Identification of small RNAs in Pseudomonas species

Summary: Bacterial small RNAs (sRNAs) are transcripts most of which have regulatory functions. Sequence and secondary structure elements enable numerous sRNAs to interact with mRNAs or with regulatory proteins resulting in diverse regulatory effects on virulence, iron storage, organization of cell envelope proteins or stress response. sRNAs having high affinity for RsmA-like RNA-binding proteins are important for posttranscriptional regulation in various Gram-negative bacteria. In Pseudomonas spp., the GacS/GacA two component system positively controls the production of such sRNAs. They titrate RsmA-like proteins and thus overcome translational repression due to these proteins. As a consequence, secondary metabolites can be produced that are implicated in the biocontrol capacity of P. fluorescens or in the virulence of P. aeruginosa. A genome-wide search carried out in P. aeruginosa PAO1 and in closely related Pseudomonas spp. resulted in the identification of 15 genes coding for sRNAs. Eight of these are novel, the remaining seven have previously been observed. Among them, the 1698 sRNA gene was expressed under GacA control, whereas the transcription of 1887 sRNA gene was transcribed under the control of the anaerobic regulator Anr in an oxygen-limited environment. Overexpression of 1698 sRNA in P. fluorescens strain CHAO did not affect the expression of the GacA-regulated hcnA gene (first gene of the operon coding for HCN synthase), indicating that 1698 sRNA is probably not part of the secondary metabolite regulation pathway. The expression of 1698 sRNA was positively regulated by RpoS in both P. aeruginosa PAO 1 and P. ,fluorescens CHAO and appeared to be modulated temporarily by oxidative stress conditions. However, the effect of 1698 sRNA on oxidative stress survival has not yet been established. Hfq protein interacted with 1698 sRNA in vitro and improved 1698 sRNA expression in vivo in P. aeruginosa. In P. fluorescens, GacA and Hfq were both required for expression of rpoS and GacA showed a positively control on the hfq expression; therefore, at least in this organism, GacA control of 1698 sRNA expression may act indirectly via Hfq and RpoS. Different methods were employed to find abase-pairing target for 1698 sRNA. In a proteomic analysis carried out in P. aeruginosa, positive regulation by 1698 sRNA was observed for Soda, the iron-associated superoxide dismutase, an enzyme involved in oxidative stress resistance. A sequence complementary with 1698 sRNA was predicted to be located in the 5' leader of soda mRNA. However, base-pairing between soda mRNA and 1698 sRNA remains to be proven. In conclusion, this work has revealed eight novel sRNAs and novel functions of two sRNAs in Pseudomonas spp. Résumé Les petits ARNs non-codants (sRNAs) produits par les bactéries sont des transcrits ayant pour la plupart des activités régulatrices importantes. Leurs séquences nucléotidiques ainsi que leurs structures secondaires permettent aux sRNAs d'interagir soit avec des RNA messagers (mRNAs), de sorte à modifier l'expression des protéines pour lesquelles ils codent, soit avec des protéines régulatrices liant des rnRNAs, ce qui a pour effet de modifier l'expression de ces mRNAs. Des sRNAs sont impliqués dans diverses voies de régulation, telles que celles qui régissent la virulence, le stockage du fer, l'organisation des protéines de l'enveloppe bactérienne ou la réponse au stress. Chez les Pseudomonas spp., le système à deux composantes GacS/GacA contrôle la production de métabolites secondaires. Ceux-ci sont engagés dans l'établissement du biocontrôle, chez P. fluorescens, ou. de la virulence, chez P. aeruginosa. La régulation génique dirigée par le système GacS/GacA fait intervenir les sRNAs du type RsmZ, capables de contrecarrer l'action au niveau traductionnel exercée par les protéines régulatrices du type RsmA. Une recherche au niveau du génome a été menée chez P. aeruginosa PAO1 de même que chez des espèces qui lui sont étroitement apparentées, débouchant sur la mise en évidence de 15 gènes codant pour des sRNAs. Parmi ceux-ci, huit ont été découverts pour la première fois et sept confirment des travaux publiés. L'expression du gène du sRNAs 1698 s'avère être régulée par GacA, vraisemblablement de manière indirecte. La transcription du gène du sRNA 1887 montre une dépendance envers Anr, régulateur de l'anaérobiose, et envers une carence en oxygène. La surexpression du sRNA 1698 chez P. fluorescens CHAO n'affecte pas l'expression de hcnA, un gène du régulon GacA, laissant supposer que le sRNA n'intervient pas dans la régulation des métabolites secondaires. Chez P. aeruginosa PAOI et chez P. fluorescens CHAO, RpoS, le facteur sigma du stress, est nécessaire à l'expression du sRNA 1698, et la concentration de ce dernier est modulée par des conditions de stress oxydatif. Toutefois, un effet du sRNA 1698 quant à la survie suite au stress oxydatif n'a pas été établi. Par ailleurs, l'interaction entre le sRNA 1698 et Hfq, la protéine chaperone de RNAs, in vitro ainsi qu'un rôle positif de Hfq pour l'expression du sRNA 1698 in vivo ont été démontrés chez P. aeruginosa. L'induction de l'expression par GacA de rpoS et de hfq a été confirmée chez P. fluorescens CHAO, suggérant que la régulation par GacA du sRNA 1698 pourrait se faire par l'intermédiaire de RpoS et Hfq. Diverses méthodes ont été employées pour identifier un transcrit qui puisse être apparié par le sRNA 1698. Une analyse de protéome chez P. aeruginosa montre que l'expression de Soda, la superoxyde dismutase associée au fer, est positivement régulée par le sRNA 1698. Soda est une enzyme impliquée dans la résistance au stress oxydatif. Une séquence de complémentarité avec le sRNA 1698 a bien été prédite sur le leader 5' du mRNA de soda. Cependant, l'appariement entre le sRNA et son transcrit cible est encore à prouver. En conclusion, ce travail a dévoilé huit nouveaux sRNAs et de nouvelles fonctions pour deux sRNAs chez les Pseudomonas.

