Ormosils loaded with SiO2 nanoparticles functionalized with Ag as multifunctional superhydrophobic/biocidal/consolidant treatments for buildings conservation.

The alarming increase of pollution has significantly increased buildings maintenance. Nowadays, the economic figures associated to repairing activities are even more relevant than those corresponding to new construction works, especially on heritage buildings. Since the degradation of building materials is the result of a complex combination of physical, chemical and biological agents, the development of multifunctional protective treatments remains a significant challenge. We report a simple strategy to produce a versatile biocidal/superhydrophobic/consolidant treatment by incorporating biocidal Ag nanoparticles (AgNPs) grafted to functionalized SiO2NPs into a silica sol, which can be applied by simple procedures such as spraying. The use of an Ag-SiO2 coupling agent increases biocidal effectiveness up to >90% values due to: (1) an increase of the AgNPs stability; (2) a hierarchical roughness due to the formation of Ag/SiO2NPs clusters; and (3) an enhanced contact with the cell walls. In addition, the synergistic effect allows for an easier removal of the dead cells, increasing the durability of the treatment.

TiO2-SiO2 Coatings with a Low Content of AuNPs for Producing Self-Cleaning Building Materials.

The high pollution levels in our cities are producing a significant increase of dust on buildings. An application of photoactive coatings on building materials can produce buildings with self-cleaning surfaces. In this study, we have developed a simple sol-gel route for producing Au-TiO2/SiO2 photocatalysts with application on buildings. The gold nanoparticles (AuNPs) improved the TiO2 photoactivity under solar radiation because they promoted absorption in the visible range. We varied the content of AuNPs in the sols under study, in order to investigate their effect on self-cleaning properties. The sols obtained were sprayed on a common building stone, producing coatings which adhere firmly to the stone and preserve their aesthetic qualities. We studied the decolourization efficiency of the photocatalysts under study against methylene blue and against soot (a real staining agent for buildings). Finally, we established that the coating with an intermediate Au content presented the best self-cleaning performance, due to the role played by its structure and texture on its photoactivity.

Large scale, prospective screening of EGFR mutations in the blood of advanced NSCLC patients to guide treatment decisions.

BACKGROUND: In a significant percentage of advanced non-small-cell lung cancer (NSCLC) patients, tumor tissue is unavailable or insufficient for genetic analyses. We prospectively analyzed if circulating-free DNA (cfDNA) purified from blood can be used as a surrogate in this setting to select patients for treatment with epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs). PATIENTS AND METHODS: Blood samples were collected in 119 hospitals from 1138 advanced NSCLC patients at presentation (n = 1033) or at progression to EGFR-TKIs (n = 105) with no biopsy or insufficient tumor tissue. Serum and plasma were sent to a central laboratory, cfDNA purified and EGFR mutations analyzed and quantified using a real-time PCR assay. Response data from a subset of patients (n = 18) were retrospectively collected. RESULTS: Of 1033 NSCLC patients at presentation, 1026 were assessable; with a prevalence of males and former or current smokers. Sensitizing mutations were found in the cfDNA of 113 patients (11%); with a majority of females, never smokers and exon 19 deletions. Thirty-one patients were positive only in plasma and 11 in serum alone and mutation load was higher in plasma and in cases with exon 19 deletions. More than 50% of samples had <10 pg mutated genomes/µl with allelic fractions below 0.25%. Patients treated first line with TKIs based exclusively on EGFR positivity in blood had an ORR of 72% and a median PFS of 11 months. Of 105 patients screened after progression to EGFR-TKIs, sensitizing mutations were found in 56.2% and the p.T790M resistance mutation in 35.2%. CONCLUSIONS: Large-scale EGFR testing in the blood of unselected advanced NSCLC patients is feasible and can be used to select patients for targeted therapy when testing cannot be done in tissue. The characteristics and clinical outcomes to TKI treatment of the EGFR-mutated patients identified are undistinguishable from those positive in tumor.

Formation of siliceous sediments in brandy after diatomite filtration.

Brandy is quite a stable spirit but sometimes light sediment appears. This sediment was separated and analysed by IR and SEM-EDX. It was revealed that the sediment is composed mostly of silica and residual organic matter. Silica was present as an amorphous phase and as microparticles. In an attempt to reproduce the formation of the sediment, a diatomite extract was prepared with an ethanol/water mixture (36% vol.) and a calcined diatomite similar to that used in brandy filtration. This extract was added to unfiltered brandy in different amounts. After 1 month, the Si concentration decreased in all samples and sediments with similar compositions and features to those found in the unstable brandy appeared. The amounts of sediment obtained were directly related to the decrease in Si concentration in solution. Consequently, it can be concluded that siliceous sediment in brandy originates from Si released during diatomite filtration.

