Mapping of a restriction fragment length polymorphism within the human aldolase B gene

Summary Peripheral blood DNA was hybridized to the full-length cDNA and the cloned structural gene of human aldolase B. With PvuII endonuclease a restriction fragment length polymorphism was detected that was present in the heterozygous state in about 21% of the individuals tested. A map of the human aldolase gene was constructed for the two groups of individuals found to produce different fragments after PvuII digestion. This allowed the localization of the polymorphic site within the gene, which was found to be due to the loss of a PvuII site in the last intron upstream from the 3 end. This polymorphism may be used as a genetic marker to study individuals affected by hereditary fructose intolerance.     

Maintenance of photosynthesis at low leaf water potential in wheat : role of potassium status and irrigation history

The interaction of low water potential effects on photosynthesis, and leaf K⁺ levels in wheat (Triticum aestivum L.) plants was studied. Plants were grown at three K⁺ fertilization levels; 0.2, 2, and 6 millimolar. With well watered plants, 2 millimolar K⁺ supported maximal photosynthetic rates; 0.2 millimolar K⁺ was inhibitory, and 6 millimolar K⁺ was superoptimal (i.e. rates were no greater than at 2 millimolar K⁺). Photosynthesis was monitored at high (930 parts per million) and low (330 parts per million) external CO₂ throughout a series of water stress cycles. Plants subjected to one stress cycle were considered nonacclimated; plants subjected to two successive cycles were considered acclimated during the second cycle. Sensitivity of photosynthesis to declining leaf water potential was affected by K⁺ status; 6 millimolar K⁺ plants were less sensitive, and 0.2 millimolar K⁺ plants were more sensitive than 2 millimolar K⁺ plants to declining water potential. This occurred with nonacclimated and acclimated plants at both high and low assay CO₂. It was concluded that the K⁺ effect on photosynthesis under stress was not mediated by treatment effects on stomatal resistance. Differences between the K⁺ treatments were much less pronounced, however, when photosynthesis of nonacclimated and acclimated plants was plotted at a function of declining relative water content during the stress cycles. These results suggest that K⁺ effects on the relationship between relative water content and water potential in stressed plants was primarily responsible for the bulk of the K⁺-protective effect on photosynthesis in stressed plants. In vitro experiments with chloroplasts and protoplasts isolated from 2 millimolar K⁺ and 6 millimolar K⁺ plants indicated that upon dehydration, K⁺ efflux from the chloroplast stroma into the cytoplasm is less pronounced in 6 millimolar K⁺ protoplasts.     

Effects of cyclopiazonic acid and aflatoxin singly and in combination on selected clinical,pathological and immunological responses of guinea pigs

Cyclopiazonic acid (CPA) and aflatoxin are known sometimes to coexist in nature but little is known of possible biological interaction in mammals that consume mixtures of these two mycotoxins. Guinea pigs were dosed orally with CPA (2.2 mg/kg) or aflatoxin (0.045 mg B₁/kg) singly or in combination. Effects of toxin consumption were determined on clinical health, body weight gain, pathological change, and several immunologically related parameters including delayed cutaneous hypersensitivity, antibody response, complement hemolytic titer, intracutaneous mitogen (PHA) and in vitro lymphocyte blastogenesis. In contrast to an earlier study by others, significant synergy between these two toxins was demonstrated in reduced rate of body weight gain, lethality and histologic changes (vacuolization) in hepatocytes. Reductions in complement titer, intradermal PHA, delayed cutaneous hypersensitivity response and in vitro lymphocyte blastogenesis were related to aflatoxin activity. No effects on antibody formation to Brucella abortus were observed with either toxin or the combination of toxins. Cyclopiazonic acid appeared to restore the suppressive effects of aflatoxin in delayed cutaneous hypersensitivity response and in vitro lymphocyte blastogenesis.     

Altered growth factor sensitivity in EL2 rat fibroblasts: influence of this biological characteristic on cell growth

Extensive evidence indicate that platelet-derived growth factor (PDGF) and epidermal growth factor (EGF) play a key role in the stimulation of the 3T3 fibroblast replication: in this connection, PDGF and EGF act as a competence and a progression factor, respectively. We have previously demonstrated that EGF alone leads density-arrested EL2 rat fibroblasts to synthesize DNA and proliferate in serum-free cultures. Here, we have analyzed the role of EGF in the control of EL2 cell proliferation. Our data show a dose-related effect of EGF on DNA synthesis and cell growth, with maximal stimulation for both parameters at 20 ng/ml. On the other hand, autocrine production of PDGF or PDGF-like substances by EL2 cells is seemingly excluded by experiments with anti-PDGF serum or medium conditioned by EL2 fibroblasts. EGF binding studies show that EL2 cells possess high affinity EGF receptors, at a density level 3 to 4-fold higher than other fibroblastic lines. In addition, EL2 cells show a normal down-regulation of EGF receptors, following exposure to EGF, but PDGF, fibroblast growth factor (FGF), transforming growth factor beta (TGF beta) and bombesin have not decreased the affinity of EGF receptor for its ligand. Moreover, in EL2 cells, the EGF is able to induce the synthesis of putative intracellular regulatory proteins that govern the PDGF-induced competence in 3T3 cells. Our data indicate that EGF in EL2 cells may act as both a competence and a progression factor, via induction of the mechanisms, regulated in other cell lines by cooperation between different growth factors.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pericentric inversion of chromosome 19 in three families

Summary Pericentric inversion of chromosome 19 has been found in several members of three unrelated families from a restricted geographical region. In one of the families, an additional pericentric inversion of chromosome 9 was observed. Reproductive problems, multiple abortions in two families and a neonatal death in the third, were present. A review of previously described cases is included, and the genetic risk connected with this type of rearrangement is also discussed.     