The origin and dispersion of human parasitic diseases in the Old World (Africa, Europe and Madagascar)

The ancestors of present-day man (Homo sapiens sapiens) appeared in East Africa some three and a half million years ago (Australopithecs), and then migrated to Europe, Asia, and later to the Americas, thus beginning the differentiation process. The passage from nomadic to sedentary life took place in the Middle East in around 8000 BC. Wars, spontaneous migrations and forced migrations (slave trade) led to enormous mixtures of populations in Europe and Africa and favoured the spread of numerous parasitic diseases with specific strains according to geographic area. The three human plasmodia (Plasmodium falciparum, P. vivax, and P. malariae) were imported from Africa into the Mediterranean region with the first human migrations, but it was the Neolithic revolution (sedentarisation, irrigation, population increase) which brought about actual foci for malaria. The reservoir for Leishmania infantum and L. donovani - the dog - has been domesticated for thousands of years. Wild rodents as reservoirs of L. major have also long been in contact with man and probably were imported from tropical Africa across the Sahara. L. tropica, by contrast, followed the migrations of man, its only reservoir. L. infantum and L. donovani spread with man and his dogs from West Africa. Likewise, for thousands of years, the dog has played an important role in the spread and the endemic character of hydatidosis through sheep (in Europe and North Africa) and dromadary (in the Sahara and North Africa). Schistosoma haematobium and S. mansoni have existed since prehistoric times in populations living in or passing through the Sahara. These populations then transported them to countries of Northern Africa where the specific, intermediary hosts were already present. Madagascar was inhabited by populations of Indonesian origin who imported lymphatic filariosis across the Indian Ocean (possibly of African origin since the Indonesian sailors had spent time on the African coast before reaching Madagascar). Migrants coming from Africa and Arabia brought with them the two African forms of bilharziosis: S. haematobium and S. mansoni.

The state of the art of paleoparasitological research in the old world

Paleoparasitology in the Old World has mainly concerned the study of latrine sediments and coprolites collected from mummified bodies or archaeological strata, mostly preserved by natural conditions. Human parasites recovered include cestodes, trematodes, and nematodes. The well preserved conditions of helminth eggs allowed paleoepidemiological approaches taking into account the number of eggs found by archaeological stratum. Tentatively, sanitation conditions were assessed for each archaeological period.

Relationships of new world Phlebotomine sand flies (Diptera: Psychodidae) based on fossil evidence

The fossil record and systematics of phlebotomid sand flies, vectors of leishmaniasis and arbovirus in several regions of the world, strongly support that living genera existed long before the Oligocene (38 million years, myr). A common Phlebotominae ancestor was present in the Triassic period before the separations of continents (248 myr).

Small changes, big benefits

Being overweight is a major health problem for Northern Ireland. This leaflet helps the public assess whether or not they are overweight and contains useful information on what to do about it, including identifying healthy options, setting targets, getting active and staying motivated.

