Suggestion of a national diagnostic reference level for 18F-FDG/PET scans in adult cancer patients in Brazil

Objective To suggest a national value for the diagnostic reference level (DRL) in terms of activity in MBq.kg–1, for nuclear medicine procedures with fluorodeoxyglucose (18F-FDG) in whole body positron emission tomography (PET) scans of adult patients. Materials and Methods A survey on values of 18F-FDG activity administered in Brazilian clinics was undertaken by means of a questionnaire including questions about number and manufacturer of the installed equipment, model and detector type. The suggested DRL value was based on the calculation of the third quartile of the activity values distribution reported by the clinics. Results Among the surveyed Brazilian clinics, 58% responded completely or partially the questionnaire; and the results demonstrated variation of up to 100% in the reported radiopharmaceutical activity. The suggested DRL for 18F-FDG/PET activity was 5.54 MBq.kg–1 (0.149 mCi.kg–1). Conclusion The present study has demonstrated the lack of standardization in administered radiopharmaceutical activities for PET procedures in Brazil, corroborating the necessity of an official DRL value to be adopted in the country. The suggested DLR value demonstrates that there is room for optimization of the procedures and 18F-FDG/PET activities administered in Brazilian clinics to reduce the doses delivered to patients. It is important to highlight that this value should be continually revised and optimized at least every five years.

Computed tomography-guided percutaneous trephine removal of the nidus in osteoid osteoma patients: experience of a single center in Brazil

AbstractObjective:To report the results of computed tomography (CT)-guided percutaneous resection of the nidus in 18 cases of osteoid osteoma.Materials and Methods:The medical records of 18 cases of osteoid osteoma in children, adolescents and young adults, who underwent CT-guided removal of the nidus between November, 2004 and March, 2009 were reviewed retrospectively for demographic data, lesion site, clinical outcome and complications after procedure.Results:Clinical follow-up was available for all cases at a median of 29 months (range 6–60 months). No persistence of pre-procedural pain was noted on 17 patients. Only one patient experienced recurrence of symptoms 12 months after percutaneous resection, and was successfully retreated by the same technique, resulting in a secondary success rate of 18/18 (100%).Conclusion:CT-guided removal or destruction of the nidus is a safe and effective alternative to surgical resection of the osteoid osteoma nidus.

Chemical composition and antibacterial activities from the essential oils of myrtaceae species planted in Brazil

The essential oils of seven Myrtaceae species were investigated for its chemical composition and antibacterial activity. The volatile oils were characterized by a high content of monoterpenoids of which 1,8-cineole (88.0, 65.0 and 77.0% for Melaleuca hypericifolia, Callistemon viminalis and Callistemon citrinus respectively), terpinen-4-ol (47.0 and 49.8% for Melaleuca thymifolia and Callistemon polandii respectively) and α-pinene (54.5% for Kunzea ericoides) were the major components. The oil from M. linariifolia was characterized by a high concentration of methyleugenol (87.2%). The oil from Melaleuca thymifolia was the most active, exhibiting high antimicrobial activity against all tested bacteria.

Inhalable particulate matter characterization in a medium-sized urban region in Brazil (São José dos Campos Town) - Part I: Morphology

In this study, the concentration and morphological characteristics of inhalable particulate material (PM10) were evaluated and associated with climatic conditions. The mean annual concentration was 11.0 µg m−3, varying between 0,647 µg m−3 and 36.8 µg m−3. Wind speed has a higher influence on PM10 dispersion, but direction was associated with particle source. During the wet period, wind speed is the main dispersion factor, while speed and direction both are important during the dry period. Based on the morphological characteristics, it is concluded that biogenic particles prevail during the rainy season and terrigenous particles during the dry period, depending on the wind direction and intensity.

Variability in isolates of Puccinia polysora in Brazil

The main objective of this work was to evaluate the variability of the southern rust pathogen Puccinia polysora in Brazil, based on its virulence on a set of maize (Zea mays) cultivars. Sixty single pustule isolates, from different areas of occurrence of southern rust, were evaluated for their virulence to 50 maize experimental hybrids. Six cultivars showed a clear distinction between susceptible and resistant reaction, and were used to characterize the variability of the pathogen. Seventeen virulence patterns were identified among the 60 isolates tested. The most frequent virulence patterns identified, were observed in all locations of sampling, which suggests the absence of geographical differentiation among prevalent populations of P. polysora in Brazil.

