Tumor slices as a model to evaluate doxorubicin in vitro treatment and expression of trios of genes PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2 in canine mammary gland cancer

Background: In women with breast cancer submitted to neoadjuvant chemotherapy based in doxorubicin, tumor expression of groups of three genes (PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2) have classified them as responsive or resistant. We have investigated whether expression of these trios of genes could predict mammary carcinoma response in dogs and whether tumor slices, which maintain epithelial-mesenchymal interactions, could be used to evaluate drug response in vitro. Methods: Tumors from 38 dogs were sliced and cultured with or without doxorubicin 1 mu M for 24 h. Tumor cells were counted by two observers to establish a percentage variation in cell number, between slices. Based on these results, a reduction in cell number between treated and control samples >= 21.7%, arbitrarily classified samples, as drug responsive. Tumor expression of PRSS11, MTSS1, CLPTM1 and SMYD2, was evaluated by real time PCR. Relative expression results were then transformed to their natural logarithm values, which were spatially disposed according to the expression of trios of genes, comprising PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2. Fisher linear discrimination test was used to generate a separation plane between responsive and non-responsive tumors. Results: Culture of tumor slices for 24 h was feasible. Nine samples were considered responsive and 29 non-responsive to doxorubicin, considering the pre-established cut-off value of cell number reduction = 21.7%, between doxorubicin treated and control samples. Relative gene expression was evaluated and tumor samples were then spatially distributed according to the expression of the trios of genes: PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2. A separation plane was generated. However, no clear separation between responsive and non-responsive samples could be observed. Conclusion: Three-dimensional distribution of samples according to the expression of the trios of genes PRSS11, MTSS1, CLPTM1 and PRSS11, MTSS1, SMYD2 could not predict doxorubicin in vitro responsiveness. Short term culture of mammary gland cancer slices may be an interesting model to evaluate chemotherapy activity.

Evaluation of the Bond Strength Between a Composite Resin and Enamel Submitted to Bleaching Treatment and Etched with Er:YAG Laser

Background: The use of laser irradiation for dental surface treatment may increase tooth-composite bond strength. Its use on bleached teeth may decrease the waiting time between bleaching and restorative procedures. Objective: This study aimed to evaluate the bond strength between a composite resin and bovine enamel bleached with 35% hydrogen peroxide and etched with Er:YAG laser. Materials and Methods: Thirty bovine teeth were randomly divided into six groups (n = 5): G1, unbleached and restored 24 h after storage in artificial saliva, etching with 35% phosphoric acid (PA) (control); G2, unbleached and restored 24 h after storage in artificial saliva, etching with Er:YAG laser and 35% PA; G3, bleached and restored immediately afterward, etching with 35% PA; G4, bleached and restored 24 h after bleaching, etching with 35% PA; G5, bleached and restored immediately afterward, etching with Er:YAG and 35% PA laser; G6, bleached and restored 24 h after bleaching, etching with Er:YAG laser and 35% PA. Bond strength was quantitatively evaluated by microtensile test (1.0 mm/min). Data were submitted to statistical analysis using ANOVA and Tukey tests (alpha - 0.05). Results: Bond strength values (MPa) were G1, 26.17 +/- 4.44; G2, 28.87 +/- 3.94; G3, 17.25 +/- 4.58; G4, 21.93 +/- 5.02; G5, 16.69 +/- 2.31; and G6, 29.06 +/- 8.31. There was no statistically significant difference among groups G1, G2, and G6 (p - 0.119), which presented higher bond strength than group G4, followed by groups G3 and G5. Conclusion: Er:YAG irradiation of bleached surfaces may favor bonding procedures when performed 24 h after bleaching.

Porcine skin as a source of biodegradable matrices: alkaline treatment and glutaraldehyde crosslinking

In this work, the modifications promoted by alkaline hydrolysis and glutaraldehyde (GA) crosslinking on type I collagen found in porcine skin have been studied. Collagen matrices were obtained from the alkaline hydrolysis of porcine skin, with subsequent GA crosslinking in different concentrations and reaction times. The elastin content determination showed that independent of the treatment, elastin was present in the matrices. Results obtained from in vitro trypsin degradation indicated that with the increase of GA concentration and reaction time, the degradation rate decreased. From thermogravimetry and differential scanning calorimetry analysis it can be observed that the collagen in the matrices becomes more resistant to thermal degradation as a consequence of the increasing crosslink degree. Scanning electron microscopy analysis indicated that after the GA crosslinking, collagen fibers become more organized and well-defined. Therefore, the preparations of porcine skin matrices with different degradation rates, which can be used in soft tissue reconstruction, are viable.

