Cultivar-related differences in the distribution of cell-wall-bound thionins in compatible and incompatible interactions between barley and powdery mildew

Leaf-specific thionins of barley (Hordeum vulgare L.) have been identified as a novel class of cell-wall proteins toxic to plant-pathogenic fungi and possibly involved in the defence mechanism of plants. The distribution of these polypeptides has been studied in the host-pathogen system of barley and Erisyphe graminis DC.f.sp. hordei Marchal (powdery mildew). Immunogold-labelling of thionins in several barley cultivars indicates that resistance or susceptibility may be attributed to the presence or absence of thionins at the penetration site in walls and papillae of epidermal leaf cells.All of the leaf-specific thionin genes are confined to the distal end of the short arm of chromosome 6 of barley. None of the genes for cultivarspecific resistance to powdery mildew which have previously been mapped on barley chromosomes are found close to this locus.     

On non-metric multidimensional scaling ordination and interpretation of the matorral vegetation in lowland Murcía

The plant-environment relationships in a range of matorral communities, having different rainfall conditions in semi-arid lowland habitats in Murcía, S.E. Spain, were examined using the non-metric multidimensional scaling ordination technique. Hypotheses on floristic variations were derived based on an interpretative strategy which involved a site configuration rotation, followed by stepwise multiple regression analysis. An environmental data set was used to isolate variables associated with site co-ordinate trends. Results showed that floristic variation in these communities was mainly determined by aspect induced radiation receipt. Besides, most environmental trends in the study areas were found to be oblique to original site ordination axes and configuration rotation seemed to be a prerequisite in quantitative interpretation. The interpretative strategy introduced in this study was effective. It enhanced straightforward, quantitative and objective interpretation whereby inductive inferences on environmental trends could be readily formulated.Abbreviations ARAD radiation receipt surrogate - DEPTH soil depth - DISTURB disturbance index - NMDS non-metric multidimensional scaling - NUT nutrient scalar - SLOPE slope angle - TEXTIN texture index     

Survey of allergic respiratory symptoms in grain terminal workers in the Port of Genoa

Summary Fifty workers from two grain elevator terminals were examined to evaluate the prevalence of respiratory symptoms and their relationship with grain dust exposure.Fifty per cent of subjects complained of respiratory symptoms (rhinitis, asthma, chronic cough and dyspnea on exertion). In 34% of the workers the ventilatory function revealed some abnormalities (slight or moderate obstruction).Twenty-two (44%) showed a positive cutaneous reaction to one or more of the allergens tested, mostly towardsDermatophagoides and storage mites. The self-measurement of PEF over 14 days in 27 workers, showed significant differences between symptomatic and asymptomatic subjects. In particular, the results obtained from the cutaneous reactions could suggest a bronchial hypereactivity, worsened by the working exposure to dusts. The monitoring of PEF appears to be a simple and useful method for investigating the relationship between respiratory symptoms and the working environment.     

The picoplankton in Antarctic lakes of northern Victoria Land during summer 1989–1990

Summary Photoautotrophic picoplankton is reported from some lakes located near the Italian Antarctic station of Terra Nova. Observations, carried out by both flow cytometry on water samples and electron microscopy on micro-organisms in cultures from each lake, have confirmed the occurrence in all the environments studied of this fraction accounting, in several cases, for more than the 50% of the phytoplankton, measured as chlorophyll. Cultures of the picoplankton fraction from these waters contained known prokaryotic (Synechococcus) and eukaryotic (Chlorella) genera as well as two unidentified entities, possibly prochlorophytes.     

Direct modulation of insulin receptor protein tyrosine kinase by vanadate and anti-insulin receptor monoclonal antibodies

Sodium vanadate activates "in vitro" insulin receptor autophosphorylation and protein tyrosine kinase in a dose-dependent manner. Insulin receptor protein tyrosine kinase is directly activated also by the anti-insulin receptor beta subunit monoclonal antibody 18-44. We previously demonstrated that the anti-insulin receptor monoclonal antibody MA-10 decreases insulin-stimulated receptor protein tyrosine kinase activity "in vitro", without inhibiting insulin receptor binding. In this report we show that insulin receptor protein tyrosine kinase, activated by sodium vanadate or by monoclonal antibody 18-44, is inhibited by MA-10 antibody. These data suggest that insulin receptor protein tyrosine kinase activity can be either activated and inhibited through mechanisms different from insulin binding.     

