SELNET clinical practice guidelines for bone sarcoma.

Bone sarcoma are infrequent diseases, representing < 0.2% of all adult neoplasms. A multidisciplinary management within reference centers for sarcoma, with discussion of the diagnostic and therapeutic strategies within an expert multidisciplinary tumour board, is essential for these patients, given its heterogeneity and low frequency. This approach leads to an improvement in patient's outcome, as demonstrated in several studies. The Sarcoma European Latin-American Network (SELNET), aims to improve clinical outcome in sarcoma care, with a special focus in Latin-American countries. These Clinical Practice Guidelines (CPG) have been developed and agreed by a multidisciplinary expert group (including medical and radiation oncologist, surgical oncologist, orthopaedic surgeons, radiologist, pathologist, molecular biologist and representatives of patients advocacy groups) of the SELNET consortium, and are conceived to provide the standard approach to diagnosis, treatment and follow-up of bone sarcoma patients in the Latin-American context.

First Report of Potato Spindle Tuber Viroid in Costa Rica.

During 1997 to 1998, symptoms of leaf roll, dwarfism, chlorosis, and occasional leaf necrosis were observed on Solanum tuberosum in several plots in Cartago, the principal potato-production region of Costa Rica. Because of the known association between potato leafroll virus (PLRV) and viroids (1) and previous reports of PLRV in Costa Rica, the presence of potato spindle tuber viroid (PSTVd) was suspected. Leaf samples from 122 symptomatic potato plants, cvs. Atzimba, Floresta, Idiafrit, and Birris, were collected from 10 plots. Total nucleic acids (TNAs) were extracted and purified (2) from collected symptomatic samples and six healthy potato controls. TNAs were spotted on nylon membranes and hybridized to a digoxigenin-labeled DNA probe specific for PSTVd. Of 122 symptomatic plants, 71 were positive for PSTVd based on dot blot hybridization. TNAs from 12 positive potato samples, including at least 1 sample from each cultivar, were used to inoculate Lycopersicum esculentum cv. Super Marmande. Eleven of twelve inoculated tomato plants showed symptoms of dwarfism, leaf deformation, and grayish foliage, often with a dull surface. TNAs were extracted from inoculated tomato and hybridized to the PSTVd probe. All inoculated symptomatic plants were positive for PSTVd based on dot blot hybridization. This is the first report of PSTVd in Costa Rica. References: (1) M. Querci et al. J. Gen. Virol. 78:1207, 1997. (2) W. Villalobos et al. Rev. Biol. Trop. 45:983, 1997.

PCR-RFLP identification of endemic Chilean species of Rhagoletis (Diptera: Tephritidae) attacking Solanaceae.

Four species of the genus Rhagoletis are native to Chile: R. nova (Schiner), R. conversa, (Brèthes), R. penela Foote and R. tomatis Foote. Currently, identification of these species is based on morphological criteria, but their strong similarity makes precise recognition difficult. To clarify species separation for quarantine purposes, a reliable method based on a PCR-RFLP procedure is reported. A DNA region containing mitochondrial NADH dehydrogenase genes was selected as a target sequence for the analysis. The amplification products (c. 1 kb) were digested with either SspI or DdeI, yielding specific patterns that differentiated each of the endemic species. Complete nucleotide sequences were determined, confirming empirical restriction maps. This report updates information on the geographical distribution of Rhagoletis species in Chile.