Mycorrhiza-induced differential response to a yellows disease in tomato

The protective effects induced by arbuscular mycorrhizal (AM) fungi against a phytoplasma of the Stolbur group have been investigated in tomato by morphometry and flow cytometry. Symptoms induced by the phytoplasma were less severe when the plants also harboured AM fungi. Morphological parameters such as shoot and root fresh weight, shoot height, internode length, leaf number and adventitious root diameter were closer to those of healthy plants when arbuscular mycorrhiza were present. Reduced nuclear senescence was observed in AM plants infected with phytoplasmas; the percentages of nuclear populations with different ploidy levels were intermediate between AM and phytoplasma-infected plants. The mechanisms underlying these interactions are discussed and a direct action of the AM fungus is hypothesized.     

Antitumor complexes of platinum with carrier molecules. 2 [1]. Mixed complexes of amino acids and tert-butylamine

In the search for a fine modulation of cisplatin analogues we have synthesized complexes with two different inert ligands bound to platinum in the cis- position. This paper reports on compounds of formula cis-[PtCl₂(aaH)(tba)] (aaH, amino acid; tba, tert-butylamine). These complexes have been synthesized with the aim of obtaining liposoluble cisplatin analogues bound to natural carrier groups. The derivatives of glycine, D-alanine, L-threonine, and L-serine were found to be moderately active against murine P388 and L1210 leukemia models. The compound K[PtCl₃(tba)] was also found to be active against the same tumor models. Their activity and potency was, however, much lower than that of cisplatin.     

Determination of superoxide dismutase-like activity of copper(II) complexes. Relevance of the speciation for the correct interpretation of in vitro O2 scavenger activity.

The superoxide dismutase activity of several copper(II) complexes of linear and cyclic dipeptides has been measured. The results of a classic indirect method (xanthine-xanthine oxidase) have been compared with those obtained by generation of the superoxide radical through 2-(-3-benzoylphenyl)propionic acid (ketoprofen) photolysis. A simulation approach, based on the knowledge of the stability constants of the different complex species existing in experimental conditions, has allowed us to obtain the correct speciation and to use these data to calculate the pertinent catalytic constants.     

The life history of Chirocephalus kerkyrensis Pesta (Crustacea: Anostraca) in temporary waters of Circeo National Park (Latium,Italy)

The life cycle of Chirocephalus kerkyrensis, a typicalspecies of the Mediterranean plain forest, was studied in thefield during 1990/91 and 1991/92.Temperature, and its variation, was the major factor affectinglife history. Marked, sudden temperature fluctuations resultedin depressed growth and longevity. Fertility was positivelycorrelated (P<0.001) with female body length. Nodecline in egg production was observed at the end of life, incontrast to other species. Hatching was observed after a longdrought followed by alternating wet and dry phases. Laboratorytests on hatching gave contrasting results and showed thatdrying is not obligatory. Cysts stored in 100% relativehumidity gave higher numbers of nauplii after a shorter timethan dried ones, at all temperatures tested.     

Circadian rhythms of blood clotting time and coagulation factors II, VII, IX and X in rats

The 24-hr variations in clotting times and vitamin K-dependent blood coagulation factors were studied in rats kept on a 12-hr light-dark cycle (light on: 0600-1800 hours). Clotting times were determined under a binocular microscope by measuring the time required for the formation of the first fibrin thread. Factors II, VII and X were analyzed by the prothrombin test while the factor IX was quantified using the activated partial thromboplastin time assay. Results indicated that the clotting times were significantly longer during the dark (activity) period with a peak at 1:00 and a trough at 17:00. Similarly, a variation was found in factor activity levels: prothrombin (II), factor VII and factor X had higher activities during the light span (rest period). The highest activities found at 13:00 and 09:00 were statistically different from the minimum activity levels obtained at 21:00. Factor IX did not show a significant circadian variation.     

Linkage disequilibrium between cystic fibrosis and linked DNA polymorphisms in Italian families: A collaborative study

The locus D7S23 includes a CpG-enriched methylation-free island that maps midway between the markers J3.11 and met and is genetically very close to the mutation causing cystic fibrosis (CF). We have studied the linkage disequilibrium between four polymorphic markers from this locus (KM.19, CS.7, XV-2c, and PT-3) and the CF mutation (CF) in 127 Italian families. Strong linkage disequilibrium is found between KM.19, CS.7, and CF, and weaker but significant disequilibrium is found between XV-2c, PT-3, and CF. The disequilibrium between markers and CF for the Italian population provides additional information on the origin and homogeneity of the CF defect. This panel of probes is sufficiently informative to permit accurate prenatal diagnosis of CF in most families with an affected person, and the disequilibrium also allows indirect carrier detection/exclusion in some cases.     

Phenotypic and functional analysis of lymphocytes infiltrating paediatric tumours,with a characterization of the tumour phenotype

Summary Tumour-infiltrating lymphocytes (TIL) of paediatric tumours obtained from 37 lesions of different histo-type (12 osteosarcomas, 5 Wilms' tumours, 7 soft-tissue sarcomas, 5 neuroblastomas and 8 miscellaneous) were studied to establish their potential for therapy. Fresh isolated TIL were cultured for the first 2 weeks with low doses of interleukin-2 (IL-2) (20 Cetus U/ml) to select for tumour-specific lymphocytes potentially present in the neoplastic lesion, followed by culture with high doses of IL-2 (1000 Cetus U/ml) to achieve TIL expansion. TIL were grown with more than 10-fold expansion in only 9 cases (mean expansion: 58-fold, range 13.5–346). In 17 cases no viable cells were obtained. After 30 days of culture with IL-2 the proliferative ability of TIL declined sharply in the majority of cases and TIL became refractory to any further stimulus, including addition of IL-4, tumour necrosis factor (TNF) or interferon , and activation with OKT3 in solid phase. In 20 out of 37 cases TIL were available for phenotypic and functional analysis. TIL after long-term culture were predominantly CD3⁺ but 2 cases of osteosarcoma showed a predominance of CD3⁺TcR / cells. The CD4/CD8 ratio was more than 1 in 10 cases, without correlation with tumour histology, site of lesion or TIL growth. The number of CD16⁺ and CD25⁺ lymphocytes decreased progressively during culture, the latter concomitantly with a reduction of TIL growth rate. The lytic pattern of TIL against allogeneic and autologous tumour (Auto-Tu) cells was variable, but specific lysis of Auto-Tu was seen in only one case (Wilms' tumour) after culture with TNF and irradiated Auto-Tu cells. The immunohistochemical analysis of tumour lesions revealed a limited lymphocyte infiltrate, a low expression of histocompatibility leukocyte antigens (HLA) class I and of the adhesion molecules ICAM1, LFA3, and a significant production of transforming growth factor (TGF). These data indicate that TIL obtained from paediatric patients are difficult to expand at levels required for immunotherapy and lack a significant number of tumour-specific T lymphocytes. A low expression of immunomodulatory molecules on tumour cells or the production of suppressive factors may prevent activation and expansion of TIL in paediatric tumours.