Effects of the addition of nanoparticulate calcium carbonate on setting time, dimensional change, compressive strength, solubility and pH of MTA.

AIM: To evaluate nanoparticulate calcium carbonate (NPCC) using transmission electron microscopy and the effects of NPCC addition to MTA in regard to the setting time, dimensional change, compressive strength, solubility and pH. METHODOLOGY: The experimental groups were G1 (MTA), G2 (MTA with 5% NPCC) and G3 (MTA with 10% NPCC). The tests followed ISO and ADA standards. The specimens in the dimensional change and compressive strength tests were measured immediately after setting, after 24 h and after 30 days. In the solubility test, rings filled with cement were weighed after setting and after 30 days. The pH was measured after 24 h and 30 days. The data were analysed with the ANOVA, Tukey's and Kruskal-Wallis tests (α = 5%). RESULTS: The setting time was reduced (P < 0.05) in samples from G2 and G3 compared to G1. After 24 h, the dimensional change was similar amongst the groups, and after 30 days, G2 was associated with less alteration than G1 and G3. There was a difference in the compressive strength (P < 0.001) after 24 h and 30 days (G1 > G2 > G3). The solubility test revealed a difference amongst the groups when the specimens were hydrated: G2 > G1 > G3 and dehydrated: G3 > G2 > G1. The pH of the groups was similar at 24 h with higher values in each group after 30 days (P < 0.05), and G2 and G3 had similar mean pH values but both were higher than G1. CONCLUSIONS: Nanoparticulate calcium carbonate had a cubic morphology with few impurities. The addition of nanoparticulate calcium carbonate to MTA accelerated the setting time, decreased compressive strength and, after 30 days, resulted in lower dimensional change (G2), higher solubility and a higher pH.

Development and validation of the first SSR markers for Mimosa scabrella Benth.

Mimosa scabrella Benth., popularly known as ''bracatinga'', is a pioneer and endemic species of Brazil, occurring in Mixed Ombrophilous Forest associated with Brazilian Atlantic Rainforest biomes. It is a fast-growing tree of the Fabaceae family that facilitates the dynamics of ecological succession. SSR development, when there is no genome sequence, is time and labor intensive and there are no molecular markers for M. scabrella. We developed and validated the first microsatellite markers for this tetraploid species, evaluating mother trees and progenies. Using Illumina sequencing, we identified 290 SSR loci and 211 primer pairs. After 31 SSR loci PCR/agarose electrophoresis selection, a subset of 11 primer pairs was synthetized with fluorescence in the forward primer for PCR and capillary electrophoresis validation with leaf DNA of 33 adult and 411 progeny individuals. Polymorphic locus percentage was 36, 4 in 11 loci, 3 chloroplast SSRs, and 1 nuclear SSR. Allele number of polymorphic loci ranged from 2 to 11 alleles considering all sampling. All 11 primer pairs were also tested for cross-species amplification for five Fabaceae-Mimosoideae species, ranging from 2 loci transferred to Calliandra tweedii Benth. and all 11 loci transferred to Mimosa taimbensis Burkart. The assessed and validated SSR markers for M. scabrella are suitable and useful for analysis and population genetic studies.

Detection and quantitative analysis of two independent binding modes of a small ligand responsible for DC-SIGN clustering.

DC-SIGN (dendritic cell-specific ICAM-3 grabbing non-integrin) is a C-type lectin receptor (CLR) present, mainly in dendritic cells (DCs), as one of the major pattern recognition receptors (PRRs). This receptor has a relevant role in viral infection processes. Recent approaches aiming to block DC-SIGN have been presented as attractive anti-HIV strategies. DC-SIGN binds mannose or fucose-containing carbohydrates from viral proteins such as the HIV envelope glycoprotein gp120. We have previously demonstrated that multivalent dendrons bearing multiple copies of glycomimetic ligands were able to inhibit DC-SIGN-dependent HIV infection in cervical explant models. Optimization of glycomimetic ligands requires detailed characterization and analysis of their binding modes because they notably influence binding affinities. In a previous study we characterized the binding mode of DC-SIGN with ligand 1, which shows a single binding mode as demonstrated by NMR and X-ray crystallography. In this work we report the binding studies of DC-SIGN with pseudotrisaccharide 2, which has a larger affinity. Their binding was analysed by TR-NOESY and STD NMR experiments, combined with the CORCEMA-ST protocol and molecular modelling. These studies demonstrate that in solution the complex cannot be explained by a single binding mode. We describe the ensemble of ligand bound modes that best fit the experimental data and explain the higher inhibition values found for ligand 2.

