Pilot randomised experimental study evaluating isopropyl alcohol and UVC radiation in the disinfection of healthcare workers' smartphones

Smartphones in medical settings pose infection risks due to harbouring pathogenic bacteria. This pilot study assesses the effectiveness duration of sanitisation methods, focusing on 70% isopropyl alcohol wipes and UVC boxes, aiming to obtain preliminary data on the reduction in Total Bacterial Load 3 hours post-sanitisation. A randomised monocentric trial with two intervention arms (wipes and UVC boxes) was designed. As participants, healthcare workers from three wards at Fondazione Policlinico Universitario "A. Gemelli" IRCCS Hospital were recruited, stratified by ward, and block randomised within each ward to control confounders. Seventy-one healthcare workers, mostly nurses (62%) were included in the study. Initial bacterial load reduction was significant with both disinfection techniques, but after 3 hours both methods showed increased bacterial levels, with wipes displaying potentially higher residual efficacy (p=0.056). To adequately size a trial (89% power, significance level 0.05) for assessing the residual efficacy of alcohol-impregnated wipes compared to UVC boxes at 3 hours post-sanitisation, 503 professionals per group were required. This study highlights the necessity for guidelines on hospital smartphone sanitisation and educational initiatives for healthcare workers and patients. Further studies, adequately sized, are necessary to determine optimal sanitisation intervals and assess pathogen transmission risks.

Potential Use of a Combined Bacteriophage–Probiotic Sanitation System to Control Microbial Contamination and AMR in Healthcare Settings: A Pre-Post Intervention Study

Microbial contamination in the hospital environment is a major concern for public health, since it significantly contributes to the onset of healthcare-associated infections (HAIs), which are further complicated by the alarming level of antimicrobial resistance (AMR) of HAI-associated pathogens. Chemical disinfection to control bioburden has a temporary effect and can favor the selection of resistant pathogens, as observed during the COVID-19 pandemic. Instead, probiotic-based sanitation (probiotic cleaning hygiene system, PCHS) was reported to stably abate pathogens, AMR, and HAIs. PCHS action is not rapid nor specific, being based on competitive exclusion, but the addition of lytic bacteriophages that quickly and specifically kill selected bacteria was shown to improve PCHS effectiveness. This study aimed to investigate the effect of such combined probiotic–phage sanitation (PCHSφ) in two Italian hospitals, targeting staphylococcal contamination. The results showed that PCHSφ could provide a significantly higher removal of staphylococci, including resistant strains, compared with disinfectants (−76%, p < 0.05) and PCHS alone (−50%, p < 0.05). Extraordinary sporadic chlorine disinfection appeared compatible with PCHSφ, while frequent routine chlorine usage inactivated the probiotic/phage components, preventing PCHSφ action. The collected data highlight the potential of a biological sanitation for better control of the infectious risk in healthcare facilities, without worsening pollution and AMR concerns.

Persistent mullerian duct syndrome in a dog

INTRODUCTION

This case report describes a 14-year-old, male castrated York Shire Terrier, which was presented due to stranguria and tenesmus. An abdominal computed tomography (CT) scan raised a high suspicion of a persistent mullerian duct. During laparotomy structures were found that were suspected to be a persistent ovary and uterus. The abnormal uterus was filled with fluid and had a blind end on both sides. The abnormal structures were surgically removed and pathologically examined. Pathology confirmed a persistent mullerian duct. The patient recovered well from the surgery and was able to urinate spontaneously the same day and was discharged the next day.

Microbiological surveillance post-reprocessing of flexible endoscopes used in digestive endoscopy: a national study

INTRODUCTION

Microbiological surveillance of endoscopes is a safety measure for verifying the quality of reprocessing procedures and identifying contaminated devices, but duodenoscope-related outbreaks are still reported.

AIM

To assess the effectiveness of duodenoscope reprocessing procedures in Italy.

METHODS

Between December 2019 and April 2020, data obtained from microbiological surveillance post-reprocessing in 15 Italian endoscopy units were collected. Sampling was carried out after reprocessing or during storage in a cabinet. In keeping with international guidelines and the Italian position paper, the micro-organisms were classified as high-concern organisms (HCOs) and low-concern organisms (LCOs).