Diatomite releases silica during spirit filtration.

The purpose of this study was to ascertain whether diatomite is an inert filter aid during spirit filtration. Surely, any compound with a negative effect on the spirit composition or the consumer's health could be dissolved. In this study different diatomites were treated with 36% vol. ethanol/water mixtures and the amounts and structures of the extracted compounds were determined. Furthermore, Brandy de Jerez was diatomite- and membrane-filtered at different temperatures and the silicon content was analysed. It was found that up to 0.36% by weight of diatomite dissolved in the aqueous ethanol and amorphous silica, in the form of hollow spherical microparticles, was the most abundant component. Silicon concentrations in Brandy de Jerez increased by up to 163.0% after contact with diatomite and these changes were more marked for calcined diatomite. In contrast, reductions of more than 30% in silicon concentrations were achieved after membrane filtration at low temperatures.

Sonosynthesis of gold nanoparticles from a geranium leaf extract.

A rapid in situ biosynthesis of gold nanoparticles (AuNPs) is proposed in which a geranium (Pelargonium zonale) leaf extract was used as a non-toxic reducing and stabilizing agent in a sonocatalysis process based on high-power ultrasound. The synthesis process took only 3.5 min in aqueous solution under ambient conditions. The stability of the nanoparticles was studied by UV-Vis absorption spectroscopy with reference to the surface plasmon resonance (SPR) band. AuNPs have an average lifetime of about 8 weeks at 4 °C in the absence of light. The morphology and crystalline phase of the gold nanoparticles were characterized by transmission electron microscopy (TEM). The composition of the nanoparticles was evaluated by electron diffraction and X-ray energy dispersive spectroscopy (EDS). A total of 80% of the gold nanoparticles obtained in this way have a diameter in the range 8-20 nm, with an average size of 12±3 nm. Fourier transform infrared spectroscopy (FTIR) indicated the presence of biomolecules that could be responsible for reducing and capping the biosynthesized gold nanoparticles. A hypothesis concerning the type of organic molecules involved in this process is also given. Experimental design linked to the simplex method was used to optimize the experimental conditions for this green synthesis route. To the best of our knowledge, this is the first time that a high-power ultrasound-based sonocatalytic process and experimental design coupled to a simplex optimization process has been used in the biosynthesis of AuNPs.

New, fast and green procedure for the synthesis of gold nanoparticles based on sonocatalysis.

An easy, cheap and green synthetic route, using high-power ultrasounds and sodium citrate dihydrate as non-toxic reducing and stabilizer agent, produces gold nanoparticles in aqueous solution, and at ambient conditions. The time required for the synthesis is 5.5 min. The spherical nanoparticles obtained by this route show a homogeneous size distribution, within the range 5-17 nm, with an average diameter of 10±1 nm. Moreover, 90% of the particles have a diameter ranging from 7 to 13 nm, and their half-life is more than 30 days. The gold nanoparticles synthesized following this route are known as sononanoparticles. Gold sononanoparticles have been characterized by TEM and XRD and their stability has been studied by UV-Vis spectroscopy. Alternative experimental designs are compared to optimize the proposed synthesis procedure.

Toll-like receptor 4 defective mice carrying point or null mutations do not show increased susceptibility to Candida albicans in a model of hematogenously disseminated infection.

We have studied the role of TLR4 in murine defenses against Candida albicans in two TLR4-defective mouse strains: C3H/HeJ mice which have defective TLR4 signaling, and TLR4-/- knockout mice. Both TLR4-defective mice strains experimentally infected with virulent C. albicans cells showed no significant difference in survival as compared with their respective controls. Recruitment of neutrophils to the peritoneal cavity of i.p. infected mice was not affected in TLR4-/-animals, but significantly enhanced in C3H/HeJ mice, compared with their control mice. In vitro production of TNF-alpha by macrophages from both types of TLR4-defective mice, in response to yeasts and hyphae of C. albicans, was not diminished as compared with production by macrophages from wild-type mice. In vitro production of TNF-alpha by yeast-stimulated splenocytes from mice intravenously infected with the low-virulence C. albicans PCA2 strain was not affected in TLR4-defective mice, but the TNF-alpha production in response to hyphae was higher in TLR4-defective than in control animals; the production of IFN-gamma by these splenocytes was similar to controls, as well as the frequency of IFN-gamma-producing CD4+T lymphocytes, indicating that TLR4-defective mice are capable of mounting a Th1 adaptive immune response. Our data indicate that TLR4 is dispensable for murine immune resistance to C. albicans.