Microbiological contamination in peanut confectionery processing plants.

AIMS: In order to investigate Enterobacteriaceae, coliforms, Escherichia coli and Salmonella contamination, a survey was conducted at three peanut confectionery processing companies (A, B and C) in Brazil. METHODS AND RESULTS: Samples of different peanut confectionery products (n = 59), peanut raw material (n = 30), manufacturing environment (n = 116) and workers' hand surfaces (n = 12) were analysed. Salmonella and E. coli were not detected in any final product or raw material analysed. Enterobacteriaceae was isolated from 15% of final products. Coliforms were detected in only one sample. Referring to the raw material, six samples showed contamination by Enterobacteriaceae and three samples by coliforms. For the process environment, 19% and 11% of samples presented Enterobacteriaceae and coliforms. Escherichia coli was detected in 5% of samples, and one of these samples tested positive for Salmonella; this strain was serotyping as S. Heidelberg. All food handlers surveyed in Company C showed Enterobacteriaceae and coliforms on their hands. Escherichia coli was isolated from one food worker's hand. CONCLUSION: The results showed that the manufacturing environment, including food handlers were considered the main sources for possible contamination of peanut confectionery products. SIGNIFICANCE AND IMPACT OF THE STUDY: This has been the first study to investigate the occurrence of Salmonella and other Enterobacteriaceae throughout peanut confectionery processing lines. The results might be used to assist risk assessment studies and to establish more effective control measures.

The application of antimicrobial photodynamic therapy (aPDT) in dentistry: a critical review.

In recent years there have been an increasing number of in vitro and in vivo studies that show positive results regarding antimicrobial photodynamic therapy (aPDT) used in dentistry. These include applications in periodontics, endodontics, and mucosal infections caused by bacteria present as biofilms. Antimicrobial photodynamic therapy is a therapy based on the combination of a non-toxic photosensitizer (PS) and appropriate wavelength visible light, which in the presence of oxygen is activated to produce reactive oxygen species (ROS). ROS induce a series of photochemical and biological events that cause irreversible damage leading to the death of microorganisms. Many light-absorbing dyes have been mentioned as potential PS for aPDT and different wavelengths have been tested. However, there is no consensus on a standard protocol yet. Thus, the goal of this review was to summarize the results of research on aPDT in dentistry using the PubMed database focusing on recent studies of the effectiveness aPDT in decreasing microorganisms and microbial biofilms, and also to describe aPDT effects, mechanisms of action and applications.

Modified Stranski-Krastanov growth in Ge/Si heterostructures via nanostenciled pulsed laser deposition.

The combination of nanostenciling with pulsed laser deposition (PLD) provides a flexible, fast approach for patterning the growth of Ge on Si. Within each stencilled site, the morphological evolution of the Ge structures with deposition follows a modified Stranski-Krastanov (SK) growth mode. By systematically varying the PLD parameters (laser repetition rate and number of pulses) on two different substrate orientations (111 and 100), we have observed corresponding changes in growth morphology, strain and elemental composition using scanning electron microscopy, atomic force microscopy and µ-Raman spectroscopy. The growth behaviour is well predicted within a classical SK scheme, although the Si(100) growth exhibits significant relaxation and ripening with increasing coverage. Other novel aspects of the growth include the increased thickness of the wetting layer and the kinetic control of Si/Ge intermixing via the PLD repetition rate.

Crystallisation of amorphous germanium thin films.

By combining cross-sectional transmission and scanning electron microscopy with Raman scattering we have investigated the mechanism of nanocrystal formation in ultrathin amorphous SiO2/Ge/SiO2 trilayers grown by e-beam evaporation as a function of annealing temperature and a-Ge layer thickness. We observe that with decreasing a-Ge thickness the amorphous-to-crystalline (a-to-c) transition occurs at considerably higher temperatures, even avoiding crystallisation for very thin films below 2 nm thickness. Furthermore, we demonstrate that the formation of Ge nanocrystals by annealing at around 900 degrees C takes place driven by a liquid-mediated mechanism. As indicated by the observed microstructure, the metallic liquid film dewets from the surface forming droplets that upon cooling and under the influence of the SiO2 capping layer, solidify into barrel-type nanocrystals.

C-reactive protein and coronary composition in patients with percutaneous revascularization.