FINDINGS

In total, 144 samples were collected from 51 duodenoscopes. Of these, 36.81% were contaminated: 22.92% were contaminated with HCOs and 13.89% were contaminated with LCOs [2.08% with an LCO load of 11-100 colony-forming units (CFU)/device and 0.69% with an LCO load of >100 CFU/device]. The contamination rate was 27.5% in samples collected after reprocessing, 40% in samples collected during storage in a cabinet that was compliant with EN 16442:2015 (C-I), and 100% in samples collected during storage in a cabinet that was not compliant with EN 16442:2015 (NC-I). The respective HCO rates were 15.00%, 27.27% and 66.67%. Correlation between LCO contamination and storage time was demonstrated (Spearman's rho=0.3701; P=0.0026). The Olympus duodenoscope TJFQ180V demonstrated the lowest rate of contamination (29.82%), although the contamination rate was 100% for duodenoscopes stored in an NC-I cabinet.

CONCLUSION

Microbiological surveillance, along with strict adherence to reprocessing protocols, may help to detect endoscope contamination at an early stage, and reduce the risk of duodenoscope-associated infections.

From infections to preventive actions monitoring in health facilities: an experience on MDROs

 

Healthcare-Associated Infections (HAIs) and Antimicrobial Resistance (AMR) involve high costs both in health and economic terms for patients and health systems. Implementing Infection Prevention and Control (IPC) programs is critical to decrease infectious agents' transmission in healthcare settings. The aim of this study is to assess if the monitoring of Contact Precautions could decrease the incidence of Multi-Drug Resistant Organisms (MRDOs) infections. This pilot study was conducted in a teaching hospital in Rome. A checklist of 16 items was developed to assess the compliance to Contact Precautions in 11 hospital wards in which MRDOs were detected between November and December 2020. It was administered on-site both interviewing healthcare professionals and through direct observation. A paired t-test with α = 5% was used to compare the number of alert organisms in the first quarter of 2020 respect to the first quarter of 2021 before and after implementing the surveillance checklist. A total of 30 checklists were analyzed. The rate of compliance to Contact Precautions was high for the proper use of personal protective equipment (100%), the intensified room cleaning (100%) and the presence of isolation mark (100%), while it was low for the active screening of contacts (53%). Mean MDROs infections rate decreased from 4.94 to 4.37 for every 1000 hospitalization day, with an average decrease of 0.57. However, the paired t-test showed that there was no statistically significant difference between the mean number of MDROs infections before and after the implementation of the checklist (p > 0.05). Despite the good adherence to IPC program, the low infection rate decrease, is probably due to the impact of COVID-19 on the HAIs surveillance and prevention practices. Even if the check-list administration could be a useful tool to reduce MDROs infections, it should be associated to other prevention strategies during the COVID-19 pandemic in order to achieve a successful outcome.

Key messages

Preventing Healthcare-Associated Infections represents a priority public health challenge in order to improve patient safety and health system economic sustainability.

The COVID-19 pandemic has shown that healthcare facilities should enhance efforts in their IPC programs to reduce Healthcare-Associated Infections.

Media Fill Test for validation of non-radioactive kit for radiopharmaceutical preparations

INTRODUCTION

The administration of improperly prepared intravenous fluids might determine healthcare-associated infections. Quality and sterility assurance in radiopharmaceutical manufacturing products must be evaluated by media fill tests that simulate the performance of the aseptic manufacturing procedure. The aim of this study is to show a methodological modification of a specific step of media fill tests, giving an overview of economic and organizational advantages that it might bring.

MATERIALS AND METHODS

Media fill tests were conducted to ensure that they reproduce as strictly as possible the routine aseptic production process with all the critical steps described in the internal Standard Operating Procedures. We introduced an innovative modification in the step 1: instead of using a completely decayed 99Mo/99mTc generator, we used 99Mo/99mTc generator just before its disposal and eluting it with saline solution aspirated in an empty vacuum vial.

RESULTS

A total of 47 production runs were performed, and a total of 799 vials were tested for sterility. Thirteen nuclear medicine technicians were assessed. We found contamination in 1% of the total number of vials analyzed).

CONCLUSIONS

The modification proposed shows several advantages: reduction of the costs of the media fill tests, the possibility to manage these without referring to external services, and decreased injuries for technicians who perform the tests.

Effect of ClO2 on the distribution of Legionella pneumophila serogroups in a Teaching Hospital

The prevention of Legionella colonization of water systems is one of the goals of hospital management. Among chemical disinfection methods, chlorine dioxide (ClO2) has been largely used to control Legionella in water systems. We analysed the distribution of Legionella pneumophila serogroups (sg) and Legionella other spp before (PRE) and after (POST) installation of chlorine dioxide (ClO2) continuous disinfection systems in a Teaching Hospital in Rome.

