membrane permeability has been developed. Partitioning of OS between liquid paraffin and aqueous receptor phases was conducted. Partition coefficients increased with increase in OS concentration. A range of OS concentrations in liquid paraffin was diffused across human epidermis and synthetic membranes into 4% bovine serum albumin in phosphate-buffered saline and 50% ethanol. Absorption profiles of OS obtained from silicone and low-density polyethylene (LDPE) membranes were similar to each other but higher than for the high-density polyethylene [HDPE (3 times)] membrane and human epidermis (15 times). The steady state fluxes and apparent permeability coefficients (K-p') obtained from the diffusion studies showed the same trends with all membranes, except for the HDPE membrane which showed greater increase in flux and K-p' at concentrations above 30%. IR spectra showed that several bands of OS were shifted with concentrations, and the molecular models further suggested that the main contribution to the self-association is from non-1,4 van der Waals interactions.

Expression of activated mutants of the human interleukin-3/interleukin-5 granulocyte-macrophage colony-stimulating factor receptor common beta subunit in primary hematopoietic cells induces factor-independent proliferation and differentiation

To date, several activating mutations have been discovered in the common signal-transducing subunit (h beta c) of the receptors for human granulocyte-macrophage colony-stimulating factor, interleukin-3, and interleukin-5. Two of these, Fl Delta and 1374N, result in a 37 amino acid duplication and a single amino acid substitution in the extracellular domain of h beta c, respectively. A third, V449E, results in a single amino acid substitution in the transmembrane domain, Previous studies comparing the activity of these mutants in different hematopoietic cell lines imply that the transmembrane and extracellular mutations act by different mechanisms and suggest the requirement for cell type-specific molecules in signalling. To characterize the ability of these mutant hpc subunits to mediate growth and differentiation of primary cells and hence investigate their oncogenic potential, we have expressed all three mutants in primary murine hematopoietic cells using retroviral transduction. It is shown that, whereas expression of either extracellular hpc mutant confers factor-independent proliferation and differentiation on cells of the neutrophil and monocyte lineages only, expression of the transmembrane mutant does so on these lineages as well as the eosinophil, basophil, megakaryocyte, and erythroid lineages, Factor-independent myeloid precursors expressing the transmembrane mutant display extended proliferation in liquid culture and in some cases yielded immortalized cell lines. (C) 1997 by The American Society of Hematology.

An ergonomic approach to reorganize parking inspection agents` work productivity, health and safety in Sao Paulo, Brazil

Objective: The Traffic Engineering Company of the City of Sao Paulo (Brazil) observed a decrease in productivity, and an increase in sick leave, accidents and psychological distress among their parking inspection agents. To document this situation, qualitative research was undertaken to obtain an in-depth comprehension of work activity. Participants: Workers, managers and health and safety professionals contributed to the documentation of the problem and to the proposal of possible solutions. Methods: Ergonomic work analysis focusing on real work activity, as well as interviews with individual or groups of stakeholders, were conducted. Results: This research revealed that political-economic factors gradually contributed to: 1) an increasing work load; 2) growing fatigue throughout the day, increasing the workers` vulnerability to incidents and accidents and their tendency to react inappropriately to violence experienced on the street; and 3) excessive individual responsibility to manage dangerous situations. Conclusions: Recommendations to ameliorate the situation are proposed. These suggestions are discussed in terms of feasibility given the impact of macro social factors upon micro work activity, and the associated potential expansion of the ergonomist`s role.

Bioactivation of Phenytoin by Human Cytochrome P450: Characterization of the Mechanism and Targets of Covalent Adduct Formation

The cytochrome P450-dependent covalent binding of radiolabel derived fi om phenytoin (DPH) and its phenol and catechol metabolites, 5-(4'-hydroxyphenyl)-5-phenylhydantoin (HPPH) and 5-(3',4'-dihydroxyphenyl)-5-phenylhydantoin (CAT), was examined in liver microsomes. Radiolabeled HPPH and CAT and unlabeled CAT were obtained from microsomal incubations and isolated by preparative HPLC. NADPH-dependent covalent binding was demonstrated in incubations of human liver microsomes with HPPH. When CAT was used as substrate, covalent adduct formation was independent of NADPH, was enhanced in the presence of systems generating reactive oxygen species, and was diminished under anaerobic conditions or in the presence of cytoprotective reducing agents. Fluorographic analysis showed that radiolabel derived from DPH and HPPH was selectively associated with proteins migrating with approximate relative molecular weights of 57-59 kDa and at the dye front (molecular weights < 23 kDa) on denaturing gels. Lower levels of radiolabel were distributed throughout the molecular weight range. In contrast, little selectivity was seen in covalent adducts formed from CAT. HPPH was shown to be a mechanism-based inactivator of P450, supporting the contention that a cytochrome P450 is one target of covalent binding. These results suggest that covalent binding of radiolabel derived from DPH in rat and human Liver microsomes occurs via initial P450-dependent catechol formation followed by spontaneous oxidation to quinone and semiquinone derivatives that ultimately react with microsomal protein. Targets for covalent binding may include P450s, though the catechol appears to be sufficiently stable to migrate out of the P450 active site to form adducts with other proteins. In conclusion, we have demonstrated that DPH can be bioactivated in human liver to metabolites capable of covalently binding to proteins. The relationship of adduct formation to DPH-induced hypersensitivity reactions remains to be clarified.

