Use of cholesterol-rich nanoparticles that bind to lipoprotein receptors as a vehicle to paclitaxel in the treatment of breast cancer: pharmacokinetics, tumor uptake and a pilot clinical study

Purpose In animal experiments paclitaxel oleate associated with a cholesterol-rich nanoemulsion concentrated in the neoplastic tissues and showed reduced toxicity and increased antitumor activity compared with paclitaxel-Cremophor EL. Here, a clinical study was performed in breast cancer patients to evaluate the tumoral uptake, pharmacokinetics and toxicity of paclitaxel associated to nanoemulsions. Methods Twenty-four hours before mastectomy [(3)H]paclitaxel oleate associated with [(14)C]-cholesteryl oleatenanoemulsion or [(3)H]- paclitaxel in Cremophor EL were injected into five patients for collection of blood samples and fragments of tumor and normal breast tissue. A pilot clinical study of paclitaxel-nanoemulsion administered at 3-week intervals was performed in four breast cancer patients with refractory advanced disease at 175 and 220 mg/m(2) dose levels. Results T(1/2) of paclitaxel oleate associated to the nanoemulsion was greater than that of paclitaxel (t(1/2) = 15.4 +/- 4.7 and 3.5 +/- 0.80 h). Uptake of the [(14)C]-cholesteryl ester nanoemulsion and [(3)H]- paclitaxel oleate by breast malignant tissue was threefold greater than the normal breast tissue and toxicity was minimal at the two dose levels. Conclusions Our results suggest that the paclitaxel-nanoemulsion preparation can be advantageous for use in the treatment of breast cancer because the pharmacokinetic parameters are improved, the drug is concentrated in the neoplastic tissue and the toxicity of paclitaxel is reduced.

Fed State Protein Turnover in Healthy Older Persons under a Usual Protein-Rich Diet

The objective of this study was to verify the protein turnover rates of healthy older persons under a usual protein-rich diet and to compare values to those described in the literature. This cross-sectional study was conducted at Metabolism Unit, Univ. Hospital of the School of Medicine of Ribeirao Preto, Univ. of Sao Paulo, Brazil. In this study, 7 healthy older persons aged 65.4 +/- 2.8 y, with BMI 22.7 +/- 2.4 kg/m(2) and a mean daily protein intake of 1.34 g of protein/kg were studied. A 9-h whole-body (15)N-glycine single-dose study was performed after an overnight fast. During the study, each subject received 6 isoenergetic, isonitrogenous meals at 2-h intervals based on their average intake. Ammonium, urea, and total nitrogen were quantified and analyzed by mass spectrometry, with the determination of total protein turnover rates by the (15)N-glycine method. The results show that total nitrogen output was 3.2 +/- 0.96 g/N and intake 7.7 +/- 1 g/N, (15)N nitrogen flux was 30.6 +/- 6.3 g/9 h. Endogenous nitrogen balance was positive (4.5g +/- g/N in 9 h). In conclusion, the protein turnover of healthy older persons under a usual protein-rich diet is positive during the fed state and has synthesis and degradation rates similar to those previously described in studies involving diet adaptation periods.

Vascular proinflammatory responses by aldosterone are mediated via c-Src trafficking to cholesterol-rich microdomains: role of PDGFR

Aims We demonstrated c-Src activation as a novel non-genomic signalling pathway for aldosterone in vascular smooth muscle cells (VSMCs). Here, we investigated molecular mechanisms and biological responses of this phenomenon, focusing on the role of lipid rafts/caveolae and platelet-derived growth factor receptor (PDGFR) in c-Src-regulated proinflammatory responses by aldosterone. Methods and results Studies were performed in cultured VSMCs from Wistar-Kyoto (WKY) rats and caveolin-1 knockout (Cav 1(-/-)) and wild-type mice. Aldosterone stimulation increased c-Src phosphorylation and trafficking to lipid rafts/caveolae. Cholesterol depletion with methyl-beta-cyclodextrin abrogated aldosterone-induced phosphorylation of c-Src and its target, Pyk2. Aldosterone effects were recovered by cholesterol reload. Aldosterone-induced c-Src and cortactin phosphorylation was reduced in caveolin-1-silenced and Cav 1(-/-) VSMCs. PDGFR is phosphorylated by aldosterone within cholesterol-rich fractions of VSMCs. AG1296, a PDGFR inhibitor, prevented c-Src phosphorylation and translocation to cholesterol-rich fractions. Aldosterone induced an increase in adhesion molecule protein content and promoted monocyte adhesion to VSMCs, responses that were inhibited an by cholesterol depletion, caveolin-1 deficiency, AG1296 and PP2, a c-Src inhibitor. Mineralocorticoid receptor (MR) content in flotillin-2-rich fractions and co-immunoprecipitation with c-Src and PDGFR increased upon aldosterone stimulation, indicating MR-lipid raft/signalling association. Conclusion We demonstrate that aldosterone-mediated c-Src trafficking/activation and proinflammatory signalling involve lipid rafts/caveolae via PDGFR.