According to the Italian National Guidelines, our surveillance plan involved a systematic sampling of the water system. The sampling was performed from Jan. 2010 to Dec. 2019. From 2011 to 2019, ClO2 continuous disinfection systems were installed in all hot water system of the hospital, and maintained at a concentration of 0.25 mg/l at the end point. The isolated strains of Legionella were first serotyped using a kit that identifies sg1, other species and that discriminate sg from 2 to 15.

1505 hot water samples were collected from the Hospital and analysed. 363 samples are PRE and 1142 are POST activation of ClO2. Only the 16.74% of monitored sampling points were colonized by Legionella during the study period. This percentage decrease from 31.40% of PRE samples, to 12.08% of POST samples (p ≤ 0.000). The sg isolated were: sg3 (60.31%), sg8 (17.12%), sg1 (16.73%), sg6 (1.95%) and other species (3.89%). Comparing the distribution of sg between the PRE and POST samples, the sg8 showed a high increase (+136.84%) and the sg3 a slight decrease (-17.94%). These variations were statistically significative.

The results showed a predominance of Legionella pneumophila sg3, compared to what was observed in a multicenter study conducted between different hospitals of various regions of Italy, where sg6 was the major isolate. The ClO2 affect the distribution of sg, in particular for sg8. This interesting result will be further investigated.

Key messages

Our data deriving from an environmental monitoring plan, show that the ClO2 affects the distribution of Legionella’s serogroups. The ClO2 reduces the percentage of samples colonized by Legionella. The ClO2 reduces the percentage of samples colonized by Legionella.

Monitoring of Particle Environmental Pollution and Fungal Isolations During Hospital Building-Work Activities in a Hematology Ward

Building-work activities could cause dust contamination and fungal spores' dissemination. A significant relationship was found between building-work activities and the incidence of invasive aspergillosis, in profoundly immunocompromised patients. Renovation-works activities were carried out by four building sites of the hematology ward in a Teaching Hospital without the interruption of clinical activities. These sites were monitored by environmental sampling to determine the particles and fungi count. Clinical surveillance was made using galactomannan antigen test as a proxy for invasive aspergillosis diagnosis. A definitive diagnosis of IA was confirmed by clinical and radiological features. The galactomannan antigen test showed no significant difference between presence (2,75%) and absence (5,03%) of renovation work activities (p=0,522). During the renovation activities, an increment of IA cases with respect to the control period was not recorded. The particle counts showed higher values of small and big-diameter particles before the renovation works if compared to the end of the activities. It was probably due to the containment measures implemented during and immediately after the final phases of the building site. The Fungi counts showed no significant differences between the phase before and after the renovation activities. Our findings show that is possible to perform renovation work, during clinical activities, by increasing clinical and environmental surveillance.

Biochemical and nutritional characteristics of buffalo meat and potential implications on human health for a personalized nutrition

The human consumption of food animal products is the main topic of an important debate among professionals in this sector: dietologists, dietitians and nutritional biologists. The red meat provides all the essential amino acids, bioavailable iron, zinc, calcium, lipids and B-group vitamins. A valid alternative to beef could be the buffalo meat. Italy is the largest European producer of buffalo meat and derivatives. The high nutritional characteristics of buffalo meat make it suitable to be included in the Mediterranean diet to customize it in relation to the needs and conditions of the population. Polyunsaturated/saturated fatty acids ratio can be influenced by diet, breed and type of breeding, but muscle tissue fat percentage is the main factor in determining a favorable fatty acid composition. This review focuses on the biochemical and nutritional characteristics of the buffalo meat (content of fats, cholesterol, amino acids, vitamins and minerals), explaining their variability depending on the different breeds, and the favorable implications on the human health. These results suggest that buffalo meat can be a healthier alternative to beef, not only for healthy people in particular physiological conditions (i.e. pregnancy), but also for persons at risk for cardiovascular and cerebrovascular diseases, thus achieving the goal of a personalized nutrition.

