Role of entomopathogenic fungi in the control of Tetranychus evansi and Tetranychus urticae (Acari: Tetranychidae), pests of horticultural crops

The spider mites Tetranychus urticae Koch and Tetranychus evansi Baker and Pritchard are important pests of horticultural crops. They are infected by entomopathogenic fungi naturally or experimentally. Fungal pathogens known to cause high infection in spider mite populations belong to the order Entomophthorales and include Neozygites spp. Studies are being carried out to develop some of these fungi as mycoacaricides, as standalone control measures in an inundative strategy to replace the synthetic acaricides currently in use or as a component of integrated mite management. Although emphasis has been put on inundative releases, entomopathogenic fungi can also be used in classical, conservation and augmentative biological control. Permanent establishment of an exotic agent in a new area of introduction may be possible in the case of spider mites. Conservation biological control can be achieved by identifying strategies to promote any natural enemies already present within crop ecosystems, based on a thorough understanding of their biology, ecology and behaviour. Further research should focus on development of efficient mass production systems, formulation, and delivery systems of fungal pathogens.

Development and validation of HPLC method for imiquimod determination in skin penetration studies

A simple, rapid and sensitive analytical procedure for the measurement of imiquimod in skin samples after in vitro penetration studies has been developed and validated. In vitro penetration studies were carried out in Franz diffusion cells with porcine skin. Tape stripping technique was used to separate the stratum corneum (SC) from the viable epidermis and dermis. Imiquimod was extracted from skin samples using a 7:3 (v/v) methanol:acetate buffer (100 mm, pH 4.0) solution and ultrasonication. Imiquimod was analyzed by H-PLC using C(8) column and UV detection at 242 ran. The mobile phase used was acetonitrile:acetate buffer (pH 4.0, 100 mM):diethylamine (30:69.85:0.15, v/v) with flow rate 1 mL/min. Imiquimod eluted at 4.1 min and the running time was limited to 6.0 min. The procedure was linear across the following concentration ranges: 100-2500 ng/mL for both SC and tape-stripped skin and 20-800 ng/mL for receptor solution. Intra-day and inter-day accuracy and precision values were lower than 20% at the limit of quantitation. The recovery values ranged from 80 to 100%. The method is adequate to assay imiquimod from skin samples, enabling the determination of the cutaneous penetration profile of uniquimod by in vitro studies. Copyright (C) 2008 John Wiley & Sons, Ltd.

Genotoxic studies in hypertensive and normotensive rats treated with amiodarone

Amiodarone, a benzofuran derivative. is a very effective antiarrhythmic medication, but has potential to cause side effects. Although its cytotoxicity potential is very well-known, there are few reports about its genotoxicity effects. Since amiodarone has not been investigated in genotoxicity studies, and the spontaneously hypertensive rat (SHR) is a well-characterized model for hypertension, the aim of the present study was to perform cytogenetic analysis on chromosome aberrations in bone marrow cells of SHRs and normotensive Wistar-Kyoto rats (WKYs) that received oral amiodarone treatment for 4 weeks. Amiodarone activity was also monitored using electrocardiograms. The presence of bradycardia in amiodarone-treated rats confirmed that this drug was really active. Metaphase analysis on bone marrow cells showed that there were significant differences in total chromosomal damage and percentage abnormal metaphase between WKY and SHR negative controls. In the SHR negative control, the frequencies of basal chromosomal aberrations and abnormal metaphases were significantly higher (p < 0.05). There were high numbers of chromosomal aberrations in all amiodarone-treated groups, compared with negative controls. In amiodarone-treated groups, the most frequent chromosomal aberration was chromatid breaks. More chromosomal aberrations were found in WKYs that received amiodarone, with a statistically significant difference in comparison with negative controls (p < 0.05). However, in SHR rats there was no significant difference between the amiodarone and negative groups regarding chromosomal damage induction. These results showed that treatment with amiodarone was genotoxic in WKYs, but not in SHRs. Further studies are needed to confirm whether amiodarone is genotoxic or efficient and harmless, among humans undergoing therapy. (c) 2008 Published by Elsevier B.V.

