In this study, cDNA-amplified fragment length polymorphism (cDNA-AFLP) analysis was employed to identify genes that exhibited a modulated expression following cadmium (Cd) treatment in Brassica juncea grown in hydroponic culture. Plants were treated for 6 h, 24 h, and 6 weeks with 10 microM Cd(NO3)2 and untreated 6-week-old plants were used as controls. Cd content was measured at these four time points. Long exposure to Cd affected root morphology: roots appeared thinner and sent out side roots. Seventy-three transcript-derived fragments were identified as Cd responsive. Fifty-two of them showed significant homology to genes with known or putative function, 10 transcript-derived fragments were homologous to uncharacterized genes, while 11 transcript-derived fragments did not show significant matches. The expression pattern of several of these genes was confirmed by northern blot analysis. Fifty-two genes of known or putative function were transcriptional factors, expression regulators, and stress responding and transport facilitation genes, as well as genes involved in cellular metabolism and organization and the photosynthetic process, suggesting that a multitude of processes are implicated in Cd stress response. The transcription of drought- and abscisic acid-responsive genes observed in this study also suggested that Cd imposes water stress and that abscisic acid may be involved in the Cd plant response.

No abstract

SUMMARY T‐cell cytokines play a crucial role in the pathogenesis and progression of rheumatoid arthritis (RA). Their detection in the joint, however, is impaired by the complex network present in the synovium. Although many synovial T cells show signs of previous activation, only a few express interleukin (IL)‐2 receptor, marker of recent activation. The aim of this study was to analyse the cytokine production by in vivo activated (IL‐2R +) T cells from RA at different stages of the disease. For this purpose, T cells were isolated from peripheral blood and synovial fluid of four patients with active RA, two at the onset of the disease, one in the early phase during treatment, one in long‐lasting chronic phase. One patient was studied at the onset of the disease and 52 months later. Cells were initially expanded with a low dose of IL‐2, cloned and analysed for cytokine production. The results showed a strong predominance of T helper (Th) 1 clones in the blood and a slight prevalence of Th0 clones in the joint of all the four patients. Interferon‐γ and IL‐2 production was higher in the long‐lasting RA, whereas IL‐4 synthesis was prevalent in early RA. Enrichment in IL‐10‐producing clones was present only in the joint of the untreated patients. The longitudinal study confirmed the differences in cytokine production between early and late phases of disease. These data confirm that RA is mainly a Th1‐driven condition. However, in vivo activated synovial T cells produce also Th2‐type anti‐inflammatory cytokines, such as IL‐4 and IL‐10. The synthesis of both cytokines is a feature of the very early phase of RA, although the selective recruitment of IL‐10‐producing T cells is quickly lost.

Human parvovirus B19 infection in adults shows some clinical features similar to those found in autoimmune connective tissue diseases. To better clarify the relationship between viral infection and autoimmunity, we have evaluated the ability of anti-parvovirus antibodies to specifically recognize autoantigens in ten patients with chronic symmetric arthritis resembling rheumatoid arthritis or with recurrent episodes of arthritis and cutaneous manifestations and persistence of specific IgM antibodies against B19 parvovirus. We synthetized a 24-amino acid immunodominant peptide corresponding to a part of the virus protein 1 and virus protein 2 overlapping region. The peptide has been used to test patients' sera at different time points with an enzyme-linked immunosorbent assay (ELISA) and to purify antivirus antibodies by affinity chromatography on a peptide-Sepharose column. Eluted immunoglobulins recognized the B19 peptide in both direct and competitive ELISA. Affinitypurified anti-parvovirus antibodies were then tested on a panel of autoantigens including human keratin, collagen type II, thyreoglobulin, single-strand (ss)DNA, cardiolipin and ribonucleoprotein antigen Sm. Eluted antibodies specifically recognized keratin, collagen type II, ssDNA and cardiolipin. Autoantibody activity was not detected in the immunoglobulin fraction after complete removal of anti-peptide antibodies and in antibodies eluted from normal donors. Epstein-Barr virus-transformed cell clones obtained from two subjects produced antibodies which simultaneously recognize the viral peptide and several autoantigens. To further confirm the role of the virus in inducing an autoantibody response, eight BALB/c mice were immunized with the viral peptide coupled to a carrier protein. Autoantibody activity against keratin, collagen II, cardiolipin and ssDNA was detected in six of the eight mice which developed a strong anti-virus response. Together, these data indicate that B19 parvovirus may be linked to the induction of an autoimmune response.