Environmental surveillance of Legionella spp. colonization in the water system of a large academic hospital: Analysis of the four-year results on the effectiveness of the chlorine dioxide disinfection method

The prevention of Legionella colonization of water systems is one of the goals of hospital management. Among chemical disinfection methods, chlorine dioxide (ClO₂) has been largely used to control Legionella spp. in water systems. We performed a retrospective study to analyse data deriving from the surveillance plan of the water system in a large academic hospital in Rome (Italy) during the period August 2011 and August 2018. We collected the data deriving from the routine water samples used to monitor Legionella spp. colonization. Data from the water samples collected from 163 selected sampling points (hot water tanks, the return loop and distal outlets) was analysed using a life table analysis in order to investigate the duration of the effectiveness of the ClO₂ method in eradicating Legionella spp. The colonization of the water sample by Legionella spp. was considered as the outcome. Our results show that in 81,59% of the sampling points Legionella spp. were never detected at four years of follow up. Chemical and physical characteristics of the water were also compared between the samples which were positive for Legionella spp. and those which were not. No association was found between these factors. The knowledge of the duration over time of the effectiveness of the ClO₂ disinfection method could support decision-making processes in the framework of Risk Management activities in hospitals. Future studies could also be conducted in hospitals to compare the long-term cost-effectiveness of different Legionella spp. colonization prevention methods.

[Resident physicians' participation to the activities of the hospital hygiene unit in a teaching hospital: a pilot study]

INTRODUCTION

The Hospital Hygiene Unit ensures hospital patient safety, through surveillance and control of environmental conditions of risk. In this context, resident physicians in Hygiene and Preventive Medicine of the Catholic University of the Sacred Heart (UCSC) are required to attend the unit to acquire professional skills, for two months (four weeks in the first year of residency and four weeks in the second year). In the initial phase of the rotation, residents are acquainted with the organization and assigned activities. Ongoing meetings with the tutor take place to verify the progress of activities in which they are involved; verification of acquired skills is performed at the end of the period of attendance. The aim of the study was to evaluate resident doctors' opinions about their training experience, in order to assess the perceived quality and pursue continuous improvement of the training program.

MATERIALS AND METHODS

A questionnaire was administered to resident physicians attending the first three years of residency; the survey consisted of 11 multiple choice questions on organization, attendance, training and overall satisfaction and 3 open-ended questions on strengths, weaknesses and proposals for improvement.

RESULTS

Fourteen of 15 residents (93.3%) completed the questionnaire: seven were male, five were first-year residents, five were second-year and four were third-year residents. Overall, 78% gave a positive assessment of the quality of training; in particular, 11 of 14 residents reported that the experience was very relevant to their training in Hygiene and Preventive Medicine. Responses regarding the training organization were also mostly positive (75%), as were those regarding attendance (57%) and overall satisfaction (67%). Fifty percent reported difficulties in combining this internship with the other activities planned with their tutor.

CONCLUSIONS

Positive opinions prevail in all areas of assessment, although there are some aspects that can be improved, including the possibility to extend the period of attendance. Overall, training activities at the Operative Unit of Hospital Hygiene are appreciated by resident physicians, who consider them an important opportunity for professional growth.

[Hygienic safety of infant milk powder formulas in hospital setting]

The authors present the results of a study whose aim was to assess the hygienic quality of powder and reconstituted milk for early childhood, in a University General Hospital in Rome, Italy. This procedure is an integral part of the systematic verification activities that the hospital Health Management department considers as a priority for patient safety. The absence of contamination in all tested samples confirms the suitability of adopted procedures to ensure a safe product, considering the increased vulnerability of newborns, especially if preterm.

Enterobacteriaceae Antibiotic Resistance in Ready-to-Eat Foods Collected from Hospital and Community Canteens: Analysis of Prevalence

Foodborne diseases and antibiotic resistance are serious widespread health problems in the contemporary world. In this study, we compared the microbiological quality of ready-to-eat (RTE) foods found in community canteens versus hospital canteens in Rome, Italy, focusing on detection and quantification of Enterobacteriaceae and the antibiotic resistance of these bacteria. Our findings show a remarkable difference in Enterobacteriaceae contamination between RTE foods distributed in community canteens (33.5% of samples) and those distributed in hospital canteens (5.3% of samples). This result highlights greater attention to good manufacturing practices and good hygiene practices by the food operators in hospitals compared with food operators in community canteens. As expected, a higher percentage of cold food samples (70.9%) than of hot food samples (10.8%) were positive for these bacteria. Excluding the intrinsic resistance of each bacterial strain, 92.3% of the isolated strains were resistant to at least one antibiotic, and about half of the isolated strains were classified as multidrug resistant. The prevalence of multidrug-resistant strains was 50% in the community samples and 33.3% in hospital canteens. Our results indicate that approximately 38% of RTE foods provided in community canteens is not compliant with microbiological food safety criteria and could be a special risk for consumers through spread of antibiotic-resistant strains. Hygienic processing and handling of foods is necessary for both hospital and community canteens.