BACKGROUND: C-Reactive Protein (CRP) is considered a predictive factor for cardiovascular events and its serum levels have been shown to correlate with thin cap coronary plaques in sudden coronary death. Whether serum CRP levels are associated with in vivo atherothrombotic features is unclear. We thus analysed samples from coronary atherectomy specimens obtained during percutaneous coronary intervention. MATERIALS AND METHODS: Patients with coronary artery disease undergoing directional atherectomy, distinguished by unstable versus stable coronary syndrome diagnosis, provided coronary specimens from culprit lesions. Assessment was conducted by means of conventional histology, morphometry and immunohistochemistry. Specific antibodies against erythrocyte-specific protein glycophorin A, endothelial and macrophage antigens were also used. RESULTS: There were 51 patients with unstable coronary disease and 47 patients with stable angina. Serum CRP levels >/= 1 mg L(-1) were detected in 24/98 patients, and were significantly associated with hypercellularity, macrophage infiltrates, neoangiogenesis and intraplaque haemorrhage (all P < 0.05). Furthermore, coronary plaques from patients with unstable angina contained larger atheromas, more hypercellular plaques, with abundant macrophages, neoangiogenesis and intraplaque haemorrhages and lesser fibrous tissue (all P < 0.05). CONCLUSIONS: We observed a positive correlation between increased serum CRP levels and typical pathological features of complex atherothrombotic coronary disease, confirming in vivo the mechanistic role of CRP in coronary atherothrombosis.

The ethics of off-label use of drugs: oncology pharmacy in Italy.

The off-label use of drugs is very common in cancer treatment for many reasons. This practice is challenging for pharmacists who practice in oncology, for bureaucratic and medico-legal reasons and for reasons concerning ethics. Several Italian legislative Acts and Laws allow pharmacists to have a voice in the management of off-label use of drugs in oncology and offer instruments to allow reasoning from an ethical perspective. The main aim of this paper was to identify the role of pharmacists within the ethical context in the off-label use of drugs in oncology, taking into account the legislative framework and clinical oncology setting. We consider the existing norms to develop an ethical perspective, through the values underlying the Laws and Acts. From a hermeneutical perspective, we focus on the actual oncology setting to identify the ethical space. The off-label use of drugs in Italy is currently regulated by Law 648/96, Law 94/98 and Decree Law on the therapeutic use of drugs under clinical investigation. From the oncology pharmacist's perspective, the application of the Laws mentioned is often problematic. The disease itself brings forth many ethical issues. In particular, human experience is extremely important in oncology and cannot be separated from other considerations. When faced with the common choice of oncologists to use drugs off-label the late stages of the disease or after many chemotherapy attempts, pharmacists have to take responsibility for the sick person. This usually involves collaboration with the physician, within a process oriented by the 'circumstances of compromise in ethics'. The pharmacist practising in oncology should promote real collaboration especially with the physician for the benefit of the sick person. The pharmacist has to maintain his/her professional integrity, and orient it towards accurate evaluation of the so-called 'circumstances of compromise in ethics'.

Salmonella, Escherichia coli and Enterobacteriaceae in the peanut supply chain: From farm to table.

Due to recent foodborne outbreaks, peanuts have been considered a potential risk for Salmonella transmission. For this reason, the aim of this study was to determine the prevalence and contamination load of Salmonella, Escherichia coli and Enterobacteriaceae throughout the peanut supply chain in Brazil. Samples of peanuts and peanut-containing processed products from post-harvest (n=129), secondary processing (n=185) and retail market (n=100) were analyzed. The results showed high Enterobacteriaceae counts in the post-harvest samples. At the end of the secondary processing, 16% of the samples remained contaminated by this group of microorganisms. Six peanut samples from primary production and one sample of peanut butter were tested positive for E. coli while Salmonella was detected in nine samples (2.2%): six from post-harvest, two from the initial stage of the secondary processing and one from retail. The Salmonella counts ranged between 0.004 and 0.092MPN/g and five serotypes were identified (Muenster, Miami, Javiana, Oranienburg, Glostrup). The results demonstrated a high prevalence of Enterobacteriaceae and low prevalence of E. coli throughout the peanut supply chain. Furthermore, it was verified that peanuts may become contaminated by Salmonella during different stages of the supply chain, especially at post-harvest.

Perfluoropolyether phosphate: skin exfoliation after a topical pre-treatment, TEWL and skin elasticity, by in-vivo non-invasive methods.