IL-6 stimulates osteoclast-like multinucleated cell formation in long term human marrow cultures by inducing IL-1 release

IL-6 enhances the differentiation of pluripotent hematopoietic stem cells but predominantly affects the differentiation of hematopoietic cells in the granulocyte-macrophage lineage. We have previously shown that multinucleated cells (MNC) with many features of the osteoclast phenotype form in long term human marrow cultures. Addition of rhIL-6 (10 to 100 pg/ml) to these cultures significantly increased MNC formation, with greater than 80% of the MNC expressing an Ag that cross-reacts with the mAb 23c6. This antibody preferentially binds to osteoclasts. rhIL-6 did not enhance MNC formation in marrow cultures treated with 1,25 dihydroxyvitamin D3, a potent stimulator of MNC formation, but significantly increased the percentage of MNC that cross-reacted with the 23c6 mAb. Addition of antihuman IL-1 to cultures treated with rhIL-6 totally inhibited the increase in MNC formation stimulated by rhIL-6. In contrast, anti-IL-1 did not affect MNC formation stimulated by 1,25 dihydroxyvitamin D3. Further, conditioned media from marrow cultures exposed to rhIL-6 contained elevated levels of IL-1 beta (500 pg/ml compared to 23 pg/ml in control cultures 15 h after IL-6 addition). These results suggest that the capacity of rhIL-6 to stimulate formation of MNC which cross-react with 23c6 is mediated by induction of release of IL-1 beta.     

A large deletion in the LDL receptor gene--the cause of familial hypercholesterolemia in three Italian families: a study that dates back to the 17th century (FH-Pavia).

In the LDL-receptor gene, a large rearrangement causing hypercholesterolemia was detected in three apparently unrelated families living in northern Italy. In all probands, binding, internalization, and degradation of 125I-LDL measured in skin fibroblasts were found to be 40%-50% of control values, indicative of heterozygous familial hypercholesterolemia (FH). Southern blot analysis revealed that the probands were heterozygous for a large (25-kb) deletion of the LDL-receptor gene eliminating exons 2-12. The affected subjects possessed two LDL-receptor mRNA species: one of normal size (5.3 kb) and one of smaller size (3.5 kb). In the latter mRNA, the coding sequence of exon 1 is joined to the coding sequence of exon 13, causing a change in the reading frame and thereby giving rise to a premature stop codon. The receptor protein deduced from the sequence of the defective mRNA is a short polypeptide of 29 amino acids, devoid of any function. Tracing these three families back to the 17th century, we found both their common ancestor and the possible origin of the mutation, in a region which is called "Lomellina" and which is located in southwest Lombardy, near the old city of Pavia. Therefore we named the mutation "FH-Pavia."     

Minor pollinosis fromCryptomeria japonica in Varese,northern Italy. Aerobiological monitoring and main clinical features

In the last 2 years we have conducted an aerobiological monitoring program ofCryptomeria japonica, a plant belonging to the family of Taxodiaceae that sometimes causes pollinosis in the period from February to April. Throughout 1994, we checked the incidence of its sensitization and the clinical effects in 85 subjects with correlated seasonal symptoms, who gave a positive skin prick test (SPT) for Betulaceae and/or Corylaceae. Twenty-five patients (29.4%; 19 M; 6 F; mean age, 38.8 years) all with oculorhinitis, were SPT positive to an allergenic extract ofCryptomeria. RAST confirmed this positivity in 44% of the cases. No patients showed monosensitization forCryptomeria to either SPT or RAST. Two subjects gave a positive result on specific nasal provocation. RAST inhibition showed no cross-reaction betweenCryptomeria and birch pollen. During the pollen season each patient made a list, scoring symptoms and specifying any drugs used, so we could correlate these elements with aerobiological observations. The pollen concentration probably exceeded the allergizing threshold forCryptomeria on 8 days during 3 months of recording. The intensity and duration of symptoms seemed to be mainly influenced by sensitization to Betulaceae and Corylaceae. It is thus possible that a combination of minor pollinosis may produce seasonal symptoms in allergic patients.