Influence of treatment on the outcome of dogs with incompletely excised grade-2 mast cell tumors

INTRODUCTION

In this study we compared the outcomes of dogs with incompletely-excised grade-2 mast cell tumors (incompletely- excised grade-2 MCTs) either adjuvantly treated or not. Dogs with a grade-2 mast cell tumour (MCT) excised either incompletely or with narrow (.

[Comparison of conventional culture methods and quantitative real-time PCR methods for the detection of Legionella pneumophila in water samples in a large University teaching hospital in Rome, Italy]

The aims of this study were to identify the best threshold value for the real-time PCR method in detecting the presence of Legionella pneumophila in water samples, and to evaluate the prognostic significance of negative results obtained with the molecular method. From 2011 to 2014, 77 water samples were collected from hospital wards of a large University teaching hospital in Rome (Italy) and screened for L.pneumophila by the standard culture method and by real-time PCR. The high sensitivity and negative predictive value of real-time PCR make this method suitable as a quick screening tool to exclude the presence of L. pneumophila in water samples in the hospital setting.

Modulation of microRNA editing, expression and processing by ADAR2 deaminase in glioblastoma

BACKGROUND

ADAR enzymes convert adenosines to inosines within double-stranded RNAs, including microRNA (miRNA) precursors, with important consequences on miRNA retargeting and expression. ADAR2 activity is impaired in glioblastoma and its rescue has anti-tumoral effects. However, how ADAR2 activity may impact the miRNome and the progression of glioblastoma is not known.

RESULTS

By integrating deep-sequencing and array approaches with bioinformatics analyses and molecular studies, we show that ADAR2 is essential to edit a small number of mature miRNAs and to significantly modulate the expression of about 90 miRNAs in glioblastoma cells. Specifically, the rescue of ADAR2 activity in cancer cells recovers the edited miRNA population lost in glioblastoma cell lines and tissues, and rebalances expression of onco-miRNAs and tumor suppressor miRNAs to the levels observed in normal human brain. We report that the major effect of ADAR2 is to reduce the expression of a large number of miRNAs, most of which act as onco-miRNAs. ADAR2 can edit miR-222/221 and miR-21 precursors and decrease the expression of the corresponding mature onco-miRNAs in vivo and in vitro, with important effects on cell proliferation and migration.

CONCLUSIONS

Our findings disclose an additional layer of complexity in miRNome regulation and provide information to better understand the impact of ADAR2 editing enzyme in glioblastoma. We propose that ADAR2 is a key factor for maintaining edited-miRNA population and balancing the expression of several essential miRNAs involved in cancer.

[Vocational training in public health during medical school: a pilot study]

The need to integrate clinical and public health training of medical students is increasingly important. Future physicians need to be able to deal with new, complex and growing public health challenges.

MATERIALS AND METHODS

A literature search was performed through Pubmed to identify the conceptual reference framework. Meetings were carried out to identify the most appropriate modalities and priorities required for drafting the project, to identify the skills to be acquired by students, to decide on teaching formats and methods to assess student learning, to draw up the teaching schedule, to define the statistical methods to be used to assess student satisfaction, and to perform the statistical analysis of results. Training in hospital hygiene and environmental safety was carried out through presentation of a relevant case. After being divided into groups the students attended the three units (Environmental Microbiology, Environmental Xenobiotics, Genetic Epidemiology and Molecular Biology) of the Hygiene Section of a Public Health Institute. Training in Organization and Health Programming involved presentation of a set of indicators for the definition of objectives and assessment of health systems or services.

RESULTS

The literature search led to the identification of the relevant literature. With regard to student satisfaction, 96% of those who replied to the questionnaire gave an overall positive review of the training course (at least 3 on a scale from 1 to 5).

CONCLUSIONS

the overall high level of student satisfaction suggests that the proposed model may be exportable. Further developments will be the assessment of trends regarding functioning of the organizational model and perceived teaching quality.

Non-fermentative gram-negative bacteria in hospital tap water and water used for haemodialysis and bronchoscope flushing: prevalence and distribution of antibiotic resistant strains