Ubiquitinated granular structures and initial neurofibrillary changes in the human brain.

Ubiquitin-positive dots and granular structures from insular, temporopolar, hippocampal and parahippocampal cortices of nondemented and Alzheimer's disease patients have been studied with both light and electron microscopes. The relationship of both types of ubiquitin-positive elements with pretangle neurons and neurofibrillary tangles has been analyzed by comparing adjacent or nearly adjacent sections immunostained for either ubiquitin or an antibody that recognizes hyperphosphorylated tau protein (AT-8). Moreover, a double protocol with both antibodies was used in order to obtain double-stained sections. The presence of ubiquitin-positive dots and granular structures precedes the appearance of pretangle neurons in the youngest cases. In aged and Alzheimer disease cases, both types of ubiquitin-positive elements decrease in number as pretangle neurons are replaced by mature and ghost tangles. Ultrastructurally, dots and granular structures appear to be degenerating neuronal processes and/or terminals. Our results suggest that the degeneration of these processes and/or terminals might be related with the initiation of neurofibrillary degeneration.

The Candida albicans cell wall-associated glyceraldehyde-3-phosphate dehydrogenase activity increases in response to starvation and temperature upshift.

We have determined the effect of environmental factors (mild thermal upshift and starvation) on the Candida albicans cell wall-associated glyceraldehyde-3-phosphate dehydrogenase (cwGAPDH) activity. Temperature upshift (from 28 to 37 degrees C) and/ or starvation (at 28 or 37 degrees C in water) of exponentially growing yeast cells caused an increase in cwGAPDH activity (3 to 5-, and 7 to 8-fold, respectively). This increase in activity did not correlate with an increase in the amount of cwGAPDH protein present, as determined by flow cytometry, immunoelectron microscopy and Western-blotting. These results indicate that thermal upshift and starvation cause an activation of the cwGAPDH in C. albicans cells.

Molecular cloning and characterization of the Candida albicans UBI3 gene coding for a ubiquitin-hybrid protein.

Using a polyubiquitin cDNA as a probe, we have isolated a clone (pPR3, a pEMBLYe23 derivative plasmid) containing the Candida albicans UBI3 gene coding for a fusion protein. This protein is formed by one ubiquitin subunit fused, at its C-terminus, to an unrelated peptide which is similar to the ribosomal protein encoded by the 3' tail of the Saccharomyces cerevisiae UBI3 gene. Southern blot analysis of chromosomal DNA probed with the 3' non-ubiquitin tail of UBI3 indicated that only one homologous gene is present in the C. albicans genome. Heterelogous expression of pPR3 in a S. cerevisiae ubi3 mutant strain complements the mutant phenotype (slow growth) conferred by the ubi3 defect; this provides direct evidence indicating that the clone contains the C. albicans UBI3 gene Northern blot analysis showed that UBI3 gene is expressed in yeast and germ-tube cells of C. albicans, although the UBI3 mRNA levels in starved yeast cells are below the detection limit; UBI3 mRNA drops to undetectable levels on shifting the temperature of growing yeast cells from 28 degrees C to 42 degrees C. When Northern blot analysis was performed using a specific probe for the polyubiquitin (UBI4) gene, no drop in the mRNA levels was detected following thermal upshift or in starved cells. These results indicate that stress conditions (starvation or thermal upshift) negatively regulate UBI3 expression (transcriptional arrest and/or enhanced mRNA decay), and suggest that UBI4 gene provides ubiquitin during the stress response. In addition, we failed to obtain C. albicans UBI3 null mutant cells by sequential disruption of both alleles using the hisG::URA3::hisG ('ura-blaster') cassette, suggesting that null mutants cells may be unable to grow on selective media after transformation.

[Knowledge, opinions and attitudes of the Canarian Islands population towards nutrition]. / Conocimientos, opiniones y actitudes de la población de las Islas Canarias en relación con la nutrición.

OBJECTIVE: To estimate knowledge and identify opinions and attitudes of the Canary Island population towards eating in relation to health. DESIGN: Epidemiological, cross-sectional descriptive or prevalence study. SUBJECTS: 1747 people from the Canary Islands: 821 males (47%) and 926 females (53%) aged 6 to 75 years. RESULTS: In the Canary Islands, 46.7% of the study population considered their knowledge of food and nutrition to be adequate, although an important percentage of the population didn't know the foods they had to restrict to prevent hypercholesterolemia. 43% of the population studied declared to be ready to modify their diet for health reasons and 78.7% of the people surveyed considered physicians as the most reliable source of food and nutrition information. CONCLUSIONS: An important proportion of the Canarian population considers that they should change their diet to improve their health. Likewise, a large number of this population admits to being ready to positively modify their eating habits, and health professionals are a key element in this process.