Characterization of a chromium-rich tannery waste and its potential use in ceramics

Leather industries which promote hide stabilization by the conventional chrome-tanning process are a major source of pollution because of the resultant chromium-rich wastes. In this work, an extensive characterization of such a chromium-rich waste sludge is presented, regarding its chemical composition (XRF), crystalline phase contents (XRD), organic carbon content (TOC), thermal behavior by thermogravimetry (TG) and differential scanning calorimetry (DSC), as well as its stability under chemical attack (the concentration of important ions in the leachates being determined by capillary electrophoresis) and when submitted to temperatures as high as 1100 degrees C, in air. The material showed the tendency to produce some undesirable, and previously non-detected hexavalent chromium when exposed to high temperatures, but after washing off the soluble salts and the elimination of the organic matter by firing, the resultant material was succesfully tested as a ceramic pigment in a conventional glaze composition usually employed in the ceramic the industry. (C) 2009 Elsevier Ltd and Techna Group S.r.l. All rights reserved.

Bursts of transposition from non-long terminal repeat retrotransposon families of the RTE clade in Schistosoma mansoni

The genus Schistosoma is composed of blood flukes that infect vertebrates, from which three species are major causative agents of human schistosomiasis, a tropical disease that affects more than 200 million people. Current models of the recent evolution of Schistosoma indicate multiple events of migration and speciation from an Asian ancestral species. Transposable elements are important drivers of genome evolution and have been hypothesised to have an important role in speciation. In this work, we describe a comprehensive inventory of Schistosoma mansoni and Schistosoma japonicum retrotransposons, based on their recently published genomic data. We find a considerable difference in retrotransposon representation between the two species (22% and 13%, respectively). A large part of this difference can be attributed to higher representation of two previously described families of S. mansoni retrotransposons (SR2 and Perere-3/SR3), compared with the representation of their closest relative families in S. japonicum. A more detailed analysis suggests that these two S. mansoni families were the subject of recent bursts of transposition that were not paralleled by their S. japonicum counterparts. We hypothesise that these bursts could be a consequence of the evolutionary pressure resulting from migration of Schistosoma from Asia to Africa and their establishment in this new environment, helping both speciation and adaptation. (C) 2009 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.

Antidepressant-like effects of N-acetyl-L-cysteine in rats

Oxidative stress disturbances have been reported in depressed patients and in animals submitted to stress. Recent evidence suggests that antidepressants may have antioxidant properties. However, the therapeutic potential of antioxidants as antidepressant drugs has not been systematically investigated. Therefore, this study tested the hypothesis that N-acetyl-L-cysteine (NAC), a cysteine prodrug with powerful antioxidant activity, would possess anti depressant-like properties in the forced swimming test. Male Wistar rats were subjected to 15 min of forced swimming and immediately afterward, 5, and 23 h later received intraperitoneal injections of NAC (5, 15, 50, 150, and 250 mg/kg), imipramine, 0 5 mg/kg) or vehicle. One hour later they were submitted to the 5 min test swimming session, where immobility time was recorded. Independent groups of animals received the same treatments and their exploratory activity was measured in an open arena for 5 min. NAC (at the doses of 15, 50, and 150 mg/kg) and imipramine induced a significant decrease in immobility time without changing exploratory behavior measured in an open arena. These results suggest that antioxidants such as NAC may have antidepressant effects. Behavioural Pharmacology (C) 19:747-750 2008 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

The low fertility of repeat-breeder cows during summer heat stress is related to a low oocyte competence to develop into blastocysts

