Responses of antioxidant systems after exposition to rare earths and their role in chilling stress in common duckweed (Lemna minor L.): a defensive weapon or a boomerang?

Extensive agriculture application of rare earth elements (REEs) in Far East countries might cause spreading of these metals in aquatic and terrestrial ecosystems, thus inducing a growing concern about their environmental impact. In this work the effects of a mix of different REE nitrate (RE) and of lanthanum nitrate (LA) on catalase and antioxidant systems involved in the ascorbate-glutathione cycle were investigated in common duckweed Lemna minor L. The results indicated that L. minor shows an overall good tolerance to the presence of REEs in the media. Treatments at concentrations up to 5 mM RE and 5 mM LA did not cause either visible symptoms on plants or significant effects on reactive oxygen species (ROS) production, chlorophyll content, and lipid peroxidation. Toxic effects were observed after 5 days of exposition to 10 mM RE and 10 mM LA. A remarkable increase in glutathione content as well as in enzymatic antioxidants was observed before the appearance of the stress symptoms in treated plants. Duckweed plants pretreated with RE and LA were also exposed to chilling stress to verify whether antioxidants variations induced by RE and LA improve plant resistance to the chilling stress. In pretreated plants, a decrease in ascorbate and glutathione redox state and in chlorophyll content and an increase in lipid peroxidation and ROS production levels were observed. The use of antioxidant levels as a stress marker for monitoring REE toxicity in aquatic ecosystems by means of common duckweed is discussed.

Production of strain specific antibodies against a synthetic polypeptide corresponding to the N-terminal region of the plum pox potyvirus coat protein.

Comparison of the predicted coat protein amino acid sequence of the 'sweet cherry' strain of plum pox potyvirus (PPV-SwC) with the corresponding regions of several other PPV strains indicated that the main differences are in the N-terminal region. Polyclonal antibodies were produced against a synthetic peptide corresponding to the 1-14 sequence of the N-terminal region of PPV-SwC coat protein. They specifically detected PPV-SwC in different immunochemical tests.

Characterization of the Sweet Cherry Isolate of Plum Pox Potyvirus.

An isolate of plum pox potyvirus from sweet cherry (PPV-SwC) in southern Italy was investigated. The isolate was mechanically or graft transmissible to different Prunus and Nicotiana spp. but not to Chenopodium spp. It was transmitted also by Aphis fabae and Myzus persicae in a nonpersistent manner. Restriction fragment length polymorphism analysis indicated and nucleotide sequencing confirmed that the isolate lacks AluI and RsaI sites in the C-terminal region of the coat protein (CP) gene. Western immunoblot results showed that the PPV-SwC CP has an electrophoretic mobility similar to that of strain PPV-D and faster than that of strain PPV-M. Double-antibody sandwich indirect enzyme-linked immunosorbent assay of the CP showed that PPV-SwC, although reacting with universal monoclonal antibodies to PPV, failed to react with antibodies specific to strains M and D. Results indicate that PPV-SwC is different from conventional strains of PPV but closely related to the sour cherry isolate of PPV from Moldova.

Comparison between peak expiratory flow rates (PEFR) and FEV1 in the monitoring of asthmatic subjects at an outpatient clinic.

Peak expiratory flow rate (PEFR) monitoring is often used alone in evaluating bronchial caliber and the response to a bronchodilator in the assessment of asthmatic subjects. A 15% change in airway caliber has been proposed as the criteria for modifying treatment. Our aim was to determine if changes in PEFR from one visit to the next can adequately evaluate changes in airway caliber as assessed by FEV1, which is considered the gold standard, and to identify the characteristics of subjects whose evaluations were inadequate. This was a retrospective study of 197 asthmatic subjects seen regularly at an outpatient clinic for whom FEV1 and PEFR assessments, prebronchodilator and postbronchodilator, were available for two visits. There was a high correlation between PEFR and FEV1 (in absolute value or percent predicted) (r = 0.83 and r = 0.75). However, 24 of 56 (43%) of those who had a change in FEV1 of 15% or more between two visits (mean change [%] +/- SD, range [best-lowest/best] = 20.9 +/- 5.1%, 15 to 36%) showed changes in PEFR of less than 15% (6.7 +/- 6.5%, 8.0 to 13.9%). On the other hand, 14 of 42 (33%) subjects with changes in FEV1 of less than 15% (9.8 +/- 3.2%, 1.1 to 13.8%) had changes in PEFR of 15% or more (22.2 +/- 10.9%, 16 to 35%). This discrepancy was not related to differences in baseline FEV1, control status, or the relationship between changes in FEV1 and PEFR in response to a bronchodilator. In conclusion, assessment of airway caliber through PEFR monitoring may not be valid in some asthmatic subjects and can often lead to underestimation or overestimation of changes in FEV1. None of the explanations considered made it possible to identify these subjects.

[The importance of esthetics in orthognathic surgery]. / L'importanza dell'estetica in chirurgia ortognatica.

The authors deal with an analytic method utilized in the diagnosis and treatment of dysmorphosis of the oral-maxillo-facial area. The aesthetic improvement that patients obtain as a result of surgical operation is also pointed out. An aesthetic improvement that offers the patient the conditions of a more comfortable social life. The psychological troubles which are a consequence of their outward appearance are also eliminated in this way.