Sevoflurane versus propofol for induction and maintenance of anaesthesia with the laryngeal mask airway in children.

We compared patient outcomes for propofol vs sevoflurane with the laryngeal mask airway (LMA) using either spontaneous breathing (SB) or pressure controlled ventilation (PCV). One hundred and twenty children undergoing minor surgery below the umbilicus were randomly assigned to receive either (1) propofol 3 mg.kg-1 followed by a maintenance infusion of 5 mg.kg-1.h-1, or (2) induction with sevoflurane 7% followed by maintenance with 1.7%. Following LMA insertion, patients were given atracurium and underwent PCV if surgery was expected to last > or = 30 min. The following assessments were made: time to LMA insertion/removal, airway problems, cardiorespiratory effects and recovery characteristics. The first time insertion success rates were similar, but insertion time was shorter with sevoflurane (115 +/- 67 s vs 252 +/- 107 s, P < 0.0001). One patient coughed during placement, but there were no other problems during any phase of anaesthesia in any group. Heart rate was higher in the sevoflurane group following insertion, during maintenance and emergence (all P < 0.03). There were no differences in blood pressure and oxygen saturation among groups PECO2 in the SB group was unaffected by the agent used. Emergence was more rapid (232 +/- 104 s vs 348 +/- 127 s, P < 0.0001) and postoperative agitation more common (15% vs 0%, P = 0.02) with sevoflurane. There were no differences in the Aldrete scores among groups. Patient outcome was similar for the SB and PCV groups. We concluded that the techniques described here using propofol and sevoflurane are equally suitable for induction and maintenance of anaesthesia with the LMA in children undergoing minor surgery below the umbilicus. Emergence is more rapid, but postoperative agitation more common with sevoflurane.

Purification of a biologically active recombinant glyceraldehyde 3-phosphate dehydrogenase from Candida albicans.

We report here the purification of a functionally active recombinant glyceraldehyde 3-phosphate dehydrogenase (GAPDH) from Candida albicans. The GAPDH protein encoded by the TDH1 gene was obtained as a glutathione S-transferase fusion protein by expression in the vector pGEX-4T-3, and purified by affinity chromatography and thrombin digestion. The purified protein displays GAPDH enzymatic activity (42 micromol NADH min(-1) mg(-1)) as well as the laminin and fibronectin binding activities previously described. In addition, the recombinant GAPDH is covalently modified by NAD linkage; this modification is stimulated by nitric oxide and probably involves a sulfhydryl group (cysteine) residue since it is inhibited by Hg(2+) and cysteine.

Clinical strains of Candida albicans express the surface antigen glyceraldehyde 3-phosphate dehydrogenase in vitro and in infected tissues.

We have previously described the presence of an enzymatically active form of glyceraldehyde 3-phosphate-dehydrogenase (GAPDH) in the cell surface of Candida albicans ATCC 26555 which is also a fibronectin and laminin binding protein. Immunohistochemical analysis of tissue sections from patients with disseminated candidiasis with a polyclonal antiserum to GAPDH from C. albicans (PAb anti-CA-GAPDH) revealed that the enzyme is expressed at the surface of fungal cells in infected tissues. The same PAb detected the presence of GAPDH species, with a molecular mass of approximately 33 kDa, in cell wall extracts obtained from clinical isolates of the fungus. These cell surface-bound GAPDH moieties exhibited a dose-dependent dehydrogenase activity. These results indicate that this cell surface-bound GAPDH plays a role during infection probably contributing to the attachment of fungal cells to host tissues.

Prevalence of serologic markers of HBV, HDV, HCV and HIV in non-injection drug users compared to injection drug users in Gran Canaria, Spain.