It was hypothesized the lower fertility of repeat-breeder (RB) Holstein cows is associated with oocyte quality and this negative effect is enhanced during summer heat stress (HS). During the summer and the winter, heifers (H; n = 36 and 34, respectively), peak-lactation (PL; n = 37 and 32, respectively), and RB (n = 36 and 31, respectively) Holstein cows were subjected to ovum retrieval to assess oocyte recovery, in vitro embryonic developmental rates, and blastocyst quality [terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and total cell number]. The environmental temperature and humidity, respiration rate, and cutaneous and rectal temperatures were recorded in both seasons. The summer HS increased the respiration rate and the rectal temperature of PL and RB cows, and increased the cutaneous temperature and lowered the in vitro embryo production of Holstein cows and heifers. Although cleavage rate was similar among groups [H = 51.7% +/- 4.5 (n = 375), PL = 37.9% +/- 5.1 (n = 390), RB = 41.9% +/- 4.5 (n = 666)], blastocyst rate was compromised by HS, especially in RB cows [H = 30.3% +/- 4.8 (n = 244) vs. 23.3% +/- 6.4 (n = 150), PL = 22.0% +/- 4.7 (n = 191) vs. 14.6% +/- 7.6 (n = 103), RB = 22.5% +/- 5.4 (n = 413) vs. 7.9% +/- 4.3 (n = 177)]. Moreover, the fragmentation rate of RB blastocysts was enhanced during the summer, compared with winter [4.9% +/- 0.7 (n = 14) vs. 2.2% +/- 0.2 (n = 78)] and other groups [H = 2.5% +/- 0.7 (n = 13), and PL = 2.7% +/- 0.6 (n = 14)] suggesting that the association of RB fertility problems and summer HS may potentially impair oocyte quality. Our findings provide evidence of a greater sensitivity of RB oocytes to summer HS.

Cysteine Cathepsins in Human Dentin-Pulp Complex

Introduction: Collagen-degrading matrix metalloproteinases (MMPs) are expressed by odontoblasts and present in dentin. We hypothesized that odontoblasts express other collagen-degrading enzymes such as cysteine cathepsins, and their activity would be present in dentin, because odontoblasts are known to express at least cathepsin D. Effect of transforming growth factor beta (TGF-beta) on cathepsin expression was also analyzed. Methods: Human odontoblasts and pulp tissue were cultured with and without TGF-beta, and cathepsin gene expression was analyzed with DNA microarrays. Dentin cathepsin and MMP activities were analyzed by degradation of respective specific fluorogenic substrates. Results: Both odontoblasts and pulp tissue demonstrated a wide range of cysteine cathepsin expression that gave minor responses to TGF-beta. Cathepsin and MMP activities were observed in all dentin samples, with significant negative correlations in their activities with tooth age. Conclusions: These results demonstrate for the first time the presence of cysteine cathepsins in dentin and suggest their role, along with MMPs, in dentin modification with aging. (J Endod 2010;36:475-481)

Consumption of a Flaxseed-Rich Food Is Not More Effective Than a Placebo in Alleviating the Climacteric Symptoms of Postmenopausal Women

Our objective in this work was to test the effects of daily intake of bread produced with partially defatted ground flaxseed on the climacteric symptoms and endometrial thickness of postmenopausal women. A double-blind, placebo-controlled, randomized clinical trial was performed with 38 women who had been postmenopausal for 1-10 y and consumed 2 slices of bread containing 25 g of flaxseed (46 mg lignans) or wheat bran (<1 mg lignans; control) every day for 12 consecutive weeks. The outcome variables were the daily number of hot flashes, the Kupperman Menopausal Index (KMI), and endometrial thickness. The plasma lipid profile (total cholesterol and HDL, LDL, and VLDL cholesterol fractions and triglycerides) and the hormones estradiol, follicle-stimulating hormone, thyroid-stimulating hormone, and free thyroxine also were measured. Food intake was evaluated by means of 2 24-hrecalls, before and after the treatment. Twenty patients in the study group and 18 in the control group completed the study. The general characteristics did not differ between the 2 groups at the start of the study. Both had significant, but similar, reductions in hot flashes and KMI after 3 mo of treatment. Moreover, endometrial thickness was not affected in either group. Our findings clearly show that although flaxseed is safe, its consumption at this level (46 mg lignans/d) is no more effective than placebo for reducing hot flashes and KMI. J. Nutr. 140: 293-297, 2010.