FibroTest is an independent predictor of virologic response in chronic hepatitis C patients retreated with pegylated interferon alfa-2b and ribavirin in the EPIC(3) program

Background & Aims: EPIC-3 is a prospective, international study that has demonstrated the efficacy of PEG-IFN alfa-2b plus weight-based ribavirin in patients with chronic hepatitis C and significant fibrosis who previously failed any interferon-alfa/ribavirin therapy. The aim of the present study was to assess FibroTest (FT), a validated non-invasive marker of fibrosis in treatment-naive patients, as a possible alternative to biopsy as the baseline predictor of subsequent early virologic (EVR) and sustained virologic response (SVR) in previously treated patients. Methods: Of 2312 patients enrolled, 1459 had an available baseline FT, biopsy, and complete data. Uni- (UV) and multi-variable (MV) analyses were performed using FT and biopsy. Results: Baseline characteristics were similar as in the overall population; METAVIR stage: 28% F2, 29% F3, and 43% F4, previous relapsers 29%, previous PEG-IFN regimen 41%, high baseline viral load (BVL) 64%. 506 patients (35%) had undetectable HCV-RNA at TW12 (TW12neg), with 58% achieving SVR. The accuracy of FT was similar to that in naive patients: AUROC curve for the diagnosis of F4 vs F2 = 0.80 (p<0.00001). Five baseline factors were associated (p<0.001) with SVR in UV and MV analyses (odds ratio: UV/MV): fibrosis stage estimated using FT (4.5/5.9) or biopsy (1.5/1.6), genotype 2/3 (4.5/5.1), BVL (1.5/1.3), prior relapse (1.6/1.6), previous treatment with non-PEG-IFN (2.6/2.0). These same factors were associated (p <= 0.001) with EVR. Among patients TW12neg, two independent factors remained highly predictive of SVR by MV analysis (p <= 0.001): genotype 2/3 (odds ratio = 2.9), fibrosis estimated with FT (4.3) or by biopsy (1.5). Conclusions: FibroTest at baseline is a possible non-invasive alternative to biopsy for the prediction of EVR at 12 weeks and SVR, in patients with previous failures and advanced fibrosis, retreated with PEG-IFN alfa-2b and ribavirin. (C) 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

Establishment and characterization of androgen-independent human prostate cancer cell lines, PcBra1, PcBra2, and PcBra3

One of the main obstacles for understanding biological events involved in cancer is the lack of experimental models for in vitro studies especially for prostate cancer (PC).There are a limited number of PC cell lines being the majority originated from metastatic tumors mostly acquired from American Tissue Cell Culture which demands importation an expensive and bureaucratic process. Also it is well known that there are ethnic differences between populations concerning the behavior of tumors and the research based on cell lines derived from Brazilians should be interesting. Our aim was to develop tumor cell lines from primary PC.

Independent component analysis applied to raman spectra for classification of in vitro human coronary arteries

Optical diagnostic methods, such as near-infrared Raman spectroscopy allow quantification and evaluation of human affecting diseases, which could be useful in identifying and diagnosing atherosclerosis in coronary arteries. The goal of the present work is to apply Independent Component Analysis (ICA) for data reduction and feature extraction of Raman spectra and to perform the Mahalanobis distance for group classification according to histopathology, obtaining feasible diagnostic information to detect atheromatous plaque. An 830nm Ti:sapphire laser pumped by an argon laser provides near-infrared excitation. A spectrograph disperses light scattered from arterial tissues over a liquid-nitrogen cooled CCD to detect the Raman spectra. A total of 111 spectra from arterial fragments were utilized.

The need for effective radiosentitizing agents: experience in patients with complete pathological response

Chemoradiation therapy is now considered the preferred initial treatment strategy for distal rectal cancer because of the observation of better local disease control and significant tumor downstaging. Downstaging has become an important clinical outcome as patients with complete pathological response are associated with improved survival. Even though radiation alone may result in low local recurrence rates, the use of additional radiosensitizing agents may provide an increase in local disease control in addition to improved tumor regression rates. Several compounds have been investigated in the setting of neoadjuvant multimodality treatment of rectal cancer with variable rates of treatment-related toxicity and complete pathological response. The balance between complete pathological response and toxicity should aid in the management decision for the use of radiosensitizing agents in the neoadjuvant setting for the treatment of rectal cancer. Anti-Cancer Drugs 22: 308-310 (C) 2011 Wolters Kluwer Health | Lippincott Williams & Wilkins.