Exploratory Approach to the use of Techniques of Regression Analysis and Pooled Analysis in Studies of Consumer Behavior

This paper is part of a large study to assess the adequacy of the use of multivariate statistical techniques in theses and dissertations of some higher education institutions in the area of marketing with theme of consumer behavior from 1997 to 2006. The regression and conjoint analysis are focused on in this paper, two techniques with great potential of use in marketing studies. The objective of this study was to analyze whether the employement of these techniques suits the needs of the research problem presented in as well as to evaluate the level of success in meeting their premisses. Overall, the results suggest the need for more involvement of researchers in the verification of all the theoretical precepts of application of the techniques classified in the category of investigation of dependence among variables.

In vitro antifungal drug susceptibilities of dermatophytes microconidia and arthroconidia

Objectives: Arthroconidia have been considered as the primary cause of infection by dermatophytes. However, the in vitro antifungal testing evaluates the responses mainly of microconidia or hyphae, and dermatophytes in vivo often produce arthroconidia, a cellular structure presumably more resistant to antifungals. The aim of this study was to compare the in vitro susceptibility of microconidia and arthroconidia of Trichophyton rubrum, Trichophyton tonsurans and Trichophyton equinum to griseofulvin, itraconazole, terbinafine, fluconazole, amphotericin B and hygromycin B. Methods: Microconidia and arthroconidia were produced in vitro, and their susceptibility to each drug was evaluated by assessing the CLSI M38-A broth microdilution method. Results: Arthroconidia of all strains analysed appeared to be more resistant to fluconazole, griseofulvin and itraconazole than microconidia. The MIC of terbinafine was the same for microconidia and arthroconidia for all strains, and the MIC of amphotericin B for microconidia and arthroconidia was the same for isolates of T. equinum and T. tonsurans, but differed for T. rubrum. Finally, the level of resistance of microconidia for all strains towards the antibiotic hygromycin B was from 25 to 400 mg/L. Conclusions: The difference in the susceptibility between microconidia and arthroconidia depends on the drug and on the strain, and may be one of the causes of therapeutic failure. Also, the level of resistance to the antibiotic hygromycin B presented by microconidia of these isolates will allow the use of hygromycin resistance as a dominant marker in fungal transformation procedures in future studies of gene function.

Total gastric transposition is better than partial gastric tube esophagoplasty for esophageal replacement in children

Whenever the surgeon uses the stomach as an esophageal substitute, either one of two techniques is generally performed: total gastric transposition or gastric tube esophagoplasty. No existing reports compare the complications associated with these two surgical procedures. The purpose of this study is to review the authors` experience with total gastric transposition and verify whether this technique is superior to gastric tube esophagoplasty in children by comparing the main complications with those reported in the publications of gastric tubes esophagoplasties in the English language literature published in the last 38 years. A total of 35 children underwent total gastric transposition according to the classical technique. Most of these patients (27, or 77.1%) had long gap esophageal atresia. The most frequently observed complications were compared to those reported in nine studies of gastric tube esophagoplasty comprising 184 patients. Mortality and graft failure rates were also compared. Seven patients (20.0%) presented with leaks, all of which closed spontaneously. Six children were reoperated, three experienced gastric outlet obstruction secondary to axial torsion of the stomach placed in the retrosternal space and the other three experienced delayed gastric emptying that required revision of the piloroplasty. There were two deaths (5.7%) and no graft failure. Strictures were observed in five patients (14.2%) and all of these were resolved with endoscopic dilatations. Six patients had diarrhea that spontaneously resolved. In the late follow-up period, all patients were on full feed and thriving well. The comparisons with gastric tube patients demonstrated that the total gastric transposition group presented with significantly less leaks and strictures (P = 0.0001 and 0.001, respectively). The incidence of death and graft failure was not statistically different. In conclusion, gastric transposition is as a simple technical procedure for esophageal replacement in children with satisfactory results, and is superior to gastric tube esophagoplasty.