Effect of enzymatic pretreatment and increasing the organic loading rate of lipid-rich wastewater treated in a hybrid UASB reactor

This study aimed at evaluating the effect of increasing organic loading rates and of enzyme pretreatment on the stability and efficiency of a hybrid upflow anaerobic sludge blanket reactor (UASBh) treating dairy effluent. The UASBh was submitted to the following average organic loading rates (OLR) 0.98 Kg.m(-3).d(-1), 4.58 Kg.m(-3).d(-1), 8.89 Kg.m(-3).d(-1) and 15.73 Kg.m(-3).d(-1), and with the higher value, the reactor was fed with effluent with and without an enzymatic pretreatment to hydrolyze fats. The hydraulic detention time was 24 h, and the temperature was 30 +/- 2 degrees C. The reactor was equipped with a superior foam bed and showed good efficiency and stability until an OLR of 8.89 Kg.m(-3).d(-1). The foam bed was efficient for solid retention and residual volatile acid concentration consumption. The enzymatic pretreatment did not contribute to the process stability, propitiating loss in both biomass and system efficiency. Specific methanogenic activity tests indicated the presence of inhibition after the sludge had been submitted to the pretreated effluent It was concluded that continuous exposure to the hydrolysis products or to the enzyme caused a dramatic drop in the efficiency and stability of the process, and the single exposure of the biomass to this condition did not inhibit methane formation. (C) 2011 Elsevier B.V. All rights reserved.

Possible signature of hypernova nucleosynthesis in a beryllium-rich halo dwarf

As part of a large survey of halo and thick disc stars, we found one halo star, HD106038, exceptionally overabundant in beryllium. In spite of its low metallicity, [Fe/H] = -1.26, the star has log(Be/H) = -10.60, which is similar to the solar meteoritic abundance, log(Be/H)=-10.58. This abundance is more than 10 times higher the abundance of stars with similar metallicity and cannot be explained by models of chemical evolution of the Galaxy that include the standard theory of cosmic ray spallation. No other halo star exhibiting such a beryllium overabundance is known. In addition, overabundances of Li, Si, Ni, Y and Ba are also observed. We suggest that all these chemical peculiarities, excepting the Ba abundance, can be simultaneously explained if the star was formed in the vicinity of a hypernova.

Curiously composite structures of a retrotransposon and a complex repeat associated with chromosome ends of Rhynchosciara americana (Diptera: Sciaridae)

In Drosophila, telomere retrotransposons counterbalance the loss of telomeric DNA. The exceptional mechanism of telomere recovery characterized in Drosophila has not been found in lower dipterans (Nematocera). However, a retroelement resembling a telomere transposon and termed ""RaTART"" has been described in the nematoceran Rhynchosciara americana. In this work, DNA and protein sequence analyses, DNA cloning, and chromosomal localization of probes obtained either by PCR or by screening a genomic library were carried out in order to examine additional features of this retroelement. The analyses performed raise the possibility that RaTART represents a genomic clone composed of distinct repetitive elements, one of which is likely to be responsible for its apparent enrichment at chromosome ends. RaTART sequence in addition allowed to assess a novel subtelomeric region of R. americana chromosomes that was analyzed in this work after subcloning a DNA fragment from a phage insert. It contains a complex repeat that is located in the vicinity of simple and complex tandem repeats characterized previously. Quantification data suggest that the copy number of the repeat is significantly lower than that observed for the ribosomal DNA in the salivary gland of R. americana. A short insertion of the RaTART was identified in the cloned segment, which hybridized preferentially to subtelomeres. Like RaTART, it displays truncated sequences related to distinct retrotransposons, one of which has a conceptual translation product with significant identity with an endonuclease from a lepidopteran retrotransposon. The composite structure of this DNA stretch probably reflects mobile element activity in the subtelomeric region analyzed in this work.