This study provides a detailed description of the distribution of non-fermentative gram-negative bacteria (NFGNB) collected in water sources (tap water and water used for haemodialysis and bronchoscope flushing) from different wards of a tertiary care hospital. The aim is to identify risk practices for patients or to alert clinicians to the possible contamination of environment and medical devices. The resistance profile of NFGNB environmental isolates has shown that more than half (55.56%) of the strains isolated were resistant to one or more antibiotics tested in different antimicrobial categories. In particular, 38.89% of these strains were multidrug resistant (MDR) and 16.67% were extensively drug resistant (XDR). The most prevalent bacterial species recovered in water samples were Pseudomonas aeruginosa, Pseudomonas fluorescens, Ralstonia pickettii and Stenotrophomonas maltophilia. Analysis of antibiotic resistance rates has shown remarkable differences between Pseudomonadaceae (P. aeruginosa and P. fluorescens) and emerging pathogens, such as S. maltophilia and R. pickettii. Multidrug resistance can be relatively common among nosocomial isolates of P. aeruginosa, which represent the large majority of clinical isolates; moreover, our findings highlight that the emergent antibiotic resistant opportunistic pathogens, such as R. pickettii and S. maltophilia, isolated from hospital environments could be potentially more dangerous than other more known waterborne pathogens, if not subjected to surveillance to direct the decontamination procedures.

[Definition of "Safety and Hygiene Packages" as a management model for the Hospital Hygiene Service (HHS)]

The purpose of this research is to identify and formalize the Hospital Hygiene Service activities and products, evaluating them in a cost accounting management view. The ultimate aim, is to evaluate the financial adverse events prevention impact, in an Hospital Hygiene Service management. A three step methodology based on affinity grouping activities, was employed. This methodology led us to identify 4 action areas, with 23 related productive processes, and 86 available safety packages. Owing to this new methodology, we was able to implement a systematic evaluation of the furnished services.

Legionella on board trains: effectiveness of environmental surveillance and decontamination

BACKGROUND

Legionella pneumophila is increasingly recognised as a significant cause of sporadic and epidemic community-acquired and nosocomial pneumonia. Many studies describe the frequency and severity of Legionella spp. contamination in spa pools, natural pools, hotels and ships, but there is no study analysing the environmental monitoring of Legionella on board trains. The aims of the present study were to conduct periodic and precise environmental surveillance of Legionella spp. in water systems and water tanks that supply the toilet systems on trains, to assess the degree of contamination of such structures and to determine the effectiveness of decontamination.

METHODS

A comparative pre-post ecological study was conducted from September 2006 to January 2011. A total of 1,245 water samples were collected from plumbing and toilet water tanks on passenger trains. The prevalence proportion of all positive samples was calculated. The unpaired t-test was performed to evaluate statistically significant differences between the mean load values before and after the decontamination procedures; statistical significance was set at p ≤ 0.05.

RESULTS

In the pre-decontamination period, 58% of the water samples were positive for Legionella. Only Legionella pneumophila was identified: 55.84% were serogroup 1, 19.03% were serogroups 2-14 and 25.13% contained both serogroups. The mean bacterial load value was 2.14 × 10(3) CFU/L. During the post-decontamination period, 42.75% of water samples were positive for Legionella spp.; 98.76% were positive for Legionella pneumophila: 74.06% contained serogroup 1, 16.32% contained serogroups 2-14 and 9.62% contained both. The mean bacterial load in the post-decontamination period was 1.72 × 10(3) CFU/L. According to the t-test, there was a statistically significant decrease in total bacterial load until approximately one and a half year after beginning the decontamination programme (p = 0.0097).

CONCLUSIONS

This study indicates that systematic environmental surveillance could be a useful approach for assessing the risk of exposure to Legionella bacteria, which still represents a public health threat. According to the study results, an environmental surveillance programme, followed by decontamination procedures where necessary, would decrease the total bacterial count, protecting the health of travellers and workers.

HUVEC respond to radiation by inducing the expression of pro-angiogenic microRNAs

MicroRNAs (miRNAs) represent a class of small non-coding RNAs that control gene expression by targeting mRNAs and triggering either repression of translation or RNA degradation. They have been shown to be involved in a variety of biological processes such as development, differentiation and cell cycle control, but little is known about their involvement in the response to irradiation. We showed here that in human umbilical vein endothelial cells (HUVEC) some miRNAs previously shown to have a crucial role in vascular biology are transiently modulated in response to a clinically relevant dose of ionizing radiation. In particular we identified an early transcriptional induction of several members of the microRNA cluster 17-92 and other microRNAs already known to be related to angiogenesis. At the same time we observed a peculiar behavior of the miR-221/222 cluster, suggesting an important role of these microRNAs in HUVEC homeostasis. We observed an increased efficiency in the formation of capillary-like structures in irradiated HUVEC. These results could lead to a new interpretation of the effect of ionizing radiation on endothelial cells and on the response of tumor endothelial bed cells to radiotherapy.