Stereological and allometric studies on neurons and axo-dendritic synapses in the superior cervical ganglia of rats, capybaras and horses

The superior cervical ganglion (SCG) in mammals varies in structure according to developmental age, body size, gender, lateral asymmetry, the size and nuclear content of neurons and the complexity and synaptic coverage of their dendritic trees. In small and medium-sized mammals, neuron number and size increase from birth to adulthood and, in phylogenetic studies, vary with body size. However, recent studies on larger animals suggest that body weight does not, in general, accurately predict neuron number. We have applied design-based stereological tools at the light-microscopic level to assess the volumetric composition of ganglia and to estimate the numbers and sizes of neurons in SCGs from rats, capybaras and horses. Using transmission electron microscopy, we have obtained design-based estimates of the surface coverage of dendrites by postsynaptic apposition zones and model-based estimates of the numbers and sizes of synaptophysin-labelled axo-dendritic synaptic disks. Linear regression analysis of log-transformed data has been undertaken in order to establish the nature of the relationships between numbers and SCG volume (V(scg)). For SCGs (five per species), the allometric relationship for neuron number (N) is N=35,067xV (scg) (0.781) and that for synapses is N=20,095,000xV (scg) (1.328) , the former being a good predictor and the latter a poor predictor of synapse number. Our findings thus reveal the nature of SCG growth in terms of its main ingredients (neurons, neuropil, blood vessels) and show that larger mammals have SCG neurons exhibiting more complex arborizations and greater numbers of axo-dendritic synapses.

Alternative diagnostic diagrams and the `forgotten` population of weak line galaxies in the SDSS

A numerous population of weak line galaxies (WLGs) is often left out of statistical studies on emission-line galaxies (ELGs) due to the absence of an adequate classification scheme, since classical diagnostic diagrams, such as [O iii]/H beta versus [N ii]/H alpha (the BPT diagram), require the measurement of at least four emission lines. This paper aims to remedy this situation by transposing the usual divisory lines between star-forming (SF) galaxies and active galactic nuclei (AGN) hosts and between Seyferts and LINERs to diagrams that are more economical in terms of line quality requirements. By doing this, we rescue from the classification limbo a substantial number of sources and modify the global census of ELGs. More specifically, (1) we use the Sloan Digital Sky Survey Data Release 7 to constitute a suitable sample of 280 000 ELGs, one-third of which are WLGs. (2) Galaxies with strong emission lines are classified using the widely applied criteria of Kewley et al., Kauffmann et al. and Stasinska et al. to distinguish SF galaxies and AGN hosts and Kewley et al. to distinguish Seyferts from LINERs. (3) We transpose these classification schemes to alternative diagrams keeping [N ii]/H alpha as a horizontal axis, but replacing H beta by a stronger line (H alpha or [O ii]), or substituting the ionization-level sensitive [O iii]/H beta ratio with the equivalent width of H alpha (W(H alpha)). Optimized equations for the transposed divisory lines are provided. (4) We show that nothing significant is lost in the translation, but that the new diagrams allow one to classify up to 50 per cent more ELGs. (5) Introducing WLGs in the census of galaxies in the local Universe increases the proportion of metal-rich SF galaxies and especially LINERs. In the course of this analysis, we were led to make the following points. (i) The Kewley et al. BPT line for galaxy classification is generally ill-used. (ii) Replacing [O iii]/H beta by W(H alpha) in the classification introduces a change in the philosophy of the distinction between LINERs and Seyferts, but not in its results. Because the W(H alpha) versus [N ii]/H alpha diagram can be applied to the largest sample of ELGs without loss of discriminating power between Seyferts and LINERs, we recommend its use in further studies. (iii) The dichotomy between Seyferts and LINERs is washed out by WLGs in the BPT plane, but it subsists in other diagnostic diagrams. This suggests that the right wing in the BPT diagram is indeed populated by at least two classes, tentatively identified with bona fide AGN and `retired` galaxies that have stopped forming stars and are ionized by their old stellar populations.