Glycolic acid (GA) and other alpha-hydroxyacids (AHAs) are common ingredients of products designed to accelerate exfoliation of the skin. It is known that acidic pHs are essential in order to increase the efficacy of AHA-based products. The formulator is, therefore, obliged to achieve a difficult balance between performance (skin exfoliation) and risks (skin irritation). In order to overcome this problem, many common organic acids, and combinations of them, have been proposed, with marginal improvements. The need for a new chemistry, in order to achieve better results, was evident, particularly from the point of view of safety. We decided, therefore, to investigate the efficacy of perfluoropolyether (PFPE) phosphate, a new acidic material, already proposed for lowering the pH without increasing skin irritation. Two gels containing PFPE phosphate at different pH values (3 and 7), an acidic gel containing GA at pH 3, and a neutral gel, without an active compound, were applied on 20 healthy volunteers and evaluated with regard to effects on the skin: *Exfoliation after a topical pre-treatment with these gels *Transepidermal water loss (TEWL) and elasticity The main conclusion of the investigation was that PFPE phosphate has effects, particularly skin exfoliation rate, quite independent of the pH, and comparable to the gel containing GA at pH 3, apparently without the typical drawbacks of AHAs.

R2R-printed inverted OPV modules--towards arbitrary patterned designs.

We describe the fabrication of roll-to-roll (R2R) printed organic photovoltaic (OPV) modules using gravure printing and rotary screen-printing processes. These two-dimensional printing techniques are differentiating factors from coated OPVs enabling the direct patterning of arbitrarily shaped and sized features into visual shapes and, increasing the freedom to connect the cells in modules. The inverted OPV structures comprise five layers that are either printed or patterned in an R2R printing process. We examined the rheological properties of the inks used and their relationship with the printability, the compatibility between the processed inks, and the morphology of the R2R-printed layers. We also evaluate the dimensional accuracy of the printed pattern, which is an important consideration in designing arbitrarily-shaped OPV structures. The photoactive layer and top electrode exhibited excellent cross-dimensional accuracy corresponding to the designed width. The transparent electron transport layer extended 300 µm beyond the designed values, whereas the hole transport layer shrank 100 µm. We also examined the repeatability of the R2R fabrication process when the active area of the module varied from 32.2 cm(2) to 96.5 cm(2). A thorough layer-by-layer optimization of the R2R printing processes resulted in realization of R2R-printed 96.5 cm(2) sized modules with a maximum power conversion efficiency of 2.1% (mean 1.8%) processed with high functionality.

DNA rearrangements in a hybrid plasmid carrying the redB imm region of coliphage lambda.

The hybrid plasmid consisting of pSC101 and the redB--N--imm region of phage lambda cI857 persists in cells grown at 30 degrees C but not in cells grown at 37 degrees C. In the latter case the plasmid was found to undergo several modifications. Restriction maps of these new plasmids indicate the following modifications: (1) the insertion of an IS1 element into gene N carried by the lambda fragment; (2) a mutation in the pL oL site of the same fragment, and (3) four large deletions (30 to 50% of the hybrid plasmid) which remove almost the entire lambda fragment. For the latter deletions, one endpoint seems to be fixed in the same restriction fragment of pSC101 while the other endpoint assumes four different positions on the lambda fragment; this might suggest a site-specific recombination event.

Site-specific deletions in the recombinant plasmid pSC101 containing the redB-ori region of phage lambda.

Large deletions occur in the hybrid plasmid formed by pSC101 and the EcoRI fragment f2 of phage lambda (redB-ori region) under well defined growth conditions (Bernardi and Bernardi, 1980). We have sequenced the novel joints of the four deletions so obtained and shown that they have one endpoint in pSC101, identical in all four cases, the other endpoint being located in four different lambda sequences. Furthermore, the nucleotide sequences of the novel joints show homologies between the conserved pSC101 sequence and the lambda sequences both conserved and deleted. The presence of an IS-type element in pSC101 is postulated; however, this element is unrelated to the 200 bp element already described in pSC101 (Ravetch et al., 1976).

Intramolecular transposition of IS102.

It has been postulated that deletions mediated by transposable elements are intramolecular transposition events. An implication of this hypothesis is that the deleted fragment may be recovered if it is capable of autonomous replication. We report here the characterization of the products of intramolecular transposition of the element IS102 in bireplicons. We show that when two origins (ori's) (of pSC101 and R6-5) generate the same copy numbers, two dissociated replicons are recovered as well as the inversions. On the contrary, when two ori's (of pSC101 and pBR322) have different copy numbers, intramolecular transposition results essentially in inversions. However, the very low frequency (5 X 10(-8)) at which intramolecular transpositions in the bireplicons occurs, as compared to the single replicon (10(-4)), suggests that a complete transposition reaction may not be necessary to generate deletions.