Human parvovirus B19 infection in adults shows some clinical features similar to those found in autoimmune connective tissue diseases. To better clarify the relationship between viral infection and autoimmunity, we have evaluated the ability of anti-parvovirus antibodies to specifically recognize autoantigens in ten patients with chronic symmetric arthritis resembling rheumatoid arthritis or with recurrent episodes of arthritis and cutaneous manifestations and persistence of specific IgM antibodies against B19 parvovirus. We synthetized a 24-amino acid immunodominant peptide corresponding to a part of the virus protein 1 and virus protein 2 overlapping region. The peptide has been used to test patients' sera at different time points with an enzyme-linked immunosorbent assay (ELISA) and to purify antivirus antibodies by affinity chromatography on a peptide-Sepharose column. Eluted immunoglobulins recognized the B19 peptide in both direct and competitive ELISA. Affinitypurified anti-parvovirus antibodies were then tested on a panel of autoantigens including human keratin, collagen type II, thyreoglobulin, single-strand (ss)DNA, cardiolipin and ribonucleoprotein antigen Sm. Eluted antibodies specifically recognized keratin, collagen type II, ssDNA and cardiolipin. Autoantibody activity was not detected in the immunoglobulin fraction after complete removal of anti-peptide antibodies and in antibodies eluted from normal donors. Epstein-Barr virus-transformed cell clones obtained from two subjects produced antibodies which simultaneously recognize the viral peptide and several autoantigens. To further confirm the role of the virus in inducing an autoantibody response, eight BALB/c mice were immunized with the viral peptide coupled to a carrier protein. Autoantibody activity against keratin, collagen II, cardiolipin and ssDNA was detected in six of the eight mice which developed a strong anti-virus response. Together, these data indicate that B19 parvovirus may be linked to the induction of an autoimmune response.

No abstract

In crop plants the shift from being annuals to perennials may allow future agricultural systems requiring less energy inputs. The practicability of this was tested for Solanum melongena. Leaf protoplasts of S. melongena (2n = 2x = 24) and one of the related arborescent species Solanum marginatum (2n = 2x = 24) were electrofused and fertile somatic hybrids with arborescent habit regenerated. The magnetic cell sorter (MACS) technique was used for the selection of heterokaryons. The hybrid nature of 18 regenerated plants was assessed on the banding patterns generated by inter-simple sequence repeat PCR. When taken to maturity in the greenhouse, hybrids grew more vigorously compared to the parental species. Their morphological traits were intermediate between those of S. melongena and S. marginatum. Hybrids flowered and produced an average of 85% stainable viable pollen and fertile fruits. The somatic hybrids were maintained in the greenhouse for more than 3 years and continued to produce flowers developing into two types of fruits with plentiful seeds. Fruits were either striated green containing non-germinable seeds or yellow with fully germinable seeds. Their S(1) progenies showed common features with S(0) hybrids, including fertility and arborescent habit. Cytologically, somatic hybrids exhibited the expected chromosome number of 2n = 4x = 48, while chromosome pairing during microsporogenesis was associated with a low frequency of intergenomic pairing. It is concluded that an arborescent perennial species has been obtained by somatic hybridization. The usefulness of this species per se or in eggplant breeding will depend not only on the transmission of the arborescent habit to cultivated eggplant varieties, but also on the variability that should be created from backcrossing the S. melongena + S. marginatum hybrids to S. melongena.

Six cases of mediastinal large B-cell lymphoma (MLCL) with sclerosis were analyzed for the presence and patterns of c-myc and bcl-2 loci rearrangements, and for the presence of Epstein-Barr virus DNA sequences by Southern blot hybridization, c-myc gene alterations were found in three of six cases. Two cases showed the presence of mutations or small rearrangements at the 3′ end of the first exon. The c-myc gene abnormalities found in these two cases are similar to those observed in the translocation 8;14 of the endemic Burkitt's lymphomas or in its variants t(2;8) and t(8;22). A third case showed a major rearrangement of c-myc gene, with truncation within its first intron, similar to those observed in sporadic Burkitt's and in acquired immunodeficiency- associated lymphomas. None of the cases displayed bcl-2 gene rearrangements or contained viral sequences. Our data suggest a possible role for a translocation-mediated c-myc activation in the pathogenesis of MLCL. Conversely, bcl-2 gene and Epstein-Barr virus do not appear to be involved in the pathogenesis of these peculiar lymphomas. The association between c-myc structural modifications and MLCL also seems to be of relevance in light of the peculiar tendency of this tumor to involve unusual extranodal site (eg, kidney), reminiscent of the spreading attitude of Burkitt's limphomas.