In situ X-ray diffraction studies of phase transition in Pb1-x La x Zr0.40Ti0.60O3 ferroelectric ceramics

The temperature dependence of the crystalline structure and the lattice parameters of Pb1-xLaxZr0.40Ti0.60O3 ferroelectric ceramic system with 0.00 x 0.21 was determined. The samples with x 0.11 show a cubic-to-tetragonal phase transition at the maximum dielectric permittivity, Tmax. Above this amount and especially for the x = 0.12 sample, a spontaneous phase transition from a relaxor ferroelectric state (cubic phase) to a ferroelectric state (tetragonal phase) is observed upon cooling below the Tmax. Unlike what has been reported in other studies, the x = 0.13, 0.14, and 0.15 samples, which present a more pronounced relaxor behavior, also presents a spontaneous normal-to-relaxor transition, indicated by a cubic to tetragonal symmetry below the Tmax. The origin of this anomaly has been associated with an increase in the degree of tetragonality, confirmed by the measurements of the X-ray diffraction patterns. The differential thermal analysis (DSC) measurements also confirm the existence of these phase transitions.

Validation of an experimental polyurethane model for biomechanical studies on implant supported prosthesis - tension tests

OBJECTIVES: The complexity and heterogeneity of human bone, as well as ethical issues, frequently hinder the development of clinical trials. The purpose of this in vitro study was to determine the modulus of elasticity of a polyurethane isotropic experimental model via tension tests, comparing the results to those reported in the literature for mandibular bone, in order to validate the use of such a model in lieu of mandibular bone in biomechanical studies. MATERIAL AND METHODS: Forty-five polyurethane test specimens were divided into 3 groups of 15 specimens each, according to the ratio (A/B) of polyurethane reagents (PU-1: 1/0.5, PU-2: 1/1, PU-3: 1/1.5). RESULTS: Tension tests were performed in each experimental group and the modulus of elasticity values found were 192.98 MPa (SD=57.20) for PU-1, 347.90 MPa (SD=109.54) for PU-2 and 304.64 MPa (SD=25.48) for PU-3. CONCLUSION: The concentration of choice for building the experimental model was 1/1.

Validation of an experimental polyurethane model for biomechanical studies on implant-supported prosthesis: compression tests

OBJECTIVES: The complexity and heterogeneity of human bone, as well as ethical issues, most always hinder the performance of clinical trials. Thus, in vitro studies become an important source of information for the understanding of biomechanical events on implant-supported prostheses, although study results cannot be considered reliable unless validation studies are conducted. The purpose of this work was to validate an artificial experimental model based on its modulus of elasticity, to simulate the performance of human bone in vivo in biomechanical studies of implant-supported prostheses. MATERIAL AND METHODS: In this study, fast-curing polyurethane (F16 polyurethane, Axson) was used to build 40 specimens that were divided into five groups. The following reagent ratios (part A/part B) were used: Group A (0.5/1.0), Group B (0.8/1.0), Group C (1.0/1.0), Group D (1.2/1.0), and Group E (1.5/1.0). A universal testing machine (Kratos model K - 2000 MP) was used to measure modulus of elasticity values by compression. RESULTS: Mean modulus of elasticity values were: Group A - 389.72 MPa, Group B - 529.19 MPa, Group C - 571.11 MPa, Group D - 470.35 MPa, Group E - 437.36 MPa. CONCLUSION: The best mechanical characteristics and modulus of elasticity value comparable to that of human trabecular bone were obtained when A/B ratio was 1:1.

A retrospective study of Traumatic Dental Injuries in a Brazilian dental urgency service

