Upotreba živinih mjernih uređaja u zdravstvenim ustanovama u Hrvatskoj

In 2009, we conducted a survey to assess the use of mercury-based thermometers and sphygmomanometers and their disposal in Croatian healthcare facilities. The questionnaire addressing the use of mercury-based medical devices, waste management, preferences between mercury-based and electronic devices, and the knowledge on mercury toxicity was filled by ward nurses affiliated with 40 (71.4 %) out of 56 contacted healthcare facilities. Only one of these facilities had given up the use of mercury-containing medical devices at the time. As many as 84.6 % of the nurses believed that broken devices did not increase the risk of mercury exposure, even though 90 % claimed they were aware of mercury toxicity. In fact, 69.4 % of the nurses preferred mercury-containing devices on account of their precision and reliability and because they received little training in the use of electronic devices. Breaking of thermometers and sphygmomanometers is common in healthcare facilities. The number of broken thermometers and sphygmomanometers was estimated to 278 and fi ve per month, respectively. Only 18 (46.2 %) of the surveyed healthcare facilities claimed to have had a proper disposal procedure for mercury from broken devices. Nurses, who most often handle these devices and collect mercury spills, are primarily exposed to mercury vapours via inhalation. Croatia has adopted the EU Directive 76/769/EEC intended to reduce mercury exposure in the living and working environment. Our survey suggests that all healthcare professionals need training in proper management of broken mercury-based medical devices, nurses in particular. To reduce the risk of exposure, all Croatian healthcare facilities should implement guidelines for staff protection and programmes to gradually replace mercury-based with electronic devices.Živa je štetni čimbenik izravno povezan s provođenjem zdravstvene zaštite. Tijekom 2009. provedeno je istraživanje u zdravstvenim ustanovama RH, s ciljem procjene uporabe živinih mjernih instrumenata, toplomjera i tlakomjera te načina odlaganja razbijenih uređaja. Upitnik o uporabi živinih uređaja, zbrinjavanju otpada, sklonostima uporabi živinih, odnosno elektroničkih mjernih uređaja te pitanja o poznavanju toksičnosti žive, ispunile su odjelne medicinske sestre iz 40 (71,4 %) od 56 zdravstvenih ustanova. Samo u jednoj ustanovi živini se mjerni uređaji uopće ne rabe. Čak 84,6 % ispitanica smatra da nisu dodatno izložene živi iz razbijenih uređaja, iako je 90 % svjesno toksičnosti Hg. Zbog njihove preciznosti, pouzdanosti i nedostatka edukacije o uporabi i održavanju elektroničkih uređaja prednost uporabi živinih uređaja daje 69,4 % medicinskih sestara. Razbijanje toplomjera i tlakomjera čest je incident u zdravstvenim ustanovama. Procijenjeni broj mjesečno razbijenih toplomjera bio je do 278, a razbijenih tlakomjera do 5. U samo 18 (46,2 %) ustanova pravilno se odlagala živa iz razbijenih uređaja. Medicinske sestre koje najčešće rukuju uređajima i prikupljaju živu najizloženije su živinim parama putem inhalacije. U Hrvatskoj su doneseni pravni akti s namjerom smanjenja prisutnosti žive u životnom i radnom okolišu. Time je stupila na snagu EU direktiva 76/769/EEZ-a o smanjenju proizvodnje i prometa uređaja koji ju sadržavaju. Rezultati upućuju na potrebu edukacije svih zdravstvenih radnika, posebno medicinskih sestara, o zbrinjavanju razbijenih živinih mjernih uređaja. Radi smanjenja potencijalne izloženosti i osiguranja boljih zdravstvenih uvjeta na radnome mjestu sve hrvatske zdravstvene ustanove trebaju provoditi smjernice za zaštitu radnika i programe za smanjenje uporabe žive uporabom zamjenskih toplomjera i tlakomjera dostupnih na tržištu

Robustness of Helicobacter pylori infection conferred by context-variable redundancy among cysteine-rich paralogs

Deletion of single genes from expanded gene families in bacterial genomes often does not elicit a phenotype thus implying redundancy or functional non-essentiality of paralogous genes. The molecular mechanisms that facilitate evolutionary maintenance of such paralogs despite selective pressures against redundancy remain mostly unexplored. Here, we investigate the evolutionary, genetic, and functional interaction between the Helicobacter pylori cysteine-rich paralogs hcpG and hcpC in the context of H. pylori infection of cultured mammalian cells. We find that in natural H. pylori populations both hcpG and hcpC are maintained by positive selection in a dual genetic relationship that switches from complete redundancy during early infection, whereby ΔhcpC or ΔhcpG mutants themselves show no growth defect but a significant growth defect is seen in the ΔhcpC,ΔhcpG double mutant, to quantitative redundancy during late infection wherein the growth defect of the ΔhcpC mutant is exacerbated in the ΔhcpC,ΔhcpG double mutant although the ΔhcpG mutant itself shows no defect. Moreover, during early infection both hcpG and hcpC are essential for optimal translocation of the H. pylori HspB/GroEL chaperone, but during middle-to-late infection hcpC alone is necessary and sufficient for HspB/GroEL translocation thereby revealing the lack of functional compensation among paralogs. We propose that evolution of context-dependent differences in the nature of genetic redundancy, and function, between hcpG and hcpC may facilitate their maintenance in H. pylori genomes, and confer robustness to H. pylori growth during infection of cultured mammalian cells