Influence of Annealing Heat Treatment and Cr, Mg, and Ti Alloying on the Mechanical Properties of High-Silicon Cast Iron

The influence of annealing on the mechanical properties of high-silicon cast iron for three alloys with distinct chromium levels was investigated. Each alloy was melted either with or without the addition of Ti and Mg. These changes in the chemical composition and heat treatment aimed to improve the material's mechanical properties by inhibiting the formation of large columnar crystals, netlike laminae, precipitation of coarse packs of graphite, changing the length and morphology of graphite, and rounding the extremities of the flakes to minimize the stress concentration. For alloys with 0.07 wt.% Cr, the annealing reduced the impact resistance and tensile strength due to an enhanced precipitation of refined carbides and the formation of interdendritic complex nets. Annealing the alloys containing Ti and Mg led to a decrease in the mechanical strength and an increase in the toughness. Alloys containing approximately 2 wt.% Cr achieved better mechanical properties as compared to the original alloy. However, with the addition of Ti and Mg to alloys containing 2% Cr, the chromium carbide formation was inhibited, impairing the mechanical properties. In the third alloy, with 3.5 wt.% of Cr additions, the mechanical strength improved. The annealing promoted a decrease in both hardness and amount of iron and silicon complex carbides. However, it led to a chromium carbide formation, which influenced the mechanical characteristics of the matrix of the studied material.

Identification and control of occupational risks in a Sao Paulo metropolitan region quarry

Crushed stone mining is the third largest mining economy in Brazil, where almost half is produced in the Sao Paulo metropolitan region. The segment registers the highest number of accidents among the extractive industries, which justifies the concern with workers` health and safety, and the importance of controlling occupational hazards. Since 2002, the NR-22 Standard (NR-22: Occupational Health and Safety in Mining) makes compulsory the elaboration of a Risk Management Program that identifies risks and establishes control measures. Considering the crushed stone mining industry importance to the state, this paper evaluates and discusses the risks identified in unit operations during the production process of crushed stone in an open pit mine in order to propose control measures for the development of the Risk Management Program. Although this study refers to a specific quarry, it can be applied to other mines from the same sector since some considerations are made regarding differences in manufacturing processes. The research was based on the identification of the main risks associated with drilling, blasting, load & haulage, crushing and screening through field measurements of some hazardous agents, together with company reports. The results contributed to the choice of the appropriate control measures for the improvement Of workers` health and safety conditions.

MODELLING AND CONTROL OF ERSW PROCESSES BY NEURONAL NETWORK

A study on the use of artificial intelligence (AI) techniques for the modelling and subsequent control of an electric resistance spot welding process (ERSW) is presented. The ERSW process is characterized by the coupling of thermal, electrical, mechanical, and metallurgical phenomena. For this reason, early attempts to model it using computational methods established as the methods of finite differences, finite element, and finite volumes, ask for simplifications that lead the model obtained far from reality or very costly in terms of computational costs, to be used in a real-time control system. In this sense, the authors have developed an ERSW controller that uses fuzzy logic to adjust the energy transferred to the weld nugget. The proposed control strategies differ in the speed with which it reaches convergence. Moreover, their application for a quality control of spot weld through artificial neural networks (ANN) is discussed.

Heat-moisture treatment and enzymatic digestibility of Peruvian carrot, sweet potato and ginger starches

The aim of this work was to study the effects of heat-moisture treatment (27% moisture, 100 degrees C, 16 h) and of enzymatic digestion (alpha-amylase and glucoamylase) on the properties of sweet potato (SP), Peruvian carrot (PC) and ginger (G) starches. The structural modification with heat-moisture treatment (HMT) affected crystallinity, enzyme susceptibility and viscosity profile. The changes in PC starch were the most pronounced, with a strong decrease of relative crystallinity (from 0.31 to 0.21) and a shift of X-ray pattern from B- to A-type. HMTof SP and G starch did not change the Xray pattern (A-type). The relative crystallinity of these starches changed only slightly, from 0.32 to 0.29 (SP) and from 0.33 to 0.32 (G). The extent of these structural changes (PC > SP > G) altered the susceptibility of the starches to enzymatic attack, but not in same order (PC > G > SP). HMT increased the starches digestion, probably due to rearrangement of disrupted crystallites, increasing accessible areas to attack of enzymes. The viscosity profiles and values changed significantly with HMT, resulting in higher pasting temperatures, decrease of viscosity values and no breakdown, i.e., stability at high temperatures and shear rates. Changes in pasting properties appeared to be more significant for PC and SP starch, whereas the changes for G starch were small. Setback was minimized following HMT in SP and G starches.