Thiol and Sulfenic Acid Oxidation of AhpE, the One-Cysteine Peroxiredoxin from Mycobacterium tuberculosis: Kinetics, Acidity Constants, and Conformational Dynamics

Drug resistance and virulence of Mycobacterium tuberculosis are partially related to the pathogen`s antioxidant systems. Peroxide detoxification in this bacterium is achieved by the heme-containing catalase peroxidase and different two-cysteine peroxiredoxins. M. tuberculosis genome also codifies for a putative one-cysteine peroxiredoxin, alkyl hydroperoxide reductase E (MtAhpE). Its expression was previously demonstrated at a transcriptional level, and the crystallographic structure of the recombinant protein was resolved under reduced and oxidized states. Herein, we report that the conformation of MtAhpE changed depending on its single cysteine redox state, as reflected by different tryptophan fluorescence properties and changes in quaternary structure. Dynamics of fluorescence changes, complemented by competition kinetic assays, were used to perform protein functional studies. MtAhE reduced peroxynitrite 2 orders of magnitude faster than hydrogen peroxide (1.9 x 10(7) M(-1) s(-1) vs 8.2 x 10(4) M(-1) s(-1) at pH 7.4 and 25 degrees C, respectively). The latter also caused cysteine overoxidation to sulfinic acid, but at much slower rate constant (40 M(-1) s(-1)). The pK(a) of the thiol in the reduced enzyme was 5.2, more than one unit lower than that of the sulfenic acid in the oxidized enzyme. The pH profile of hydrogen peroxide-mediated thiol and sulfenic acid oxidations indicated thiolate and sulfenate as the reacting species. The formation of sulfenic acid as well as the catalytic peroxidase activity of MtAhpE was demonstrated using the artificial reducing substrate thionitrobenzoate. Taken together, our results indicate that MtAhpE is a relevant component in the antioxidant repertoire of M. tuberculosis probably involved in peroxide and specially peroxynitrite detoxification.

Oligomerization of the cysteinyl-rich oligopeptidase EP24.15 is triggered by S-glutathionylation

Thimet oligopeptidase (EC 3.4.24.15; EP24.15) is a thiol-rich metallopeptidase ubiquitously distributed in mammalian tissues and involved in oligopeptide metabolism both within and outside cells. Fifteen Cys residues are present in the rat EP24.15 protein, seven are solvent accessible, and two are found inside the catalytic site cleft; no intraprotein disulfide is described. In the present investigation, we show that mammalian immunoprecipitated EP24.15 is S-glutathionylated. In vitro EP24.15 S-glutathionylation was demonstrated by the incubation of bacterial recombinant EP24.15 with oxidized glutathione concentration as low as 10 mu M. The in vitro S-glutathionylation of EP24.15 was responsible for its oxidative oligomerization to dimer and trimer complexes. EP24.15 immunoprecipitated from cells submitted to oxidative challenge showed increased trimeric forms and decreased S-glutathionylation compared to immunoprecipitated protein from control cells. Our present data also show that EP24.15 maximal enzymatic activity is maintained by partial S-glutathionylation, a mechanism that apparently regulates the protein oligomerization. Present results raise the possibility of an unconventional property of protein S-glutathionylation, inducing oligomerization by interprotein thiol-disulfide exchange. (c) 2007 Elsevier Inc. All rights reserved.

Enhancement of the citrulline-nitric oxide cycle in astroglioma cells by the proline-rich peptide-10c from Bothrops jararaca venom

The biological activity of the proline rich decapeptde Bj PRO 10c a processing product of the C type natriuretic peptide precursor protein, expressed in the brain and the venom gland of the pit viper Bothrops jararaca, was originally attributed to the inhibition of the somatic angiotensm converting enzyme activity with subsequent ant hypertensive effect However recent results suggest broader biological activity may also be involved in the cardiovascular effects of this peptide Here we show that Bj PRO 10c enhances and sustains the generation of nitric made (NO) by regulating argininosuccinate synthase activity and thereby velocity of the citrulline NO cycle Bj PRO 10c-mediated effects not restricted to the cardiovascular system since NO production was also induced in cells of astroglial origin Bj PRO 10c was internalized by C6 astroglioma cells where it induces NO production and upregulation of the citrulline NO cycle cells in a dose dependent fashion In view of that, astroglial cells function as L arginine pool for NO production in neighboring neurons, we suggest a regulatory function for Bj PRO-10c on the metabolism of this gaseous neurotransmitter in the CNS Moreover, proliferation of astroglial cells was reduced in the presence of Bj PRO 10c however, cell death was not induced Since NO donors have been studied for the treatment of solid cancers Bj PRO 10c may serve as structural model for developing drugs to improve the effects of cancer therapy based on the peptide`s ability to augment NO production (C) 2010 Elsevier B V All rights reserved