Secreted proteins induced by epidermal growth factor and transforming growth factor beta in EL2 rat fibroblasts. Role in the mitogenic response

Most growth active hormones and peptides are mitogenic only in the presence of other growth factors [e.g., Platelet Derived Growth Factor (PDGF) and Epidermal Growth Factor (EGF) in "competence-progression" fibroblast model]. We have previously described that EGF alone is able to induce the signals which appear necessary for the mitogenic stimulation of EL2 rat embryo fibroblast line. Recently, we have demonstrated that Transforming Growth Factor beta (TGF beta) slightly stimulates the mitogenic response in EL2 cells. Here, we show that in EGF-treated EL2 cells the induction of at least four inducible-secreted proteins (ISPs, range from 29,000 to 68,000 Mr) is accompanied by a marked increase in DNA synthesis. In contrast, TGF beta or different concentrations of EGF induce a slow increase of the ISPs proportional to slow induction in DNA synthesis. Our results suggest that the mitogenic response in EL2 cell line may be connected with the qualitative and quantitative induction of these secreted proteins.     

Applications of artificial ionization

Summary The effects of positive and negative ions on man and on animals have been widely studied by numerous teams of researchers. It is well-known that negative ions have beeeficial effects on chronic and allergy-related bronchopathies in man; they stimulate the activity of the endocrine glands and psychomotor, muscular and cerebral functions. They have a beneficial effect on general circulation, and in particular on the microcirculatory system, such that they are suggested for use in prophylaxis and prevention of senescence, in acute, chronic and allergy-related pneumopathies, and in neuro-vegetative dystonia. The use of artificial negative ion producers may be a useful tool for both preventive and therapeutic purposes, as well as hygienic/domestic applications. Systematic measurements ere taken of negative ions artificially produced in a confined space. The spatial distribution of artificially-produced negative ions in a confined space is presented. Applications relative to artificial generators are also suggested in order to obtain repeatable experimental conditions.     

Diffusione pollinica e caratteristiche immunologiche e broncoreattive di soggetti atopici in Pietra Ligure (Savona)

Riassunto Sono state rilevate durante un monitoraggio aerobiologico effettuato a Pietra Ligure (Savona) nel corso del 1987 le concentrazioni polliniche di 50 taxa ed è stata valutata l'influenza relativa dei fattori meteorologici. Le osservazioni palinologiche sono state rapportate alle concentrazioni sieriche delle IgE specifiche, alla reattività bronchiale specifica ed aspecifica valutate in 101 pazienti allergici (rinitici ed asmatici), sensibilizzati a Graminaceae ed Urticaceae (Parietaria) al fine di riconoscere correlazioni tra le caratteristiche aerobiologiche di questi allergeni edi meccanismi patogenetici che sostengono la reattività bronchiale.      

The Salmonella wien virulence plasmid pZM3 carries Tn1935, a multiresistance transposon containing a composite IS1936-kanamycin resistance element

Tn1935, a 23.5-kb transposon mediating resistance to ampicillin, kanamycin, mercury, spectinomycin, and sulfonamide was isolated from pZM3, an IncFIme virulence plasmid from Salmonella wien. Tn1935 possesses the entire sequence of Tn21 and contains two additional DNA segments of 0.95 and 2.7 kb carrying the ampicillin and kanamycin resistance genes, respectively. The latter is part of a composite element since it is flanked by two IS15-like insertion sequences (IS1936) in direct orientation. IS1936 is about 800 bp long and is closely related to IS15 delta, IS26, IS46, IS140, and IS176. Functional analysis of IS1936-mediated cointegrates shows that both insertion sequences are active and able to form cointegrates at the same frequency. Resolution of the cointegrates requires the presence of the host Rec system. The presence of the composite IS1936-element within Tn1935 supports the hypothesis that multidrug resistance transposons evolved by insertion of antibiotic determinants which are themselves transposable.     

Development of tool use in a macaque and a gorilla

The development of the capacity to use a stick as a tool was tested in a macaque (Macaca fuscata) and a gorilla (Gorilla gorilla gorilla) infants that had previously shown to be able to use strings and supports as dragging tools. Subjects were tested between 15 and 38 months of age. Different levels of competence between the subjects emerged over testing. The macaque developed a stereotyped strategy to cope with the problem, only getting random successes, whilst the gorilla developed a flexible strategy and revealed to be able to mentally represent the solution of the problem. In fact, when not successful using the stick, the gorilla thought out an alternative strategy, choosing and adapting a new object to use it as a tool.