Impact of antimicrobial resistance on the treatment and outcome of patients with sepsis

Antimicrobial therapy is one of the main stones of sepsis therapy. A recent study of septic shock patients showed that each hour of delay in antimicrobial administration during the ensuing 6 h after the onset of hypotension was associated with a decrease in survival rates. However, many questions regarding the impact of infection caused by antimicrobial-resistant pathogens on the mortality of patients with sepsis still need to be clarified. There is a lack of fair studies in the literature. Most studies have had inadequate sample size, inadequate adjustment for predictors of adverse outcomes, and inadequate definition of appropriate antibiotic therapy. Despite the fact that appropriate therapy is essential to treat sepsis, it seems that severity of underlying diseases and comorbidities are more important than resistance, although the studies were not well designed to examine the real impact of resistance on outcome. Finally, new technologies such as microarray that can identify different microorganisms, genes of resistance, and virulence in a few hours might have a great impact on the treatment of sepsis due to antimicrobial-resistant pathogens in the future.

A transposon toolkit for gene transfer and mutagenesis in protozoan parasites

Protozoan parasites affect millions of people around the world. Treatment and control of these diseases are complicated partly due to the intricate biology of these organisms. The interactions of species of Plasmodium, Leishmania and trypanosomes with their hosts are mediated by an unusual control of gene expression that is not fully understood. The availability of the genome sequence of these protozoa sets the stage for using more comprehensive, genome-wide strategies to study gene function. Transposons are effective tools for the systematic introduction of genetic alterations and different transposition systems have been adapted to study gene function in these human pathogens. A mariner transposon toolkit for use in vivo or in vitro in Leishmania parasites has been developed and can be used in a variety of applications. These modified mariner elements not only permit the inactivation of genes, but also mediate the rescue of translational gene fusions, bringing a major contribution to the investigation of Leishmania gene function. The piggyBac and Tn5 transposons have also been shown to mobilize across Plasmodium spp. genomes circumventing the current limitations in the genetic manipulation of these organisms.

Dynamics and Control of Stray Dog Populations

The population dynamics of stray dogs is simulated to assess the effects of sterilization and euthanasia. From simulations representing less than 5 years, sterilization is less efficient than euthanasia to reduce the stray dog population, considering similar rates, but the total number of sterilized dogs is less than the total number of euthanized dogs per km(2) per year. Over 20 years, both strategies have similar efficiency. Beyond a certain rate of dog abandonment, both strategies are inefficient.

Lateral open bite: Treatment and stability

Because of their multifactorial etiologies, dental and skeletal open bites are among the most difficult malocclusions to treat to a successful and stable result. Etiologic factors include vertical maxillary excess, skeletal pattern, abnormalities in dental eruption, and tongue-thrust problems. The purpose of this article was to report the treatment of an adult patient with a lateral open bite and a unilateral posterior crossbite. The treatment involved nonextraction therapy, including intermaxillary elastics, to obtain dentoalveolar extrusion in the region of the lateral open bite. The treatment results were successful and remained stable 2 years later. (Am J Orthod Dentofacial Orthop 2010;137:701-11)

Effects of single or repeated amphetamine treatment and withdrawal on lung allergic inflammation in rats

The effects of single or repeated amphetamine (AMPH) treatment and those of AMPH withdrawals on immune-mediated lung inflammatory response were studied in rats. Two experiments were done. In the first, rats egg-albumin (OVA) sensitized were singularly or repeatedly (21 days, once daily) treated with AMPH (1.0 mg/kg) or with a similar number and volume of 0.9% NaCl. The OVA aerosol challenge was performed 12 h after the single or last repeated AMPH treatment and also 72 and 120 h after AMPH withdrawal. In the second experiment, the effects of reserpine (1.0 mg/kg/day for 5 consecutive days) on single AMPH actions on lung allergic response of rats were analyzed. Single and repeated AMPH treatment induced opposite actions on Bronchoalveolar lavage fluid (BAL) cellularity of allergic rats: single treatment decreased and repeated treatment increased the total number of cells as well as those of macrophages, neutrophils and eosinophils. Our data also showed that single but not repeated AMPH treatment decreased the number of neutrophils, monocytes and lymphocytes in the peripheral blood, and increased the total number of bone marrow cells in rats sensitized and challenged with OVA. Furthermore, it was shown that reserpine treatment precluded the effects of single AMPH treatment on cellular migration to the lung of OVA-sensitized and challenged rats. It was concluded that AMPH effects on lung inflammatory response and cell recruitment to the lung in allergic rats rely at least partially on corticosterone serum levels. The possible involvement of vesicular monoamine transporter type 2 (VMAT2) with these observed effects was discussed. (c) 2008 Elsevier B.V. All rights reserved.

