Approaches in injections for radicular pain: the transforaminal, epidural and transfacet approaches.

Spinal injections must be carried out adhering to very strict conditions. However, these procedures have almost come to be seen as everyday and may be practised under quite questionable conditions. The recent reports of new and extremely serious neurological complications have changed the attitudes of those making referrals as well as the attitudes of the interventional radiologists carrying out these procedures. The range of indications for transforaminal injections has shrunk in favour of epidural injections. Where the transforaminal approach is still used, the needle must be positioned extremely accurately. A prior radioopaque contrast medium injection is essential from a safety perspective. The transforaminal epidural injection via the transfacet approach looks to be a promising alternative that is strictly avascular.

Partial hybridization in wide crosses between cultivated sunflower and the perennial Helianthus species H. mollis and H. orgyalis.

To obtain introgressed sunflower lines with improved disease resistance, interspecific crosses were performed with foreign perennial species. We report on several unusual features displayed by these hybrid plants. The methods used to produce the kernels affected yield and genotypes of progeny. Phenotypic traits and DNA markers were investigated in 97 plants derived from cross-pollination between annual diploid cultivated sunflower (Helianthus annuus) and the perennial diploid species H. mollis or H. orgyalis, and the reverse reciprocal crosses. The level of hybridization in progeny was determined using RAPD and RFLP markers. Hybridization was performed by leaving embryos to develop normally on the head (classical crossing) or using embryo rescue. All observed plants derived from H. mollis were diploid (2n = 34). Phenotypes were predominantly similar to the female when cultivated sunflower was the female parent. Progeny from crosses using a wild species as the female parent resembled that parent. Thus, reciprocal crosses led to different progeny. F1 sister progeny shared different sets of molecular markers representing a few of those of the wild species used as the pollen donor. Our results indicate mechanisms leading to the unusual event of partial hybridization. Possible mechanisms behind these unusual events and their possible impact on evolution are discussed.

Occurrence of partial hybrids in wide crosses between sunflower ( Helianthus annuus) and perennial species H. mollisand H. orgyalis.

Hybridisation between the annual diploid sunflower ( Helianthus annuus)and the perennial diploid species Helianthus mollis and Helianthus orgyalis was obtained by means of a normal crossing procedure or embryo rescue. Hybridisation success was low. All plants examined cytologically appeared to be diploid. However, the phenotypes of these diploids were not intermediate between the parents and, despite great variation, they resembled the female parent-type predominantly. Thirty five percent of plants issued from sunflower pollinated with perennial Helianthus had a phenotype resembling the female sunflower parent. On average, only 5% of the minimum number of expected RAPD and RFLP bands from male parents were recovered in plants produced from mature seeds after pollination of sunflower by H. mollis. More hybrids were found among plants obtained from embryo rescue, with an average of 25% of the male parent bands recovered per plant. Analysis of individual plants indicated the occurrence of various levels of hybridisation. There was a significant positive correlation between the number of phenotype traits related to hybrid status and the number of bands derived from the male parent. A single hybrid plant might possibly represent the product of a 'normal' hybridisation event. The mechanisms behind these unusual events and the consequences for the breeder are discussed.

Microcallus formation from Hevea brasiliensis protoplasts isolated from embryogenic callus.

Conditions for successful culture of rubber tree (Hevea brasiliensis) protoplasts were investigated. Protoplasts, derived from embryogenic callus, regenerated cell walls then underwent division when embedded in alginate and cultivated on a modified Murashige and Sook medium (9 µM 2,4-dichlorophenoxyacetic acid, 0.6 M glucose, 0.93 µM kinetin, NH 4 (+) reduced by half) in the presence of nurse cells (tobacco feeder cell layer). The presence of nurse cells was essential to maintain viability and sustain protoplast division. Several parameters which influenced the plating efficiency were analysed, such as the density of feeder cells and the duration of contact of the feeder layer.