Epidemiologic aspects of traumatic dental injuries (TDI) were evaluated in the permanent dentition in a sample of 847 patients treated at the Dental Urgency Service of the Dental School of the Federal University of Goiás, Brazil, between May 2000 and May 2008. The statistical treatment analyzed data from frequency distribution and chi-square test. The level of significance was set at 5% for all analyses. The results showed a higher incident among males (610; 72.01%) with mean age of 6-10 year-old. Uncomplicated crown fracture (without pulp exposure) (502; 26.95%), avulsion (341; 18.30%) and complicated crown fracture (with pulp exposure) (330; 17.71%) were the most prevalent TDI. The prevalence of trauma throughout the years showed proportionality, being observed a larger number of cases between July and September (249; 29.39%). The most affected teeth were the maxillary central incisors (65.65%), followed by the maxillary left lateral incisors (19.67%). In 311 participants (18.25%), only one tooth was involved, while in most patients (536; 81.75%), TDI occurred in more than one tooth. Significant proportion (82.27%) of traumatized teeth presented completely formed root apex. The main etiologic factors involved in TDI were falls (51.71%), traffic accidents (22.90%) and violence (5.67%). Based on the obtained data, it may be concluded that accurate policies of TDI prevention must be established, capable of stimulating the exposure of appropriate protocols for management of these lesions. The prevalence of TDI in Goiânia subpopulation is compared to the prevalence reported in epidemiological studies in others populations.

Risk indicators for aggressive periodontitis in an untreated isolated young population from Brazil

This study aimed to assess the prevalence of aggressive periodontitis (AgP), and to investigate the association between demographic, socioeconomic and behavioral risk indicators with AgP in an untreated and isolated young population in Southeastern Brazil. For this cross-sectional survey, 134 subjects aged 12-29 years were selected by a census. Of those eligible, 101 subjects received a full-mouth clinical examination, and were interviewed using a structured written questionnaire. Cases were defined as individuals with 4 or more teeth with attachment loss > 4 mm or > 5 mm in the age groups 12-19 and 20-29, respectively. Overall, 9.9% of the subjects presented AgP (10.3% of the 12-19-year-olds and 9.7% of the 20-29-year-olds). The only risk indicator significantly associated with AgP in this isolated population was a high proportion of sites (> 30%) presenting supragingival calculus [OR = 23.2]. Having experienced an urgency dental treatment was a protective factor for AgP [OR = 0.1]. The authors concluded that this isolated and untreated population from Brazil presented a high prevalence of AgP. Local plaque-retaining factors played a major role in the prevalence of AgP in this isolated population, and should be included in further studies evaluating this destructive periodontal disease form.

Comparison of radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa forel in two culture media

In vitro culture of the mutualistic fungus of leaf-cutting ants is troublesome due to its low growth rate, which leads to storage problems and contaminants accumulation. This paper aims at comparing the radial growth rate of the mutualistic fungus of Atta sexdens rubropilosa Forel in two different culture media (Pagnocca B and MEA LP). Although total MEA LP radial growth was greater all along the bioassay, no significant difference was detected between growth efficiencies of the two media. Previous evidences of low growth rate for this fungus were confirmed. Since these data cannot point greater efficiency of one culture medium over the other, MEA LP medium is indicated for in vitro studies with this mutualistic fungus due its simpler composition and translucent color, making the analysis easier.

Absorption of metals and characterization of chemical elements present in three species of Gracilaria (Gracilariaceae) Greville: a genus of economical importance

Gracilaria Greville is a genus of seaweed that is economically explored by the cosmetic, pharmaceutical and food industries. One of the biggest problems associated with growing Gracilaria is the discharge of heavy metals into the marine environment. The absorption of heavy metals was investigated with the macroalga Gracilaria tenuistipitata Zhang et Xia, cultivated in a medium containing copper (Cu) and cadmium (Cd). In biological samples, EC50 concentrations of 1 ppm for cadmium and 0.95 ppm for copper were used. These concentrations were based on seaweed growth curves obtained over a period of six days in previous studies. ICP-AES was used to determine the amount of metal that seaweeds absorbed during this period. G. tenuistipitata was able to bioaccumulate both metals, about 17% of copper and 9% of cadmium. Basal natural levels of Cu were found in control seaweeds and in G. tenuistipitata exposed to Cd. In addition, the repertoire of other important chemical elements, as well as their concentrations, was determined for G. tenuistipitata and two other important seaweeds, G. birdiae Plastino & Oliveira and G. domingensis (Kützing) Sonder ex Dickie, collected in natural environments on the Brazilian shore.