Epidemiology and control of frontier malaria in Brazil: lessons from community-based studies in rural Amazonia

We describe the epidemiology of malaria in a frontier agricultural settlement in Brazilian Amazonia. We analysed the incidence of slide-confirmed symptomatic infections diagnosed between 2001 and 2006 in a cohort of 531 individuals (2281.53 person-years of follow-up) and parasite prevalence data derived from four cross-sectional surveys. Overall, the incidence rates of Plasmodium vivax and P. falciparaum were 20.6/100 and 6.8/100 person-years at risk, respectively, with a marked decline in the incidence of both species (81.4 and 56.8%, respectively) observed between 2001 and 2006. PCR revealed 5.4-fold more infections than conventional microscopy in population-wide cross-sectional surveys carried out between 2004 and 2006 (average prevalence, 11.3 vs. 2.0%). Only 27.2% of PCR-positive (but 73.3% of slide-positive) individuals had symptoms when enrolled, indicating that asymptomatic carriage of low-grade parasitaemias is a common phenomenon in frontier settlements. A circular cluster comprising 22.3% of the households, all situated in the area of most recent occupation, comprised 69.1% of all malaria infections diagnosed during the follow-up, with malaria incidence decreasing exponentially with distance from the cluster centre. By targeting one-quarter of the households, with selective indoor spraying or other house-protection measures, malaria incidence could be reduced by more than two-thirds in this community. (C) 2010 Royal Society of Tropical Medicine and Hygiene. Published by Elsevier Ltd. All rights reserved.

TL dosimetry of natural quartz sensitized by heat-treatment and high dose irradiation

The aim of this paper is to report the sensitization of the TL peak appearing at 270 degrees C in the glow curve of natural quartz by using the combined effect of heat-treatments and irradiation with high gamma doses. For this, thirty discs with 6 x 1 mm(2) were prepared from plates parallell to a rhombolledral crystal face. The specimens were separated into four lots according to its TL read out between 160 and 320 degrees C. One lot was submitted to gamma doses of Co-60 radiation starting at 2 kGy and going up until a cumulative dose of 25 kGy. The other three lots were initially heal-treated at 500, 800 and 1000 degrees C and then irradiated with a single dose of 25kGy. The TL response of each lot was determined as a function of test-doses ranging from 0.1 to 30 mGy. As a result, it was observed that heat-treatments themselves did not produce the strong peak at 270 degrees C that was observed after the administration of high gamma doses. This peak is associated with the optical absorption band appearing at 470 rim which is due to the formation of [AlO4]degrees acting as electron-hole recombination centers. The formation of the 270 degrees C peak was preliminary analyzed in relation to aluminum- and oxygen-vacancy-related centers found in crystalline quartz. (C) 2008 Elsevier Ltd. All rights reserved.

Influence of pre-heat treatment and different light-curing units on Vickers hardness of a microhybrid composite resin

The aim of this study was to evaluate the hardness of a dental composite resin submitted to temperature changes before photo-activation with two light-curing unite (LCUs). Five samples (4 mm in diameter and 2 mm in thickness) for each group were made with pre-cure temperatures of 37, 54, and 60A degrees C. The samples were photo-activated with a conventional quartz-tungsten-halogen (QTH) and blue LED LCUs during 40 s. The hardness Vickers test (VHN) was performed on the top and bottom surfaces of the samples. According to the interaction between light-curing unit and different pre-heating temperatures of composite resin, only the light-curing unit provided influences on the mean values of initial Vickers hardness. The light-curing unit based on blue LED showed hardness mean values more homogeneous between the top and bottom surfaces. The hardness mean values were not statistically significant difference for the pre-cure temperature used. According to these results, the pre-heating of the composite resin provide no influence on Vickers hardness mean values, however the blue LED showed a cure more homogeneous than QTH LCU.