ON THE PLACEMENT OF APRON DOSEMETERS AND DOSE ASSESSMENT IN INTERVENTIONAL CARDIOLOGY PROCEDURES: PRELIMINARY RESULTS.

Personnel involved in interventional practices are likely to be exposed to higher radiation doses than other workers in the medical field. Personnel monitoring and radiation protection measures play a crucial role in keeping these doses below the limits. EURADOS (European Radiation Dosimetry Group) Working Group 12 performed a series of investigations showing how the complexity of the scattered field reaching the operators can influence the doses to the operators. The present work was aimed at determining the possible effects on the registered doses of the scattered field and the actual position of a dosemeter on apron. This study has been performed through Monte Carlo simulations and it was validated through measurements. It does not claim to identify the 'best' position for the dosemeter, but to assess the variability of its response, showing how a variability of the order of +/- 30% to 40 should be taken into account.

First results of an eye lens dosimetry survey in an interventional cardiology department.

The eye lens annual dose limit for exposed personnel to ionizing radiation has recently been revised by the ICRP--International Commission on Radiological Protection and the proposed new limit has been accepted by European legislation through the Council Directive 2013/59/EURATOM 2013. Among medical exposed personnel, the staff performing interventional cardiology are usually affected by relevant doses. For this reason a survey, employing dosemeters characterized in terms of H(p)(3), was performed in order to get the order of magnitude of the doses received by the eye lens, at least as a first guess.The survey showed that the annual dose limit can easily be reached if a proper radiation protection approach is not implemented.

Anaerobic yeast killer systems.

The influence of anaerobic conditions on the expression of the killer phenomenon of several yeast isolates belonging to recognized killer systems coded by different genetic determinants (Pichia spp., Kluyveromyces lactis, Saccharomyces cerevisiae) was studied. Anaerobiosis influenced the activity of killer toxins from some individual isolates of the genera Pichia and Saccharomyces on sensitive strains of P. anomala, K. lactis and Candida albicans. However, no influence was detectable on a S. cerevisiae sensitive isolate. Thus, anaerobic conditions seem to interfere more with the metabolic process of sensitive strains than with toxin production by killer yeasts. The selection of a panel of killer yeasts, able to display their activity against reference sensitive yeast isolates under anaerobic conditions in a medium that favored the growth of anaerobes, allowed the use of the killer system to type Bacteroides fragilis isolates for epidemiological purposes.

Differential toxinogenesis in the genus Pichia detected by an anti-yeast killer toxin monoclonal antibody.

The differential toxinogenesis of 25 isolates belonging to species of the potential yeast killer genus Pichia that were previously classified in the genus Hansenula was comparatively demonstrated by two serologic techniques (indirect immunofluorescence and double immunodiffusion) by using a monoclonal antibody against a yeast killer toxin produced by a selected strain of Pichia anomala (UCSC 25F). The killer phenotypes of the Pichia isolates were evaluated by their ability to kill each other. The results, although of insufficient taxonomic value for a reliable separation of either species or genera, attest to the genomic heterogeneity for the killer character in the genus Pichia as well as the presumptive dual killer/sensitive identity for each single isolate.

Detection by immunofluorescent anti-idiotypic antibodies of yeast killer toxin cell wall receptors of Candida albicans.

Yeast killer toxin cell wall receptors of Candida albicans were observed by indirect immunofluorescence using an affinity purified rabbit anti-idiotypic antiserum. The antiserum had been raised against a monoclonal antibody neutralizing the in vitro activity of a killer toxin produced by a selected strain of Hansenula anomala UCSC 25F. This simple procedure permitted the location of killer toxin cell wall receptors in various morphological phases of the yeast cells. The use of the indirect immunofluorescence technique with anti-idiotypic antibodies may have potential value in determining the occurrence of killer toxin receptors in other microbial systems.

[Allergic bronchopulmonary aspergillosis; an important cause of asthma sometimes ignored]. / Aspergillosi broncopolmonare allergica: un'importante causa di asma a volte ignorata.

The Authors describe a clinical case of allergic bronchopulmonary aspergillosis that remained unrecognized for a long time. The pathogenetic role of the environment, home climatology, and familiarity is considered. A possible therapeutic approach involving the use of associations of steroids and ketoconazole is also discussed. The Authors would like to draw the attention of physicians to forms of bronchial asthma with eosinophilia.

Production of yeast killer toxin in experimentally infected animals.

The ability of a killer yeast (Pichia anomala, UCSC 25F) to produce toxin in vivo was demonstrated, for the first time, in tissues of normal and immunosuppressed experimentally infected mice by means of a fluorescent antibody technique and a killer toxin specific monoclonal antibody. The possible significance of the findings is discussed.

Biotyping of bacterial isolates using the yeast killer system.

Forty-four presumptive killer yeasts were tested against bacterial isolates, including rapid-growing gram-positive and gram-negative bacteria, as well as slow-growing bacteria, such as the mycobacteria. A killer system, based on the patterns of bacterial susceptibility to the action of nine selected killer yeasts, was developed for epidemiological purposes. The killer system, previously standardized for yeasts and hyphomycetes, was adapted to the specific growth conditions of the bacterial isolates. The results obtained confirm that susceptibility to the yeast killer phenomenon is widespread among microorganisms unrelated to yeasts and that it could form the basis for a convenient and adaptable biotyping method in microbiological laboratories.

Yeast killer toxins and dimorphism.

The differential action of four selected yeast killer toxins on the mycelial and yeast forms of four isolates of the dimorphic fungus Sporothrix schenckii was comparatively evaluated. The results confirmed that the yeast killer phenomenon is present among hyphomycetes and yeasts and that both morphological forms of S. schenckii are susceptible to the action of the same yeast killer toxin. Quantitative differences in the response to the killer action of the mycelial and yeast forms in individual strains were also observed. To avoid retroconversion of the dimorphic forms, we used a modification of the conventional killer system.

Studies on the epidemiology of Aspergillus fumigatus infections in a university hospital.

The impact of the airborne opportunistic fungus pathogen, Aspergillus fumigatus in patients hospitalized at the university hospital of Parma, Italy, and its outpatients was investigated during a period of six months. Sputum and bronchial washings were collected from 986 patients. The 2,437 specimens were culturally examined for the presence of A. fumigatus regardless of the patient's clinical diagnosis. This fungus was isolated from 32 patients (3.2%). Subsequently, immunological tests for aspergillosis were performed on 22 of these culture-positive patients. Eight of these patients (36.4%) were serologically proven to be affected by aspergillosis. The 32 A. fumigatus isolates were epidemiologically investigated by the killer system to determine the mode of spread of these infections. Among the patients, fifteen different biotypes were differentiated, and their value in studying the epidemiology of aspergillosis in the hospital environment was investigated.