Smad-interacting protein-1 and microRNA 200 family define a nitric oxide-dependent molecular circuitry involved in embryonic stem cell mesendoderm differentiation

OBJECTIVE

Smad-interacting protein-1 (Sip1/ZEB2) is a transcriptional repressor of the telomerase reverse transcriptase catalytic subunit (Tert) and has recently been identified as a key regulator of embryonic cell fate with a phenotypic effect similar, in our opinion, to that reported for nitric oxide (NO). Remarkably, SIP1/ZEB2 is a known target of the microRNA 200 (miR-200) family. In this light, we postulated that Sip1/ZEB2 and the miR-200 family could play a role during the NO-dependent differentiation of mES.

METHODS AND RESULTS

The results of the present study show that Sip1/ZEB2 expression is downregulated during the NO-dependent expression of mesendoderm and early cardiovascular precursor markers, including Flk1 and CXCR4 in mES. Coincidently, members of the miR-200 family, namely miR-429, -200a, -200b, and -200c, were transcriptionally induced in parallel to mouse Tert. This regulation occurred at the level of chromatin. Remarkably, miR-429/miR-200a overexpression or Sip1/ZEB2 knockdown by short hairpin RNA interference elicited a gene expression pattern similar to that of NO regardless of the presence of leukemia inhibitory factor.

CONCLUSIONS

These results are the first demonstrating that the miR-200 family and Sip1/ZEB2 transcription factor are regulated by NO, indicating an unprecedented molecular circuitry important for telomerase regulation and early differentiation of mES.

Stress induces region specific alterations in microRNAs expression in mice

Several studies have demonstrated that exposure to both acute and chronic aversive stimuli can affect neural activity in different brain areas. In particular it has been shown that stressful events can induce not only short-term changes in neural transmission and gene regulation, but also long-term changes that can lead to structural modification. In this study we investigated, in CD1 mice, the effects of single or repeated exposures to restraint stress (2h for 1 or 5 consecutive days) in the frontal cortex on a crucial class of gene expression regulators, the microRNAs (miRs).First we performed a microarray profiling on RNA extracted from the frontal cortex of mice exposed to acute or repeated restraint stress. The results indicated a prominent increase in the expression levels of different miRs after acute stress while only minor changes were observed after repeated restraint. The Northern blot analysis on selected miRs confirmed an increase after acute restraint for let-7a, miR-9 and miR 26-a/b. Finally, Northern blot analysis of the selected miRs on RNA extracted from the hippocampus of stressed mice demonstrated that such changes were region specific, as no differences were observed in the hippocampus. These data suggest that control of mRNA translation through miRs is an additional mechanism by which stressful events regulates protein expression in the frontal cortex.

The position of yeast snoRNA-coding regions within host introns is essential for their biosynthesis and for efficient splicing of the host pre-mRNA

Genomic location of sequences encoding small nucleolar RNAs (snoRNAs) is peculiar in all eukaryotes from yeast to mammals: most of them are encoded within the introns of host genes. In Saccharomyces cerevisiae, seven snoRNAs show this location. In this work we demonstrate that the position of snoRNA-coding regions with respect to splicing consensus sequences is critical: yeast strains expressing mutant constructs containing shorter or longer spacers (the regions between snoRNA ends and intron splice sites) show a drop in accumulation of U24 and U18 snoRNAs. Further mutational analysis demonstrates that altering the distance between the 3' end of the snoRNA and the branch point is the most important constraint for snoRNA biosynthesis, and that stable external stems, which are sometimes present in introns containing snoRNAs, can overcome the positional effect. Surprisingly enough, splicing of the host introns is clearly affected in most of these constructs indicating that, at least in S. cerevisiae, an incorrect location of snoRNA-coding sequences within the host intron is detrimental to the splicing process. This is different with respect to what was demonstrated in mammals, where the activity of the splicing machinery seems to be dominant with respect to the assembly of snoRNPs, and it is not affected by the location of snoRNA sequences. We also show that intronic box C/D snoRNA recognition and assembly of snoRNPs occur during transcription when splicing sequences are recognized.

Non coding RNA and brain

Small non coding RNAs are a group of very different RNA molecules, present in virtually all cells, with a wide spectrum of regulatory functions which include RNA modification and regulation of protein synthesis. They have been isolated and characterized in all organisms and tissues, from Archaeobacteria to mammals. In mammalian brain there are a number of these small molecules, which are involved in neuronal differentiation as well as, possibly, in learning and memory. In this manuscript, we analyze the present knowledge about the function of the most important groups of small non-coding RNA present in brain: small nucleolar RNAs, small cytoplasmic RNAs, and microRNAs. The last ones, in particular, appear to be critical for dictating neuronal cell identity during development and to play an important role in neurite growth, synaptic development and neuronal plasticity.