Hormonal Contraceptives and the Length of Their Use Are Not Independent Risk Factors for High-Risk HPV Infections or High-Grade CIN

Aims: To evaluate the role of hormonal contraceptives as a risk factor of high-risk human papillomavirus (HR-HPV), cervical intraepithelial lesions (CIN) and cervical cancer in our multi-center population-based LAMS (Latin American Screening) study. Methods: A cohort study with >12,000 women from Brazil and Argentina using logistic regression to analyze the covariates of hormonal contraception (HOC - oral, injections, patches, implants, vaginal ring and progesterone intrauterine system) use followed by multivariate modeling for predictors of HR-HPV and CIN2+. Results: HR-HPV infection was a consistent risk factor of high-grade CIN in all three groups of women. The length of HOC use was not significantly related to high-grade squamous intraepithelial lesions (HSIL)+ Pap (p = 0.069), LSIL+ Pap (p = 0.781) or ASCUS+ (p = 0.231). The same was true with the length of HOC use and histology CIN3+ (p = 0.115) and CIN2+ (p = 0.515). Frequently, HOC users have previously shown more HPV-related lesions, as well as lower HPV prevalence if they were current smokers. But HOC use and time of usage were not independent risk factors of either HR-HPV infection or high-grade CIN using multiple logistic regressions. Conclusions: No evidence was found for an association between the use of HOC with an increased risk for HR-HPV infection or high-grade CIN in this cohort. Copyright (C) 2010 S. Karger AG, Basel

Salt-Induced Cardiac Hypertrophy and Interstitial Fibrosis Are Due to a Blood Pressure-Independent Mechanism in Wistar Rats

High salt intake is a known cardiovascular risk factor and is associated with cardiac alterations. To better understand this effect, male Wistar rats were fed a normal (NSD: 1.3% NaCl), high 4 (HSD4: 4%), or high 8 (HSD8: 8%) salt diet from weaning until 18 wk of age. The HSD8 group was subdivided into HSD8, HSD8+HZ (15 mg.kg(-1).d(-1) hydralazine in the drinking water), and HSD8+LOS (20 mg.kg(-1).d(-1) losartan in the drinking water) groups. The cardiomyocyte diameter was greater in the HSD4 and HSD8 groups than in the HSD8+LOS and NSD groups. Interstitial fibrosis was greater in the HSD4 and HSD8 groups than in the HSD8+HZ and NSD groups. Hydralazine prevented high blood pressure (BP) and fibrosis, but not cardiomyocyte hypertrophy. Losartan prevented high BP and cardiomyocyte hypertrophy, but not fibrosis. Angiotensin II type 1 receptor (AT(1)) protein expression in both ventricles was greater in the HSD8 group than in the NSD group. Losartan, but not hydralazine, prevented this effect. Compared with the NSD group, the binding of an AT(1) conformation-specific antibody that recognizes the activated form of the receptor was lower in both ventricles in all other groups. Losartan further lowered the binding of the anti-AT(1) antibody in both ventricles compared with all other experimental groups. Angiotensin II was greater in both ventricles in all groups compared with the NSD group. Myocardial structural alterations in response to HSD are independent of the effect on BP. Salt-induced cardiomyocyte hypertrophy and interstitial fibrosis possibly are due to different mechanisms. Evidence from the present study suggests that salt-induced AT(1) receptor internalization is probably due to angiotensin II binding. J. Nutr. 140: 1742-1751, 2010.

Adverse mucocutaneous reactions to chemotherapeutic agents - Part I

The local and systemic treatment of tumors can cause changes in the skin, mucous membranes, hair and nails. Accurate diagnosis and appropriate treatment of side effects require knowledge about the patterns of the most common adverse reactions to drugs the patient may be using. The dermatologist must be familiar with the manifestations of certain soft tissue neoplasms, as well as with the adverse mucocutaneous forms of cancer treatment.

Local renin-angiotensin system regulates left ventricular hypertrophy induced by swimming training independent of circulating renin: a pharmacological study

Introduction. This study addressed the role of the local renin-angiotensin system (RAS) in the left ventriular hypertropy (LVH) induced by swimming training using pharmacological blockade. Materials and methods. Female Wistar rats treated with enalapril maleate (60 mg.kg(-1).d(-1), n = 38), losartan (20 mg.kg(-1).d(-1), n = 36) or high salt diet (1% NaCl, n = 38) were trained by two protocols (T1: 60-min swimming session, 5 days per week for 10 weeks and T2: the same T1 protocol until the 8(th) week, then 9(th) week they trained twice a day and 10(th) week they trained three times a day). Salt loading prevented activation of the systemic RAS. Haemodynamic parameters, soleus citrate synthase (SCS) activity and LVH (left ventricular/body weight ratio, mg/g) were evaluated. Results. Resting heart rate decreased in all trained groups. SCS activity increased 41% and 106% in T1 and T2 groups, respectively. LVH was 20% and 30% in T1 and T2 groups, respectively. Enalapril prevented 39% of the LVH in T2 group (p < 0.05). Losartan prevented 41% in T1 and 50% in T2 (P < 0.05) of the LVH in trained groups. Plasma renin activity (PRA) was inhibited in all salt groups and it was increased in T2 group. Conclusions. These data provide evidence that the physiological LVH induced by swimming training is regulated by local RAS independent from the systemic, because the hypertrophic response was maintained even when PRA was inhibited by chronic salt loading. However, other systems can contribute to this process.