Progress of soybean charcoal rot under tillage and no-tillage systems in Brazil

The increase in incidence of charcoal rot caused by Macrophomina phaseolina on soybeans (Glycine max) was followed four seasons in conventional and no-till cropping systems. In the 1997/98 and 2000/01 seasons, total precipitation between sowing and harvest reached 876.3 and 846.9 mm, respectively. For these seasons, disease incidence did not differ significantly between the no-till and conventional systems. In 1998/99 and 1999/00 precipitation totaled 689.9 and 478.3 mm, respectively. In 1998/99, in the no-till system, the disease incidence was 43.7% and 53.1% in the conventional system. In 1999/00 the final incidence was 68.7% and 81.2% for the no-till and conventional systems, respectively. For these two seasons, precipitation was lower than that required for soybean crops (840 mm), and the averages of disease incidence were significantly higher in the conventional system. The concentration of microsclerotia in soil samples was higher in samples collected in conventional system at 0 - 10 cm depth. However, analysis of microsclerotia in roots showed that in years with adequate rain no difference was detected. In dry years, however, roots from plants developed under the conventional system had significantly more microsclerotia. Because of the wide host range of M. phaseolina and the long survival times of the microsclerotia, crop rotation would probably have little benefit in reducing charcoal rot. Under these study conditions it may be a better alternative to suppress charcoal rot by using the no-till cropping system to conserve soil moisture and reduce disease progress.

Identification of Rhizoctonia solani associated with soybean in Brazil by rDNA-ITS sequences

The aim of this study was to identify isolates of Rhizoctonia solani causing hypocotyl rot and foliar blight in soybean (Glycine max) in Brazil by the nucleotide sequences of ITS-5.8S regions of rDNA. The 5.8S rDNA gene sequence (155 bp) was highly conserved among all isolates but differences in length and nucleotide sequence of the ITS1 and ITS2 regions were observed between soybean isolates and AG testers. The similarity of the nucleotide sequence among AG-1 IA isolates, causing foliar blight, was 95.1-100% and 98.5-100% in the ITS1 and ITS2 regions, respectively. The nucleotide sequence similarity among subgroups IA, IB and IC ranged from 84.3 to 89% in ITS1 and from 93.3 to 95.6% in ITS2. Nucleotide sequence similarity of 99.1% and 99.3-100% for ITS1 and ITS2, respectively, was observed between AG-4 soybean isolates causing hypocotyl rots and the AG-4 HGI tester. The similarity of the nucleotide sequence of the ITS-5.8S rDNA region confirmed that the R. solani Brazilian isolates causing foliar blight are AG-1 IA and isolates causing hypocotyl rot symptoms are AG-4 HGI. The ITS-5.8S rDNA sequence was not determinant for the identification of the AG-2-2 IIIB R. solani soybean isolate.

Eryngium foetidum, Petroselinum crispum and Coriandrum sativum: new apiaceae hosts of Oidiopsis taurica in Brazil

Relata-se a infecção natural de plantas de chicória da Amazônia (Eryngium foetidum), coentro (Coriandrum sativum) e salsa (Petroselinum crispum), cultivados em casas de vegetação e campo na Embrapa Hortaliças, Brasília, DF, por Oidiopsis taurica. A provável fonte de inóculo foram plantas doentes de pimentão (Capsicum annuum) e tomate (Lycopersicon esculentum) na casa de vegetação e pimentão no campo.

Resistance spectra of wheat cultivars and virulence diversity of Magnaporthe grisea isolates in Brazil

Seventy-two monoconidial isolates of Magnaporthe grisea were obtained from the States of Mato Grosso do Sul and Paraná. The isolates were inoculated on seedlings of 20 wheat (Triticum aestivum) cultivars under greenhouse conditions. The virulence diversity of M. grisea was assessed based on compatible and incompatible reactions of leaf blast on wheat cultivars. Fifty-four distinct virulence patterns were identified on test cultivars among the isolates collected from the two wheat growing States. Sixteen of these isolates corresponding to 22.2% showed similar virulence pattern. None of the wheat cultivars was resistant to all isolates of M. grisea, but the cultivars differed in degree of resistance as measured by the relative spectrum of resistance (RSR) and disease index (DI). Among the cultivars the RSR ranged from 0 to 53.3% and DI from 0.4662 to 0.9662 (0 to 1 scale). The wheat cultivar BR18 exhibited a broad resistance spectrum in relation to the rest of the tested cultivars to the isolates of M. grisea, and can be used in wheat resistance breeding.

Bellulicauda dialii on Dialium guianense (Leguminosae) in Brazil

This is the first report of Bellulicauda dialii on Dialium guianense leaves, and the second record of this fungus, previously known only from Africa (Sierra Leone).

First report of black rot of Colocasia esculenta caused by Ceratocystis fimbriata in Brazil

Ceratocystis fimbriata was found sporulating in gray to black discolored areas on edible corms of Colocasia esculenta found in supermarkets in the states of São Paulo, Rio de Janeiro, Bahia, Rondônia and the Distrito Federal. In most cases the corms were grown in the state of São Paulo. The black rot appeared to occur post-harvest. Sequences of rDNA indicated that the Colocasia sp. isolates belong to the Latin American clade of the C. fimbriata complex, but the isolates were more aggressive than isolates from Ficus carica and Mangifera indica, in pseudopetioles of C. esculenta.