Cell proliferation of breast cancer evaluated by anti-BrdU and anti-Ki-67 antibodies: its prognostic value on short-term recurrences.

The prognostic value of breast cancer proliferative activity was evaluated in 385 women operated for primary, non-metastasised mammary carcinoma. Cell kinetics was measured using two immunohistochemical techniques. Cells in S-phase of cell cycle were labelled in vitro by incubation of fresh tissue fragments with 5-bromo 2-deoxyuridine (BrdU), a thymidine analogue. Nuclei of cells in active DNA synthesis were stained by an anti-BrdU monoclonal antibody (Mab). Cells in interphase and mitosis were detected with Ki-67, a Mab that is known to react with a nuclear antigen present in G1/S/G2/M phases of cell cycle, but not in resting cells. This reagent provides a means of evaluating the growth fraction of neoplastic cells. BrdU was incorporated in a proportion of tumour cells ranging from 0.1 to 65.5% (median 6.8%). In the panel of tumours presented in this report the median percentage of Ki-67 positive cells (Ki-67 score) was 9.0% (range 0.1-77%). The relationship between disease-free survival (DFS), BrdU labelling index, Ki-67 score and 13 different clinico-pathological variables was investigated by multivariate analysis, using the Cox proportional hazards model. Axillary node status (P = 0.009) and Ki-67 score (P = 0.038) emerged as independent prognostic factors. Nodal status and tumour growth fraction allowed division of patients into groups at different risk of relapse: tumours with a proliferative index below the median value showed a lower recurrence rate than tumours with a high proliferative activity (P < 0.001). In particular, no relapse occurred in pN0 patients bearing carcinomas with a Ki-67 labelling < 9.0% 4 years after surgery. These findings suggest that the evaluation of proliferative activity in breast cancer enhances the probability of correctly predicting outcome after surgery and could be of assistance in the planning of adjuvant therapies.

Simulation of protein-sugar interactions: a computational model of the complex between ganglioside GM1 and the heat-labile enterotoxin of Escherichia coli.

The cholera toxin from Vibrio cholerae (CT) and the 80% homologous heat-labile toxin of Escherichia coli (LT) are two well-known cases of sugar-binding proteins. The GM1:toxin complexes were chosen as test cases for the elaboration of a computational approach to the modeling of protein-saccharide interactions. The reliability of the method was evaluated on the LT:lactose complex. A model of this complex was built by performing a MC/EM conformational search of the sugar moiety within the binding pocket of LT, using the AMBER* force field and the GB/SA solvation model. The results are a reasonable reproduction of the reported X-ray structure of the complex. The same protocol was then applied to the LT:GM1 complex. The calculations were performed on a substructure that includes the protein shell within 5 A from GM1, three water molecules solvating Glu-51 carboxylate, and two water molecules at crystallographic sites 2 and 3. A satisfactory agreement was found with the recently published X-ray structure of the CT:GM1 complex. All the relevant interactions between the sugar and the residues involved in binding are well reproduced by the calculations. These results suggest that the substructure here identified can be taken as a realistic representation of the toxin binding surface and that the method presented in this paper can be used as a predictive tool in designing artificial LT (CT) binders and thus potential anticholera drugs.

Potent integrin antagonists from a small library of RGD-including cyclic pseudopeptides.

[structure: see text]. A small library of cyclic RGD pseudopentapeptides incorporating stereoisomeric 6,5- and 7,5-fused bicyclic lactams was synthesized with the aim of developing active and selective integrin antagonists. The solid-phase synthesis and activity of these RGD derivatives is described. The approach led to two of the most active known inhibitors of alpha(V)beta3 receptor.

Evidence for a second tumor suppressor gene on 17p linked to high S-phase index in primary human breast carcinomas.

The short area of chromosome 17 is a frequent target for deletions in human tumors, including breast cancer. We have investigated by restriction fragment polymorphism analysis the pattern of loss of heterozygosity (LOH) at four loci on 17p13.1-17pter in a panel of 110 primary human breast carcinomas. A copy of the p53 gene was lost in 23% of the informative cases. Point mutations in the p53 gene were statistically associated with LOH at the same locus (p = 0.003) but not at other loci on 17p13.3-17pter. A second region bordered by the loci D17S5/D17S28 (17p13.3) and D17S34 (17pter) is also affected by LOH, independent of point mutations in the p53 gene. We propose the presence of a second tumor suppressor gene within this region. In support of this hypothesis is the significant association (p = 0.005) between LOH at the D17S5/D17S28, but not at the TP53 or D17S34 loci, and tumors having a high S-phase index.