Substrate selectivity and pH dependence of KAAT1 expressed in Xenopus laevis oocytes

When expressed in Xenopus oocytes KAAT1 increases tenfold the transport of l-leucine. Substitution of NaCl with 100 mm LiCl, RbCl or KCl allows a reduced but significant activation of l-leucine uptakes. Chloride-dependence is not strict since other pseudohalide anions such as thyocyanate are accepted. KAAT1 is highly sensitive to pH. It can transport l-leucine at pH 5.5 and 8, but the maximum uptake has been observed at pH 10, near to the physiological pH value, when amino and carboxylic groups are both deprotonated. The pH value mainly influences the V(max) in Na(+) activation curves and l-leucine kinetics. The kinetic parameters are K(mNa) = 4.6 +/- 2 mm, V(maxNa) = 14.8 +/- 1.7 pmol/oocyte/5 min for pH 8.0 and K(mNa) = 2. 8 +/- 0.7 mm, V(maxNa) = 31.3 +/- 1.9 pmol/oocyte/5 min for pH 10.0. The kinetic parameters of l-leucine uptake are: K(m) = 120.4 +/- 24. 2 microm, V(max) = 23.2 +/- 1.4 pmol/oocyte/5 min at pH 8.0 and K(m) = 81.3 +/- 24.2 microm, V(max) = 65.6 +/- 3.9 pmol/oocyte/5 min at pH 10.0. On the basis of inhibition experiments, the structural features required for KAAT1 substrates are: (i) a carboxylic group, (ii) an unsubstituted alpha-amino group, (iii) the side chain is unnecessary, if present it should be uncharged regardless of length and ramification.

Simultaneous measurements of ionic currents and leucine uptake at the amino acid cotransporter KAAT1 expressed in Xenopus laevis oocytes

The transport properties of the intestinal amino acid cotransporter KAAT1, heterologously expressed in Xenopus oocytes, were studied using simultaneous voltage-clamp and tritiated leucine uptake measurements. While addition of 1 mM leucine to oocytes kept at -80 mV in presence of Na(+) or K(+) caused an increase in holding current, in presence of Li(+) the current was reduced. Uptake measurements in voltage-clamp conditions showed that a comparable accumulation of amino acid occurred in all three ionic conditions and irrespective of the direction and amount of the current change. The ratio of moles of transferred charge to moles of transported amino acid ranges from 1.45 for K(+) to 3.52 for Li(+). A hypothetical interpretation involving the coexistence of two populations of transporters, one operating in the uncoupled mode and the other in the substrate transport mode is discussed.

Ion binding and permeation through the lepidopteran amino acid transporter KAAT1 expressed in Xenopus oocytes

1. The transient and steady-state currents induced by voltage jumps in Xenopus oocytes expressing the lepidopteran amino acid co-transporter KAAT1 have been investigated by two-electrode voltage clamp. 2. KAAT1-expressing oocytes exhibited membrane currents larger than controls even in the absence of amino acid substrate (uncoupled current). The selectivity order of this uncoupled current was Li+ > Na+ approximately Rb+ approximately K+ > Cs+; in contrast, the permeability order in non-injected oocytes was Rb+ > K+ > Cs+ > Na+ > Li+. 3. KAAT1-expressing oocytes gave rise to 'pre-steady-state currents' in the absence of amino acid. The characteristics of the charge movement differed according to the bathing ion: the curves in K+ were strongly shifted (> 100 mV) towards more negative potentials compared with those in Na+, while in tetramethylammonium (TMA+) no charge movement was detected. 4. The charge-voltage (Q-V) relationship in Na+ could be fitted by a Boltzmann equation having V of -69 +/- 1 mV and slope factor of 26 +/- 1 mV; lowering the Na+ concentrations shifted the Q-V relationship to more negative potentials; the curves could be described by a generalized Hill equation with a coefficient of 1.6, suggesting two binding sites. The maximal movable charge (Qmax) in Na+, 3 days after injection, was in the range 2.5-10 nC. 5. Addition of the transported substrate leucine increased the steady-state carrier current, the increase being larger in high K+ compared with high Na+ solution; in these conditions the charge movement disappeared. 6. Applying Eyring rate theory, the energy profile of the transporter in the absence of organic substrate included a very high external energy barrier (25.8 RT units) followed by a rather deep well (1.8 RT units).