I. The Terpene Marrubiin

The biosynthesis of the diterpene marrubiin has been studied using some labelled possible precursors: [2-14C] mevalonate, [1-14C] acetate, [2-14C] acetate, [2-14C] pyruvate, [2,3-14C] succinate, [1,4-14C] succinate, [5-14C] ketoglutarate and [1,5-14C] citrate. Metabolism times of 24, 36, 48, 72 and 96 hours were used. The labelled compounds were supplied in solution to flowering white horehound (Marrubium vulgare L.), cut at the base of the stem. The incorporation results indicate that marrubiin undergoes a rapid turnover with a biological half life of about 24 hours. The rate of up-take of 14C from the prcursors is in the following order: [2-14C] mevalonate, [2-14C] acetate, [1-14C] acetate, [2-14C] pyruvate and [2,3-14C] succinate. Incorporation of 14C from the other compounds is negligible. If [2-14C] mevalonate is used, labelled marrubiin is formed 10 - 100 times more active than with the other precursors. The results suggest that all the precursors are degradated to acetic units through the Krebs cycle before their utilization, with the exception of mevalonate. Some samples of marrubiin (I) have been degradated chemically to the corresponding ketoderivative (II), in order to determine the distribution of radioactivity between the decahydronaphthalenic and furanic parts. The results are in good agreement with the distribution of the radioactivity in the molecule, as expected from the terpenoid structure of marrubiin

Očna hipertonija i zamućenja leće u zdravstvenih radnika izloženih ionizirajućem zračenju

Some activities performed by healthcare workers may still involve total or partial exposure to ionising radiation exceeding the limit values. In addition to the appearance of crystalline lens opacities which may lead to rays-cataract, recent studies have indicated possible induction of ocular hypertonia in occupationally exposed subjects. The aim of this study was to establish the actual prevalence of ocular hypertonia and crystalline lens opacities in a group of healthcare workers exposed to ionising radiation. The collected data failed to show significant risk of ocular hypertonia and suggested that crystalline lens opacity was not an important indicator of exposure. Notwithstanding, preventive and periodic (every 5 years) ophthalmologic control may prove helpful for medicolegal purposes. Namely, such control would record congenital crystalline lens opacities in many individuals and would thus rule out unjustified claims of occupational disease due to exposure to ionising radiation. Additionally, ophthalmologic control should focus on different and probably more important ocular risks for the radiologists such as the ocular fatigue resulting from a prolonged use of a video display terminal or other diagnostic screens or electrodiaphanoscopes.Neke od djelatnosti zdravstvenih radnika još uključuju rizik od potpune ili djelomične izloženosti ionizirajućem zračenju u razinama koje nadilaze granične vrijednosti. Osim različitih stupnjeva od zamućenja leće do katarakte, nova su istraživanja upozorila na mogućnost pojave očne hipertonije i zamućenja leće u profesionalno izloženih osoba. Cilj je ovoga istraživanja bio utvrditi pravu incidenciju očne hipertonije i zamućenja leće u zdravstvenih radnika koji su povremeno izloženi ionizirajućem zračenju. Rezultati pokazuju da nema značajnoga rizika od očne hipertonije u toj populaciji te upućuju na to da zamućenje leće nije značajan pokazatelj izloženosti ionizirajućem zračenju. Bez obzira na to, periodični i preventivni oftalmološki pregledi (svakih pet godina) mogli bi se pokazati korisnima u medicinskom i pravnom pogledu. Naime, ovakva bi kontrola mogla registrirati uro|ena zamućenja leće u mnogih pojedinaca, što bi isključilo mogućnost neopravdanih zahtjeva za odštetu za profesionalnu bolest zbog izloženosti ionizirajućem zračenju. Osim toga, oftalmološki bi pregledi trebali uzeti u obzir i druge, možda i važnije rizike za zdravlje oka u radiologa kao što je umor oka zbog dugotrajnog naprezanja pri uporabi videoterminala ili ostalih ekrana, odnosno elektrodijafanoskopa

