New live screening of plant-nematode interactions in the rhizosphere

Abstract Free living nematodes (FLN) are microscopic worms found in all soils. While many FLN species are beneficial to crops, some species cause significant damage by feeding on roots and vectoring viruses. With the planned legislative removal of traditionally used chemical treatments, identification of new ways to manage FLN populations has become a high priority. For this, more powerful screening systems are required to rapidly assess threats to crops and identify treatments efficiently. Here, we have developed new live assays for testing nematode responses to treatment by combining transparent soil microcosms, a new light sheet imaging technique termed Biospeckle Selective Plane Illumination Microscopy (BSPIM) for fast nematode detection, and Confocal Laser Scanning Microscopy for high resolution imaging. We show that BSPIM increased signal to noise ratios by up to 60 fold and allowed the automatic detection of FLN in transparent soil samples of 1.5 mL. Growing plant root systems were rapidly scanned for nematode abundance and activity, and FLN feeding behaviour and responses to chemical compounds observed in soil-like conditions. This approach could be used for direct monitoring of FLN activity either to develop new compounds that target economically damaging herbivorous nematodes or ensuring that beneficial species are not negatively impacted

In vitro evaluation of the antimicrobial activity of calcium hydroxide combined with chlorhexidine gel used as intracanal medicament

The aim of this study was to investigate the antimicrobial activity of calcium hydroxide (Ca(OH)(2)) combined with 2% chlorhexidine gluconate (CHX) gel against endodontic pathogens and to compare the results with the ones achieved by Ca(OH)(2) mixed with sterile water and by CHX gel alone. Two methods were used: the agar diffusion test and the direct contact test. Ca(OH)(2) + 2% CHX gel produced inhibitory zones ranging from 2.84 to 6.5 mm, and required from 30 seconds to 6 hours to eliminate all tested microorganisms. However, 2% CHX gel showed the largest microbial growth zones from 4.33 to 21.67 mm, and required I minute or less to inhibit all tested microorganisms. A paste of Ca(OH), plus sterile water inhibited only the microorganisms with which it was in direct contact and required from 30 seconds to 24 hours to kill all tested microorganisms. In conclusion, 2% CHX gel + Ca(OH)(2) showed better antimicrobial activity than Ca(OH)(2) manipulated with sterile water.102454455

Residual effects and surface alterations in disinfected gutta-percha and resilon cones

The aim of this study was to evaluate alterations on the surface of gutta-percha and Resilon cones whet posed to 2% chlorhexicline gel (CHX) and 5.25% sodium hypochlorite (NaOCI) and to evaluate their possible antibacterial residual effects against Enterococcus faecalis and Porphyromonas gingivalis. A total of 270 medium tapered cones (1135 gutta-percha and 135 Resilon) were selected and divided into three groups, according to the substance (NaOCI, CHX, and sterile saline solution). The cones were immersed in each substance (for 1, 5, 10, 20, and 30 min), rinsed in saline solution, and dried. They were placed onto inoculated agar plates and incubated under specific conditions. Scanning electron microscopy analysis was performed on additional 270 disinfected cones. Another 18 cones were used as controls. Based on the results, it was concluded that Resilon cones exposed to CHX for 10, 20, and 30 min demonstrated residual antibacterial action and that substances did not cause alterations to the cones' surface.33894895

Efficacy of various concentrations of NaOCl and instrumentation techniques in reducing Enterococcus faecalis within root canals and dentinal tubules

Aim To evaluate the efficacy of 0.5%, 2.5% and 5.25% sodium hypochlorite (NaOCl) as intracanal irrigants associated with hand and rotary instrumentation techniques against Enterococcus faecalis within root canals and dentinal tubules. Methodology A total of 180 extracted human premolar teeth were infected for 21 days with E. faecalis. The specimens were divided into 12 groups, as follows: group 1: 5.25% NaOCl + Hybrid technique (Valdrighi et al. 1998); group 2: 5.25% NaOCl + nickel-titanium (NiTi) rotary technique 4 mm shorter than the apex (by FOP-UNICAMP); group 3: 5, 25% NaOCl + NiTi rotary technique (Hero 642); group 4: 2.5% NaOCl +Hybrid technique; group 5: 2.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 6: 2.5% NaOCl + NiTi rotary technique (Hero 642); group 7: 0.5% NaOCl + Hybrid technique; group 8: 0.5% NaOCl + NiTi rotary technique 4 mm shorter than the apex; group 9: 0.5% NaOCl + NiTi rotary technique (Hero 642); group 10: sterile saline solution + Hybrid technique; group 11: sterile saline solution + NiTi rotary technique 4 mm shorter than the apex; group 12: sterile saline solution + NiTi rotary technique (Hero 642). Canals were sampled before and after preparation. After serial dilution, samples were plated onto brain heart infusion (BHI) agar, and the colony forming units (CFU) that were grown were counted. The teeth were sectioned into three thirds and dentine chips were removed from the canals with conical burs. The samples obtained with each bur were immediately collected into test tubes containing BHI broth, and were incubated at 37 degrees C and plated onto BHI agar. The CFU were counted and analysed. Results At all depths and thirds of the root canals and for all techniques used, 5.25% NaOCl was shown to be the most effective irrigant solution tested when dentinal tubules were analysed, followed by 2.5% NaOCl. No differences among concentrations in cleaning the canals were found. Conclusions Especially at higher concentrations, NaOCl, was able to disinfect the dentinal tubules, independent of the canal preparation technique used.391101