Injection drug use (IDU) is one of the most significant risk factors for viral hepatitis (B, D and C) and human immunodeficiency virus (HIV) infection. However, there is little information about the risk of infection among non-injection drug users (non-IDUs). The present study was designed to perform several objectives: (a) to evaluate the prevalence of serological markers of hepatitis B, D, C virus and HIV in IDU and non-IDU patients; (b) to compare the prevalence of these markers between both groups; (c) to identify risk factors for HCV and HIV in this population; and (d) to correlate the presence of HCV and liver function. A total of 385 consecutive patients (122 IDUs and 263 non-IDUs), admitted to the Drug Dependency Treatment Unit at the Hospital Insular of Gran Canaria between 1993 to 1994, were included in the study. The serological markers of HBV, HDV, HCV and HIV were determined by ELISA and immunoblot methods. In all cases we also measured syphilis tests (RPR and FTAabs), serum aminotransferases and serum gammaglutamiltranspeptidase. Compared to the non-IDU, the IDU group presents a higher prevalence of antiHBc (55.0% vs. 20.7%, p < 0.0001), antiHCV (87.6% vs. 35.3%, p < 0.0001) and antiHIV (21.8% vs. 2.7%, p < 0.0001). There was no significant difference in RPR positivity (0.9% vs. 4.9%, p = 0.06). Delta infection was only detected in injection drug users, and the prevalence was low. Using logistic regression, the only risk factors associated with antiHCV positivity were injection drug addiction (OR: 9.2, 95% CI: 4.9-17.0) and antiHBc positivity (OR: 5.5, 95% CI: 3.0-9.9). Similarly, the associated risk factors for HIV were injection drug addiction (OR: 5.9, 95% CI: 2.3-15.0) and antiHBc positivity (OR: 3.8, 95% CI: 1.5-9.2). However, no correlation was found between antiHCV positive and antiHIV or between these markers and RPR positivity. Patients positive for antiHCV showed significant elevations in aspartate aminotransferase and alanine aminotransferase levels, when compared with patients negative for antiHCV: 65.0 vs. 39.2 U/l (p < 0.001) and 88.4 vs. 40.3 U/l (p < 0.001), respectively. We conclude that drug users have an elevated prevalence of HCV, HBV and HIV infection, even if drug use is only inhalated. On the other hand, the main risk factors associated with HCV and HIV are injection drug addiction and exposure to hepatitis B virus. Finally, in the study population, liver dysfunction is closely related to HCV infection.

The cell wall-associated glyceraldehyde-3-phosphate dehydrogenase of Candida albicans is also a fibronectin and laminin binding protein.

By immunoelectron microscopy with a polyclonal antibody against the cytosolic glycolytic enzyme glyceraldehyde-3-phosphate dehydrogenase (GAPDH) from Candida albicans (anti-GAPDH PAb), the protein was clearly detected at the outer surface of the cell wall, particularly on blastoconidia, as well as in the cytoplasm. Intact blastoconidia were able to adhere to fibronectin and laminin immobilized on microtiter plates, and this adhesion was markedly reduced by both the anti-GAPDH PAb and soluble GAPDH from Saccharomyces cerevisiae. In addition, semiquantitative flow cytometry analysis with the anti-GAPDH PAb showed a decrease in antibody binding to cells in the presence of soluble fibronectin and laminin. Purified cytosolic C. albicans GAPDH was found to bind to fibronectin and laminin in a ligand Western blot assay. These observations suggest that the cell wall-associated form of the GAPDH in C. albicans could be involved in mediating adhesion of fungal cells to fibronectin and laminin, thus contributing to the attachment of the microorganism to host tissues and to the dissemination of Candida infection.

Serologic response to cell wall mannoproteins and proteins of Candida albicans.

The cell wall of Candida albicans not only is the structure in which many biological functions essential for the fungal cells reside but also is a significant source of candidal antigens. The major cell wall components that elicit a response from the host immune system are proteins and glycoproteins, the latter being predominantly mannoproteins. Both the carbohydrate and protein moieties are able to trigger immune responses. Although cell-mediated immunity is often considered to be the most important line of defense against candidiasis, cell wall protein and glycoprotein components also elicit a potent humoral response from the host that may include some protective antibodies. Proteins and glycoproteins exposed at the most external layers of the wall structure are involved in several types of interactions of fungal cells with the exocellular environment. Thus, coating of fungal cells with host antibodies has the potential to influence profoundly the host-parasite interaction by affecting antibody-mediated functions such as opsonin-enhanced phagocytosis and blocking the binding activity of fungal adhesins for host ligands. In this review, the various members of the protein and glycoprotein fraction of the C. albicans cell wall that elicit an antibody response in vivo are examined. Although a number of proteins have been shown to stimulate an antibody response, for some of these species the response is not universal. On the other hand, some of the studies demonstrate that certain cell wall antigens and anti-cell wall antibodies may be the basis for developing specific and sensitive serologic tests for the diagnosis of candidasis, particularly the disseminated form. In addition, recent studies have focused on the potential for antibodies to cell wall protein determinants to protect the host against infection. Hence, a better understanding of the humoral response to cell wall antigens of C. albicans may provide the basis for the development of (i) effective procedures for the serodiagnosis of disseminated candidiasis and (ii) novel prophylactic (vaccination) and therapeutic strategies for the management of this type of infection.