PHA supports World No Tobacco Day

The Public Health Agency is taking the opportunity to highlight this year's World No Tobacco Day which takes place on Tuesday 31 May.In Northern Ireland, around 340,000 people aged 16 and over smoke. Smoking contributes not only to many cancers, heart disease, bronchitis and asthma, but to other illnesses, including stroke. In fact, smoking causes around 2,700 deaths per year here, all of them avoidable.The PHA is committed to saving lives by reducing the percentage of people who smoke. The PHA:works with councils to ensure smoking-related laws are enforced; funds a range of support to smokers who want to quit; educates young people to not start smoking, through programmes like 'Teenage Kicks' and 'Smokebusters'. In January this year, the PHA also launched its smoking campaign 'Things to do before you die' to encourage smokers, particularly those aged 20-49, to stop smoking.Health Minister Edwin Poots said:"Smoking is the greatest cause of preventable illness and premature death in Northern Ireland. While good progress has been made in the last number of years to reduce the number of people who smoke, more needs to be done."I would appeal to all smokers to use the wide range of support services available to make every effort to stop smoking - it is the single best step you can take to improve your health and quality of life."Mark Mc Bride, Health Improvement Manager, PHA, said "Smoking is the single greatest preventable cause of death in the world today. Across Northern Ireland there are over 600 support services for people who wish to stop smoking. These are based in GP surgeries, community pharmacies, hospitals, community centres and workplaces."From April 2010 to end March 2011 more than 1 in 10 of all adult smokers sought help from the support services and approximately half had quit after four weeks. This is a substantial - roughly 50% increase - on previous years and shows the benefit of the PHA campaigns and the dedication of the many specialists who help smokers quit."I would encourage everyone who is either thinking about quitting or ready to log on to our Want 2 Stop website www.want2stop.info or to contacting the Smokers' Helpline on 0808 812 8008 a Quit Kit free of charge."

PHA supports World Hospice and Palliative Care Day

Saturday 8 October 2011 marks World Hospice and Palliative Care Day. The Public Health Agency would like to celebrate and support hospice and palliative care around the world by raising awareness and understanding of the needs - medical, social, practical and spiritual - of people living with a life-limiting illness, and their families.This year's World Hospice and Palliative Care Day theme is 'Many diseases, manylives, many voices - palliative care fornon-communicableconditions'.The theme will focus on how people living with conditions thatare notinfectious can benefit from palliative care.Non-communicable diseases (NCDs), which include cardiovascular diseases, cancers, chronic respiratory conditions and diabetes, make up60% of deaths worldwide. The majority of thesedeaths occur in low and middle income countries, where palliative care is often not available. To get involved in World Hospice and Palliative Care Day, log on to www.worldday.org/get-involved/ which gives you ideas and suggestions on what you can do on the day to support people living with life-limiting illnesses, and their families.Mary Hinds, Director of Nursing and Allied Health Professions, PHA, and Chair of the Implementation Process for End of Life Care in Northern Ireland, said: "Good quality palliative and end of life care will be important for us all. 'Living Matters, Dying Matters' is a five year strategy for palliative and end of life care in Northern Ireland, established to ensure that any person living with a life-threatening illness lives well and dies well, irrespective of their condition or care setting. "It has been encouraging to see the plans being taken forward by the Health and Social Care Trusts in partnership with local hospices and other providers, and involving local people."We aim to ensure that people receiving palliative care, their families and carers, are provided with high quality care across all settings and conditions, and are supported to enjoy a good quality of life, maximising their potential through the course of their illness."There is still some progress to be made within the context of the review of health and social services. We are looking for statutory and voluntary services to work together to make a significant difference in improving access to high quality services for those with life-limiting conditions, and to develop innovative approaches to care."