Alimentação nos primeiros três meses de vida dos bebês de uma coorte na cidade de Pelotas, Rio Grande do Sul Alimentación en los primeros tres meses de vida de los bebés de una coorte en la ciudad de Pelotas, Rio Grande do Sul (Brasil) Feeding during the first three months of life for infants of a cohort in Pelotas, Rio Grande do Sul, Brazil

OBJETIVO: Estudar o padrão alimentar nos primeiros três meses de vida de crianças nascidas na cidade de Pelotas (RS). MÉTODOS: Estudo de coorte prospectivo com os bebês nascidos entre setembro de 2002 e maio de 2003, na cidade de Pelotas (RS). Incluíram-se 2.741 bebês nas maternidades e uma amostra aleatória de 30% acompanhada no primeiro e terceiro meses de vida. Foram realizadas análises uni, bi e multivariada. Somente as variáveis com p<0,05 foram consideradas associadas ao desfecho de forma significante. RESULTADOS: Foram acompanhados 951 bebês no primeiro mês, dos quais 60% estavam em aleitamento materno exclusivo e 10% já estavam desmamados. As variáveis associadas ao desmame, neste período, foram: tabagismo na gravidez, escolaridade do pai inferior a quatro anos e uso de chupeta. No terceiro mês, 940 crianças foram acompanhadas: 29% haviam desmamado, 39% recebiam leite materno exclusivo e 59% utilizavam mamadeira. Tabagismo materno, escolaridade paterna e uso de chupeta, mantiveram-se associados ao desmame precoce. Houve aumento do uso de chupeta de 56 para 66% do primeiro para o terceiro mês, respectivamente. CONCLUSÕES: Comparado a estudos anteriores, evidenciou-se melhora nos índices de aleitamento materno, embora ainda inferiores aos valores ideais preconizados pela Organização Mundial de Saúde, o que ressalta a necessidade de estimulação à prática de aleitamento materno exclusivo no pré-natal e nos primeiros meses de vida.<br>OBJETIVO: Estudiar el estándar alimentar en los primeros tres meses de vida de niños nascidos en la ciudad de Pelotas (RS, Brasil). MÉTODOS: Estudio de coorte prospectivo con bebés nascidos entre septiembre de 2002 y mayo de 2003, en la ciudad de Pelotas (RS, Brasil). Se incluyó a 2.741 bebés en las maternidades y una muestra aleatoria de 30%, seguida en el primero y el tercero meses de vida. Se realizaron análisis uni, bi y multivariados, y solamente las variables con p<0,05 fueron consideradas asociadas al desfecho de modo estadísticamente significativo. RESULTADOS: Se siguió a 951 bebés el primer mes, de los que el 60% estaba en lactancia materna exclusiva y el 10% ya estaban desmamados. Las variables asociadas al destete en ese periodo fueron: tabaquismo en el embarazo, escolaridad del padre inferior a cuatro años y uso de chupete. En el tercer mes, 940 niños fueron seguidos: el 29% estaba desmamado, el 39% recibía leche materna exclusiva y el 59% usaba biberón. Tabaquismo materno, escolaridad paterna y uso de chupete se mantuvieron asociados al destete temprano. Hubo aumento del uso de chupete de 56 para 66% del primero para el tercer mes, respectivamente. CONCLUSIONES: Comparado a estudios anteriores, el presente estudio evidenció mejora en los índices de lactancia materna, aunque todavía inferiores a los valores ideales preconizados por la Organización Mundial de Salud, lo que pone de relieve la necesidad de estimulación práctica de lactancia materna exclusiva en el pre-natal y los primeros meses de vida.<br>OBJECTIVE: To study the feeding pattern in the first three months of babies born in the Pelotas city, in Sothern Brazil. METHODS: Prospective cohort study, with babies born between september 2002 and may 2003. Among 2,741 babies whose mothers were interviewed at the maternity ward, a random sample of 30% was followed up on the first and third months of age. Univariate, bivariate and multivariate analyses were applied. Variables with a p<0.05 were considered as associated. RESULTS: 951 babies were followed up on the first month, 60% were under exclusive maternal breastfeeding, and 10% were already weaned. Smoking during pregnancy, father's educational level lower than four years and the use of a pacifier were associated to weaning. On the third month, 29% had been weaned, 39% received maternal milk exclusively, and 59% were bottle fed. Smoking during pregnancy, father schooling and the use of a pacifier were associated with weaning. There was an increase in the pacifier use - from 56 to 66% between the first and the third month of life. CONCLUSIONS: When compared to previous studies, an improvement on the rates of breastfeeding was shown, though still lower than World Health Organization recommendations, which highlights the need for stimulation of exclusive breastfeeding during prenatal care and during the first months after birth