Vrtlarski rad i izloženost teškim metalima u gradskom okružju

Urban soil may be a source of occupational exposure to various pollutants in gardening and land cultivation. This paper presents data of a one-year follow-up of lead, cadmium, nickel, chromium, and vanadium in the environment of the city of Bologna. Samples of soil and leaves were collected at three locations; gardens from the inner-city high-traffic area, parks in moderatetraffic area, and parks in suburban, low-traffic area. The top and deeper layers of soil and leaves were mainly polluted by lead at all locations, which corresponded to the traffic density. Personal samplers recorded greater concentrations of airborne metals than did the area samplers but the values kept below the threshold limit established by the American Conference of Governmental Industrial Hygienists for the working environment. Due to cumulative nature and interactive effects of toxic metals with other toxic and essential elements, long-term exposure to metals in the urban environment may be a health risk for occupationally exposed gardeners.Gradsko tlo može biti izvorom profesionalne izloženosti različitim onečišćivačima u vrtlara, uključujući otrovne teške metale koji se talože iz onečišćenog zraka na tlo i lišće. U radu su prikazani podaci jednogodišnjeg praćenja koncentracija olova, kadmija, niklja, kroma i vanadija u talijanskom gradu Bologni. Uzorci tla i lišća skupljani su na tri mjesta s različitom gustoćom prometa; u središtu grada s velikom gustoćom prometa, u parkovima s umjerenim prometom u okolišu i u prigradskim parkovima sa slabim prometom. Na svim lokacijama gornji i dublji slojevi tla bili su podjednako onečišćeni ponajprije olovom i to je bilo u svezi s prometnom gustoćom. Koncentracije metala u zraku utvr|ene u filtrima osobnih skupljača bile su više od koncentracija u skupljačima na tlu. Vrijednosti metala u zraku bile su niže od graničnih vrijednosti utvr|enih za radni okoliš od Američke konferencije vladinih industrijskih higijeničara (American Conference of Governmental Industrial Hygienists). Zaključeno je da vrtlari, u usporedbi s općim stanovništvom, i pri niskim razinama izloženosti u gradskom okolišu imaju povećan zdravstveni rizik za štetna djelovanja otrovnih metala i drugih onečišćivača okoliša zbog dugotrajne izloženosti u svezi s njihovim radom

I. The Terpene Marrubiin

The biosynthesis of the diterpene marrubiin has been studied using some labelled possible precursors: [2-14C] mevalonate, [1-14C] acetate, [2-14C] acetate, [2-14C] pyruvate, [2,3-14C] succinate, [1,4-14C] succinate, [5-14C] ketoglutarate and [1,5-14C] citrate. Metabolism times of 24, 36, 48, 72 and 96 hours were used. The labelled compounds were supplied in solution to flowering white horehound (Marrubium vulgare L.), cut at the base of the stem. The incorporation results indicate that marrubiin undergoes a rapid turnover with a biological half life of about 24 hours. The rate of up-take of 14C from the prcursors is in the following order: [2-14C] mevalonate, [2-14C] acetate, [1-14C] acetate, [2-14C] pyruvate and [2,3-14C] succinate. Incorporation of 14C from the other compounds is negligible. If [2-14C] mevalonate is used, labelled marrubiin is formed 10 - 100 times more active than with the other precursors. The results suggest that all the precursors are degradated to acetic units through the Krebs cycle before their utilization, with the exception of mevalonate. Some samples of marrubiin (I) have been degradated chemically to the corresponding ketoderivative (II), in order to determine the distribution of radioactivity between the decahydronaphthalenic and furanic parts. The results are in good agreement with the distribution of the radioactivity in the molecule, as expected from the terpenoid structure of marrubiin

Sanitary conditions in lecture-halls: microbial contamination and microclimatic parameters

The aim of the paper was to evaluate the hygiene conditions (microclimatic parameters, CO2 concentration and microbial contamination) in lecture-halls during the day. Classical plate counts and rapid ATP luminescent assay have been employed to determine the microbial contamination on surfaces and in air. Microclimatic parameters and CO2 concentration have been measured by appropriate instruments, before and after the teaching activities, and during the midday break, when done. The microclimatic conditions resulted satisfying during all day in some lecture-halls, but quite never in the comfort ranges in another one. The bacterial contamination in air was very low in any case; the hygienic conditions of the surfaces were optimal in the morning. The CO2 concentration was increasing, over the recommended limit, during the day in all the lecture-halls. The cleaning procedures were optimal; the same care was not always applied to ensure good microclimatic conditions. Many people intensively visit the lecture-halls for several hours per day; to maintain comfortable climatic conditions and acceptable hygiene levels is fundamental to avoid sanitary problems. The luminescent assay, rapid and in good accordance with the plate count, can be very useful to monitor the microbial contamination levels