The PHA message is clear for World COPD Day - smoking is bad for your lungs

In 2011, 31,574 people were registered as having Chronic Obstructive Pulmonary Disease (COPD) in Northern Ireland. The most common cause of COPD is smoking and to mark this year's World COPD day, which takes place on Wednesday 16 November, the Public Health Agency is encouraging all smokers to make a decision to stop smoking today and reduce their risk of developing the disease.COPD refers to a group of diseases which includes emphysema, chronic bronchitis, and in some cases asthma. With COPD, the airways in the lungs become damaged, causing them to become narrower, therefore restricting airflow and thus making it harder to breathe. The most common symptoms of COPD are breathlessness, wheezing, abnormal sputum (a mix of saliva and mucus in the airway), and a chronic cough often mistaken for a 'smokers' cough'. Symptoms can range from mild to severe, depending upon how advanced the disease is. In advanced cases, daily activities, such as walking up a short flight of stairs, can become very difficult.There is no cure for COPD. Stopping smoking is the single most effective wayto reduce your risk of developing COPD and avoid any further damage to the lungs. Gerry Bleakney, Head of Health and Social Wellbeing Improvement, PHA, said: "Smoking causes the lining of the airways to become inflamed and damaged and is the biggest cause of COPD. The risk of developing COPD increases the more an individual smokes and the longer they smoke. "The good news is that making changes to your lifestyle can reduce your risk of developing COPD. Stopping smoking reduces the risk of developing COPD and also slows down its progression. There is support available to help you quit and I would encourage everyone thinking about stopping smoking to log on to our Want 2 Stop website www.want2stop.info and order a 'Quit Kit' free of charge. Alternatively contact the Smokers' Helpline on 0808 812 8008 for help on planning to stop smoking or to find out where your nearest Stop Smoking Service is. "The Health Minister Edwin Poots said: "The impact of living with COPD can place a considerable strain on the lives of those suffering from the condition and their families. I understand that most smokers want to quit but it is not always easy to succeed and that several attempts are frequently necessary. I would therefore urge all smokers on world COPD day, to make that commitment to stop smoking. Professional help and support are readily available. There are almost 650 smoking cessation services provided all over Northern Ireland, mostly in community pharmacies, but also in GP surgeries, hospitals, community halls and schools."

Prevent type 2 diabetes by preventing obesity

In 2011 nearly 73,000 adults in Northern Ireland are registered as having diabetes. Many cases of diabetes are preventable and are the result of obesity. With this in mind, on World Diabetes Day, 14 November 2011, the Public Health Agency is encouraging everyone across Northern Ireland to be aware of how Type 2 diabetes can be prevented, the dangers it can cause to your health and what the signs and symptoms of diabetes are to ensure early diagnosis.The links between type 2 diabetes and obesity are firmly established. Without the intervention of a healthy diet and appropriate exercise, obesity may develop into diabetes over a relatively short period of time. According to the International Diabetes Federation (IDF), worldwide 80 per cent of people with Type 2 diabetes are overweight or obese at the time of diagnosis.If you are overweight, or obese the key step to preventing or delaying the onset of Type 2 diabetes is to lose a small amount of weight by making healthy food choices and being physically active 30 minutes a day, 5 days a week.Diabetes, if left untreated can cause serious long term health complications such as heart disease, kidney damage, eye problems, which can affect vision, and foot problems leading to amputation.Dr Brid Farrell, Consultant in Public Health Medicine, PHA, said: "The increase of diabetes occurring in the population can be explained by rising levels of obesity, people living longer and improved detection and diagnosis of diabetes in primary care."Having a family history of Type 2 diabetes increases your chances of developing diabetes. Take the first step today toward lowering your risk for Type 2 diabetes and improving your health and the health of future generations." The symptoms of diabetes can include increased thirst, passing urine more, frequently (bedwetting in children), extreme tiredness, slow healing infections, blurred vision and significant or unexplained weight loss. Symptoms of diabetes can develop quickly over days or weeks, and sometimes with Type 2 diabetes, a person may have no symptoms. Early diagnosis is important. If you think you have diabetes speak to your GP or pharmacist.Dr Farrell continued: "Diabetes is a lifelong condition, but complications can be prevented or delayed by controlling your blood sugar, and treating high blood pressure and high cholesterol. If you have diabetes, a healthy diet and regular exercise is very important."Health Minister Edwin Poots said:"Diabetes is a serious condition, which affects many thousands of people across Northern Ireland. While not all diabetes is preventable, we all have a responsibility to look after our own health. "By making healthier lifestyle choices such as eating a healthy, well-balanced diet and taking regular exercise, we can reduce our risk of developing potentially life threatening conditions such as type 2 diabetes. I would urge everyone to take every possible step to improve their health and avoid developing preventable illnesses

Small RNAs as regulators of primary and secondary metabolism in Pseudomonas species.

Small RNAs (sRNAs) exert important functions in pseudomonads. Classical sRNAs comprise the 4.5S, 6S, 10Sa and 10Sb RNAs, which are known in enteric bacteria as part of the signal recognition particle, a regulatory component of RNA polymerase, transfer-messenger RNA (tmRNA) and the RNA component of RNase P, respectively. Their homologues in pseudomonads are presumed to have analogous functions. Other sRNAs of pseudomonads generally have little or no sequence similarity with sRNAs of enteric bacteria. Numerous sRNAs repress or activate the translation of target mRNAs by a base-pairing mechanism. Examples of this group in Pseudomonas aeruginosa are the iron-repressible PrrF1 and PrrF2 sRNAs, which repress the translation of genes encoding iron-containing proteins, and PhrS, an anaerobically inducible sRNA, which activates the expression of PqsR, a regulator of the Pseudomonas quinolone signal. Other sRNAs sequester RNA-binding proteins that act as translational repressors. Examples of this group in P. aeruginosa include RsmY and RsmZ, which are central regulatory elements in the GacS/GacA signal transduction pathway, and CrcZ, which is a key regulator in the CbrA/CbrB signal transduction pathway. These pathways largely control the extracellular activities (including virulence traits) and the selection of the energetically most favourable carbon sources, respectively, in pseudomonads.

Effects of tetrodotoxin and ion replacements on the short-circuit current induced by Escherichiacoli heat stable enterotoxin across small intestine of the gerbil (Gerbillus cheesmani)

The effects of mucosally added Escherichia coli heat stable enterotoxin (STa 30 ng ml-1) on the basal short-circuit current (Isc in µA cm-2) across stripped and unstripped sheets of jejuna and ilea taken from fed, starved (4 days, water ad lib) and undernourished (50% control food intake for 21 days) gerbil (Gerbillus cheesmani) were investigated. The effect of neurotoxin tetrodotoxin (TTX 10 µM) and the effects of replacing chloride by gluconate or the effects of removing bicarbonate from bathing buffers on the maximum increase in Isc induced by STa were also investigated. The maximum increase in Isc which resulted from the addition of STa were significantly higher in jejuna and ilea taken from starved and undernourished gerbils when compared with the fed control both using stripped and unstripped sheets. In the two regions of the small intestine taken from fed and starved animals TTX reduced the maximum increase in Isc induced by STa across unstripped sheets only. Moreover in jejuna and ilea taken from undernourished gerbils TTX reduced significantly the maximum increase in Isc induced by STa across stripped and unstripped sheets. Replacing chloride by gluconate decreased the maximum increase in Isc induced by STa across jejuna and ilea taken from undernourished gerbils only. Removing bicarbonates from bathing buffer decreased the maximum increase in Isc across the jejuna and ilea taken from starved and undernourished gerbils.

Slimming World on Referral

The Slimming World on Referral service has been used by a number of PCT's and NHS Trusts across England. The data reported here is from an audit including data from all schemes between 2004 and 2009. The aims of the service varied depending on the NHS trusts own priorities. Generally speaking the main aim was to achieve a weight loss of around 5% in 12 weeks. Some trusts however had different aims for example, one aimed to acheive a weight loss of 2.5kg in the 12 weeks.

World Alzheimer Report 2009

Download: World Alzheimer Report 2009 executive SummaryAlzheimer’s disease and other dementias have been reliably identified in all countries, cultures and races in which systematic research has been carried out. However, levels of awareness vary enormously. Alzheimer’s Disease International (ADI) has identified raising awareness of dementia among the general population and among health workers as a global priority.

Calculation of correction factors for ionization chamber measurements with small fields in low-density media.

The quantity of interest for high-energy photon beam therapy recommended by most dosimetric protocols is the absorbed dose to water. Thus, ionization chambers are calibrated in absorbed dose to water, which is the same quantity as what is calculated by most treatment planning systems (TPS). However, when measurements are performed in a low-density medium, the presence of the ionization chamber generates a perturbation at the level of the secondary particle range. Therefore, the measured quantity is close to the absorbed dose to a volume of water equivalent to the chamber volume. This quantity is not equivalent to the dose calculated by a TPS, which is the absorbed dose to an infinitesimally small volume of water. This phenomenon can lead to an overestimation of the absorbed dose measured with an ionization chamber of up to 40% in extreme cases. In this paper, we propose a method to calculate correction factors based on the Monte Carlo simulations. These correction factors are obtained by the ratio of the absorbed dose to water in a low-density medium □D(w,Q,V1)(low) averaged over a scoring volume V₁ for a geometry where V₁ is filled with the low-density medium and the absorbed dose to water □D(w,QV2)(low) averaged over a volume V₂ for a geometry where V₂ is filled with water. In the Monte Carlo simulations, □D(w,QV2)(low) is obtained by replacing the volume of the ionization chamber by an equivalent volume of water, according to the definition of the absorbed dose to water. The method is validated in two different configurations which allowed us to study the behavior of this correction factor as a function of depth in phantom, photon beam energy, phantom density and field size.